Changes in Patterns of Physical Activity and Risk of Heart Failure in Newly Diagnosed Diabetes Mellitus Patients

Article information

Diabetes Metab J. 2022;46(2):327-336
Publication date (electronic) : 2021 November 24
doi : https://doi.org/10.4093/dmj.2021.0046
1Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
2Department of Statistics and Actuarial Science, Soongsil University, Seoul, Korea
3Department of Biostatistics, Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, Korea
Corresponding authors: Eun-Jung Rhee https://orcid.org/0000-0002-6108-7758 Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, 29 Saemunan-ro, Jongno-gu, Seoul 03181, Korea E-mail: hongsiri@hanmail.net
Won-Young Lee https://orcid.org/0000-0002-1082-7592 Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, 29 Saemunan-ro, Jongno-gu, Seoul 03181, Korea E-mail: drlwy@hanmail.net
Received 2021 March 16; Accepted 2021 May 30.

Abstract

Background

Exercise is recommended for type 2 diabetes mellitus (T2DM) patients to prevent cardiovascular disease. However, the effects of physical activity (PA) for reducing the risk of heart failure (HF) has yet to be elucidated. We aimed to assess the effect of changes in patterns of PA on incident HF, especially in newly diagnosed diabetic patients.

Methods

We examined health examination data and claims records of 294,528 participants from the Korean National Health Insurance Service who underwent health examinations between 2009 and 2012 and were newly diagnosed with T2DM. Participants were classified into the four groups according to changes in PA between before and after the diagnosis of T2DM: continuously inactive, inactive to active, active to inactive, and continuously active. The development of HF was analyzed until 2017.

Results

As compared with those who were continuously inactive, those who became physically active after diagnosis showed a reduced risk for HF (adjusted hazard ratio [aHR], 0.79; 95% confidence interval [CI], 0.66 to 0.93). Those who were continuously active had the lowest risk for HF (aHR, 0.77; 95% CI, 0.62 to 0.96). As compared with those who were inactive, those who exercised regularly, either performing vigorous or moderate PA, had a lower HF risk (aHR, 0.79; 95% CI, 0.69 to 0.91).

Conclusion

Among individuals with newly diagnosed T2DM, the risk of HF was reduced in those with higher levels of PA after diagnosis was made. Our results suggest either increasing or maintaining the frequency of PA after the diagnosis of T2DM may lower the risk of HF.

Graphical abstract

INTRODUCTION

The number of patients with heart failure (HF) has been increasing globally and its prevalence is expected to rise continuously as the population ages. By 2030, the prevalence of HF will increase to 46% and total medical expenditures for HF patients are expected to increase from $20.9 billion to $53.1 billion [1]. As the aged population rapidly increases in South Korea, it is predicted that the prevalence of HF will increase. Recent study estimated that over 1.7 million (3.35%) Koreans will have HF by 2040 [2].

This increase in HF may be the result of an increased prevalence of risk factors such as diabetes and ischemic heart disease [3]. To date, several studies have reported that individuals with diabetes have a much higher risk for HF compared to those without [4]. As diabetes and HF have become major health problems in many countries, there is a greater focus on preventing the onset or delaying the progression of HF in patients with diabetes.

Increasing the amount of daily physical activity (PA) is one recommendation given to prevent cardiovascular disease (CVD). Recent studies have suggested that augmenting PA is associated with lower HF risk in general population and high-risk groups including diabetics [5,6]. However, epidemiological data linking changes in the patterns of PA to effects on HF prevention are rare, especially in patients with newly diagnosed type 2 diabetes mellitus (T2DM).

Therefore, using data from the National Health Insurance Service (NHIS) in the Republic of Korea, we examined the association between changes in patterns of PA after the diagnosis of T2DM and incident HF.

METHODS

Source of data

This study analyzed data from the Korean NHIS and claims database. The NHIS system is a mandatory health insurance program that covers 97.1% of the Korean population. In Korea, the NHIS is the single health care insurer and is managed by the government. The NHIS includes an eligibility database (i.e., including data such as age, sex, socioeconomic variables, type of eligibility, household income level); a medical treatment claims database (compiled based on medical bills that were claimed by medical service providers for medical expenses); a health examination database (including results of general health examinations and questionnaires on lifestyle and behavior); a medical care institution database (including types of medical care institutions, location, equipment, and number of physicians); and a death register. For this study, we used the general health examination data and NHIS claims data including diagnoses, procedures, prescription records, and mortality.

This study was approved by the Institutional Review Board of Kangbuk Samsung Hospital of Korea (KBSMC 2020-02-003). Participants who underwent national health check-up examinations provided written informed consent for the use of their data for research purposes. All personal information was deleted and only nonidentifiable data were included for analysis.

Study population and design

This study investigated adults without HF older than 40 years of age who received general health check-ups at least twice. We selected 17,314,795 participants who had undergone a health examination between 2009 and 2012, then identified participants with fasting blood glucose levels above 126 mg/dL at the baseline examination (n=1,915,024). Among these individuals, we selected patients whose diagnoses of T2DM were newly made within 2 years from the date of their baseline health examination using the claims data. A diagnosis of T2DM was defined according to the following criteria: (1) by the presence of International Classification of Diseases, 10th revision, clinical modification (ICD-10-CM) codes E11, E12, E13, or E14 and claims for at least one oral antidiabetic agent or insulin at the baseline or (2) a fasting glucose level of 126 mg/dL or higher (obtained from the health examination database). Participants who did not undergo a follow-up health examination within 18 to 30 months after their baseline examination were subsequently excluded (n=154,795). We tracked their data while observing whether HF occurred or not from 2010 to 2017. We also excluded 2,263 participants with a history of HF (ICD-10 code I50 and a history of hospitalization) to ensure that all diagnoses of HF were newly made. Further, subjects with any missing data were excluded (n=5,052). Finally, 132,418 participants were included in the analyses. The incidence of HF was analyzed using the claims data from January 1, 2010 to December 31, 2017 or until the date of death, whichever came first (Supplementary Fig. 1).

Anthropometric and laboratory measurements

Data on medical history, medication use, and health-related behaviors were collected through the administration of a self-reported questionnaire, whereas physical measurements and serum biochemical parameters were obtained by trained staff. Body mass index (BMI) was defined as the patient’s weight (kg) divided by the square of their height (m). Fasting blood glucose, aspartate aminotransferase, alanine aminotransferase, and total cholesterol levels were measured after 12 hours of fasting.

Classification of change in physical activity

Each participant was asked to report their weekly PA levels according to three categories: vigorous (≥20 min/day; e.g., running, aerobic, or fast cycling at least three times per week), moderate (≥30 min/day; e.g., brisk walking, bicycling at a usual speed, or gardening at least five times per week), and walking (≥30 min/day). Walking was defined as usual-pace walking for at least 10 minutes at a time [7]. Regular exercise was defined as performing at least 30 minutes of moderate PA at least five times per week or at least 20 minutes of strenuous PA at least three times per week.

The study participants were classified into four groups based on changes in their PA levels apparent at the time of the second examination as follows: (1) continuously physically inactive, (2) inactive to active, (3) active to inactive, and (4) continuously physically active. The validity and reliability of the self-administered questionnaire on PA deployed in the NHIS cohort are described in a previous study [8].

Definition of HF and comorbidities

A diagnosis of HF was defined by the presence of ICD-10-CM code I50 and hospitalization [9]. Hypertension was defined according to the presence of at least one claim per year for the prescription of antihypertensive agents, under ICD-10-CM codes I10 through I15, or a systolic/diastolic blood pressure of 140/90 mm Hg or higher [10,11]. The presence of dyslipidemia was defined according to the presence of at least one claim per year for the prescription of antihyperlipidemic agents under ICD-10 code E78 or a total cholesterol level of 240 mg/dL or higher [10,12]. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate of less than 60 mL/min [13]. CVD included myocardial infarction (MI) and stroke. MI was defined by the occurrence of hospitalization with the diagnostic codes of I21 and I22, while stroke was defined by the presence of ICD-10-CM codes I63 and I64 as well as a history of hospitalization with claims for brain magnetic resonance imaging or brain computed tomography [11,12].

Statistical analysis

Anthropometric and laboratory data from the baseline examination was used in analyses. Continuous variables were presented as mean±standard deviation and categorical variables were expressed as percentages. Clinical characteristics between the participants were compared using one-way analysis of variance for continuous variables and the chi-square test for categorical variables, respectively. The incidence rate of HF is presented per 1,000 person-years. Cox proportional-hazards regression analysis was adopted and we calculated the hazard ratio (HR) and 95% confidence interval (CI) for incident HF according to changes in the pattern of PA. The adjusted hazard ratio (aHR) was calculated after adjusting the following variables: age, sex, smoking, alcohol consumption, household income, BMI, hypertension, dyslipidemia, CKD, stroke, and MI.

For subgroup analysis, we stratified the participants by age (65 years and older), sex (male and female), hypertension, dyslipidemia, CKD, CVD, malignancy (yes and no), and weight change. Weight changes were calculated for each subject as the difference from follow-up health examination to baseline examination; stable, gain or loss <5% of body weight at baseline; gain, weight gain of ≥5% and loss, weight loss of ≥5% [14]. All reported P values were two-tailed and <0.05 were considered to be statistically significant. All statistical analyses were performed using SAS version 9.3 (SAS Institute Inc., Cary, NC, USA) and R version 3.2.3 (http://www.Rproject.org; The R Foundation for Statistical Computing, Vienna, Austria).

RESULTS

Baseline characteristics

The mean age of the participants was 57.7±9.58 years and 84,504 (63.8%) of the participants were male. During 639,310.15 person-years of follow-up, 1,321 total HF events occurred. Table 1 presents the baseline characteristics of the participants. As compared with subjects who did not increase their PA after diagnosis of T2DM, those who were continuously physically active or became physically active following the diagnosis of T2DM had smaller waist circumferences and were less obese (P<0.001) (Table 1). Additionally, those who were physically active at the second health check-up examination had lower fasting blood glucose levels and total cholesterol levels than those of participants in the continuously inactive group.

Socio-demographic characteristics of study participants according to patterns of physical activity

Risk for incident HF according to the intensity of physical activity during follow-up

We investigated the relationship between the level of PA and the development of HF during follow-up. As compared with those who did not exercise regularly, those who were exercising regularly, either performing vigorous or moderate activity, had a lower HF risk (aHR, 0.79; 95% CI, 0.69 to 0.91). The crude incidence rates of HF were 1.5, 1.7, and 1.9 per 1,000 person-years in the vigorous-intensity group, moderate-intensity group, and walking group, respectively. Both the vigorous- and moderate-exercise groups showed a reduced risk for HF (HR, 0.81; 95% CI, 0.69 to 0.94 in the vigorous-activity group vs. HR, 0.79; 95% CI, 0.65 to 0.95 in the moderate-activity group; P<0.001) relative to the control group. After adjustment for confounding variables, the HRs were attenuated but showed consistently reduced risks for HF (Table 2).

Risk for heart failure according to study participants’ physical activity profile during follow-up

Risk for incident HF according to changes in the pattern of physical activity

When the HR for incident HF was analyzed according to changes in the pattern of PA at follow-up, taking the continuously physically inactive group as the reference, patients in the continuously physically active group showed the lowest risk for HF after adjusting for confounding variables (aHR, 0.78; 95% CI, 0.69 to 0.97) (Fig. 1). Also, participants who became physically active during follow-up showed a reduced risk for HF in comparison with those who remained continuously physically inactive (decrease of 0.6/1,000 person-years in the incidence rate: aHR, 0.79; 95% CI, 0.67 to 0.93). Meanwhile, those who were physically active but became inactive did not show a significantly reduced risk for HF (aHR, 0.92; 95% CI, 0.78 to 1.10).

Fig. 1.

Hazard ratio for incident heart failure (HF) according to changes in the pattern of physical activity. Cox proportional-hazards regression analysis was adopted and we calculated the hazard ratio and 95% confidence interval for incident HF according to changes in the pattern of physical activity. Adjusted for age, sex, current smoking, alcohol, income, waist circumference, hypertension, dyslipidemia, chronic kidney disease, stroke, myocardial infarction, and fasting blood glucose. CI, confidence interval.

Subgroup analyses

To analyze the effects of changes in PA on the development of HF, subgroup analyses were conducted by stratifying study participants according to age, sex, comorbid chronic disease (i.e., hypertension, dyslipidemia, CKD, and CVD), presence of malignancy, and weight change (Table 3, Supplementary Table 1). When we divided the study subjects according to sex, there was a significant interaction between sex and the risk of HF according to changes in the pattern of PA; specifically, men who were continuously active showed the lowest risk for HF. However, no significant interactions between changes in PA and other subgroup variables with respect to the risk for HF were apparent (all P for interaction >0.05). The overall trends and effects of PA on risk estimates for HF were similar in most of the subgroups including those established according to age and the presence of hypertension, dyslipidemia, and CVD, respectively.

Subgroup analysis of study participants

DISCUSSION

In our study, we observed the appearance of beneficial effects of increasing PA on reducing the risk of HF after 4.8 years of follow-up. Our findings indicate that increasing or maintaining high levels of PA following the diagnosis of T2DM is associated with a lower risk of HF as compared with in individuals who are continuously inactive. Those who altered their PA from active to inactive during follow-up also had a lower risk of HF as compared with continuously inactive controls. This result could be partially explained by the sustained legacy effect of exercise [15].

In addition to these results, we observed the existence of beneficial effects of PA regardless of the amount or intensity: both vigorous exercise and walking were able to lower the risk of HF. In a meta-analysis conducted by Swain and Franklin [16], exercise performed at a vigorous intensity appeared to have greater cardioprotective benefits than exercise of a moderate intensity. Regarding the frequency and intensity of PA, our moderate-intensity group showed the greatest reduction in risk relative to the vigorous-intensity group. We found concordant results supporting that moderate-intensity exercise may have greater metabolic benefits than vigorous-intensity exercise [15]. Slentz et al. [17] reported that moderate-intensity exercise may improve the disposition index (a marker of pancreatic beta-cell function) more than the high-amount/vigorous-intensity exercise group. The data from the Studies of a Targeted Risk Reduction Intervention through Defined Exercise (STRRIDE) suggest that the same amount of exercise at lower intensity increases the percentage of energy coming from fat oxidation, which may improve metabolic parameters [18]. While the exact mechanism for this result is unclear, this finding may be partially mediated by hemodynamic effects or other biological effects such as lipid metabolism and insulin sensitivity.

There are several potential mechanisms by which PA may interact with the mechanisms of diabetes and pathophysiology of HF. There is growing evidence that insulin resistance has considerable effects on myocardium, which may be responsible for raising the risk of HF in individuals with T2DM [19]. In the hearts of diabetics, glucose utilization may be decreased and free fatty acid use is increased, resulting in insulin resistance [20]. Augmenting PA may improve insulin sensitivity, therefore, associated with a reduced rate of coronary heart disease, as well as with a lower risk of HF [19,21]. Review articles discussed other possible mechanisms by which PA might have beneficial effects in diabetic patients. PA can have beneficial effects on neurohormonal, inflammatory, metabolic adaptations, as well as on endothelial dysfunction. Exercise counterbalances the long-term detrimental effects of neurohormonal activation [22], promotes nitric oxide release, resulting in endothelium-dependent vasodilation [23]. Also, regular exercise training can have anti-inflammatory effect by increasing plasma levels of interleukin 10 (IL-10), reducing inflammatory cytokines (e.g., IL-6, tumor necrosis factor-α), platelet-related inflammatory mediators, and peripheral markers of endothelial dysfunction [24,25]. All these exercise-induced changes can be associated with halting the progression of HF in patients with diabetes.

Several studies have documented the benefits of regular exercise and PA in reducing the coronary heart disease risk in both primary and secondary prevention [26]. However, clinical studies have reported a higher incidence of HF in diabetics even without ischemic heart disease. In this study, we observed an inverse association between PA and risk of HF, regardless of the patient’s previous history of MI or stroke. Previous studies have suggested that the introduction of purposeful weight loss programs and exercise training may improve symptoms and survival rates among patients with HF [27]. Interactions between weight changes and the risk of HF were further examined in our study. We expected the benefits of increased PA might be greater in participants who lose weight via exercise than those who gained weight. However, there was no significant interaction between weight loss and incident HF.

There are expected to be other mechanisms viable in the prevention of HF besides weight loss. One possible explanation is that higher PA improves myocardial perfusion by alleviating endothelial dysfunction and therefore dilating the coronary vessels [28].

When we conducted subgroup analyses according to the presence of malignancies, we could not observe the benefits of greater PA in reducing the risk of HF in subjects with malignancies. These results may be related to their exposure to cardiotoxic chemotherapy agents. There was no benefits of being continuously active among participants with CKD, which could be partially explained by the cardiorenal syndrome among participants in advanced stages of CKD.

Our study has potential limitations that should be considered during its interpretation. First, the definition of study outcome and comorbidities was based on claims data. Participants who have not yet been diagnosed with HF may have decreased PA. Also, information on the frequency and intensity of PA was based on a self-reported questionnaire, which is subject to recall response bias. Self-report questionnaires may provide a reliable approximation of PA at the population level [29]; however, we cannot completely rule out the possibility of bias. We also did not collect the information regarding the type of exercise (i.e., resistance exercise, aerobic exercise, or both). Large, randomized controlled trials are required to determine the most effective exercise training regimen. Second, detailed information for evaluating HF such as pro-brain natriuretic peptide level and left ventricular ejection fraction was not available in the NHIS database. HF in T2DM patients is not a homogenous complication rather a heterogenous condition; however, lack of echocardiographic data is a major limitation of our study. Third, we did not consider the effects of medications, which might have potential effects on the development of cardiovascular complications. We were unable to obtain study individuals’ prescribed drug data, especially which might have beneficial effects on the development of HF (i.e., sodium-glucose co-transporter-2 [SGLT-2] inhibitor or angiotensin receptor blockers); however, according to Ko et al. [30], metformin has been the most commonly used antidiabetic drug in Korea (80.4% in 2013), while sulfonylurea is the most commonly prescribed second-line agent following metformin. According to the literature regarding the prescription patterns in T2DM in Korea so far, SGLT-2 inhibitor was first introduced in Korea at the end of 2013, has not been commonly prescribed in newly diagnosed patients due to reimbursement restriction [31,32]. We also did not consider changes in blood pressure or antihypertensive medication, other health-related behaviors including medication adherence, smoking status, and alcohol consumption after the diagnosis of diabetes. We could not adjust for changes in blood pressure or health status during follow-up, because we could not obtain time-varying confounders in our dataset. These changes in study participants during follow-up period should be considered in future studies.

Participants who exercise regularly might have healthier lifestyles involving good diets and better compliance with their medical treatments. However, after adjustment for various factors including smoking status and alcohol habits, associations between increased PA and reduced risk of HF were attenuated, yet still suggested significant benefits. When we divided participants according to their weight changes between biennial health examinations, we could not obtain clinical information about their weight changes. Patients with HF may experience a range of weight changes as manifestations of HF decompensation, from peripheral edema to cachexia [33]. Lastly, the generalization of our results may be limited because of the single ethnicity among patients included in this study.

Despite these limitations, our study has several strengths. Until now, no study has analyzed the relationship between changes in the pattern of PA and HF, especially in patients with newly diagnosed T2DM via a longitudinal design. Because of the difficulty of conducting exercise detraining studies, only a few studies have examined the effects of exercise or PA on the development of HF. Though the causal relationship of PA and the risk of HF could not be fully addressed here, our results suggest that augmenting PA might have positive effects on mitigating the onset of HF in patients with newly diagnosed T2DM. Additional studies assessing other ethnic groups with longer follow-up periods are required to clarify the role of PA in the progression of HF in high-risk diabetic patients.

Among individuals with newly diagnosed T2DM, either increasing the level of PA or remaining continuously physically active after the diagnosis of T2DM may lower the risk of HF. Even in individuals with known risk factors of HF such as a history of MI, maintaining or increasing PA was associated with a reduced risk for HF. Patients with newly diagnosed T2DM should be encouraged to increase daily PA.

Supplementary Materials

Supplementary materials related to this article can be found online at https://doi.org/10.4093/dmj.2021.0046.

Supplementary Table 1.

Subgroup analysis of study participants

dmj-2021-0046-suppl1.pdf
Supplementary Fig. 1.

Flow chart of study population.

dmj-2021-0046-suppl2.pdf

Notes

CONFLICTS OF INTEREST

No potential conflict of interest relevant to this article was reported.

AUTHOR CONTRIBUTIONS

Conception or design: I.J.

Acquisition, analysis, or interpretation of data: H.K., S.E.P., K.D.H., Y.G.P.

Drafting the work or revising: I.J., H.K., S.E.P., E.J.R., W.Y.L.

Final approval of the manuscript: I.J., H.K., S.E.P., K.D.H., Y.G.P., E.J.R., W.Y.L.

FUNDING

None

Acknowledgements

The authors acknowledge the efforts of Department of R&D Management at Kangbuk Samsung Hospital, Korea for editing figures and tables. The authors would like to thank the National Health Insurance Service for cooperation.

References

1. Heidenreich PA, Albert NM, Allen LA, Bluemke DA, Butler J, Fonarow GC, et al. Forecasting the impact of heart failure in the United States: a policy statement from the American Heart Association. Circ Heart Fail 2013;6:606–19.
2. Lee JH, Lim NK, Cho MC, Park HY. Epidemiology of heart failure in Korea: present and future. Korean Circ J 2016;46:658–64.
3. Shiba N, Nochioka K, Miura M, Kohno H, Shimokawa H, ; CHART-2 Investigators. Trend of westernization of etiology and clinical characteristics of heart failure patients in Japan: first report from the CHART-2 study. Circ J 2011;75:823–33.
4. Rhee EJ, Kwon H, Park SE, Han KD, Park YG, Kim YH, et al. Associations among obesity degree, glycemic status, and risk of heart failure in 9,720,220 Korean adults. Diabetes Metab J 2020;44:592–601.
5. Florido R, Kwak L, Lazo M, Nambi V, Ahmed HM, Hegde SM, et al. Six-year changes in physical activity and the risk of incident heart failure: ARIC study. Circulation 2018;137:2142–51.
6. Florido R, Kwak L, Lazo M, Michos ED, Nambi V, Blumenthal RS, et al. Physical activity and incident heart failure in high-risk subgroups: the ARIC study. J Am Heart Assoc 2020;9e014885.
7. Chun MY. Validity and reliability of Korean version of international physical activity questionnaire short form in the elderly. Korean J Fam Med 2012;33:144–51.
8. Jeong HG, Kim DY, Kang DW, Kim BJ, Kim CK, Kim Y, et al. Physical activity frequency and the risk of stroke: a nationwide cohort study in Korea. J Am Heart Assoc 2017;6e005671.
9. Yun JS, Park YM, Han K, Cha SA, Ahn YB, Ko SH. Severe hypoglycemia and the risk of cardiovascular disease and mortality in type 2 diabetes: a nationwide population-based cohort study. Cardiovasc Diabetol 2019;18:103.
10. Seo MH, Kim YH, Han K, Jung JH, Park YG, Lee SS, et al. Prevalence of obesity and incidence of obesity-related comorbidities in Koreans based on national health insurance service health checkup data 2006-2015. J Obes Metab Syndr 2018;27:46–52.
11. Kim MK, Han K, Koh ES, Kim ES, Lee MK, Nam GE, et al. Blood pressure and development of cardiovascular disease in Koreans with type 2 diabetes mellitus. Hypertension 2019;73:319–26.
12. Kim MK, Han K, Kim HS, Park YM, Kwon HS, Yoon KH, et al. Cholesterol variability and the risk of mortality, myocardial infarction, and stroke: a nationwide population-based study. Eur Heart J 2017;38:3560–6.
13. Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med 1999;130:461–70.
14. Kim YH, Kim SM, Han KD, Son JW, Lee SS, Oh SW, et al. Change in weight and body mass index associated with allcause mortality in Korea: a nationwide longitudinal study. J Clin Endocrinol Metab 2017;102:4041–50.
15. Johnson JL, Slentz CA, Ross LM, Huffman KM, Kraus WE. Ten-year legacy effects of three eight-month exercise training programs on cardiometabolic health parameters. Front Physiol 2019;10:452.
16. Swain DP, Franklin BA. Comparison of cardioprotective benefits of vigorous versus moderate intensity aerobic exercise. Am J Cardiol 2006;97:141–7.
17. Slentz CA, Tanner CJ, Bateman LA, Durheim MT, Huffman KM, Houmard JA, et al. Effects of exercise training intensity on pancreatic beta-cell function. Diabetes Care 2009;32:1807–11.
18. Johnson JL, Slentz CA, Houmard JA, Samsa GP, Duscha BD, Aiken LB, et al. Exercise training amount and intensity effects on metabolic syndrome (from Studies of a Targeted Risk Reduction Intervention through Defined Exercise). Am J Cardiol 2007;100:1759–66.
19. Maack C, Lehrke M, Backs J, Heinzel FR, Hulot JS, Marx N, et al. Heart failure and diabetes: metabolic alterations and therapeutic interventions: a state-of-the-art review from the Translational Research Committee of the Heart Failure Association-European Society of Cardiology. Eur Heart J 2018;39:4243–54.
20. Rodrigues B, Cam MC, McNeill JH. Metabolic disturbances in diabetic cardiomyopathy. Mol Cell Biochem 1998;180:53–7.
21. Stewart KJ. Exercise training and the cardiovascular consequences of type 2 diabetes and hypertension: plausible mechanisms for improving cardiovascular health. JAMA 2002;288:1622–31.
22. Gademan MG, Swenne CA, Verwey HF, van der Laarse A, Maan AC, van de Vooren H, et al. Effect of exercise training on autonomic derangement and neurohumoral activation in chronic heart failure. J Card Fail 2007;13:294–303.
23. Napoli C, Williams-Ignarro S, De Nigris F, Lerman LO, Rossi L, Guarino C, et al. Long-term combined beneficial effects of physical training and metabolic treatment on atherosclerosis in hypercholesterolemic mice. Proc Natl Acad Sci U S A 2004;101:8797–802.
24. Nunes RB, Tonetto M, Machado N, Chazan M, Heck TG, Veiga AB, et al. Physical exercise improves plasmatic levels of IL-10, left ventricular end-diastolic pressure, and muscle lipid peroxidation in chronic heart failure rats. J Appl Physiol (1985) 2008;104:1641–7.
25. Conraads VM, Beckers P, Bosmans J, De Clerck LS, Stevens WJ, Vrints CJ, et al. Combined endurance/resistance training reduces plasma TNF-alpha receptor levels in patients with chronic heart failure and coronary artery disease. Eur Heart J 2002;23:1854–60.
26. Lavie CJ, Thomas RJ, Squires RW, Allison TG, Milani RV. Exercise training and cardiac rehabilitation in primary and secondary prevention of coronary heart disease. Mayo Clin Proc 2009;84:373–83.
27. Lavie CJ, Alpert MA, Ventura HO. Risks and benefits of weight loss in heart failure. Heart Fail Clin 2015;11:125–31.
28. Laughlin MH, McAllister RM. Exercise training-induced coronary vascular adaptation. J Appl Physiol (1985) 1992;73:2209–25.
29. Loney T, Standage M, Thompson D, Sebire SJ, Cumming S. Self-report vs. objectively assessed physical activity: which is right for public health? J Phys Act Health 2011;8:62–70.
30. Ko SH, Kim DJ, Park JH, Park CY, Jung CH, Kwon HS, et al. Trends of antidiabetic drug use in adult type 2 diabetes in Korea in 2002-2013: nationwide population-based cohort study. Medicine (Baltimore) 2016;95e4018.
31. Ko SH, Han K, Lee YH, Noh J, Park CY, Kim DJ, et al. Past and current status of adult type 2 diabetes mellitus management in Korea: a national health insurance service database analysis. Diabetes Metab J 2018;42:93–100.
32. Kim JY, Kim SJ, Nam CM, Moon KT, Park EC. Changes in prescription pattern, pharmaceutical expenditure and quality of care after introduction of reimbursement restriction in diabetes in Korea. Eur J Public Health 2018;28:209–14.
33. Chaudhry SI, Wang Y, Concato J, Gill TM, Krumholz HM. Patterns of weight change preceding hospitalization for heart failure. Circulation 2007;116:1549–54.

Article information Continued

Fig. 1.

Hazard ratio for incident heart failure (HF) according to changes in the pattern of physical activity. Cox proportional-hazards regression analysis was adopted and we calculated the hazard ratio and 95% confidence interval for incident HF according to changes in the pattern of physical activity. Adjusted for age, sex, current smoking, alcohol, income, waist circumference, hypertension, dyslipidemia, chronic kidney disease, stroke, myocardial infarction, and fasting blood glucose. CI, confidence interval.

Table 1.

Socio-demographic characteristics of study participants according to patterns of physical activity

Characteristic Total Continuity of physical activity
P value
Continuously physically inactive Physically active to inactive Physically inactive to active Continuously physically active
Number 132,418 85,733 14,259 20,986 11,440
Age, yr 57.7±9.58 57.54±9.79 59.03±9.3 57.15±9.11 58.2±8.98 <0.0001
Male sex 84,504 (63.8) 52,586 (61.3) 9,289 (65.1) 14,144 (67.4) 8,485 (74.2) <0.0001
Smoking status <0.0001
Never smoker 68,930 (52.1) 45,522 (53.1) 7,675 (53.8) 10,416 (49.6) 5,317 (46.5)
Former smoker 31,019 (23.4) 17,866 (20.8) 3,433 (24.1) 5,908 (28.2) 3,812 (33.3)
Current smoker 32,469 (24.5) 22,345 (26.1) 3,151 (22.1) 4,662 (22.2) 2,311 (20.2)
Alcohol drinking <0.0001
Never 71,159 (53.7) 47,205 (55.1) 7,741 (54.3) 10,903 (52.0) 5,310 (46.4)
Mild (<30 g/day) 48,761 (36.8) 30,371 (35.4) 5,263 (36.9) 8,209 (39.1) 4,918 (43.0)
Heavy (≥30 g/day) 12,498 (9.4) 8,157 (9.5) 1,255 (8.8) 1,874 (8.9) 1,212 (10.6)
Household incomea 33,030 (24.9) 21,808 (25.4) 3,640 (25.5) 5,056 (24.1) 2,526 (22.1) <0.0001
Residential area (urban) 59,136 (44.7) 36,939 (43.1) 6,559 (46.0) 9,935 (47.4) 5,703 (49.9) <0.0001
CKD 7,986 (6.0) 5,212 (6.1) 958 (6.7) 1,143 (5.5) 673 (5.9) <0.0001
Dyslipidemia 68,022 (51.4) 44,649 (52.1) 7,304 (51.2) 10,472 (50.0) 5,597 (48.9) <0.0001
Hypertension 74,235 (56.1) 48,081 (56.1) 8,366 (58.7) 11,322 (54.0) 6,466 (56.5) <0.0001
Strokeb 1,465 (1.1) 923 (1.1) 168 (1.2) 245 (1.2) 129 (1.1) 0.5459
MIc 1,851 (1.4) 1,199 (1.4) 188 (1.3) 303 (1.4) 161 (1.4) 0.8057
CVDd 3,249 (2.5) 2,080 (2.4) 346 (2.4) 541 (2.6) 282 (2.5) 0.6425
No. of oral antidiabetic drugse <0.0001
1 54,362 (41.1) 34,381 (40.1) 6,031 (42.3) 8,760 (41.7) 5,190 (45.4)
2 58,579 (44.2) 38,315 (44.7) 6,194 (43.4) 9,204 (43.9) 4,866 (42.5)
≥3 19,477 (14.7) 13,037 (15.2) 2,034 (14.3) 3,022 (14.4) 1,384 (12.1)
Use of insulinf 10,514 (7.9) 6,849 (8.0) 1,160 (8.1) 1,701 (8.1) 804 (7.0) 0.0002
Fasting blood glucose, mg/dL 163.9±43.32 164.8±44.01 160.9±40.76 164.5±43.78 159.7±39.76 <0.0001
Body weight, kg 68.6±11.16 68.4±11.34 68.4±10.88 69.1±10.89 69.5±10.47 <0.0001
Waist circumference, cm 85.7±8.3 85.9±8.42 85.7±8.25 85.1±8.08 85.1±7.79 <0.0001
Abdominal obesityg 61,716 (46.6) 42,004 (49.0) 6,588 (46.2) 8,773 (41.8) 4,351 (38.0) <0.0001
BMI, kg/m2 25.6±3.18 25.7±3.26 25.5±3.09 25.6±3.08 25.4±2.92 <0.0001
BMI ≥25 kg/m2 67,116 (50.7) 44,403 (51.8) 7,081 (49.7) 10,225 (48.7) 5,407 (47.3) <0.0001
SBP, mm Hg 129.9±15.46 129.8±15.61 129.9±15.27 129.9±15.29 130.1±14.85 0.2447
DBP, mm Hg 80.7±10.13 80.7±10.2 80.4±9.97 80.8±10.09 80.7±9.86 0.0004
Total cholesterol, mg/dL 213.8±41.66 214.6±41.95 211.3±40.99 214.1±41.39 210.3±40.49 <0.0001
ALTh, IU/L 27.8 (27.8–27.9) 28.1 (28.0–28.2) 27.9 (27.7–28.2) 27.0 (26.8–27.2) 27.1 (26.8–27.3) <0.0001
ASTh, IU/L 27.2 (27.1–27.2) 27.2 (27.1–27.3) 27.3 (27.2–27.5) 26.7 (26.6–26.9) 27.2 (27.0–27.4) <0.0001

Values are presented as mean±standard deviation, number (%), or median (interquartile range).

CKD, chronic kidney disease; MI, myocardial infarction; CVD, cardiovascular disease; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; ALT, alanine aminotransferase; AST, aspartate transaminase.

a

Low 20% and recipient of medical aid,

b

Stroke was defined by the presence of International Classification of Diseases, 10th revision, clinical modification (ICD-10-CM) codes I63 and I64 as well as a history of hospitalization with claims for brain magnetic resonance imaging or brain computed tomography,

c

MI was defined as hospitalization with the diagnostic codes of I21 and I22,

d

CVD included myocardial infarction and stroke,

e,f

Within 1 year before the index date,

g

Waist circumference: male ≥90 cm, female ≥85 cm,

h

Geometric mean.

Table 2.

Risk for heart failure according to study participants’ physical activity profile during follow-up

Variable Number CHF Duration IR (1,000 person-years) HR (95% CI)
Model 1 Model 2 Model 3 Model 4
Regular exercisea
No 99,992 1,072 481,952.14 2.2 1 (reference) 1 (reference) 1 (reference) 1 (reference)
Yes 32,426 249 157,358.01 1.6 0.77 (0.67–0.89) 0.78 (0.68–0.89) 0.79 (0.69–0.91) 0.79 (0.69–0.91)
Intensity of exercise
Vigorousb
 No 105,262 1,119 507,567.75 2.2 1 (reference) 1 (reference) 1 (reference) 1 (reference)
 Yes 27,156 202 131,742.41 1.5 0.79 (0.68–0.92) 0.80 (0.69–0.93) 0.81 (0.69–0.94) 0.81 (0.70–0.95)
Moderatec
 No 118,265 1,204 570,540.71 2.1 1 (reference) 1 (reference) 1 (reference) 1 (reference)
 Yes 14,153 117 68,769.44 1.7 0.76 (0.63–0.92) 0.76 (0.63–0.92) 0.79 (0.65–0.95) 0.79 (0.65–0.95)
Walkingd
 No 92,554 947 446,895.47 2.1 1 (reference) 1 (reference) 1 (reference) 1 (reference)
 Yes 39,864 374 192,414.68 1.9 0.81 (0.71–0.91) 0.81 (0.72–0.91) 0.83 (0.73–0.93) 0.83 (0.73–0.93)

Model 1: Adjusted for age and sex; Model 2: Adjusted model 1+current smoking, alcohol, and income; Model 3: Adjusted model 2+body mass index, hypertension, dyslipidemia, chronic kidney disease (CKD), stroke, and myocardial infarction (MI); Model 4: Adjusted model 2+waist circumference, hypertension, dyslipidemia, CKD, stroke, MI, and fasting blood glucose.

CHF, congestive heart failure; IR, incidence rate; HR, hazard ratio; CI, confidence interval.

a

Regular exercise was defined as performing at least 30 minutes of moderate-intensity physical activity at least five times per week or at least 20 minutes of strenuous physical activity at least three times per week. Each participant was asked to report their weekly physical activity levels according to three categories: vigorous, moderate, and walking,

b

Vigorous intensity was defined as at least 20 minutes of exercise per day (e.g., running, aerobic, or fast cycling at least three times per week),

c

Moderate intensity was defined as at least 30 minutes of exercise per day (e.g., brisk walking, bicycling at a usual speed, or gardening at least five times per week),

d

Walking was defined as usual-pace walking for at least 10 minutes at a time.

Table 3.

Subgroup analysis of study participants

Variable Continuity of physical activity
P value for interaction
Continuously physically inactive Physically active to inactive Physically inactive to active Continuously physically active
Age, yr 0.6837
 <65 1 (reference) 1.02 (0.78–1.33) 0.81 (0.63–1.04) 0.72 (0.51–1.02)
 ≥65 1 (reference) 0.87 (0.69–1.09) 0.79 (0.62–0.99) 0.84 (0.63–1.12)
Sex 0.0216
 Male 1 (reference) 1.10 (0.89–1.36) 0.81 (0.66–1.01) 0.70 (0.53–0.92)
 Female 1 (reference) 0.68 (0.50–0.92) 0.76 (0.58–1.00) 1.001 (0.70–1.44)
Hypertension 0.6907
 No 1 (reference) 0.79 (0.53–1.16) 0.73 (0.52–1.03) 0.86 (0.56–1.31)
 Yes 1 (reference) 0.96 (0.79–1.17) 0.81 (0.66–0.98) 0.75 (0.58–0.97)
Dyslipidemia 0.3024
 No 1 (reference) 0.77 (0.58–1.02) 0.70 (0.54–0.91) 0.76 (0.55–1.06)
 Yes 1 (reference) 1.05 (0.84–1.30) 0.86 (0.69–1.07) 0.79 (0.59–1.06)
CKD 0.6063
 No 1 (reference) 0.93 (0.77–1.12) 0.78 (0.65–0.94) 0.73 (0.57–0.93)
 Yes 1 (reference) 0.85 (0.54–1.33) 0.80 (0.52–1.24) 1.06 (0.63–1.78)
CVD 0.6556
 No 1 (reference) 0.94 (0.78–1.12) 0.77 (0.65–0.92) 0.77 (0.61–0.96)
 Yes 1 (reference) 0.74 (0.35–1.55) 1.02 (0.57–1.79) 0.99 (0.45–2.18)
Obesitya 0.5058
 No 1 (reference) 0.81 (0.62–1.05) 0.75 (0.59–0.96) 0.70 (0.50–0.96)
 Yes 1 (reference) 1.04 (0.83–1.31) 0.83 (0.66–1.04) 0.87 (0.65–1.18)
Weight changeb 0.4933
 Gain 1 (reference) 0.96 (0.67–1.39) 1.03 (0.75–1.41) 0.73 (0.45–1.19)
 Stable 1 (reference) 0.96 (0.78–1.18) 0.72 (0.58–0.89) 0.79 (0.60–1.02)
 Loss 1 (reference) 0.70 (0.39–1.24) 0.68 (0.40–1.15) 0.87 (0.45–1.67)
Malignancy 0.1431
 No 1 (reference) 0.90 (0.75–1.07) 0.79 (0.66–0.93) 0.74 (0.59–0.93)
 Yes 1 (reference) 1.39 (0.70–2.73) 0.85 (0.40–1.84) 1.47 (0.70–3.08)

Adjusted for age, sex, current smoking, alcohol, income, waist circumference, hypertension, dyslipidemia, CKD, stroke, myocardial infarction, and fasting blood glucose.

CKD, chronic kidney disease; CVD, cardiovascular disease.

a

The body mass index cutoff of 25 kg/m2 was used to define obesity in the Korean population in this study,

b

Weight change was calculated for each subject as the difference in weight between the follow-up health examination and baseline examination and divided into three categories: stable, gain or loss of less than 5% of body weight at baseline; gain, gain of 5% or more of body weight at baseline; loss, loss of 5% or more of body weight at baseline.