1Health Services and Systems Research, Duke-NUS Medical School, Singapore.
2Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore.
3UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA.
4Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
5Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Copyright © 2020 Korean Diabetes Association
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
CONFLICTS OF INTEREST: No potential conflict of interest relevant to this article was reported.
AUTHOR CONTRIBUTIONS:
Values are presented as mean±standard deviation, number (%), or median (interquartile range). Cases and controls are matched on age at blood taken (±3 years), gender, dialect, and date of blood collection (±6 months).
TG, triglycerides; HDL-C, high density lipoprotein cholesterol; ALT, alanine aminotransferase; hs-CRP, high-sensitivity C-reactive protein; RBP4, retinol-binding protein 4; HbA1c, glycosylated hemoglobin.
aP values were based conditional logistic regression models.
OR, odds ratio; CI, confidence interval; TG-to-HDL ratio, the ratio of triglycerides to high density lipoprotein cholesterol; ALT, alanine aminotransferase; hs-CRP, high-sensitivity C-reactive protein; RBP4, retinol-binding protein 4.
aThe sample size for all the biomarkers was 485 type 2 diabetes mellitus cases and 485 controls. Cases and controls were matched on age at blood taken (±3 years), sex, dialect, and date of blood collection (±6 months), bModel 1 was calculated using conditional logistic regression model with adjustment for age at blood taken (continuous), smoking (never, former, and current smoker), alcohol intake (never, weekly, or daily), weekly activity (<0.5, 0.5 to 3.9, and ≥4.0 hr/wk), education level (primary school and below, secondary or above), history of hypertension (yes, no), body mass index (continuous), and fasting status (yes, no), cModel 2: model 1 plus adjustment for all the other biomarkers (per quartile increment).
HbA1c, glycosylated hemoglobin.
aThe biomarker score was constructed using each biomarker (triglycerides to high density lipoprotein cholesterol ratio, alanine aminotransferase, ferritin, and adiponectin) as ordinal variables, bLinear trend was tested by using the median level of each quartile of the biomarker score, cModel 1 was calculated using conditional logistic regression models after adjusting for age at blood taken (continuous), smoking (never, former, and current smoker), alcohol intake (never, weekly, or daily), weekly activity (<0.5, 0.5 to 3.9, and ≥4.0 hr/wk), education level (primary school and below, secondary or above), history of hypertension (yes, no), body mass index (continuous), and fasting status (yes, no), dModel 2: model 1 plus levels of random glucose and random insulin (both in quartiles).
AUC, area under the receiver operating characteristic curve; CI, confidence interval; AIC, Akaike information criterion; NRI, net reclassification improvement; IDI, integrated discrimination improvement; HbA1c, glycosylated hemoglobin.
aBase model 1 included age at blood taken (continuous), smoking (never, former, and current smoker), history of hypertension (yes, no), and body mass index (continuous), bThe biomarker score was constructed using each biomarker (triglycerides to high density lipoprotein cholesterol ratio, alanine aminotransferase, ferritin, and adiponectin) as ordinal variables, and was used as categorical variables (in quartiles) in the prediction model, cCompared with the base model, the increment in AUC value was statistically significant (P<0.05), dBase model 2: base model 1 plus random levels of glucose and insulin (both in quartiles), eBase model 3: base model 1 plus levels of HbA1c and random insulin (both in quartiles), fCompared with the base model, the increment in AUC value was marginally significant (P=0.052).
Characteristic | Cases | Controls | P valuea |
---|---|---|---|
Age at blood taken, yr | 59.4±5.94 | 59.4±6.05 | - |
Female sex | 273 (56.3) | 273 (56.3) | - |
Dialect | - | ||
Cantonese | 242 (49.9) | 242 (49.9) | |
Hokkien | 243 (50.1) | 243 (50.1) | |
Body mass index, kg/m2 | 24.9±3.62 | 22.8±3.26 | <0.001 |
Level of education | 0.423 | ||
No formal education | 77 (15.9) | 73 (15.1) | |
Primary school | 220 (45.4) | 204 (42.1) | |
Secondary and above | 188 (38.8) | 208 (42.9) | |
History of hypertension | 229 (47.2) | 121 (25.0) | <0.001 |
Cigarette smoking | 0.107 | ||
Never smokers | 344 (70.9) | 360 (74.2) | |
Former smoker | 58 (12.0) | 65 (13.4) | |
Current smokers | 83 (17.1) | 60 (12.4) | |
Weekly moderate-to-vigorous activity, hr/wk | 0.058 | ||
<0.5 | 387 (79.8) | 384 (79.2) | |
0.5–3.9 | 72 (14.9) | 58 (12.0) | |
≥4.0 | 26 (5.4) | 42 (8.9) | |
Alcohol intake | 0.950 | ||
Abstainers | 424 (87.4) | 421 (86.8) | |
Weekly drinkers | 47 (9.7) | 50 (10.3) | |
Daily drinkers | 14 (2.9) | 14 (2.9) | |
Fasting status (yes) | 157 (32.4) | 145 (29.9) | 0.405 |
TG, mmol/L | 2.12 (1.45–2.85) | 1.51 (1.05–2.14) | <0.001 |
HDL-C, mmol/L | 1.09 ± 0.24 | 1.24±0.32 | <0.001 |
TG-to-HDL ratio | 1.94 (1.27–2.93) | 1.23 (0.78–2.01) | <0.001 |
ALT, IU/L | 27 (21–37) | 20 (15–27) | <0.001 |
hs-CRP, mg/L | 1.8 (1.0–3.5) | 1.2 (0.6–2.2) | <0.001 |
Ferritin, µg/L | 185 (106–283) | 131 (77–201) | <0.001 |
Adiponectin, µg/mL | 6.8 (5.2–8.4) | 8.4 (6.5–10.7) | <0.001 |
Fetuin-A, µg/mL | 730 (564–931) | 650 (506–861) | <0.001 |
RBP4, µg/mL | 28 (23–34) | 26 (23–32) | <0.001 |
HbA1c, % | 6.4 (5.9–7.2) | 5.6 (5.4–5.7) | <0.001 |
HbA1c, mmol/mol | 46 (41–55) | 38 (36–39) | <0.001 |
Biomarker score | 9.1 (7.2–10.9) | 6.3 (3.9–8.9) | <0.001 |
Variable | OR (95% CI) per quartile increment | β Coefficient from model 2c | |
---|---|---|---|
Model 1b | Model 2c | ||
TG-to-HDL ratio | 1.90 (1.58–2.28) | 1.48 (1.21–1.82) | 0.39 |
ALT | 1.68 (1.42–1.98) | 1.30 (1.08–1.57) | 0.26 |
hs-CRP | 1.37 (1.17–1.59) | 1.16 (0.98–1.38) | 0.15 |
Ferritin | 1.40 (1.20–1.63) | 1.24 (1.04–1.48) | 0.21 |
Adiponectin | 0.58 (0.49–0.68) | 0.72 (0.60–0.86) | −0.33 |
Fetuin-A | 1.27 (1.08–1.49) | 1.10 (0.92–1.32) | 0.10 |
RBP4 | 1.12 (0.96–1.32) | 1.00 (0.83–1.21) | 0.01 |
Variable | Biomarker score | P trendb | |||
---|---|---|---|---|---|
Q1 | Q2 | Q3 | Q4 | ||
Total dataset | |||||
Median (range) | 2.29 (0–3.87) | 5.24 (3.93–6.29) | 7.73 (6.32–8.87) | 10.5 (8.91–12.0) | |
No. of cases/controls | 28/123 | 58/123 | 132/118 | 267/121 | |
Model 1c | 1.00 | 2.63 (1.36–5.09) | 7.24 (3.76–13.9) | 13.3 (6.79–26.0) | <0.001 |
Model 2d | 1.00 | 2.71 (1.24–5.92) | 6.40 (2.94–13.9) | 12.0 (5.43–26.6) | <0.001 |
Limited to cases with baseline HbA1c <6.5% and matched controls | |||||
Median (range) | 2.28 (0–3.87) | 5.14 (3.93–6.29) | 7.60 (6.32–8.87) | 10.6 (8.91–12.0) | |
No. of cases/controls | 20/65 | 34/65 | 71/63 | 121/53 | |
Model 1c | 1.00 | 2.46 (1.05–5.76) | 4.90 (2.15–11.2) | 9.68 (4.03–23.3) | <0.001 |
Model 2d | 1.00 | 2.88 (1.14–7.28) | 4.14 (1.60–10.7) | 8.62 (3.32–22.4) | <0.001 |
Limited to cases with baseline HbA1c <6.0% and matched controls | |||||
Median (range) | 2.12 (0–3.87) | 5.21 (3.93–6.29) | 8.00 (6.45–8.87) | 10.7 (8.91–12.0) | |
No. of cases/controls | 14/34 | 25/30 | 35/35 | 55/30 | |
Model 1c | 1.00 | 3.17 (1.07–9.39) | 4.89 (1.56–15.4) | 8.25 (249–27.4) | 0.001 |
Model 2d | 1.00 | 3.71 (1.12–12.4) | 4.94 (1.18–20.7) | 10.1 (2.47–41.4) | 0.002 |
Variable | Multivariable model | |||
---|---|---|---|---|
Discrimination AUC (95% CI) | Calibration (AIC) | NRI | IDI | |
Total dataset | ||||
Base model 1a | 0.70 (0.66–0.73) | 558 | ||
Base model 1a+biomarker scoreb | 0.76 (0.73–0.79)c | 501 | 0.56 | 0.08 |
Base model 2d | 0.81 (0.78–0.83) | 418 | ||
Base model 2d+biomarker scoreb | 0.83 (0.81–0.86)c | 369 | 0.59 | 0.06 |
Base model 3e | 0.85 (0.83–0.88) | 338 | ||
Base model 3e+biomarker scoreb | 0.86 (0.84–0.89)c | 303 | 0.47 | 0.04 |
Limited to cases with baseline HbA1c <6.5% and matched controls | ||||
Base model 1a | 0.70 (0.66–0.75) | 280 | ||
Base model 1a+biomarker scoreb | 0.75 (0.70–0.79)c | 252 | 0.54 | 0.06 |
Base model 2d | 0.75 (0.71–0.80) | 261 | ||
Base model 2d+biomarker scoreb | 0.78 (0.74–0.82)c | 242 | 0.50 | 0.05 |
Base model 3e | 0.81 (0.78–0.85) | 215 | ||
Base model 3e+biomarker scoreb | 0.83 (0.79–0.87)f | 204 | 0.46 | 0.04 |
Limited to cases with baseline HbA1c <6.0% and matched controls | ||||
Base model 1a | 0.65 (0.59–0.72) | 177 | ||
Base model 1a+biomarker scoreb | 0.68 (0.62–0.75)c | 172 | 0.36 | 0.03 |
Base model 2d | 0.71 (0.65–0.77) | 194 | ||
Base model 2d+biomarker scoreb | 0.73 (0.67–0.79) | 189 | 0.37 | 0.03 |
Base model 3e | 0.71 (0.65–0.78) | 194 | ||
Base model 3e+biomarker scoreb | 0.74 (0.68–0.80) | 186 | 0.33 | 0.03 |
Values are presented as mean±standard deviation, number (%), or median (interquartile range). Cases and controls are matched on age at blood taken (±3 years), gender, dialect, and date of blood collection (±6 months). TG, triglycerides; HDL-C, high density lipoprotein cholesterol; ALT, alanine aminotransferase; hs-CRP, high-sensitivity C-reactive protein; RBP4, retinol-binding protein 4; HbA1c, glycosylated hemoglobin. a
OR, odds ratio; CI, confidence interval; TG-to-HDL ratio, the ratio of triglycerides to high density lipoprotein cholesterol; ALT, alanine aminotransferase; hs-CRP, high-sensitivity C-reactive protein; RBP4, retinol-binding protein 4. aThe sample size for all the biomarkers was 485 type 2 diabetes mellitus cases and 485 controls. Cases and controls were matched on age at blood taken (±3 years), sex, dialect, and date of blood collection (±6 months), bModel 1 was calculated using conditional logistic regression model with adjustment for age at blood taken (continuous), smoking (never, former, and current smoker), alcohol intake (never, weekly, or daily), weekly activity (<0.5, 0.5 to 3.9, and ≥4.0 hr/wk), education level (primary school and below, secondary or above), history of hypertension (yes, no), body mass index (continuous), and fasting status (yes, no), cModel 2: model 1 plus adjustment for all the other biomarkers (per quartile increment).
HbA1c, glycosylated hemoglobin. aThe biomarker score was constructed using each biomarker (triglycerides to high density lipoprotein cholesterol ratio, alanine aminotransferase, ferritin, and adiponectin) as ordinal variables, bLinear trend was tested by using the median level of each quartile of the biomarker score, cModel 1 was calculated using conditional logistic regression models after adjusting for age at blood taken (continuous), smoking (never, former, and current smoker), alcohol intake (never, weekly, or daily), weekly activity (<0.5, 0.5 to 3.9, and ≥4.0 hr/wk), education level (primary school and below, secondary or above), history of hypertension (yes, no), body mass index (continuous), and fasting status (yes, no), dModel 2: model 1 plus levels of random glucose and random insulin (both in quartiles).
AUC, area under the receiver operating characteristic curve; CI, confidence interval; AIC, Akaike information criterion; NRI, net reclassification improvement; IDI, integrated discrimination improvement; HbA1c, glycosylated hemoglobin. aBase model 1 included age at blood taken (continuous), smoking (never, former, and current smoker), history of hypertension (yes, no), and body mass index (continuous), bThe biomarker score was constructed using each biomarker (triglycerides to high density lipoprotein cholesterol ratio, alanine aminotransferase, ferritin, and adiponectin) as ordinal variables, and was used as categorical variables (in quartiles) in the prediction model, cCompared with the base model, the increment in AUC value was statistically significant (