The aim of this study was to explore the differences in the clinical characteristics and diagnostic rates of diabetes mellitus (DM) according to various criteria in different age groups and to evaluate the efficacy of each criterion for screening older patients.

We studied 515 patients and measured the fasting plasma glucose level (FPG), 2-hour plasma glucose level after the 75 g oral glucose tolerance test (2-hour postload glucose [2-h PG]), and glycosylated hemoglobin (HbA1c) for re-evaluation of hyperglycemia without a history of diabetes. Patients with newly diagnosed DM were grouped by age as younger (<65 years) or older (≥65 years).

Older patients had significantly lower HbA1c, FPG, and 2-h PG levels and a higher homeostatic level of pancreatic β-cell function compared with younger patients (P<0.001). The older group had the lowest diagnostic rate when using the FPG level (45.5%) and the highest diagnostic rate when using the 2-h PG level (84.6%). These results were mostly due to the higher frequency of isolated post-challenge hyperglycemia in the older patients than in the younger group (28.8% vs. 9.2%). The use of both the FPG and HbA1c levels significantly enhanced the low diagnostic power when employing only the FPG levels in the older group (71.2% vs. 45.5%).

In the older patients, the 2-h PG level was the most accurate diagnostic criterion. When we consider the costs and convenience, a combination of the FPG and HbA1c criteria may be recommended as a screening test for DM in older people.

Recent studies have shown the importance of postprandial glucose (PPG) in the development of diabetes complications. This study was conducted in order to survey the perceptions of clinicians and diabetic patients with respect to PPG management and the current status of diabetes education.

This was a cross-sectional study involving face-to-face interviews and an open questionnaire survey conducted in Korea. A total of 300 patients and 130 clinicians completed questionnaires, which included current education status, self monitoring of blood glucose (SMBG), criteria of diagnosis and management, and perceptions relating to PPG management.

While there was a significantly higher perceived need for diabetes education, the sufficiency of the current education was considered to be severely lacking. Fasting plasma glucose (FPG), PPG, and glycosylated hemoglobin (HbA1c) were all important considerations for clinicians when making a diagnosis of diabetes, although PPG was considered less important than FPG or HbA1c in the treatment of diabetes. Most clinicians and patients were aware of the importance of PPG, but actual education on the importance of PPG was not actively being delivered.

Our study showed that the current status of diabetes education is insufficient to meet the needs of the Korean population. A considerable gap was found to exist between awareness and what was actually taught in the current education program in regard to the importance of PPG. These results suggest that clinicians need to be more active in patient education, especially in regard to the importance of PPG.