Hemoglobin A1c as a marker for identifying diabetes and cardiovascular risk factors: the China Health and Nutrition Survey 2009

Hemoglobin A(1c) (HbA(1c)) has been recommended as an optional method for diagnosing diabetes. The impact of HbA(1c) on the diagnosis of diabetes has not been evaluated in China, a country with the greatest number of people with diabetes in the world. Hence, we aim to examine how well HbA(1c) performs as compared with fasting plasma glucose (FPG) for diagnosing diabetes in Chinese population. We conducted a cross-sectional analysis of 7,641 Chinese men and women aged a parts per thousand yen18 years using data from the China Health and Nutrition Survey 2009 in which FPG and standardized HbA(1c) were measured. HbA(1c) was measured with high-performance liquid chromatography system. Diabetes is defined as having FPG a parts per thousand yen7 mmol/l or HbA(1c) a parts per thousand yen6.5 %. Overall, 5.0 and 5.8 % had undiagnosed diabetes by FPG a parts per thousand yen7 mmol/l and HbA(1c) a parts per thousand yen6.5 %, respectively. Overlap between HbA(1c)- and FPG-based diagnosis of diabetes was limited (n = 214, 34.9 %). Similar trends were noted in both genders, all age groups, urban/rural settings, regions, body mass index (BMI) categories, waist circumference (WC) groups, and blood pressure status. Solely HbA(1c)-defined individuals exhibited higher levels of BMI, WC, total cholesterol, and hypersensitive C-reactive protein and lower levels of homeostasis model assessment of insulin resistance. We note limited overlap between FPG- and HbA(1c)-based diagnosis of diabetes. The limited overlap between FPG- and HbA(1c)-based diagnosis of diabetes persisted in each evaluated subgroup. HbA(1c) criterion for the diagnosis of diabetes identifies individuals with a worse cardiovascular risk profile compared with FPG.