Associations of body mass index with glycated albumin and glycated albumin/glycated hemoglobin A1c ratio in Chinese diabetic and non-diabetic populations

Background: Recent studies have discussed the relationship between body mass index (BMI) and glycated albumin (GA) level. However, the extent of the influence of BMI on GA remains uncertain. We investigated the associations between BMI and GA, glycated hemoglobin Ale (HbA(1c)) and GA/HbA(1c), and to analyze the influence of obesity on GA, HbA(1c) and GA/HbA(1c) in both Chinese diabetic and non-diabetic populations. Methods: A total of 2562 participants, including 1177 men and 1385 women (age 20-80 y), were enrolled. Each subject underwent a 75-g oral glucose tolerance test. Serum GA was detected using a liquid enzyme method, and HbA(1c) was assayed using high-performance liquid chromatography. Results: In the diabetic patients (n = 1223), the GA, HbA(1c), and GA/HbA(1c) levels were 16.7 +/- 3.0%, 6.6 +/- .9% (49 +/- 9 mmol/mol), and 2.51 +/- .33, respectively. In the non-diabetic subjects (n = 1339), the GA, HbA(1c) and GA/HbA(1c) concentrations were 13.8 +/- 1.7%, 5.6 +/- .4% (38 +/- 4 mmol/mol), and 2.47 +/- .31, respectively. Decreasing trends in the GA and GA/HbAic concentrations and an increasing trend in the HbA(1c) concentration (all P for trend <.05) were found to accompany with the increase in BMI, regardless of diabetes status. Multiple regression analysis revealed that BMI was independently related to HbA(1c) in the non-diabetic population (standardized beta = .158, P<.001); however, the relationship disappeared in the diabetic population (P>.05). Moreover, in the diabetic and non-diabetic populations, BMI was negatively correlated with GA (standardized beta = .167 and -.231, both P<.001) and GA/HbA(1c) (standardized beta = -.273 and -.310, both P<.001). Further analysis showed that a 1 kg/m(2) increment in BMI was associated with a .13% decrease in the absolute value of GA. Conclusions: In both diabetic and non-diabetic populations, GA and GA/HbA(1c) levels are independently and negatively associated with BMI. For every 1 kg/m(2) increment in BMI, the absolute value of GA decreases approximately .13%.