The Effect of BMI on the Ratio of Glycated Albumin to Glycated Hemoglobin May Depend on Compensatory Insulin Secretory Function

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 690-701-Obesity Pathophysiology
Translational
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-698
Ji Hye Huh*1 and Byung-Wan Lee2
1Yonsei University College of Medicine, Seoul, Seoul, South Korea, 2Yonsei University College of Medicine
Context: Controversy remains regarding the negative correlation between body mass index (BMI) and the ratio of glycated albumin (GA) to glycated hemoglobin (A1c) ((1)).

Objectives: Based on both facts that BMI is associated with insulin resistance, and insulin secretory function negatively associates with GA/A1c ratio but not insulin resistance ((2),(3),(4),(5)), the objective of this study was to evaluated whether the negative correlation between GA/A1c ratio and BMI is due to compensatory insulin secretory function, which overshadows the contribution of insulin resistance or not.

Design and Methods: In a retrospective study, we analyzed 242 drug-naïve patients recently diagnosed with type 2 diabetes, 185 pre-diabetic patients, and 69 patients with normal glucose tolerance (NGT). To assess the effects of BMI, homeostasis model assessment-insulin resistance (HOMA-IR), and homeostasis model assessment- pancreatic beta-cell function (HOMA-β) on GA/A1c ratio, a statistical analysis was performed using multivariate regression analysis. And to evaluate the direct and indirect effects of insulin secretory function and BMI on GA/A1c ratio, we employed structural equation models (SEM)((6)).

Results: The negative association between GA/A1c ratio and BMI were most prominent in the NGT group. (NGT: R = –0.594, P < 0.001; prediabetes: R = –0.227, P < 0.01; and type 2 diabetes: R = –0.224, P< 0.001). And in SEM analysis, the estimates of total effect of BMI on GA/A1c ratio were –0.621 (P < 0.001) , –0.251 (P = 0.053) , and –0.235 (P = 0.08)  in the NGT, pre-diabetes, and type 2 diabetes groups, respectively. This result might be explained because in NGT group, compensatory insulin secretory fuction is preserved, so, the more BMI is higher, the more HOMA-β is higher, and therefore GA/A1c ratio is more prominent lower because of the negative association between HOMA-β an GA/A1c ratio. But, in prediabetes and diabetes group, relatively impaired compensatory insulin secretory fuction group, in spite of higher BMI, HOMA-β can not be fully increased, so, the degree of decrease in GA/A1c is lower than other group.

Conclusions: Degrees of negative influence of BMI on the ratio of GA/A1c ratio might be dependent on compensatory secretory function over insulin resistance and these effects are different between NGT and diabetes group.

(1) Furusyo N et al.,Diabetologia 2011; 54:3028-3036 (2)Miyashita Y et al., Diabetes Res Clin Pract 2007;78:51-55 (3) Koga M et al., Endocr J 2006; 53:387-391 10. (4) Koga M et al., Clin Chim Acta 2007;378:48-52 (5) Koga et al., Diabetes Care 2010;33:270-272 (6) Stein CM et al., Methods Mol Biol ;850:495-512

Nothing to Disclose: JHH, BWL

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm