Abstract P246: Lean Body Mass, Percent Body Fat, and HbA1c in the U.S. Population: The National Health and Nutrition Examination Survey (NHANES 1999-2006)

Abstract

Introduction: Weight loss is an important component of diabetes prevention and management because of the known effect of adiposity on insulin resistance. While both muscle (lean mass) and fat mass are known to serve important metabolic functions, most studies of obesity and diabetes use proxy measures for overall or abdominal obesity without accounting for the composition of that mass. The aim of this study was to examine the association of total and trunk lean body mass and fat mass with hemoglobin A1c (HbA1c) - an indicator of glucose control in persons with diabetes and a risk marker in non-diabetic populations - in the general U.S. population. Methods: We conducted a cross-sectional analysis of data from the NHANES collected in 1999-2006 in participants aged 18-69 years. Lean body mass and percent body fat were determined using dual energy x-ray absorptiometry (DXA); analyses were weighted and multiple imputation was applied to account for missing DXA data. Associations of body composition with HbA1C were evaluated using multiple linear regression. Results: The study sample included 1,085 participants with diagnosed diabetes (mean age 56 years, 50% male, mean HbA1c=7.6%) and 15,597 participants without diabetes (mean age 40 years, 51% women, mean HbA1c=5.3%). Trunk lean mass and total lean mass were significantly associated with lower HbA1c in adults without diabetes, independent of body mass index (BMI) and waist circumference. After adjustment for age, sex, race/ethnicity, and waist circumference, each 10 kg increase in trunk lean mass was associated with 0.07-% points lower HbA1c (95% CI: -0.09, -0.03). After adjustment for age, sex, race/ethnicity, and BMI, each 10kg increase in total lean mass was associated with 0.03-% points lower HbA1c (95% CI: -0.05, -0.0). Each 5% increase in trunk fat was associated with 0.5-% point higher HbA1c (95% CI: 0.45, 0.55) and each 5% increase in total fat was associated with 0.05-% point higher HbA1c (95% CI: 0.05, 0.06). Lean mass and percent body fat were not associated with HbA1c in participants with diagnosed diabetes (p > 0.05). Conclusions: Lean mass is independently associated with HbA1c in adults without diabetes. Interventions that target both weight loss where warranted and increasing lean mass via resistance training may have the most beneficial impact for diabetes prevention.