Association of Body Mass Index-Adjusted Body Cell Mass and Lean Body Mass with Metabolic Syndrome and Insulin Resistance in Middle-Aged and Older Adults: A Cross-Sectional Study

Background: This study was conducted to examine the association of body mass index (BMI)-adjusted body cell mass (BCM; BCMbmi) and lean body mass (LBM; LBMbmi) with metabolic markers, metabolic syndrome (MetS), and insulin resistance (IR) in middle-aged and older Korean adults.Methods: This cross-sectional study included 9,522 adults (4,456 males and 5,066 females) without a history of myocardial infarction, stroke, or cancer from the Ansan-Ansung Study of the Korean Genome and Epidemiology Study.Multivariable linear regression was conducted to evaluate the association of BCMbmi and LBMbmi with metabolic markers.Logistic regression analyses were conducted to evaluate the association of BCMbmi and LBMbmi with metabolic abnormalities, including MetS and IR.MetS diagnosis followed National Cholesterol Education Program Adult Treatment Panel III criteria, and IR was assessed using the homeostatic model assessment index of insulin resistance (HOMA-IR).Results: BCMbmi and LBMbmi were negatively associated with fasting glucose, fasting insulin, HOMA-IR, triglycerides, alanine/aspartate aminotransferase, uric acid, and high-sensitivity C-reactive protein, while they were positively associated with high-density lipoprotein cholesterol.The magnitudes of regression coefficients were generally greater for BCMbmi than for LBMbmi.A total of 3,590 (37.7%) and 3,490 (36.7%) participants were categorized as having MetS and IR.Compared to the lowest tertile of BCMbmi, the highest tertiles were associated with lower odds ratio of MetS (males: 0.36 [95% confidence interval, CI, 0.30 to 0.42], females: 0.23 [95% CI, 0.20 to 0.27]) and IR (males: 0.34 [95% CI, 0.30 to 0.40], females, 0.33 [95% CI, 0.28 to 0.38]), all with significant trends (P for trend