Obesity Influence on Insulin Activity and Resting Metabolic Rate in Type 2 Diabetes

Background and Aims. Diabetes mellitus and obesity modify the resting metabolic rate (RMR) in opposite directions. This study aimed to evaluate the relationship between RMR, insulin activity and adipocytokines in type 2 diabetes patients with associated obesity. Material and Method. Anthropometric and biochemical measurements, bioimpedance body composition, C peptide, insulin, proinsulin, adiponectin, leptin, indirect calorimetry measured RMR were determined in 306 (53% male, 54.9% obese) diabetic patients. Results. RMR, C peptide, insulin, proinsulin, Homeostasis Model Assessment (HOMA) IR, HOMA %B, leptin increased and adiponectin decreased with body mass index (BMI). BMI had a statistical significant higher effect size on fat mass (FM), leptin (0.652-0.339 eta squared), moderate positive effect size on fat-free mass (FFM), insulin, C peptide, RMR, HOMA %B (0.228 - 0.155 eta squared) and lower effect size on HOMA-IR, adiponectin, proinsulin-to-adiponectin ratio, proinsulin (0.098-0.062 eta squared). RMR had positive correlations with FFM (r=0.633), BMI (r=0.300), proinsulin-to-adiponectin ratio (r=0.218), HOMA1-IR (r=0.176), proinsulin (r=0.151), insulin (r=0.144), fasting plasma glucose (r=0.132), fat mass (r= 0.131), triglycerides (r = 0.119), proinsulin-to-insulin ratio (r= 0.117) and negative with age (r=-0.368), HDL cholesterol (r=-0.284), adiponectin(r=-0.282) and leptin (r=-0.178). Conclusions RMR was correlated with HOMA IR and insulin resistance biomarkers, but not with HOMA %B and C peptide