A low resting metabolic rate is associated with metabolic syndrome

Background & aims The metabolic syndrome is associated with central accumulation of fat. Previous studies showed that some obese subjects are characterized by a sparing energy metabolism. The aim of this study was to investigate whether obese subjects with metabolic syndrome have a lower resting metabolic rate than obese subjects without metabolic syndrome. Methods Forty obese subjects were divided into three groups according to the presence of metabolic syndrome and type 2 diabetes; 15 non-obese healthy control subjects were also enrolled. Body composition (bio-impedance analysis) and resting metabolic rate (indirect calorimetry) were performed. Results The group with metabolic syndrome exhibited a significantly lower resting metabolic rate adjusted for fat-free mass with respect to the control group and the obese group without metabolic syndrome (respectively: 108±3 vs. 118±3, p<0.01 and 123±3 kJ/kg fat-free mass 24 h, p<0.01; mean±sem). The obese group with metabolic syndrome and type 2 diabetes (T2D) had a not different adjusted resting metabolic rate (114±6 kJ/kg fat-free mass 24 h) with respect to other groups. Conclusions An energy sparing condition seems to characterize non-diabetic obese subjects with metabolic syndrome.