Cardiometabolic risk in overweight subjects with or without relative fat-free mass deficiency: the Strong Heart Study

Sarcopenia is a condition mainly due to loss of fat-free mass (FFM) in elderly individuals. RFFMD, however, is also frequent in obese subjects due to abnormal body composition. Objective of this study was to evaluate the impact of relative fat-free mass deficiency (RFFMD) on cardiometabolic (CM) risk in obese normoglycemic individuals.

Overweight/obese American Indians from the Strong Heart Study population, without diabetes and with FBG ≤ 110 mg/dL and with GFR >60 mg/mL/1.73 m(2) were selected for this analysis (n = 742). RFFMD was defined on the basis of a multivariable equation previously reported. Fasting glucose and 2 h-OGTT were measured together with urine albumin/creatinine excretion, laboratory and anthropometric parameters. In addition to lower FFM and greater adipose mass, participants with RFFMD had higher body mass index, waist circumference, C-reactive protein, fibrinogen, insulin resistance and urinary albumin/creatinine than participants with normal FFM (all p < 0.001); they also had a greater prevalence of hypertension, impaired glucose tolerance (IGT) or OGTT-diabetes than participants with normal FFM (all p < 0.003) and a near 2-fold greater probability of significant proteinuria (p < 0.01). RFFMD was more frequent in women than in men: significant sex-RFFMD interactions were found for BMI and waist circumference (both p < 0.0001).

RFFMD in overweight/obese normoglycemic individuals is associated with greater probability of hypertension, abnormalities of glucose tolerance and proteinuria. Assessment of RFFRMD might, therefore, help stratifying cardiometabolic risk among normoglycemic individuals with overweight/obesity.