Relationship between body composition and both cardiovascular risk factors and lung function in systemic sclerosis

The aims of this study were to evaluate body composition in systemic sclerosis (SSc) and to assess its association with the traditional risk factors for atherosclerosis and parameters of lung function. Eighty-six patients affected by SSc (13 men and 73 women, mean age 58.5 years, mean disease duration 10.7 years, 31 with diffuse form and 55 with limited pattern) underwent evaluation of body composition using a dual-energy X-ray (DXA) fan beam densitometer (GE Lunar iDXA) in order to assess total and regional body fat mass and fat-free mass. Clinical features, pulmonary function parameters, and the concomitant presence of the traditional cardiovascular risk factors were recorded. Android fat resulted to be higher in SSc patients with coexistence of hypercholesterolemia (P = 0.021), hypertension (P = 0.028), and overweight/obesity (P < 0.001) and positively correlated with body mass index (P < 0.001). Forced vital capacity (FVC) was inversely correlated with android fat (P = 0.034) and with the android fat/gynoid fat ratio (P = 0.013) and positively correlated with android lean (P = 0.041); the correlations were improved when FVC data were adjusted for sex, age, disease duration, and smoking habits (P = 0.010 for android fat, P = 0.010 for android fat/gynoid fat ratio, P = 0.011 for android lean). In this study, we showed that visceral abdominal fat, measured by DXA, is correlated with the main cardiovascular risk factors and lung volumes in SSc patients. Longitudinal studies are needed to evaluate if decrease of abdominal fat would improve lung function.