Fat distribution influences the cardio-metabolic profile in a clinically healthy European population

Waist and hip circumferences are largely influenced by Fat Mass and several other determinants. To evaluate the specific effects of a preferential fat distribution, we corrected the waist and hip circumferences for all their determinants. We then examined the association between fat distribution and several cardio-metabolic parameters in a clinically healthy population.

In a subgroup of 625 females (F) and 490 males (M) from the RISC (Relationship between Insulin Sensitivity and Cardiovascular Disease) study, we evaluated insulin sensitivity by hyperinsulinaemic euglycaemic clamp and intima-media thickness (IMT) of the common (CCA) and internal (ICA) carotid artery by ultrasound imaging. Waist and hip circumferences were adjusted for age, height, fat and fat-free mass; in males, waist was also adjusted by hip and vice versa.

Both F and M with enlarged waist showed significantly increased plasma insulin, C-peptide, total cholesterol, non-high density lipoprotein-cholesterol, low density lipoprotein cholesterol and triglycerides, when compared with subjects with a smaller waist circumference. Males also showed lower glucose uptake and higher heart rate and ICA-IMT. A larger hip in both females and males was linked to a significantly greater inhibition of free fatty acids during the clamp test.

Adjustment of waist circumference for its determinants permits the detection of early impairment of cardiovascular function and of glucose and lipid metabolism in a clinically healthy population, in particular in normal body weight subjects. Enlarged hip adjusted values are associated with greater insulin sensitivity.