Association of central obesity with early Carotid intima-media thickening is independent of that from other risk factors.

AIM: We investigated whether anthropometric measurements or metabolic risk factors correlated more with vascular changes associated with obesity.

METHODS: One hundred never smoking subjects (71 women, 29 men) without vascular events, with blood pressure (BP) <140/90 mm Hg, LDL cholesterol <4 mmol/l, glucose <6.2 mmol/l participated. Anthropometric measurements (body mass index (BMI), waist/hip ratio (WHR), waist circumference (WC) and Waist/height ratio WHTR) and metabolic risk factors (glucose, insulin, lipid and uric acid levels plus BP) were assessed. Subjects underwent vascular measurements (Carotid intima-media thickness (IMT) using duplex ultrasonography, vascular stiffness assessment (Augmentation Index) by applanation tonometry and brachial artery reactivity tests).

RESULTS: Risk factors were in the 'normal distribution'. BMI, WHR, WC, WHTR correlated significantly with triglyceride, HDL, LDL, insulin, glucose, uric acid and systolic BP levels (P<0.001). IMT correlated with WHTR, BMI, WC, Glucose (P<0.001), Homoeostasis Model Assessment (HOMA) and cholesterol levels (P<0.05). Only Age, WHTR or BMI were significant correlates of IMT in a multivariate analysis (P<0.01) including WHTR or BMI, with age, sex, systolic BP, HDLc and HOMA. Augmentation Index correlated with age (P<0.0001), WHTR and WC (P<0.0005) but with age only in a multivariate analysis. Brachial reactivity did not correlate with any anthropometric or metabolic parameters. Anthropometric cutoff points, (BMI > or =25, WC > or =102 cm men, > or =88 cm women, WHR > or =0.9 men, > or =0.8 women and WHTR > or =0.5 men and women) significantly differentiated normal from abnormal metabolic and vascular measurements. The WHTR ratio > or =0.5 was as reliable as the BMI cutoff > or =25 in determining metabolic and vascular abnormalities. BMI and WHTR were strongly associated with 89% agreement (P<0.0001).

CONCLUSION: These results demonstrated that in 'healthy individuals', anthropometric parameters and metabolic risk factors correlated with each other, but anthropometric parameters were the only significant correlates of carotid IMT. A waist/height ratio > or =0.5 predicts both early vascular and metabolic changes. These data support a risk factor independent vasculotrophic effect of obesity.