Effects of an intensive behavioral weight loss intervention consisting of caloric restriction with or without physical activity on common carotid artery remodeling in severely obese adults

Objective. Obesity increases cardiovascular disease risk and adversely affects vascular structure and function. Few studies have evaluated the vascular effects of non-surgical weight reduction in the severely obese. We hypothesized that weight loss and improvements in cardiometabolic factors would reduce common carotid artery intimamedia thickness (CIMT) and inter-adventitial diameter (AD) in severely obese adults. Methods. We performed carotid ultrasound and measured cardiometabolic factors in 90 severely obese participants (body mass index (BMI)>= 35 kg/m(2), age 30-55) at baseline and 6 months in a randomized clinical trial of dietary intervention with (n=45) or without (n=45) physical activity. Results. The achieved weight loss (mean=8%) did not differ significantly by intervention group (P=0.10) and resulted in a 0.07 mm mean decrease in AD (P=0.001). AD change was positively correlated with changes in BMI, waist circumference, abdominal visceral and subcutaneous fat, and body fat mass, and AD decreased more in men (P<0.05 for all). After multivariable adjustment, changes in BMI (P=0.03) and abdominal subcutaneous fat (P=0.04) were significant determinants of AD change. Although CIMT did not decrease significantly overall (-0.008 mm, P=0.16), individuals who lost at least 5% of their body weight experienced a significant mean reduction in CIMT of 0.02 mm (P=0.002). CIMT change was positively correlated with changes in BMI, waist circumference, fat-free mass, leptin, and insulin (P<0.05 for all). After multivariable adjustment, insulin reduction remained a significant determinant of CIMT decrease (P=0.03). Conclusion. A 6 month intensive behavioral intervention can significantly reverse metabolic and vascular abnormalities in severely obese adults. (C) 2012 Elsevier Inc. All rights reserved.