P.048 Identifying Associations of Reduced Adiposity and Improved Early Markers of Atherosclerosis from a Lifestyle Intervention Aimed at Overweight Adolescents

Abstract

Purpose

Overweight adolescents have increased early markers of atherosclerosis (flow-mediated dilation [FMD], carotid intima-media thickening [CIMT], pulse wave velocity [PWV]). We sought to identify associations of reduced adiposity (body mass index z-score [BMIz]) and improvement in these early markers over a 24-week diet-activity-behavior intervention.

Methods

N = 32 subjects (BMI >85%ile, age 12-16 years) underwent vascular, lipid and glycemic assessments at baseline and 24 weeks. Univariate models evaluated associations of changes in markers with patient characteristics at baseline.

Results

After intervention, there was a significant reduction in BMIz (-0.09 ± 0.04, p = 0.05) and increase in HDL cholesterol (0.10 ± 0.02 mmol/L, p = 0.001), but non-significant improvements in CIMT (-0.005 ± 0.004 mm, p = 0.16), FMD (0.25 ±0.68 %, p = 0.72) and PWV (-0.24 ± 0.13 m/sec, p = 0.08). Greater reduction in adiposity was associated with, at baseline, more episodes/week of vigorous activity (-0.05 ± 0.03 BMIz per 1 episode/ week increase, p = 0.04), and more hours/day screen time (-0.06 ± 0.03 BMIz per 1 hour/day increase, p = 0.03). Improved CIMT was associated with, at baseline, more high-fat or high-sugar food servings/day (-0.002 ± 0.001 mm per 1 serving/day increase, p = 0.05). Improved FMD was associated with, at baseline, lower fasting insulin (0.03 ± 0.01 % per 1 unit insulin decrease, p = 0.01). Improved PWV was associated with at baseline more hours/day screen time (-0.06 ± 0.03 m/sec per1 hour/day increase, p = 0.05).

Conclusions

Reduction in adiposity and cardiovascular risk factors associated with our intervention may be insufficient to cause significant improvements in early atherosclerosis markers. A longer, more intensive intervention may be needed and subjects with more risk factors to target may benefit most.