Effects of obesity phenotype on coronary heart disease risk factors in response to weight loss

Objective: To determine whether there is a difference in risk-factor improvement for coronary heart disease (CHD) between the intra-abdominal fat (IF) and subcutaneous fat (SF) obesity phenotypes after weight loss. Research Methods and Procedures: Subjects included 55 mildly obese women (body mass index, 25 to 36 kg/m(2); age range, 34 to 63 years) who had at least two of three CHD risk factors [systolic blood pressure (SBP), > 140 mm Hg; total cholesterol (TC), >220 mg/dL; fasting plasma glucose, >110 mg/dL). Using computed tomography, IF obesity was classified as greater than or equal to110 cm(2) of the IF area measured; subjects with <110 cm(2) were classified as having SF obesity. The IF and SF obesity groups were divided into diet only and diet-plus-exercise groups. Assays and measurements were performed before and after a 14-week (98-day) intervention. Results: Weight was reduced by 7 to 10 kg in each group. The IF and SF areas, SBP, diastolic blood pressure, TC, and low-density lipoprotein-cholesterol were significantly reduced in all groups (p < 0.01). Reduction in IF area was greater in IF obesity than in SF obesity, whereas no differences were observed in the improvement of CHD risk factors. Sample sizes needed for observing a significant difference for SBP, TC, triglycerides, and fasting plasma glucose were greater than the number of subjects in this study. Discussion: Our results suggest that the influence of the obesity phenotype on improving CHD risk factors is not apparent. A larger study is needed to prove the validity of this finding.