OBESITY WORSENS CARDIOVASCULAR RISK PROFILES INDEPENDENTLY OF HYPERINSULINEMIA

Objective. To investigate whether human obesity is characterized by a worse cardiovascular risk profile (than no obesity) even in the absenc e of hyperinsulinaemia. Subjects and design. A total of 367 healthy su bjects (247 nonobese and 120 obese) with normal glucose tolerance and without family history of diabetes mellitus. Interventions. A 75-g ora l glucose tolerance test was performed in all participants. Main outco me measures. Anthropometry, blood pressure, fasting plasma lipids and mate, plasma glucose and insulin concentrations at fasting, Ih and 2 h after oral glucose load. Results. In a multivariate linear regression analysis, body mass index was strongly related to all cardiovascular risk factors, independently of sex, age and plasma insulin. When risk factors were compared in 37 normoinsulinaemic obese subjects (plasma i nsulin within one standard deviation of the mean values observed in th e 247 nonobese subjects), and in 37 sex- and age-matched normoinsulina emic nonobese subjects, we found that plasma glucose levels were simil ar in the two groups, whereas plasma triglyceride (1.50 +/- 0.13 vs. 1 .13 +/- 0.08 mmol L-1; mean +/- SE), low-density lipoprotein cholester ol (3.42+/-0.25 vs. 2.77 +/- 0.18 mmol L-1) and urate (290 +/- 12 vs. 255 +/- 12 mu mol L-1) levels were significantly higher, and plasma hi gh-density lipoprotein cholesterol concentrations were lower (1.27 +/- 0.04 vs. 1.46 +/- 0.06 mmol L-1) in obese than in nonobese subjects w ith normal plasma insulin levels (P < 0.01). Also systolic (132 +/- 2 vs. 124 +/- 2 mmHg) and diastolic (86 +/- 1 vs. 81 +/- 1 mmHg) blood p ressure values were significantly higher in normoinsulinaemic obese su bjects than in normoinsulinaemic nonobese individuals (P < 0.001). Con clusions. These results suggest that in human obesity a worse cardiova scular risk profile is found (than in the nonobese) independently of t he presence of hyperinsulnaemia.