Influence of obesity on plasma lipoproteins, glycaemia and insulinaemia in patients with familial combined hyperlipidaemia

The influence of obesity on blood pressure and plasma lipoproteins, glucose and insulin levels was investigated in patients with familial combined hyperlipidaemia (FCH), Sixty seven FCH patients mean age 49.0 +/- 8.9 y (45 male, 22 female) defined as obese (BMI greater than or equal to 27 kg/m(2), n = 39) or non-obese (BMI < 27 kg/m(2), n = 28) were compared with control subjects matched for age, gender and body weight. Blood pressure, plasma lipoproteins, glucose and insulin were measured at baseline and following standard oral glucose load. The analysis indicate that FCH subjects with BMI greater than or equal to 27kg/m(2) had significantly higher systolic and diastolic blood pressure, blood glucose and insulin levels following oral glucose tolerance test than those with BMl<27kg/m(2), Fasting plasma insulin values were also significantly higher in the BMI greater than or equal to 27 kg/m(2) subjects (138.5 +/- 66.6 vs 111.0 +/- 29.9 pmol/l, respectively, P < 0.05). Quantification of the area under the curve of the insulin secretion showed hyperinsulinaemia in 64.1% of patients with BMI greater than or equal to 27 kg/m(2) compared to 28.5% in the group with BMI < 27 kg/m(2) (P < 0.01). Plasma insulin values were positively related to triglyceridaemia. There were no differences in the plasma lipid values between the two FCH groups. We conclude that fasting and post-glucose stimulated plasma insulin levels are frequent findings in patients with FGH when compared with control subjects of similar age, gender and BMI. Moreover, obesity (BMI greater than or equal to 27 kg/m(2)) exacerbates the hyperglycaemia, hyperinsulinaemia and blood pressure values in these FCH subjects. These factors, together with lipid abnormalities, can predispose to the elevated risk of cardiovascular disease observed in FCH subjects.