BACKGROUND: We have studied the abnormalities in glucose and insulin m
etabolism in a group of nondiabetic subjects with familial combined hy
perlipidemia (FCH) in order to ascertain the contribution of metabolic
risk factors to the elevated coronary heart disease incidence observe
d in FCH. PATIENTS AND METHODS: The study includes 42 non-diabetic sub
jects (25 male and 17 women, mean age 49.1 +/- 9.3 years), diagnosed w
ith FCH by clinical and analytical studies of the probands and first d
egree relatives. Forty two control subjects of similar age, sex and bo
dy weight were also studied. In both groups plasma lipids and lipoprot
eins, plasma glucose and insulin basal and after oral glucose toleranc
e test (OGTT) were studied. RESULTS: The mean age, BMI and the separat
ion by gender was similar in the two groups. The mean systolic and dia
stolic blood pressures were higher (p < 0.01) in the FCH group compare
d with controls (145.4/90.1 and 131.5/76.3 mmHg, respectively). The le
vels of lipids and ape B were also higher in the FCH group. The plasma
glucose values were significantly higher at 30, 60, 90 and 120 minute
s during OGTT and the plasma insulin at 0, 60, 90 and 120 minutes of O
GTT in FCH respect to controls. The area under the curve of the secret
ion of insulin was 11652.0 +/- 2281.1 and 7205.4 +/- 2289.1 pmol/l/min
in FCH and controls (p < 0.01), respectively. The percentage of subje
cts with basal hyperinsulinemia was 66.6% in the FCH group and 9.5% in
the controls (p < 0.01); at 2 hours OGTT, 78.5% and 9.5% in FCH and c
ontrols, respectively (p < 0.01). The insulin secretion was significan
tly related with the plasma triglycerides levels, cholesterol bourded
to very low density lipoproteins and systolic and diastolic blood pres
sure. CONCLUSIONS: Hyperinsulinism is a frequent finding in non-diabet
ic subjects with FCH, both with normal and abnormal glucose tolerance
and could contribute to the high incidence of cardiovascular risk in t
hese patients.