Studies in hypertriglyceridaemia - VI: serum lathosterol concentration is raised in hypertriglyceridaemic non-diabetic males with hyperinsulinaemia

Objectives. To assess the cholesterol synthesis rate in primary hypertrigly ceridaemia using the serum unesterified lathosterol concentration as an ind icator. Design. A cross-sectional. case-control study. Setting, The Karolinslia Hospital, Stockholm. Subjects. Randomly selected hyper- (n = 53) and normotriglyceridaemic (n = 57) males, 40-50 years, with a fasting serum triglyceride concentration (me an +/- SD) of 3.81 +/- 1.65 and 1.28 +/- 0.53 mmol L-1, respectively. The e xclusion criterion was diabetes mellitus, defined according to the World He alth Organization (WHO) guidelines, Main outcome measures. To compare the fasting serum concentration distribut ions of lathosterol, a cholesterol precursor, in hyper- and normotriglyceri daemic groups. Results. Thirty-six per cent of the hypertriglycerdaemic group had raised s erum lathosterol concentrations, based on the 90th percentile of the lathos terol distribution of the normotriglyceridaemic group. In the hyper- but no t in the normotriglyceridaemic group, lathosterol concentration was directl y correlated with serum insulin responses to oral (r = 0,38; P = 0.007) and intravenous (r = 0.41; P = 0.005) glucose challenges. Conclusions. One-third of a randomly selected nondiabetic hypertriglycerida emic population had an increased serum lathosterol concentration and this m ight indicate an increased cholesterol synthesis rate compatible with incre ased production of VLDL particles, possibly as the result of chronic hyperi nsulinaemia.