Prevalence of hyperlipoproteinaemias in a random sample of men and in patients with ischaemic heart disease.

Lipoprotein patterns were estimated by membrane filtration and nephelometry in a random sample of men aged 30 to 69years and in an age-matchedgroup of male patients with ischaemic heart disease. The lipoprotein patterns were classified according to the SML classification. Significantly abnormal lipoprotein patterns were found in 20 per cent of the random sample and 40 per cent of the ischaemic heart disease group. Five types of abnormal SML profile were found (S, SM, MS, M, and ML), which corresponded to Fredrickson types IIa, IIb, IV, and V. The frequency distribution of these patterns was not significantly different in the random sample and ischaemic heart disease group. Type IV hyperlipoproteinaemias (M+ML types) comprised 53 per cent of all abnormal patterns in the random sample and 57 per cent in the ischaemic heart disease group. Thirty-one per cent of abnormal patterns in both the random sample and ischaemic heart disease group were Type IIa (S type), and about I2 per cent ofabnormalpatterns in each group had an increased concentration of both Sf 0-20 and Sf 20-400 lipoproteins, Type IIb (SM+MS types). In the random sample, Type IV hyperlipoproteinaemias were significantly more common in obese than in slim men, whereas in the ischaemic heart disease group there was a smaller non-significant difference between them. However, slim ischaemic heart disease patients had a 3 times greater prevalence of abnormal lipoprotein patterns compared with slim random sample subjects. In recent years the diagnosis of hyperlipidaemia has been rationalized by resolving hypercholesterol-aemias and hypertriglyceridaemias into one of six types of abnormal lipoprotein pattern (Fredrickson, Levy, and Lees, I967; World Health Organization, I970). Studies have been conducted in patients with genetically determined hyperlipoproteinaemias (Fre-drickson et al., I968), but the prevalence of the various types of abnormal pattern in different populations is virtually unknown, and there are, as yet, few studies in subjects with ischaemic heart disease. In this paper we report the use of a simple, inexpensive method of lipoprotein analysis, i.e. membrane filtration and nephelometry (Stone and Thorp, I966; Stone et al., 1970), to estimate the prevalence and distribution of abnormal lipoprotein patterns in a sample of U.K. men aged 30 to 69 years and in an age-matched group of patients with ischaemic heart disease. Subjects The subjects of this investigation were 429 men aged 30 to 69 years from the industrial town of Leigh, Lancashire, and from the immediate surrounding area. Two groups of …