The sterol content of a cataractous lens from a patient with cerebrotendinous xanthomatosis (CTX)

94 The stability of lipoprotein lipase (LPL) in tissue frozen by liquid nitrogen remains controversial. We have compared activities in fresh and snap frozen portions of 14 samples of gluteal adipose tissue obtained by needle biopsy. Eluates were prepared by incubating tissue samples (mean weight 22.02 + 13.1 mg) for 30 min at 37“ C in a medium containing Krebs Ringers Phosphate buffer, heparin and serum (25%), and immediately assayed. The LPL activity (umoles FFA/hr/g) in the fresh and frozen samples were highly correlated (r = 0.95) according to the regression equation y = 0.83 X 0.31. The mean activity in the frozen tissue was 71% of that in fresh tissue, and the 5”oloss of activity appeared related to the mass of tissue frozen. The smaller biopsies demonstrated the greatest % loss of activity in line with their higher surface area to volume ratio. In addition, preliminary studies indicate that no loss of activity occurs when eluates from fresh tissue are snap frozen, and this may offer an alternative approach. Increased body weight and oral contraceptive use as variables influencing the prevalence of elevated cholesterol levels in women aged 20 to 39 years. J. Revill, MB, B. Chir, G.P., (Sheffield, 8. R. Kay, PHD, Statistician, University of Sheffield) In a random sample of women aged 20-39, in Sheffield, the mean total cholesterol level was found to be significantly elevated in current oral contraceptive users (p c 0.01) and in woman whose body weight exceeded their ideal (p < 0.001). The prevalence of increasing elevated levels of total cholesterol above the mean rose in association with oral contraceptive use and excess weight. 31% of oral contraceptive users who exceeded their ideal body weight, had total cholesterol levels > 6.5 mmol/l in contrast with 1% of the converse group. Withdrawal of oral contraception in all ladies whose cholesterol exceeded 6.5 mmol/l resulted in a mean fall of 1.14 mmol/l in total cholesterol (p = 0.003) and of 0.88 mmol/l in LDL cholesterol (p = 0.003). We conclude that all pre-menopausal women who exceed their ideal weight whilst using oral contraception, should have a precautionary assessment of their lipid profile before prolonged exposure to the therapy. The sterol content of a cataractous lens from a patient with cerebrotendinous xanthomatosis (CIX) P. McKenna ‘, S.J. Morgan 2, R.C. Bosanquet 2, M.F. Laker ’(’ Clin. Biochem. Royal Victoria Infirmary & ’ Ophthalmology, Newcastle General Hospital, Newcastle upon Tyne) CTX is a rare inherited metabolic disorder of bile acid synthesis characterised clinically by tendon xanthoma, neurological dysfunction and early onset cataracts. Serum cholestanol (but not cholesterol) levels are raised and both sterols accumulate in body tissues. A 42 year old man with the typical clinical features of CTX and a serum cholestanol/cholesterol ratio of 1.5% (reference range < 0.2%) underwent cataract extraction. The lipid content of the lens nucleus, together with those from three senile cataracts, was extracted and the free

sterol content estimated using GCMS. The total cholestanol content of the CTX lens (corresponding mean data for the senile cataracts in parenthesis) was 13.1 pg (2.8 pg) cholestanol per mg of lens tissue was 0.27 pg (0.07 pg) and cholesterol/cholesterol ratio was 1.7% (0.3%). Thus in this CTX patient the development of cataracts was associated with the deposition of cholestanol in the lens nucleus. Elevated Sodium-lithium countertransport: A genetic marker of hyperlipidaemia and hypertension. S. Carr, T. Thomas. * M. Laker. R. Wilkinson (Department of Nephrology, Freeman Hospital, * Department of Medicine, Royal Victoria Infirmary, Newcastle Upon Tyne) Erythrocyte sodium-lithium countertransport (SLC) was measured in normolipidaemic and hyperlipidaemic hypertensive and hyperlipidaemic normotensive patients and normal controls. Hypertension and hyperlipidaemia were each independently associated with raised SLC (ANOVA P < 0.01 and P < 0.01). The effects were additive so that hyperlipidaemia could not explain raised SLC in hypertension. In hyperlipidaemic hypertensive patients plasma cholesterol, triglyceride and very low density and low density lipoproteins were increased and high density lipoproteins was reduced. Of these patients 73.38 had a known family history of hypertension and their normotensive first degree relatives were studied of whom 48% also had raised SLC and abnormal plasma lipids of the same pattern as the probands. Relatives with normal SLC had normal lipids. Therefore, raised SLC was associated with the inheritance of both hypertension and hyperlipidaemia and this could explain why raised SLC has been associated with a family history of both hypertension and associated cardiovascular disease. Economics of intervention on blood cholesterol for coronary heart disease prevention: evidence for cost effectiveness Reckless, J.P.D. (School of Postgraduate Medicine, University of Bath Royal United Hospital, Combe Park, Bath, BAl 3NG) In the United Kingdom frequency of cholesterol measurement, and treatment of hypercholesterolaemia, are inadequate, although coronary heart disease is the major cause of death. A 10 yr programme of opportunistic cholesterol screening for 29 million men and women aged 20-64 yrs in England and Wales was costed at E235 million per year. These costs included doctor and nurse in the primary health care team, dietitian, specialist, sampling, assays, and drugs. Discounted quality adjusted life years (QALY) that can be saved were calculated, for a cholesterol lowering of 12% by diet, and of a total of 25% for diet and drugs. The cost per QALY was E551 overall, being more expensive in the young, for drug treatment and in females. QALY cost compares well with those for hip replacement, coronary heart bypass surgery and breast screening (f1100, El300 and f5000 respectively), and supports the need for a national management scheme to detect and treat individuals with high levels of blood cholesterol.