LONG-TERM METABOLIC EFFECTS OF 2 DIETARY METHODS OF TREATING HYPERLIPEMIA

Objectives-To compare the long term metabolic effects of two diets for treating hyperlipidaemia. Design-Randomised controlled study: after t hree weeks of normal (control) diet, subjects were randomly allocated to one of two test diets and followed up for six months. Setting-Lipid clinic of tertiary referral centre in Naples. Subjects-63 subjects wi th primary type IIa and IIb hyperlipoproteinaemia entered the study, a nd 44 completed it. Exclusion criteria were taking drugs known to infl uence lipid metabolism, evidence of cardiovascular disease, homozygous familial hypercholesterolaemia, and body mass index over 30. Interven tions-Two test diets with reduced saturated fat (8%) and cholesterol ( approximately 200 mg/day): one was also low in total fat and rich in c arbohydrate and fibre, and the other was low in carbohydrate and fibre and rich in polyunsaturated and monounsaturated fats. Main outcome me asures-Fasting plasma lipid and lipoprotein concentrations; blood gluc ose, insulin, and triglyceride concentrations before and after a test meal. Results-In comparison with the control diet, both test diets ind uced significant and similar decreases in low density lipoprotein chol esterol concentrations (by a mean of 0.72 (SE 0.15) mmol/l, P<0.001, f or low total fat diet; by 0.49 (0.18) mmol/l, P<0.05, for high unsatur ated fat diet) and plasma triglyceride concentrations (by 0.21 (0.09) mmol/l, P < 0.05, for low total fat diet; by 0.39 (0.15) mmol/l, P<0.0 5, for high unsaturated fat diet), while high density lipoprotein chol esterol concentrations after fasting and plasma glucose and insulin co ncentrations during test meals were not modified by either diet. Concl usions-Both test diets are suitable (alone or in combination) for trea tment of hypercholesterolaemia.