Effect of gemfibrozil on erythrocyte membrane lipids in geriatric patients

Abstract

Twenty geriatric patients with primary or secondary hyperlipidemia and suffering from various other diseases received for three weeks once daily 900 mg gemfibrozil. The hyperlipidemia had not been treated before, and a cholesterol-reduced diet did not succeed in lowering total cholesterol below 6.75 mmol/l (260 mg/100 ml) and serum triglycerides below 1.97 mmol/l (175 mg/100 ml). The purpose of this study was to analyze the lipid composition of the erythrocyte membrane, serum lipids and rheological parameters before and after the therapy. Mean serum total cholesterol and triglyceride content decreased significantly by 16.3% ( p < 0.05) and 35.2% ( p < 0.01) on average, respectively. Aggregation of thrombocytes and of erythrocytes, thrombin time and partial thromboplastin time slightly varied during the three weeks' treatment, but without statistical significance. The content of total long-chain saturated fatty acids in the phospholipid fraction of the erythrocyte membrane decreased slightly from 41.3% to 40.9% ( p < 0.05), whereas the total w6-unsaturated fatty acids without the precursor linoleic acid increased by about the same extent from 15.66% to 16.0% ( p < 0.05). The molar ratio of phospholipid to cholesterol content decreased significantly ( p < 0.01) due to a reduced phospholipid content at the end of the therapy. In conclusion, in addition to reducing the serum lipids, gemfibrozil slightly effects the lipid composition of erythrocytes, but the effects of the varied concentrations of long-chain saturated and long-chain w6-unsaturated fatty acids in the phospholipid fraction on membrane fluidity might be compensated, at least partly, by the decrease of the ratio of membrane phospholipid to cholesterol.