GLYCEMIA AND BODY-MASS AS DETERMINANTS OF PLASMA LECITHIN - CHOLESTEROL ACYLTRANSFERASE ACTIVITY IN NIGERIAN PATIENTS WITH NON-INSULIN-DEPENDENT DIABETES-MELLITUS

There is an inverse correlation between plasma high density lipoprotei n (HDL) concentrations and atherogenic vascular morbidity risk. An imp ortant pathway for modulating circulating HDL levels is the reaction c atalysed by the plasma enzyme, lecithin :cholesterol acyltransferase ( LCAT). Thus, determinants of LCAT activity should influence plasma HDL levels and be accessible targets for intervention. We therefore asses sed such determinants in Nigerian patients with non-insulin dependent diabetes mellitus (NIDDM), classified into age- and sex-matched groups of obese (body mass index, BMI, > 25 kg/m(2)) and non-obese (BMI < 25 kg/m(2)). Our results indicated that 10 obese diabetic patients had s ignificantly reduced plasma LCAT activity and HDL levels and increased plasma triglyceride (TG) levels, in comparison with the observations in 9 non-obese diabetic patients (all P < 0.05). Furthermore, worsenin g of glycaemic control, when oral hypoglycaemic treatment was disconti nued for 1 week in 10 diabetic (5 obese) patients, further reduced fas ting levels of HDL and plasma LCAT activity (both P < 0.05). Although plasma HDL concentrations and LCAT activity levels did not correlate s ignificantly, the latter nonetheless had a significant inverse relatio nship with fasting plasma glucose levels in the obese diabetic subject s (r -0.51, P < 0.05). These results indicate that glycaemia and body mass are important determinants of plasma LCAT activity. Both variable s are subject to pharmacological and dietary intervention with the obj ective of increasing circulating HDL levels.