Background and aim: A family history of myocardial infarction (MI) is an independent risk factor for future coronary events. Decreased plasma lipoprotein lipase (LPL) activity is associated with delayed clearance of triglyceride-rich lipoproteins (TRL) and low fasting HDL cholesterol. The aim of the study was to investigate the relations between plasma LPL activity, postprandial TRL and HDL cholesterol in offspring of MI patients.
Methods and results: A case-control study was performed in 17 healthy middle-aged offspring of MI patients and 13 healthy age-and sex-matched controls. Fasting blood samples were collected and each subject was given a standardized oral fat load (1g fat/kg body weight) with subsequent blood samples collected for an 8-h period. Offspring of MI patients had significantly lower postheparin LPL activity (62.9 mU/ml+/-22.8 mU/ml) (mean+/-SD) than healthy controls (93.0 mU/ml+/-21.7 mU/ml) (p=0.002). Decreased postheparin LPL activity was accompanied by significantly increased and delayed clearance of postprandial TRL and subsequent lower fasting HDL cholesterol in offspring of MI patients. Postheparin LPL activity was associated with HDL cholesterol (r=0.40, p=0.036) and trend analysis revealed a decrease in incremental area under the curve (AUCi) for chylomicrons with increasing LPL activity (p=0.013).
Conclusions: Offspring of MI patients had decreased postheparin LPL activity accompanied by increased postprandial TRL and subsequent decreased HDL cholesterol, an unfavourable lipid profile which may contribute to their increased risk for future coronary events.