Daytime triglyceridemia in normocholesterolemic patients with premature atherosclerosis and in their first-degree relatives.

Postprandial hypertriglyceridemia tested under metabolic ward conditions with unphysiological high fat loads has been reported in CAD patients and their relatives even in the presence of normal fasting lipids. It is unclear whether this also occurs in the daytime situation. Twenty-seven normocholesterolemic, non-obese and nondiabetic patients with premature coronary artery disease (CAD) and 56 first-degree relatives without CAD measured daytime capillary triglyceride profiles (TGc-AUC) as an estimate of postprandial lipemia. Fasting capillary triglycerides (TGc) were not significantly different between CAD index patients and their relatives (1.68 +/- 0.63 and 1.54 +/- 0.71 mmol/L, respectively). In contrast, daytime triglyceridemia was significantly higher in CAD patients (30.7 +/- 13.6 mmol. h/L) compared to their relatives (24.4 +/- 9.4 mmol. h/L) and this was also the case after correction for fasting TGc (7.24 +/- 7.41 and 2.79 +/- 6.89 mmol. h/L; P <.05). The best predictors of TGc-AUC by multiple regression analysis in CAD families were fasting TGc, systolic blood pressure, and high-density lipoprotein cholesterol (HDL-C), which are all components of the metabolic syndrome, explaining 65% of the variation. Since there were no major differences in nutritional intake between index patients and their relatives, this could not explain the differences Daytime triglyceridemia, measured under physiological conditions, is increased in patients with premature atherosclerosis and normal fasting TG levels, when compared to their non-CAD relatives. This study confirms previous observations using standardized oral fat loading tests and underlines the importance of postprandial hyperlipidemia in CAD.