Which fasting triglyceride levels best reflect coronary risk? Evidence from the Turkish Adult Risk Factor Study

Background. Association between raised low-density lipoprotein cholesterol (LDL-C) levels and high risk fur coronary heart disease (CHD) is well estab lished and taken into account in guidelines on coronary prevention. Hypothesis: The relationship between risk for coronary heart disease (CHD) and the levels of fasting plasma triglycerides: was studied ill the cohort of the Turkish Adult Risk Factor Study, a representative random sample of a n adult population. Methods In 829 men and 907 women aged greater than or equal to 27 pears (me an 48.5 +/- 11), plasma lipids and lipoproteins were measured by the enzyma tic dry method in the postabsorptive state. A sample of values was validate d in a reference laboratory. Apoliprotein (apo) A-I and B were measured by the turbidimetric immunoassay using commercial kits in part of the cohort. Blood pressure and anthropometric measurements were made. Criteria for the diagnosis of CHD were based on history, cardiovascular examination, and Min nesota, coding of resting electrocardiograms. Coronary heart disease was di agnosed in about 7% Of the subjects, Participants were divided into four ca tegories depending on their triglyceride levels: I = < 100 mg/dl (282 men, 400 women), II = 100-139 mg/dl (204 men, 228 women), III = 140-212 mg/dl (1 88 men, 180 women), and IV = <greater than or equal to>212 mg/dl (155 men, 99 women). Results: After adjustment fur age, high-density lipoprotein (HDL) and low-d ensity lipoprotein (LDL) cholesterol, smoking, and body mass index by logis tic regression analysis, and after assigning the CI-ID risk of 1 to Categor y I, the relative risk for men and women combined rose to 1.42 in Category In (p < 0.045) while it diminished to 0.94 in Category IV (p 0.79). In wome n, the odds ratio (OR) rose gradually up to 1.78 (p < 0.025) in Category II I, only to decline in Category IV. The OR in men was slightly, insignifican tly, and equally elevated in Categories III and IV. Patients with CHD in Ca tegory III were not distinguished from those in Category IV by the studied risk parameters. It was suggested that high risk for CHD-particularly in su bjects with slightly elevated or normal cholesterol levels-is often not ref lected by extreme increases of fasting triglycerides but best by modest ele vations (140-212 mg/dl), which serve better as a marker of triglyceride-ric h lipoprotein particles. This knowledge may prove to be of value in populat ion screening and individual risk assessment.