Richard Benfante

Combined Effects of HDL Cholesterol, Triglyceride, and Total Cholesterol Concentrations on 18-Year Risk of Atherosclerotic Disease

BACKGROUND Whether the combination of a low level of HDL cholesterol (HDL-C) and high level of triglyceride (TG) confers increased risk of cardiovascular disease and whether risk varies across levels of total cholesterol (TC) are not well established. Combined effects of HDL-C, TG, and TC on the incidence of atherosclerotic disease were examined prospectively in Japanese-American men from the Honolulu Heart Program. METHODS AND RESULTS Among 1,646 men aged 51 to 72 years who were free of coronary heart disease (CHD), stroke, and cancer and were not taking lipid-lowering medication, 318 developed atherosclerotic events (angina, coronary insufficiency, aortic aneurysm, definite CHD, or thromboembolic stroke) and 170 developed definite CHD between 1970 and 1988. Subjects were stratified by TC level (desirable, < 200 mg/dL; borderline high, 200 to 239 mg/dL; high, > or = 240 mg/dL), HDL-C level (< 35 and > or = 35 mg/dL), and TG level (< 200 and > or = 200 mg/dL). With Cox regression with high HDL-C and low TG as reference, age-adjusted relative risks (RR) of atherosclerotic events were significantly elevated in men with low HDL-C and high TG at borderline-high (RR, 2.46; 95% CI, 1.48 to 4.09) and high (RR, 2.21; 95% CI, 1.34 to 3.66) TC levels but not in men with desirable TC levels (RR, 0.89; 95% CI, 0.38 to 2.09). Elevated risks were independent of blood pressure, obesity, fat distribution, diabetes, smoking, and alcohol. Results were not materially altered by exclusion of subjects with angina alone and were similar but somewhat weaker for CHD. CONCLUSIONS Risk of atherosclerotic disease appears elevated in subjects with low HDL-C and high TG levels when TC is borderline high or high, independent of other cardiovascular risk factors. These findings support recent cholesterol screening recommendations and suggest that joint effects of HDL-C and TG may be important to consider.

Do coronary heart disease risk factors measured in the elderly have the same predictive roles as in the middle aged comparisons of relative and attributable risks

Risk factors for the 12-year incidence of definite coronary heart disease (CHD) among 3440 men who were middle-aged (51 to 59 years old) and 1419 men who were elderly (65 to 74 years old) at baseline examination were examined for differences in predictive values in terms of both relative risk and attributable (excess) risk of the highest versus the lowest quartile or appropriate categories. In multivariate models using Cox life-table regression procedures, serum cholesterol level, cigarette smoking, systolic blood pressure, and history of treatment for diabetes were significant predictors of incident CHD for both age groups. Alcohol consumption when modeled as drinker versus nondrinker showed a protective effect in both younger and older men. There was no dose relationship, however, among elderly drinkers. While the relative risks for the variables studied were similar between the two age groups, the excess risk was typically between 1.5 to 2.0 times higher for the older than the middle-aged men. In contrast, the detrimental effect of adiposity as measured by body mass index appeared to decline after age 65 for both measures of risk. This may partly be attributed to diminished adiposity overall in the older age group. The implications of these results are that serum cholesterol level, smoking, hypertension, diabetes, and possibly alcohol consumption continue to be important predictors for CHD when measured after age 65, and that the public health impact of these risk factors, in terms of excess risk, may be more important in the elderly.

Risk factors in middle age that predict early and late onset of coronary heart disease

Twelve biological and lifestyle characteristics measured in a group of 5919 middle aged men free of clinical coronary heart disease (CHD), stroke and cancer were analyzed for differences in predicting early and late onset of new cases of definite CHD (non-fatal myocardial infarction and fatal CHD) over a 12-year follow-up period. Among these men, 151 cases of definite CHD occurred early (under age 60) and 135 cases occurred later in life (age 60 and over). Serum triglyceride was the only risk factor that was an independent predictor of early onset disease and not of late onset disease. While cigarette smoking was a predictor for both onset groups, the effect of smoking was greater in people who developed CHD earlier in life. Systolic blood pressure, alcohol intake, serum cholesterol and serum glucose were independent predictors for both onset groups, with no difference in effect between groups. The findings indicate that it is possible for some factors to affect CHD risk differently in terms of premature vs delayed onset of disease. The findings for serum triglyceride may account for some of the inconsistencies in reports regarding it as an independent risk factor for CHD. In general, however, most of the characteristics studied here had a similar effect on both early and late onset and thus remain important in the prevention of both premature and late onset of CHD.