Low high-density lipoprotein cholesterol and other coronary heart disease risk factors in patients with total cholesterol levels greater than 5.17 mmol/L (200 mg/dL) in family practice. A report from CEN.

BACKGROUND

A multisite, open-label, prospective study in 327 family practices across the United States analyzed the demography of a large population of dyslipidemic patients and examined the effects of diet and exercise, as well as of gemfibrozil therapy, on serum levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides.

METHODS

The 3328 patients enrolled comprised a heterogenous population who had wide age range (20 to 88 years), were of both sexes and various ethnic backgrounds, and had multiple cardiac risk factors. All had a history of serum cholesterol levels of 5.17 mmol/L (200 mg/dL) or more, and some may have been previously identified as having an HDL of 1.03 mmol/L (40 mg/dL). After determining their cardiac risk factor and lipid profiles, eligible patients were assigned to a protocol of diet and exercise, followed by concomitant gemfibrozil therapy, if warranted. Treatment efficacy data will be reported in a subsequent paper.

RESULTS

The study population was 60 percent men. Ninety-four percent of the patients were white, 4.1 percent were black, and 1.9 percent were of other races. Women patients tended to be more overweight, and elderly women had more hypertension; they were less likely to have angina pectoris or to have had previous myocardial infarctions, angioplasty, or bypass surgery. The prevalence of low HDL cholesterol (less than 1.03 mmol/L [40 mg/dL]) was substantially higher in men. Statistically significant differences between men and women were observed for mean values of total cholesterol, 6.47 versus 6.84 mmol/L (250.3 versus 264.4 mg/dL); HDL cholesterol, 0.94 versus 1.18 mmol/L (36.3 versus 45.5 mg/dL); LDL cholesterol, 4.62 versus 4.76 mmol/L (178.7 versus 184.2 mg/dL); non-HDL cholesterol, 5.54 versus 5.66 mmol/L (214.1 versus 218.9 mg/dL); and the total cholesterol-HDL ratio, 6.84 versus 5.64.

CONCLUSIONS

Current National Cholesterol Education Program (NCEP) guidelines suggest lipoprotein analysis at cholesterol levels between 5.17 and 6.21 mmol/L (200 and 240 mg/dL) only if two or more risk factors are also present. Persons whose total cholesterol values are less than 6.21 mmol/L (240 mg/dL) can still be at risk because of the presence of other cardiovascular risk factors or a low level of HDL cholesterol. In this study, 74.3 percent of men and 41.3 percent of women with total cholesterol greater than or equal to 5.17 mmol/L (200 mg/dL) were also found to have a low HDL level, less than 1.03 mmol/L (40 mg/dL). The prevalence of other risk factors in this patient population was also high: 40.5 percent had hypertension, 9.6 percent had diabetes, and 20.3 percent smoked. These data suggest that routine lipoprotein analysis in the family practice setting could reveal low HDL cholesterol as an additional risk factor in a patient population where other risk factors have already been identified.