CUMULATIVE EFFECTS OF HIGH CHOLESTEROL LEVELS, HIGH BLOOD-PRESSURE, AND CIGARETTE-SMOKING ON CAROTID STENOSIS

Background Single measurements of cardiovascular risk factors may not accurately reflect a person's past exposure to those risk factors. We therefore studied the long-term associations of cardiovascular risk fa ctors such as high serum cholesterol levels, high blood pressure, and cigarette smoking with the prevalence of carotid stenosis. Methods We studied cross-sectional and longitudinal information from a sample of 429 men and 661 women in the Framingham Heart Study who underwent B-mo de ultrasound measurements of the carotid artery. Their mean age was 7 5 years, and each had attended most of the biennial clinic examination s over the 34 years before the carotid ultrasound study. We used time- integrated measurements to assess the associations between various car diovascular risk factors and the degree of carotid stenosis. Results M oderate carotid stenosis (greater than or equal to 25 percent) was pre sent in 189 men and 226 women. We assessed the odds ratios for this de gree of stenosis as compared with minimal stenosis (<25 percent) accor ding to increases in risk factors. In the men, the odds ratio for mode rate carotid stenosis associated with an increase of 20 mm Hg in systo lic blood pressure was 2.11 (95 percent confidence interval, 1.51 to 2 .97). The odds ratio for an increase of 10 mg per deciliter (0.26 mmol per liter) in the cholesterol level was 1.10 (95 percent confidence i nterval, 1.03 to 1.16), and for an increase of five pack-years of smok ing it was 1.03 (95 percent confidence interval, 1.03 to 1.13). The re sults were similar in the women. Time-integrated measurements of diast olic blood pressure showed significant associations with carotid steno sis in men and insignificant associations in women. Conclusions Over t he long term, high systolic blood pressure, high cholesterol levels, a nd smoking were associated with an increased risk of carotid stenosis in this elderly population. (C) 1997, Massachusetts Medical Society.