Objective: Total cholesterol (TC) is an important risk factor for myocardial infarction (MI), but the effect of TC on MI in Chinese male hypertension population has not been well documented. We conducted a prospective cohort study to determine the incidence and relative risk for MI across a wide range of TC levels in Chinese male hypertension population.
Methods: A cohort of 5298 male employees aged 18-74 years recruited from Capital Steel and Iron Company in Beijing of China in 1974-1980 was followed up for an average of 20.84 years. A total of 122 incident MI cases were identified during the period of follow-up.
Results: The incidence of MI among participants with elevated TC and those with desirable TC in male non-hypertension population was 137.20 and 63.81 per 100,000 person-years, respectively; and the corresponding incidence in male hypertension population was 279.80 and 130.96 per 100,000 person-years, respectively. After adjustment for important covariables, 10.38%, 16.71%, and 23.80% of MI cases were attributable to hypertension, elevated TC, and hypertension plus elevated TC, respectively. In male hypertension population, the multivariate adjusted hazard ratios of MI were 1.21, 2.39, 3.38, and 3.95 for participants with TC level of 5.17-5.68, 5.69-6.20, 6.21-6.71, and > or = 6.72 mmol/L, compared with those with TC < 5.17 mmol/L. The corresponding population attributable risks were 2.92%, 9.20%, 8.87%, and 9.84%, respectively.
Conclusion: Elevated TC is an important independent risk factor of MI both in male non-hypertension and hypertension populations. There is a linear association between TC level and MI incidence in Chinese male hypertension population.