Factors Associated with Cause-Specific Death in Russia. Data from Longitudinal Prospective Study 1977-2001

Abstract

Aim. To evaluate the associations between main risk factors (RF) with cause-specific death in cohorts of Russian men and women.Material and methods. Data of a number of crossectional studies conducted in different years by unified base protocol had become the subjects for the study. A total of 12,497 men and 5,039 women aged 35-74 years, residents of Moscow and S-Petersburg (former Leningrad) cities at the moment of examination, were enrolled into the study. We analyzed 17 previously selected risk factors and their associations with cause-specific mortalities: coronary heart disease (CHD), stroke, cardiovascular diseases (CVD), non-CVD, all causes. A total of 10,650 deaths were registered: 8,726 in men (for 10 years) and 1,924 – in women (for 20 years).Results. Men died more often from all the examined causes except for stroke, what was more typical to women. Mortality in men was associated with significantly larger number of RF than in women and correlations were stronger. In particular, smoking (hazard ratio [HR] 2.25; 95% confidence interval [95%CI] 1.75-2.89; р=0.0001), high blood pressure (HR 1.78; 95%CI 1.43-2.22; р=0.0001) and history of CHD (HR 3.23; 95%CI 2.71- 3.84; р=0.0001) significantly increased CHD-related mortality in the men’s cohort but were much less significant for women. The total cholesterol level demonstrated significance in men but was not even selected in the model for women. The main RF for stroke-related mortality were smoking, high blood pressure and atrial fibrillation, while for non-cardiovascular mortality there was only one common factor – smoking. Factors associated with CVD and all-cause mortality were almost the same because CVD cover more than half in the all-cause mortality, however a larger number of predictors were reported in men.Conclusion. The data obtained indicate: 1) considerably larger number of unfavorable risk factors in the men’s cohort, which significantly increased risk for death from any cause; 2) statistically more pronounced relation between risk factors and mortality rates in men as compared to women, especially note that mortality rates were followed up for 10 years in men and 20 years in women. It is obvious that successful prevention focused on risk factors must be gender-based.

Keywords

• cause-specific mortality
• coronary heart disease
• stroke
• cardiovascular disease
• risk factors