408 person years of follow-up we documented 8882 deaths, including 1790 from cardiovascular disease and 4527 from cancer. Table 1 shows the multivariate adjusted relative risks for lifestyle factors and death during follow-up. Cigarette smoking, higher body mass index, less physical activity, and a lower healthy diet score were all associated with increased cardiovascular, cancer, and all cause mortality. Alcohol consumption was associated with a lower risk of cardiovascular mortality than alcohol abstinence. However, heavy alcohol consumption was associated with an increased risk of cancer mortality. As a result, light to moderate alcohol consumption was associated with the lowest all cause mortality.
Table 1 Multivariate relative risk of death from any cause, cardiovascular disease, and cancer during 24 years of follow-up according to body mass index, cigarette smoking, alcohol consumption, physical activity, and diet*
Table 2 shows the multivariate adjusted relative risks and population attributable risks of mortality for the high risk compared with the low risk category of lifestyle factors. The estimated population attributable risks were 28% for cigarette smoking, 14% for being overweight, 17% for lack of physical activity, 13% for low diet quality, and 7% for not having light to moderate alcohol consumption. Population attributable risks were higher for cardiovascular mortality than for cancer mortality. Among never smokers, the relative risk of mortality for being overweight was higher than that for the whole study population (1.55, 95% confidence interval 1.44 to 1.66), resulting in a higher population attributable risk (22%, 18% to 27%).
Table 2 Relative risk and population attributable risk (PAR) (95% confidence intervals) of all cause, cardiovascular, and cancer mortality during 24 years of follow-up*
We also evaluated combinations of lifestyle risk factors in relation to mortality. As shown in the figure, cardiovascular, cancer, and all cause mortality increased with an increasing number of risk factors. The relative risk for combining cigarette smoking, being overweight, lack of physical activity, and a low healthy diet score compared with none of the risk factors was 6.91 (4.50 to 10.63) for cardiovascular mortality, 2.65 (2.14 to 3.28) for cancer mortality, and 3.41 (2.90 to 4.00) for all cause mortality (table 3). The population attributable risk for having any of these four risk factors was 72% for cardiovascular mortality, 44% for cancer mortality, and 55% for all cause mortality. When we also considered alcohol consumption, the population attributable risks for having any of the five lifestyle risk factors were modestly greater than for the four risk factors (table 3).
Age standardised all cause, cancer, and cardiovascular mortality during 24 years of follow-up by number of lifestyle risk factors. Lifestyle risk factors included cigarette smoking (ever), lack of physical activity (<30 min/day moderate to vigorous (more ...)
Table 3 Risk of mortality during 24 years of follow-up according to combinations of lifestyle risk factors*
Results among never smokers were consistent with those for the whole study population (table 4). We also examined whether results differed for younger (<60 years) and older (≥60 years) participants by recalculating the relative risks for these subgroups and using the prevalence of risk factor specific for these subgroups. The population attributable risk for all cause mortality for the five risk factors combined (smoking, diet, physical activity, overweight, alcohol consumption) was 51% (30% to 67%) for younger women and 63% (52% to 72%) for older women. Finally, we examined potential confounding by measures of socioeconomic status (father’s occupation, education level of participant and husband). Adjustment for these variables did not materially alter the association between any of the lifestyle factors and mortality during follow-up (data not shown).
Table 4 Risk of mortality during 24 years of follow-up according to number of lifestyle risk factors in never smokers*