Healthy lifestyle and life expectancy free of major chronic diseases at age 40 in Chinese population: a prospective cohort study

Abstract

Abstract Background A healthy lifestyle has been associated with a longer life expectancy (LE). However, whether it also helps achieve gains in LE free of major non-communicable diseases (NCDs) and its share of total LE in Chinese adults remains unknown. Methods We used data from China Kadoorie Biobank (CKB) of 451,233 adults aged 30–79 free of heart disease, stroke, cancer, chronic obstructive pulmonary disease (COPD), and asthma at baseline. Low-risk lifestyle factors included never smoking or quitting for reasons other than illness, no excessive alcohol use, being physically active, healthy eating habits, and healthy body shape. We built multistate life tables for individuals with different risk levels of lifestyle factors to calculate LE with and without diseases (cardiovascular diseases [CVDs], cancer, chronic respiratory diseases [CRDs, including COPD and asthma]) at age 40. For life table calculation, we used prevalence of lifestyle factors, transition rates, and hazard ratios (HRs) for three transitions (disease-free to disease onset, disease-free to death, and presence of disease to all-cause mortality). Results During a median follow-up of 11.1 years, we documented 111,002 new CVD cases, 24,635 cancer cases, 12,506 CRD cases, and 34,740 deaths. The adjusted HRs (95% confidence intervals [CIs]) of men adopting all five versus 0–1 low-risk factors was 0.56 (0.50, 0.63), 0.40 (0.20, 0.80), and 0.64 (0.50, 0.83) for baseline to disease, baseline to death, and disease to death, respectively; the corresponding values for women were 0.69 (0.64, 0.75), 0.57 (0.34, 0.94), and 0.57 (0.47, 0.69). The LE free of the three NCDs (95%CI) at age 40 for individuals with 0–1 low-risk factor was on average 23.9 (23.2, 24.6) years for men and 24.2 (23.5, 24.9) years for women. For individuals adopting all five low-risk factors, it was 30.2 (28.8, 31.6) years for men and 28.4 (27.2, 29.6) years for women, with an increase of 6.3 (5.1, 7.5) years (men) and 4.2 (3.6, 5.4) years (women). Correspondingly, the proportion of LE free of the three NCDs to total LE increased from 73.1–76.3% for men and from 67.6–68.4% for women. Conclusions Our findings suggest that promoting healthy lifestyles through public health interventions could be associated with increased LE free of major NCDs and “relative compression of morbidity” in the Chinese population.