Associations of healthy lifestyle and socioeconomic status with mortality and incident cardiovascular disease: two prospective cohort studies.
To examine whether overall lifestyles mediate associations of socioeconomic status (SES) with mortality and incident cardiovascular disease (CVD) and the extent of interaction or joint relations of lifestyles and SES with health outcomes.
Population based cohort study.
US National Health and Nutrition Examination Survey (US NHANES, 1988-94 and 1999-2014) and UK Biobank.
44 462 US adults aged 20 years or older and 399 537 UK adults aged 37-73 years.
SES was derived by latent class analysis using family income, occupation or employment status, education level, and health insurance (US NHANES only), and three levels (low, medium, and high) were defined according to item response probabilities. A healthy lifestyle score was constructed using information on never smoking, no heavy alcohol consumption (women ≤1 drink/day; men ≤2 drinks/day; one drink contains 14 g of ethanol in the US and 8 g in the UK), top third of physical activity, and higher dietary quality.
All cause mortality was the primary outcome in both studies, and CVD mortality and morbidity in UK Biobank, which were obtained through linkage to registries.
US NHANES documented 8906 deaths over a mean follow-up of 11.2 years, and UK Biobank documented 22 309 deaths and 6903 incident CVD cases over a mean follow-up of 8.8-11.0 years. Among adults of low SES, age adjusted risk of death was 22.5 (95% confidence interval 21.7 to 23.3) and 7.4 (7.3 to 7.6) per 1000 person years in US NHANES and UK Biobank, respectively, and age adjusted risk of CVD was 2.5 (2.4 to 2.6) per 1000 person years in UK Biobank. The corresponding risks among adults of high SES were 11.4 (10.6 to 12.1), 3.3 (3.1 to 3.5), and 1.4 (1.3 to 1.5) per 1000 person years. Compared with adults of high SES, those of low SES had higher risks of all cause mortality (hazard ratio 2.13, 95% confidence interval 1.90 to 2.38 in US NHANES; 1.96, 1.87 to 2.06 in UK Biobank), CVD mortality (2.25, 2.00 to 2.53), and incident CVD (1.65, 1.52 to 1.79) in UK Biobank, and the proportions mediated by lifestyle were 12.3% (10.7% to 13.9%), 4.0% (3.5% to 4.4%), 3.0% (2.5% to 3.6%), and 3.7% (3.1% to 4.5%), respectively. No significant interaction was observed between lifestyle and SES in US NHANES, whereas associations between lifestyle and outcomes were stronger among those of low SES in UK Biobank. Compared with adults of high SES and three or four healthy lifestyle factors, those with low SES and no or one healthy lifestyle factor had higher risks of all cause mortality (3.53, 3.01 to 4.14 in US NHANES; 2.65, 2.39 to 2.94 in UK Biobank), CVD mortality (2.65, 2.09 to 3.38), and incident CVD (2.09, 1.78 to 2.46) in UK Biobank.
Unhealthy lifestyles mediated a small proportion of the socioeconomic inequity in health in both US and UK adults; therefore, healthy lifestyle promotion alone might not substantially reduce the socioeconomic inequity in health, and other measures tackling social determinants of health are warranted. Nevertheless, healthy lifestyles were associated with lower mortality and CVD risk in different SES subgroups, supporting an important role of healthy lifestyles in reducing disease burden.
Zhang YB
,Chen C
,Pan XF
,Guo J
,Li Y
,Franco OH
,Liu G
,Pan A
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《BMJ-British Medical Journal》
Associations of healthy lifestyle and three latent socioeconomic status patterns with physical multimorbidity among middle-aged and older adults in China.
Multimorbidity is an emerging global public health concern. However, complex associations of healthy lifestyle and socioeconomic status (SES) with multimorbidity have not been identified.
This population-based prospective cohort study used data from four waves of the China Health and Retirement Longitudinal Study (CHARLS) to explore these relationships. Physical multimorbidity was measured using 12 non-communicable diseases. Latent class analysis (LCA) was conducted to determine the optimal SES patterns based on annual per-capita household expenditure, occupation, education level, and health insurance. The healthy lifestyle score (0-5) was constructed comprising information on smoking, drinking, physical activity, sleep, and body shape.
Of 17,708 participants in the CHARLS, 7776 were eligible for inclusion in our analysis (13.3% with high SES, 26.1% with medium SES, and 60.6% with low SES). Compared with high SES participants, those with low SES had higher risks of incident physical multimorbidity (OR 1.22, 95% CI 1.05, 1.42), which was competitively mediated by lifestyle (mediation proportion, -10.17%, 95% CI -19.12%, -1.23%). Significant interactions were observed between lifestyle factors and SES in patients with incident diabetes. Participants with low SES and no or one healthy lifestyle factor had a higher risk of incident physical multimorbidity than those with high SES and four to five healthy lifestyle factors (OR 2.19, 95% CI 1.57, 3.04).
Healthy lifestyles competitively mediate a fractional proportion of socioeconomic inequity in incident physical multimorbidity. Furthermore, healthy lifestyles were associated with lower multimorbidity risk in the SES subgroups, supporting the important role of lifestyle in reducing physical multimorbidity burden.
Guo C
,Liu Z
,Fan H
,Wang H
,Zhang X
,Fan C
,Li Y
,Han X
,Zhang T
... -
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Socioeconomic Inequalities in Dementia Risk Among a Population-Based Cohort: Quantifying the Role of a Broad Combination of Lifestyle Factors.
The complex associations of socioeconomic status (SES) and lifestyle with dementia are unclear. Our objective was to examine whether a broad combination of lifestyle factors mediates the associations of SES with incident dementia and the extent of interaction or joint relations of lifestyles and SES with dementia.
A total of 274,871 participants from the UK Biobank were included. SES was assessed using the Townsend Deprivation Index. A lifestyle index was created based on smoking status, alcohol consumption, physical activity, social connections, sleep duration, diet, and sedentary behavior. Cox proportional hazards models were fitted. Mediation and interaction analyses were conducted to explore the relationship between lifestyles and SES in dementia.
The hazard ratios (HRs) and 95% confidence intervals (CIs) for when participants with low SES were compared with participants with high SES were 1.32 (1.22-1.42) for all-cause dementia, 1.25 (1.11-1.40) for Alzheimer's disease (AD), and 1.61 (1.37-1.90) for vascular dementia (VD). Lifestyles explained ≤7.8% of socioeconomic disparities in dementia. Unhealthy lifestyle categories were associated with a higher risk of dementia and its subtypes across all SES levels. The HRs (95% CIs) for all-cause dementia, AD, and VD comparing participants with low SES and the least healthy lifestyle versus those with high SES and the healthiest lifestyle were 1.82 (1.56-2.11), 1.51 (1.20-1.90), and 2.56 (1.81-3.61), respectively.
Adhering to a healthy lifestyle may prevent dementia across all socioeconomic groups, but socioeconomic inequalities in dementia cannot be fully addressed by promoting healthy lifestyles alone. The social determinants of dementia need to be better addressed.
Zhao Z
,Yin X
,Xu M
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