Tobacco smoking and risks of more than 470 diseases in China: a prospective cohort study.

BACKGROUND: Tobacco smoking is estimated to account for more than 1 million annual deaths in China, and the epidemic continues to increase in men. Large nationwide prospective studies linked to different health records can help to periodically assess disease burden attributed to smoking. We aimed to examine associations of smoking with incidence of and mortality from an extensive range of diseases in China. METHODS: We analysed data from the prospective China Kadoorie Biobank, which recruited 512 726 adults aged 30-79 years, of whom 210 201 were men and 302 525 were women. Participants who had no major disabilities were identified through local residential records in 100-150 administrative units, which were randomly selected by use of multistage cluster sampling, from each of the ten diverse study areas of China. They were invited and recruited between June 25, 2004, and July 15, 2008. Upon study entry, trained health workers administered a questionnaire assessing detailed smoking behaviours and other key characteristics (eg, sociodemographics, lifestyle, and medical history). Participants were followed up via electronic record linkages to death and disease registries and health insurance databases, from baseline to Jan 1, 2018. During a median 11-year follow-up (IQR 10-12), 285 542 (55·7%) participants were ever hospitalised, 48 869 (9·5%) died, and 5252 (1·0%) were lost to follow-up during the age-at-risk of 35-84 years. Cox regression yielded hazard ratios (HRs) associating smoking with disease incidence and mortality, adjusting for multiple testing. FINDINGS: At baseline, 74·3% of men and 3·2% of women (overall 32·4%) ever smoked regularly. During follow-up, 1 137 603 International Classification of Diseases, 10th revision (ICD-10)-coded incident events occurred, involving 476 distinct conditions and 85 causes of death, each with at least 100 cases. Compared with never-regular smokers, ever-regular smokers had significantly higher risks for nine of 18 ICD-10 chapters examined at age-at-risk of 35-84 years. For individual conditions, smokers had significantly higher risks of 56 diseases (50 for men and 24 for women) and 22 causes of death (17 for men and nine for women). Among men, ever-regular smokers had an HR of 1·09 (95% CI 1·08-1·11) for any disease incidence when compared with never-regular smokers, and significantly more episodes and longer duration of hospitalisation, particularly those due to cancer and respiratory diseases. For overall mortality, the HRs were greater in men from urban areas than in men from rural areas (1·50 [1·42-1·58] vs 1·25 [1·20-1·30]). Among men from urban areas who began smoking at younger than 18 years, the HRs were 2·06 (1·89-2·24) for overall mortality and 1·32 (1·27-1·37) for any disease incidence. In this population, 19·6% of male (24·3% of men residing in urban settings and 16·2% of men residing in rural settings) and 2·8% of female deaths were attributed to ever-regular smoking. INTERPRETATION: Among Chinese adults, smoking was associated with higher risks of morbidity and mortality from a wide range of diseases. Among men, the future smoking-attributed disease burden will increase further, highlighting a pressing need for reducing consumption through widespread cessation and uptake prevention. FUNDING: British Heart Foundation, Cancer Research UK, Chinese Ministry of Science and Technology, Kadoorie Charitable Foundation, UK Medical Research Council, National Natural Science Foundation of China, Wellcome Trust.

Socioeconomic Status in Relation to Risks of Major Gastrointestinal Cancers in Chinese Adults: A Prospective Study of 0.5 Million People.

BACKGROUND: Low socioeconomic status (SES) is associated with higher risk of certain gastrointestinal (e.g., colorectal, pancreatic, and liver) cancers in Western populations. Evidence is very limited in China, where correlates and determinants of SES differ from those in the West. METHODS: The prospective China Kadoorie Biobank recruited 512,715 adults (59% women, mean age 51 years) from 10 (5 urban, 5 rural) regions. During 10 years of follow-up, 27,940 incident cancers (including 3,061 colorectal, 805 pancreatic, and 2,904 liver) were recorded among 510,131 participants without prior cancer at baseline. Cox regression was used to estimate adjusted HRs for specific cancers associated with area-level (e.g., per capita gross domestic product, disposable income) and individual-level (e.g., education, household income) SES. RESULTS: Area-level SES and household income showed positive associations with incident colorectal and pancreatic cancers and inverse associations with liver cancer (P trend < 0.05). Education showed no association with colorectal cancer but inverse associations with pancreatic and liver cancers, with adjusted HRs comparing university to no formal schooling being 1.05 [95% confidence interval (CI), 0.85-1.29], 0.49 (95% CI, 0.28-0.85), and 0.61 (95% CI, 0.47-0.81), respectively. Potential risk factors (e.g., smoking, alcohol) partly explained the inverse associations of education with pancreatic and liver cancers (17.6% and 60.4%), respectively. CONCLUSIONS: Among Chinese adults, the associations of SES with gastrointestinal cancers differed by cancer type and SES indicator. Potential risk factors partially explained the inverse associations of education with pancreatic and liver cancers. IMPACT: The different associations between SES with gastrointestinal cancers may inform cancer prevention strategies.

Patterns and trends of alcohol consumption in rural and urban areas of China: findings from the China Kadoorie Biobank.

BACKGROUND: In China, alcohol consumption has increased significantly in recent decades. Little evidence exists, however, about temporal trends in levels and patterns of alcohol consumption and associated factors in adult populations. METHODS: In 2004-08, the China Kadoorie Biobank recruited ~ 512,000 adults (41% men, mean age 52 years [SD 10.7]) from 10 (5 urban, 5 rural) geographically diverse regions across China, with ~ 25,000 randomly selected participants resurveyed in 2013-14. The self-reported prevalence and patterns (e.g., amount, beverage type, heavy drinking episodes) of alcohol drinking at baseline and resurvey were compared and related to socio-demographic, health and other factors. RESULTS: At baseline, 33% of men drank alcohol at least weekly (i.e., current regular), compared to only 2% of women. In men, current regular drinking was more common in urban (38%) than in rural (29%) areas at baseline. Among men, the proportion of current regular drinkers slightly decreased at resurvey (33% baseline vs. 29% resurvey), while the proportion of ex-regular drinkers slightly increased (4% vs. 6%), particularly among older men, with more than half of ex-regular drinkers stopping for health reasons. Among current regular drinkers, the proportion engaging in heavy episodic drinking (i.e., > 60 g/session) increased (30% baseline vs. 35% resurvey) in both rural (29% vs. 33%) and urban (31% vs. 36%) areas, particularly among younger men born in the 1970s (41% vs. 47%). Alcohol intake involved primarily spirits, at both baseline and resurvey. Those engaging in heavy drinking episodes tended to have multiple other health-related risk factors (e.g., regular smoking, low fruit intake, low physical activity and hypertension). CONCLUSIONS: Among Chinese men, the proportion of drinkers engaging in harmful drinking behaviours increased in the past decade, particularly among younger men. Harmful drinking patterns tended to cluster with other unhealthy lifestyles and health-related risk factors.

Alcohol consumption in 0.5 million people from 10 diverse regions of China: prevalence, patterns and socio-demographic and health-related correlates.

BACKGROUND: Drinking alcohol has a long tradition in Chinese culture. However, data on the prevalence and patterns of alcohol consumption in China, and its main correlates, are limited. METHODS: During 2004-08 the China Kadoorie Biobank recruited 512,891 men and women aged 30-79 years from 10 urban and rural areas of China. Detailed information on alcohol consumption was collected using a standardized questionnaire, and related to socio-demographic, physical and behavioural characteristics in men and women separately. RESULTS: Overall, 76% of men and 36% of women reported drinking some alcohol during the past 12 months, with 33% of men and 2% of women drinking at least weekly; the prevalence of weekly drinking in men varied from 7% to 51% across the 10 study areas. Mean consumption was 286 g/week and was higher in those with less education. Most weekly drinkers habitually drank spirits, although this varied by area, and beer consumption was highest among younger drinkers; 37% of male weekly drinkers (12% of all men) reported weekly heavy drinking episodes, with the prevalence highest in younger men. Drinking alcohol was positively correlated with regular smoking, blood pressure and heart rate. Among male weekly drinkers, each 20 g/day alcohol consumed was associated with 2 mmHg higher systolic blood pressure. Potential indicators of problem drinking were reported by 24% of male weekly drinkers. CONCLUSION: The prevalence and patterns of drinking in China differ greatly by age, sex and geographical region. Alcohol consumption is associated with a number of unfavourable health behaviours and characteristics.