Evaluating the impact of sugar-sweetened beverages tax on overweight, obesity, and type 2 diabetes in an affluent Asian setting: A willingness-to-pay survey and simulation analysis.

BACKGROUND: The potential health effects of taxing sugar-sweetened beverages (SSBs) has been insufficiently examined in Asian contexts. This study aimed to assess the impact of SSB taxation on the prevalence of obesity/overweight and type 2 diabetes mellitus (T2DM) in Hong Kong using a willingness-to-pay (WTP) survey and simulation analysis. METHODS: A random telephone survey was conducted with 1000 adults from May to June 2020. We used a contingent valuation approach to assess individuals' WTP for SSBs under four tax payment scenarios (5%, 10%, 40%, and 50% of the current market price). Based on the WTP, a simulation analysis was conducted to project changes in SSB purchase and associated reductions in the prevalence of obesity/overweight and T2DM over a 10-year simulation period. FINDINGS: When 5% and 10% taxation rates were introduced, approximately one-third of the population were unwilling to maintain their SSB purchase. Our simulation demonstrated a gradual decline in the prevalence of obesity/overweight and diabetes with a more pronounced decrease when higher taxation rates were introduced. 10% taxation resulted in a mean reduction of 1532.7 cases of overweight/obesity per 100 thousand population at the sixth year, while T2DM prevalence decreased by 267.1 (0.3%). CONCLUSIONS: This study underscores the effects of an SSB tax on purchase behaviors and health outcomes in an affluent Asia setting, with a more pronounced influence on adult population. These findings are expected to inform policymakers in making decisions regarding an effective and equitable tax rate on SSBs.

Sex differences in the association between socioeconomic status and diabetes prevalence and incidence in China: cross-sectional and prospective studies of 0.5 million adults.

AIMS/HYPOTHESIS: China has undergone rapid socioeconomic transition accompanied by lifestyle changes that are expected to have a profound impact on the health of its population. However, there is limited evidence from large nationwide studies about the relevance of socioeconomic status (SES) to risk of diabetes. We describe the associations of two key measures of SES with prevalent and incident diabetes in Chinese men and women. METHODS: The China Kadoorie Biobank study included 0.5 million adults aged 30-79 years recruited from ten diverse areas in China during 2004-2008. SES was assessed using the highest educational level attained and annual household income. Prevalent diabetes was identified from self-report and plasma glucose measurements. Incident diabetes was identified from linkage to disease and death registries and national health insurance claim databases. We estimated adjusted ORs and HRs for prevalent and incident diabetes associated with SES using logistic and Cox regression models, respectively. RESULTS: At baseline, 30,066 (5.9%) participants had previously diagnosed (3.1%) or screen-detected (2.8%) diabetes among 510,219 participants included for cross-sectional analyses. There were 480,153 people without prevalent diabetes at baseline, of whom 9544 (2.0%) had new-onset diabetes during follow-up (median 7 years). Adjusted ORs (95% CIs) for prevalent diabetes, comparing highest vs lowest educational level, were 1.21 (1.09, 1.35) in men and 0.69 (0.63, 0.76) in women; for incident diabetes, the corresponding HRs were 1.27 (1.07, 1.51) and 0.80 (0.67, 0.95), respectively. For household income, the adjusted ORs for prevalent diabetes, comparing highest vs lowest categories, were 1.45 (1.34, 1.56) in men and 1.26 (1.19, 1.34) in women; for incident diabetes, the HRs were 1.36 (1.19, 1.55) and 1.06 (0.95, 1.17), respectively. CONCLUSIONS/INTERPRETATION: Among Chinese adults, the associations between education and diabetes prevalence and incidence differed qualitatively between men and women, whereas higher household income was positively associated with diabetes prevalence and incidence in both sexes, with a stronger relationship in men than in women.

Socioeconomic status and self-reported, screen-detected and total diabetes prevalence in Chinese men and women in 2011-2012: a nationwide cross-sectional study.

BACKGROUND: A rapid epidemiological transition is taking place in China and the association between socioeconomic status (SES) and diabetes prevalence is not clear and may vary by population characteristics and geography within the country. We describe the associations between educational level, annual household living expenditure (AHLE) and diabetes prevalence in a large middle-aged and elderly Chinese population using data from a nationwide cross-sectional study. METHODS: We used data from the China Health and Retirement Longitudinal Study, which collected information from interviews and blood tests from a nationwide sample of people over 44 years of age in 2011-2012. We used multivariable logistic regression to describe the association between highest levels of education (high school or above compared to illiterate) or AHLE (top vs bottom quartile) and self-reported, screen-detected or total diabetes prevalence. We stratified by sex and adjusted for age, education or AHLE (as appropriate), urban, rural or migrant residence status and geographical area. RESULTS: Complete data were available for 10 100 participants of whom 10.5% and 28.9% had the highest and the lowest levels of education respectively. Overall prevalence of self-reported diabetes was 6.0% and of screen-detected diabetes was 9.8%. Higher education level was associated with both self-reported diabetes (odds ratio (OR) = 2.41, 95% confidence interval CI = 1.36-4.46) and total diabetes (OR = 1.53 95%, CI = 1.10-2.15) only in men. AHLE was associated with self-reported diabetes in men (OR = 1.87, 95% CI = 1.26-2.84) and women (OR = 2.31, 95% CI = 1.62-3.34). There was no association between SES and screen-detected diabetes for men or women. CONCLUSIONS: SES inequalities exist in prevalence of diabetes in China and can be used to inform approaches to prevention. Identification and appropriate intervention for people with undiagnosed diabetes is required for all SES groups.

Socioeconomic status and prevalence of type 2 diabetes in mainland China, Hong Kong and Taiwan: a systematic review.

BACKGROUND: China is estimated to have had the largest number of people with diabetes in the world in 2015, with extrapolation of existing data suggesting that this situation will continue until at least 2030. Type 2 diabetes has been reported to be more prevalent among people with low socioeconomic status (SES) in high-income countries, whereas the opposite pattern has been found in studies from low- and middle-income countries. We conducted a systematic review to describe the cross-sectional association between SES and prevalence of type 2 diabetes in Chinese in mainland China, Hong Kong and Taiwan. METHODS: We conducted a systematic literature search in Medline, Embase and Global Health electronic databases for English language studies reporting prevalence or odds ratio for type 2 diabetes in a Chinese population for different SES groups measured by education, income and occupation. We appraised the quality of included studies using a modified Newcastle-Ottawa Scale. Heterogeneity of studies precluded meta-analyses, therefore we summarized study results using a narrative synthesis. RESULTS: Thirty-three studies met the inclusion criteria and were included in the systematic review. The association between education, income and occupation and type 2 diabetes was reported by 27, 19 and 12 studies, respectively. Most, but not all, studies reported an inverse association between education and type 2 diabetes, with odds ratios (OR) and 95% confidence interval (CI) ranging from 0.39 (CI not reported) to 1.52 (95% CI 0.91 - 2.54) for the highest compared to the lowest education level. The association between income and type 2 diabetes was inconsistent between studies. Only a small number of studies identified a significant association between occupation and type 2 diabetes. Retired people and people working in white collar jobs were reported to have a higher risk of type 2 diabetes than other occupational groups even after adjusting for age. CONCLUSIONS: This first systematic review of the association between individual SES and prevalence of type 2 diabetes in China found that low education is probably associated with an increased prevalence of type 2 diabetes, while the association between income and occupation and type 2 diabetes is unclear.