Generational differences in longitudinal blood pressure trajectories by geographic region during socioeconomic transitions in China

Gender Disparities in Blood Pressure and the Role of Body Mass Index: A Birth Cohort Analysis in China

BACKGROUND

The slow decline in cardiovascular disease (CVD) mortality and the stagnant or increasing hypertension prevalence in low- and middle-income countries necessitate investigation. Evolving gender disparities suggested that male cardiovascular health disadvantage may be preventable, offering potential for enhancing population cardiovascular health. Despite global body mass index (BMI) increases, its role in shaping the gender disparities remains underexplored.

OBJECTIVE

This study investigated the birth cohort dynamics of gender disparities in systolic/diastolic blood pressure (SBP/DBP) in China, one of the world's largest low- and middle-income countries, and explored the potential role of BMI in explaining the changing gender disparities.

METHODS

Data from the China Health and Nutrition Survey (1991-2015) were analyzed using multilevel growth-curve models to estimate gender- and cohort-specific SBP/DBP trajectories among individuals born between 1950 and 1975.

RESULTS

Men had higher SBP and DBP than women at the sample's mean age of 41.7 years. The gender disparities in SBP and DBP increased with each successive one-year cohort from 1950 to 1975 by 0.14 mm Hg and 0.09 mm Hg, respectively. Adjusting for BMI reduced the increasing gender disparities in SBP and DBP by 31.9% and 34.4%, respectively.

CONCLUSION

Chinese men experienced a greater increase in SBP/DBP across successive cohorts compared to women. The increasing gender disparities in SBP/DBP were partially attributable to a greater BMI increase across cohorts among men. Given these findings, prioritizing interventions that aim to reduce BMI, particularly among men, could potentially alleviate the burden of CVD in China through lowering SBP/DBP.

Urbanization and systolic/diastolic blood pressure from a gender perspective: Separating longitudinal from cross-sectional association

There has been a generally negative view of the impact of urbanization on a rising burden of non-communicable diseases including cardiovascular disease. However, the evidence on the relationship between urbanization and cardiovascular health has remained inconclusive. A comprehensive picture of the relationship is lacking, given an implicit assumption that the longitudinal association between changes in cardiovascular health and an increasingly urbanized environment is similar between less and more urbanized communities, men and women. We used the longitudinal data on adults (18-64 years) from the China Health and Nutrition Survey (1991-2015) and employed within-between random-effects models to disaggregates the longitudinal and cross-sectional associations between urbanization and systolic/diastolic blood pressure (SBP/DBP) and examined heterogeneities in the longitudinal association by average urbanization level and gender. We found that the positive longitudinal association of urbanization with SBP/DBP was stronger in less urbanized than more urbanized communities. The cross-sectional association between urbanization and SBP was negative and significant, although the cross-sectional association between urbanization and DBP was of no statistical significance. Moreover, the positive longitudinal association between urbanization and DBP was stronger among men than women, although the gender heterogeneity in the longitudinal association of urbanization with SBP was not significant.

Hypertension Prevalence Rates Among Urban and Rural Older Adults of China, 1991-2015: A Standardization and Decomposition Analysis

Objectives: The prevalence of hypertension (HTN) among older adults is becoming an important issue in public health in China as it is now stepping into the super-aged society with high pressure of a chronic disease burden. With urban–rural differences in population composition and health facilities, this study aimed to assess the gaps in the prevalence trends of HTN among older adults by considering demographic factors such as age, gender, education level, and regional differences during 1991–2015 in China.

Methods: We adopted the consistent sampling design and measure of HTN of the cross-longitudinal surveys of the China Health and Nutrition survey, and we compared the HTN prevalence rates between urban and rural older adults by taking each wave of the survey as a cross-sectional sample of the Chinese population by the following and supplementary samples. The classic standardization and decomposition analysis method was utilized with four factor-specific rates, and contributions were calculated, i.e., age, gender, education, and region, which reflects the aspect of demographic and social development differences between urban and rural areas of China.

Results: The prevalence rates of HTN of the whole of older adults were increasing in 1991–2015. However, the gaps of prevalence rates of HTN between urban and rural areas show different trends accompanied by the health policies launched by the government. Namely, the gap was narrowed during 1993–1997 and then enlarged during 1997–2011 and narrowing again. Those trends reflect the policy effects with the health resource allocation and utilization of health services for urban and rural older adults.

Conclusions: With the four factors of decomposition analysis, the differences reflect the results of health policy effects, considering the urban–rural discrepancy on older adults with different demographic characteristics. Hence, the differentiated policies should be considered with the urban–rural population, such as HTN prevention and the population health promotion.

Association of age and blood pressure among 3.3 million adults: insights from China PEACE million persons project

OBJECTIVE

To assess the association between blood pressure (BP) with age and its heterogeneity across various sociodemographic subgroups in China.

METHODS

In this cross-sectional study, we analysed the data from nearly 3.3 million individuals aged 35-75 years from all 31 provinces in mainland China collected from September 2014 through August 2019. On the basis of possible combinations of eight characteristics and antihypertensive status, subgroups of at least 10 000 individuals were created and the age--blood pressure relationship was determined for each group.

RESULTS

The study included 3 291 058 participants (59.6% women), with a mean age of 55.8 ± 9.8 years. The prevalence of hypertension was 47.6%, of which 30.0% were taking antihypertensive medications. The mean SBP was 135.9 ± 20.2 mmHg. SBP increased at a mean unadjusted rate of 0.639 ± 0.001 mmHg/year. For 95% of the 25 145 subgroups, the SBP increased by 0.28--0.85 mmHg/year. The most common characteristics in the subgroups with the steepest association were female sex, rural area, low education, low-income family, Tibet region, and farmer occupation. The increase in SBP ranged from 0.13 to 0.41 mmHg/year for 95% of the treated subgroups and from 0.33 to 0.82 mmHg/year for 95% of the untreated subgroups.

CONCLUSION

Blood pressure is positively associated with age in this study, with almost three-fold variation across subgroups, indicating subgroup differences in biology, behaviour, or exposures. Antihypertension strongly blunts the association of age and blood pressure and diminishes the variation.

Blood Pressure Trajectories Across the Life Course

High blood pressure (BP) is a strong modifiable risk factor for cardiovascular disease (CVD). Longitudinal BP patterns themselves may reflect the burden of risk and vascular damage due to prolonged cumulative exposure to high BP levels. Current studies have begun to characterize BP patterns as a trajectory over an individual's lifetime. These BP trajectories take into account the absolute BP levels as well as the slope of BP changes throughout the lifetime thus incorporating longitudinal BP patterns into a single metric. Methodologic issues that need to be considered when examining BP trajectories include individual-level vs. population-level group-based modeling, use of distinct but complementary BP metrics (systolic, diastolic, mean arterial, mid, and pulse pressure), and potential for measurement errors related to varied settings, devices, and number of readings utilized. There appear to be very specific developmental periods during which divergent BP trajectories may emerge, specifically adolescence, the pregnancy period, and older adulthood. Lifetime BP trajectories are impacted by both individual-level and community-level factors and have been associated with incident hypertension, multimorbidity (CVD, renal disease, cognitive impairment), and overall life expectancy. Key unanswered questions remain around the additive predictive value of BP trajectories, intergenerational contributions to BP patterns (in utero BP exposure), and potential genetic drivers of BP patterns. The next phase in understanding BP trajectories needs to focus on how best to incorporate this knowledge into clinical care to reduce the burden of hypertensive-related outcomes and improve health equity.

Community context, birth cohorts and childhood body mass index trajectories: Evidence from the China nutrition and health survey 1991-2011

Childhood overweight and obesity have shown an increase in recent birth cohorts. China has undergone rapid socioeconomic transitions accompanied by lifestyle changes that have profoundly affected the physical growth of children. Less empirical research has considered the role of community context on the cohort effects of children's body mass index (BMI) z-score trajectories. We used the mixed effect models for repeated measurements with restricted cubic spline to predict the BMI z-score trajectories in children aged 1-17 years, influenced by different birth cohorts and community context using data from the China Health and Nutrition Survey from 1991 to 2011, and stratified by sex. Results indicated that the mean of BMI z-scores of children aged 1-17 years have increased in the 2000s cohort. Community context contributed to significant differences in BMI z-score increase with age from middle childhood, and this trend of community inequalities divergences in middle childhood in recent birth cohorts. Therefore, to promote equitable growth for all children in China, policy interventions focusing on the community context may have far-reaching effects on the health of children and adolescents.

Spatiotemporal Variation of the Association between Urbanicity and Incident Hypertension among Chinese Adults

Urbanization is believed to result in a transition towards energy-dense diets, sedentary lifestyles, and a subsequent increase in the burden of hypertension (HTN) and other cardiovascular diseases (CVDs) in developing countries. However, the extent to which this occurs is likely dependent on social contexts. We performed multilevel logistic regression models to examine whether the association between incident HTN and the degree to which a community exhibits urban features varied by region (the Northeast, East Coast, Central, and West) within China and period. We used longitudinal data from the China Health and Nutrition Survey (1991–2015) and stratified analyses by sex. Among women, the positive association between medium-to-high urbanicity and HTN onset generally shifted to negative between 1991 and 2015. The high urbanicity was associated with lower odds of developing HTN in the East Coast from the early 1990s. The negative association between high urbanicity and HTN occurrence became statistically significant during 1991–2015 in the Northeastern and Central Regions, while the association remained positive and non-significant in the West. Among men, the relationship between urbanicity and incident HTN was generally non-significant, except for the East Coast in which the negative association between high urbanicity and HTN occurrence became statistically-significant in more recent years. Our findings suggest that, when a subnational region or the society as a whole has become more economically developed, higher urbanicity might turn out to be a protective factor of cardiovascular health. Moreover, improvements made to communities’ urban features might be more effective in preventing HTN for women than for men.