Trends in the association between blood pressure and obesity in a Taiwanese population between 1996 and 2006

Changes in the body mass index and blood pressure association across time: Evidence from multiple cross-sectional and cohort studies

Although body mass index (BMI) is considered a key determinant of high blood pressure, its importance may differ over time and by age group. We utilised separate data sources to investigate temporal changes in this association: 23 independent (newly sampled), repeated cross-sectional studies (Health Survey for England (HSE)) at ≥25 years (1994-2018; N = 126,742); and three British birth cohorts at 43-46 years (born 1946, 1958, and 1970; N = 18,657). In HSE, associations were weaker in more recent years, with this trend most pronounced amongst older adults. After adjustment for sex, anti-hypertensive treatment and education, the mean difference in systolic blood pressure (SBP) per 1 kg/m² increase in BMI amongst adults ≥55 years was 0.75 mmHg (95%CI: 0.60-0.90) in 1994, 0.66 mmHg (0.46-0.85) in 2003, and 0.53 mmHg (0.35-0.71) in 2018. In the 1958 and 1970 cohorts, BMI and SBP associations were of similar magnitude yet weaker in the 1946 cohort, potentially due to differences in blood pressure measurement device. Quantile regression analyses suggested that associations between BMI and SBP were present both below and above the hypertension threshold. A weaker association between BMI and blood pressure may partly offset the public health impacts of increasing obesity prevalence. However, despite sizable increases in use of antihypertensive medication, BMI remains positively associated with SBP in all ages. Our findings highlight the need to tackle non-medical factors such as population diet which influence both BMI and blood pressure, and the utility of using multiple datasets to obtain robust inferences on trends in risk factor-outcome associations across time.

Secular Trends of the Impact of Overweight and Obesity on Hypertension in Yi People: Yi Migrant Study, 1996-2015

Background

Rising hypertension prevalence, coupled with increasing overweight and obesity rates, has been observed in Yi people. Moreover, the growing blood pressure level among Yi people was mostly attributable to the continuous increase of body mass index (BMI). However, little is known about the trend of association between them.

Methods

Consequently, we investigated the impact of overweight/obesity on hypertension over three periods (1996, 2007-2008, 2015) using data from Yi Migrant Study (n = 8749). The Yi Migrant Study incorporated three successive cross-sectional studies which were implemented by the same team with consistent protocols.

Results

Compared with period 1 (1996), the influence of overweight/obesity on hypertension risk significantly increased in period 2 (2007-2008) and period 3 (2015); relative excess risk due to interaction (RERI) was 1.59 (95% CI: 0.12, 3.05) and 1.41 (95% CI: 0.30, 2.78), respectively. Meanwhile, the overweight/obese population in period 3 did not show hypertension risk higher than that in period 2 (RERI = 0.15; 95% CI: -0.76, 1.07). Additionally, we observed a continuously growing trend of hypertension risk among normal weight Yi people.

Conclusions

During the past two decades, there was a significant increase in the association between overweight/obesity and hypertension in Yi people, whereas the increasing trend has leveled off in more recent years. These findings suggest that overweight/obesity and hypertension are becoming more epidemic comorbidity over time. Interventions to prevent hypertension should focus not only on the overweight/obese population, but also on those with normal weight.

Body Mass Index Trajectories in Early Life Is Predictive of Cardiometabolic Risk

OBJECTIVE

To identify distinct body mass index (BMI) trajectories across the life-course and explore the effects of BMI trajectories on the adult cardiovascular disease outcomes using a dataset with 30 years of follow-up in northern China.

STUDY DESIGN

A total of 2839 participants aged 6-18 years whose BMIs were measured 3-6 times during the Hanzhong Adolescent Hypertension Study were included in our analysis. Latent mixture modeling was used to clarify distinct BMI trajectories in longitudinal analyses.

RESULTS

Three groups with distinct trajectories in BMI were identified by the latent mixed models: a low-increasing group (n = 1324 [36.64%]), a moderate-increasing group (n = 1178 [16.89%]), and a high-increasing group (n = 337 [39.46%]). Compared with the participants in the low-increasing group, the risk ratios of hypertension, type 2 diabetes mellitus, high-risk triglycerides, and high-risk high-density lipoprotein cholesterol were more than 3.0 in the high-increasing group (all P < .001) after being fully adjusted. Increased risks existed in high brachial-ankle pulse wave velocity for the high-increasing group compared with the low-increasing group (RR, 2.75; 95% CI, 1.94-3.91; P < .001). Additionally, participants in the moderate-increasing group had a 2.31-fold increased risks of left ventricular hypertrophy (95% CI, 1.25-4.30; P = .008).

CONCLUSIONS

Our study indicates that BMI trajectories from childhood to adulthood vary and that an elevated BMI trajectory in early life is predictive of an increased the risk of developing cardiovascular disease risks.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02734472.

Change in the association of body mass index and systolic blood pressure in Germany - national cross-sectional surveys 1998 and 2008-2011

Background

A recent weakening and even decoupling of the association of body mass index (BMI) and systolic blood pressure (SBP) in population data was reported, i. a. for Western Europe.

Methods

The association of BMI and SBP in recent cross-sectional population data from Germany was investigated in participants aged 18–79 years with BMI 17.5-40 kg/m² from national health examination surveys 1998 (n = 6,931) and 2008–2011 (n = 6,861) in Germany. The association was analyzed both in the overall samples and in participants without antihypertensive medication.

Results

From 1998 to 2008–11, age- and sex-standardized mean SBP decreased from 129.0 (CI 128.2-129.7) to 124.1 (123.5-124.6) mmHg in all participants and from 126.0 (125.4-126.7) to 122.3 (121.7-122.8) mmHg among persons not on antihypertensive medication. The proportion of persons treated with antihypertensives augmented from 19.2 % (17.7-20.8) to 25.3 % (24.0-26.6). Mean BMI remained constant at around 27 kg/m² with a slight increase in obesity prevalence. BMI was positively associated with SBP both in 1998 and 2008–11, yet the association tended to level out with increasing BMI suggesting a non-linear association. The strength of the BMI-SBP-association decreased over time in all and untreated men. In women, the association weakened in the overall sample, but remained similarly strong in untreated women. The unadjusted linear regression models were used to estimate the increase in SBP within 5-unit BMI increases. E. g. for men in 1998, SBP was higher by 7.0 mmHg for a BMI increase from 20 to 25 kg/m² and by 3.6 mmHg for BMI 30 to 35 kg/m². The corresponding values for 2008–11 were 3.8 mmHg and 1.7 mmHg.

Conclusions

The cross-sectional association of BMI and SBP decreased between 1998 and 2008–11 in Germany, however it did not disappear and it is in part explained by improvements in the diagnosis and treatment of high blood pressure.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2023-8) contains supplementary material, which is available to authorized users.

Life-course body mass index trajectories and blood pressure in mid life in two British birth cohorts: stronger associations in the later-born generation

Background: Little is known about the impact of recent increases in obesity and more rapid gains in body mass index (BMI) on cardiovascular risk factors. We investigated life-course BMI trajectories associations with adult blood pressure (BP) across two generations.

Methods: We used the the 1946 and 1958 British birth cohorts. Joint multivariate response models were fitted to longitudinal BMI measures [7, 11, 16, 20, 26, 36, 43 and 50 y (years): 1946 cohort, n = 4787; 7, 11, 16, 23, 33 and 45 y: 1958 cohort, n = 16 820] and mid-adult BP. We adopted linear spline models with random coefficients to characterize childhood and adult BMI slopes.

Results: Mean systolic BP (SBP) decreased from the earlier- to later-born cohort by 2.8 mmHg in females, not males; mean diastolic BP (DBP) decreased by 3.2-3.3 mmHg (both sexes). Adult BMI was higher in the later- than the earlier-born cohort by 1.3-1.8 kg/m², slopes of BMI trajectory were steeper from early adulthood and associations with adult BP were stronger. Associations between adult BMI and SBP were stronger in the later-born cohort. For males, childhood BMI slope was associated with SBP only in the later-born cohort; the association for adult BMI slope was stronger in the later-born cohort: correlation coefficient r = 0.28 [95% confidence interval (CI): 0.25,0.33] versus 0.13 (0.06,0.20). For females, childhood slope was associated with SBP in both cohorts; adult slope was associated with SBP only in the 1958 cohort [r = 0.34 (0.31,0.37)]. Patterns of child-to-adult BMI associations were similar in relation to DBP.

Conclusions: BP did not increase between two generations born 12 y apart despite higher BMI levels. A stronger association between BMI trajectory and BP in the later-born cohort suggests that BMI-related effects may have been offset by improvements in other factors linked to BP, such as diet and smoking.

Interplay of overweight and insulin resistance on hypertension development

OBJECTIVES

Obesity and hypertension are associated, possibly through causal pathways involving insulin resistance and metabolic derangements. We aimed to investigate in a whites sample if overweight or obese persons without insulin resistance are at risk of developing hypertension or blood pressure progression.

METHODS

In a meta-analysis, using multivariable-adjusted mixed-effects logistic regression models, we investigated the risks of hypertension development and blood pressure progression by combinations of relative weight classes and presence or absence of insulin resistance (defined as highest vs. lower three quartiles using the homeostatic model assessment method) in the Uppsala Longitudinal Study of Adult Men (n = 2322) and the Prospective Investigation of the Vasculature in Uppsala Seniors studies (n = 1066). These two samples, consisting mainly of middle-aged and elderly men, provided 1846 observations for the development of hypertension in normotensive individuals and 4223 observations for progressing to a higher blood pressure stage.

RESULTS

During a median of 10 years of follow-up, 884 (47.9%) developed hypertension and 1639 (38.8%) progressed to a higher blood pressure stage. Overweight or obese persons without insulin resistance had an increased risk of hypertension development [odds ratio (OR) 1.46, 95% confidence interval 1.14-1.88] and blood pressure progression (OR 1.32, 1.10-1.59) compared with normal-weight persons without insulin resistance.

CONCLUSION

According to this study, being overweight or obese without insulin resistance increases the risk of hypertension and blood pressure progression. This adds to the evidence that overweight and obesity may be harmful per se, and that overweight and obesity without glucometabolic derangements are not benign conditions.

Variations in aging, gender, menopause, and obesity and their effects on hypertension in taiwan

Aim. We assessed obesity, sex, menopause, and gender differences on hypertension in a Hakka-majority Taiwanese sample. Methods. 9621 subjects aged 20 and over participated in this community-based study. Trained nurses collected blood pressure (BP) measurements and anthropometric indices, including weight, height, hip circumference (HC), waist circumference (WC), body mass index (BMI), waist to height ratio (WHtR), and waist to hip ratio (WHR). Results. Levels of systolic and diastolic BP significantly increased at a dose-dependent relationship based on four anthropometric indices (BMI, WC, WHR, and WHtR); the slopes for SBP and DBP differed. After controlling for other covariates using multivariate logistic regression, we found the adjusted odds ratios (OR) of hypertension to be significantly related to the four anthropometric indices. Notably, the effect of obesity on the ORs for hypertension was considerably higher in premenopausal women, but we found no such phenomenon among men. BMI, WC, WHR, and WHtR had significant linear associations with BP. Conclusion. Obesity indices are significantly correlated with the risk of hypertension across gender and age, with BMI having the highest relative potency. The effect of obesity on the risk of hypertension is especially high in premenopausal women, implying a relationship between hormones and hypertension.

Seasonal variation in blood pressure is modulated by gender and age but not by BMI in a large Taiwanese population, 1996-2006

Previous research has found that blood pressure tends to be higher in winter and lower in summer. The present study examined seasonal variation in blood pressure by gender, hypertension medication, age group, and body mass index using contemporary Taiwanese data. Over 400,000 health screening records collected biennially between 1996 and 2006 were used to calculate average monthly systolic (SBP) and diastolic blood pressure (DBP) measurements. Generalized estimating equations were used to estimate the difference between the highest and lowest mean monthly blood pressure measurements. Mean monthly blood pressure measurements were higher in winter than in summer for all age groups, regardless of medication for hypertension. The largest difference in mean monthly blood pressure between summer and winter months was 5.3 mm Hg (Standard error = 0.7) for SBP and 3.2 mm Hg (Standard error = 0.7) for DBP. These differences were more pronounced: in SBP than in DBP; in men than in women; and in older than in younger participants. Body mass index was not clearly associated with seasonal variation in blood pressure. Seasonal variation in blood pressure among contemporary Taiwanese populations is modest and may only approach clinical significance for the diagnosis and treatment of hypertension and the prevention of cardiovascular disease amongst older male individuals.

Is the health burden associated with obesity changing?

Prioritization of obesity prevention and management policy is based on one's understanding of the health risks associated with increasing body weight. However, there is evidence that the magnitude of these health risks may be changing over time. Here, the authors analyze the theoretical drivers of these changes and then examine whether there is empirical evidence to support the theory. They conclude that, although the mortality risks associated with increasing body weight may be decreasing over time, the overall health burden appears likely to increase.

Unravelling the effects of age, period and cohort on metabolic syndrome components in a Taiwanese population using partial least squares regression

Background

We investigate whether the changing environment caused by rapid economic growth yielded differential effects for successive Taiwanese generations on 8 components of metabolic syndrome (MetS): body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), triglycerides (TG), high-density lipoprotein (HDL), Low-density lipoproteins (LDL) and uric acid (UA).

Methods

To assess the impact of age, birth year and year of examination on MetS components, we used partial least squares regression to analyze data collected by Mei-Jaw clinics in Taiwan in years 1996 and 2006. Confounders, such as the number of years in formal education, alcohol intake, smoking history status, and betel-nut chewing were adjusted for.

Results

As the age of individuals increased, the values of components generally increased except for UA. Men born after 1970 had lower FPG, lower BMI, lower DBP, lower TG, Lower LDL and greater HDL; women born after 1970 had lower BMI, lower DBP, lower TG, Lower LDL and greater HDL and UA. There is a similar pattern between the trend in levels of metabolic syndrome components against birth year of birth and economic growth in Taiwan.

Conclusions

We found cohort effects in some MetS components, suggesting associations between the changing environment and health outcomes in later life. This ecological association is worthy of further investigation.

The trend of hypertension and its relationship to the weight status among Taiwanese young adolescents

This study evaluates prevalence of hypertension in 1996 and 2006, and examines the relationship between hypertension and weight of Taiwanese young adolescents. Two cross-sectional surveys, administered in 1996 and 2006, to junior-high school in Taipei were included. Anthropometric and blood pressure were measured using standard methods, and structured questionnaire was used to collect personal history and lifestyle characteristics. Overweight and obesity are defined based on Taiwan's Department of Health criteria and bases pre-hypertension and hypertension on the 90th and 95th percentile distribution of blood pressure of the population of both surveys. The prevalence of pre-hypertension in Taiwan between 1996 and 2006 increased from 12.0 to 14.4% for boys and decreased from 9.5 to 9.4% for girls. Hypertension increased from 22.8-29.7% and 12.5-20.7% for both boys and girls, respectively. In 1996, compared with normal young adolescents, the risk of hypertension for overweight was 1.8 times higher for boys and 3.4 times for girls. However, the risk of hypertension for overweight in 2006 was 1.7 times higher for boys and 1.5 times higher for girls compared with normal. Every unit increment of body mass index and waist circumference was associated with 17-27% and 6-11% risk of hypertension in both genders in 1996, and was associated with 9-13% and 4% risk of hypertension among young adolescents in 2006, respectively. The prevalence of hypertension has increased significantly in young adolescents, especially for overweight. It is necessary to enrol young adolescents in weight management programs to prevent hypertension-related co-morbidities.