Gender disparities in hypertension among different ethnic groups in Amsterdam, The Netherlands: the SUNSET study

Sex-biased gene regulation varies across human populations as a result of adaptive evolution

OBJECTIVES

Studies of human sexual dimorphism and gender disparities in health focus on ostensibly universal molecular sex differences, such as sex chromosomes and circulating hormone levels, while ignoring the extraordinary diversity in biology, behavior, and culture acquired by different human populations over their unique evolutionary histories.

MATERIALS AND METHODS

Using RNA-Seq data and whole genome sequences from 1000G and HGDP, we investigate variation in sex-biased gene expression across 11 human populations and test whether population-level variation in sex-biased expression may have resulted from adaptive evolution in regions containing sex-specific regulatory variants.

RESULTS

We find that sex-biased gene expression in humans is highly variable, mostly population-specific, and demonstrates between population reversals. Expression quantitative trait locus mapping reveals sex-specific regulatory regions with evidence of recent positive natural selection, suggesting that variation in sex-biased expression may have evolved as an adaptive response to ancestral environments experienced by human populations.

DISCUSSION

These results indicate that sex-biased gene expression is more flexible than previously thought and is not generally shared among human populations. Instead, molecular phenotypes associated with sex depend on complex interactions between population-specific molecular evolution and physiological responses to contemporary socioecologies.

Ambient air pollution as a mediator in the pathway linking race/ethnicity to blood pressure elevation: The multi-ethnic study of atherosclerosis (MESA)

BACKGROUND

Racial/ethnic disparities in blood pressure and hypertension have been evident in previous studies, as were associations between race/ethnicity with ambient air pollution and those between air pollution with hypertension. The role of air pollution exposure to racial/ethnic differences in hypertension has not been explored.

OBJECTIVE

To assess the potential mediating effects of ambient air pollution on the association between race/ethnicity and blood pressure levels.

METHODS

We studied 6,463 White, Black, Hispanic and Chinese adults enrolled across 6 US cities. Systolic (SBP) and diastolic blood pressure (DBP) were measured at Exam 1 (2000-2002) and Exam 2 (2002-2004). Household-level annual average concentrations of fine particulate matter (PM_2.5), oxides of nitrogen (NO_X), and ozone (O₃) for the year 2000 were estimated for participants.

RESULTS

The difference in SBP levels by race/ethnicity that was related to higher PM_2.5 concentrations compared with White men ("indirect associations") was 0.3 (95% CI: 0.1, 0.6) mmHg for Black men, 0.3 (95% CI: 0.1, 0.6) mmHg for Hispanic men and 1.0 (95% CI: 0.2, 1.8) mmHg for Chinese men. Findings were similar although not statistically significant for women. PM_2.5 did not mediate racial/ethnic differences in DBP. Indirect associations were significant for O₃ for SBP among women and men and for DBP among men. In contrast, racial/ethnic disparities were attenuated due to exposure to NO_X.

CONCLUSION

Racial disparities in blood pressure were reduced after accounting for PM_2.5 and ozone while increased after accounting for NO_X.

Differential associations between psychosocial stress and obesity among Ghanaians in Europe and in Ghana: findings from the RODAM study

PURPOSE

Psychosocial stress is associated with obesity in some populations, but it is unclear whether the association is related to migration. This study explored associations between psychosocial stress and obesity among Ghanaian migrants in Europe and non-migrant Ghanaians in Ghana.

METHODS

Cross-sectional data from the RODAM study were used, including 5898 Ghanaians residing in Germany, the UK, the Netherlands, rural Ghana, and urban Ghana. Perceived discrimination, negative life events and stress at work or at home were examined in relation to body mass index (BMI) and waist circumference (WC). Linear regression analyses were performed separately for migrants and non-migrants stratified by sex.

RESULTS

Perceived discrimination was not associated with BMI and WC in both migrants and non-migrants. However, negative life events were positively associated with BMI (β = 0.78, 95% CI 0.34-1.22) and WC (β = 1.96, 95% CI 0.79-3.12) among male Ghanaian migrants. Similarly, stress at work or at home was positively associated with BMI (β = 0.28, 95% CI 0.00-0.56) and WC (β = 0.84, 95% CI 0.05-1.63) among male Ghanaian migrants. Among non-migrant Ghanaians, in contrast, stress at work or at home was inversely associated with BMI and WC in both males (β = - 0.66, 95% CI - 1.03 to - 0.28; β = - 1.71 95% CI - 2.69 to - 0.73, respectively) and females (β = - 0.81, 95% CI - 1.20 to - 0.42; β = - 1.46, 95% CI - 2.30 to - 0.61, respectively).

CONCLUSIONS

Negative life events and stress at work or at home are associated with increased body weight among male Ghanaians in European settings, whereas stress at work or at home is associated with reduced body weight among Ghanaians in Ghana. More work is needed to understand the underlying factors driving these differential associations to assist prevention efforts.

Prevalence of type 2 diabetes and its association with measures of body composition among African residents in the Netherlands--The HELIUS study

AIMS

To compare type 2 diabetes prevalence among three ethnic groups resident in the Netherlands: Ghanaians, African Surinamese and Dutch origin. Secondly, to determine the contribution of measures of body composition to ethnic differences in type 2 diabetes.

METHODS

Baseline data from Ghanaian (n=1873), African Surinamese (n=2189) and Dutch (n=2151) origin participants of the HELIUS study (aged 18-70 years) were analyzed. Type 2 diabetes was determined according to the WHO criteria. Logistic regression tested ethnic differences in type 2 diabetes and the contribution of body fat percentage and waist-to-hip ratio.

RESULTS

Among men, type 2 diabetes prevalence was higher in Ghanaians (14.9%) than in African Surinamese (10.4%) and Dutch (5.0%). Among women, type 2 diabetes prevalence in Ghanaian (11.1%) was higher than in Dutch (2.3%), but similar to African Surinamese (11.5%). After adjusting for age, body fat percentage and waist-to-hip ratio, the odds ratios for having type 2 diabetes were 1.55 (95% CI: 1.12-2.15) for Ghanaian men compared with African Surinamese and 4.19 (95% CI: 2.86-6.12) compared with Dutch. Among women these odds ratios were 0.94 (95% CI: 0.70-1.26) and 4.78 (95% CI: 2.82-8.11).

CONCLUSIONS

The higher prevalence of type 2 diabetes among Ghanaian compared with African Surinamese men suggests a need to distinguish between African descent populations when assessing their type 2 diabetes risk. The higher odds for type 2 diabetes among Ghanaians cannot be attributed to differences in body composition. Further research on the contribution of lifestyle factors as well as genetic and epigenetic factors is needed to identify the reasons for the observed disparities.

Quality of primary care for resettled refugees in the Netherlands with chronic mental and physical health problems: a cross-sectional analysis of medical records and interview data

BACKGROUND

A high prevalence of mental and physical ill health among refugees resettled in the Netherlands has been reported. With this study we aim to assess the quality of primary healthcare for resettled refugees in the Netherlands with chronic mental and non-communicable health problems, we examined: a) general practitioners' (GP) recognition of common mental disorders (CMD) (depression and anxiety, and post-traumatic stress disorder (PTSD) symptoms); b) patients' awareness of diabetes type II (DMII) and hypertension (HT); and c) GPs' adherence to guidelines for CMD, DMII and HT.

METHODS

From 172 refugees resettled in the Netherlands, interview data (2010-2011) and medical records (n = 106), were examined. Inclusion was based on medical record diagnoses for DMII and HT, and on questionnaire-based CMD measures (Hopkins Symptom Checklist for depression and anxiety; Harvard Trauma Questionnaire for PTSD). GP recognition of CMD was calculated as the number of CMD cases registered in the medical record compared with those found in interviews. Patient awareness of HT and DMII was scored as the percentage of subjects diagnosed by the GP who reported their condition during the interview. GPs' adherence to guidelines for CMD, DMII and HT was measured using established indicators.

RESULTS

We identified 37 resettled refugees with CMD of which 18 (49%) had been recognised by the GP. We identified 16 refugees with DMII and 14 with HT from the medical record; 24 (80%) were aware of their condition. Thirty-five out of these 53 (66%) resettled refugees with chronic mental and non-communicable disorders received guideline-adherent treatment.

CONCLUSION

This study shows that awareness in resettled refugees of GP diagnosed DMII and HT is high, whereas GP recognition of CMD and overall guideline adherence are moderate.

Heterogeneity in sex differences in the metabolic syndrome in Dutch white, Surinamese African and South Asian populations

AIM

To determine whether sex differences in the prevalence of the metabolic syndrome and its components differ among different ethnic groups.

METHODS

A random sample of non-institutionalized adults aged 35-60 years in Amsterdam, the Netherlands (white Dutch men n = 242, women n = 244; African-Surinamese men n = 193, women n = 399, Hindustani-Surinamese men n = 149, women n = 186). The metabolic syndrome was defined according to the International Diabetes Federation criteria.

RESULTS

In all ethnic groups, the prevalence of central obesity and reduced HDL cholesterol were higher in women than in men, but the prevalence of elevated blood pressure, fasting glucose and triglycerides were lower in women than in men. However, the magnitude of the differences varied. The sex differences in the prevalence of central obesity and reduced HDL cholesterol were particularly larger in ethnic minority groups, especially in African-Surinamese than in white Dutch. After adjustment for education, smoking, alcohol intake and physical activity, the prevalence of the metabolic syndrome was lower in white Dutch women than in white Dutch men (adjusted prevalence ratio 0.70, 95% CI 0.52-0.94). By contrast, the prevalence of the metabolic syndrome was higher in African-Surinamese women than in African-Surinamese men (adjusted prevalence ratio 1.56, 95% CI 1.12-2.18). Among Hindustani-Surinamese, men and women had a similar prevalence of the metabolic syndrome (adjusted prevalence ratio 1.00, 95% CI 0.76-1.31).

CONCLUSIONS

Our findings suggest different patterns in sex differences in the metabolic syndrome among the ethnic groups. The relatively high prevalence of central obesity in African-Surinamese women may underlie their higher prevalence of the metabolic syndrome. Strategies to improve metabolic profiles among African-Surinamese and white Dutch people need to take sex differences into account.

Sex difference in blood pressure among South Asian diaspora in Europe and North America and the role of BMI: a meta-analysis

It is unclear whether the sex difference that is known to occur in blood pressure (BP) is similar in some South Asian populations. This study presents a meta-analysis of the sex difference in BP, hypertension and the role of body mass index (BMI) in South Asian diaspora compared with populations of European descent. We systematically searched for studies that reported BP and hypertension among South Asian descent populations living in Europe and North America. Weighted mean differences in BP and risk ratios (RR) for hypertension were calculated for men and women. We included 11 studies in this meta-analysis. In general, men had a higher BP and prevalence of hypertension than women, for example, systolic BP was higher in men than in women among the Indian (7.21 mm Hg, 95% confidence interval (CI): 4.46-9.95) and European populations (6.12 mm Hg, 95% CI: 4.45-7.80). The difference was less in the Pakistani population (4.00 mm Hg, 95% CI: 2.65-5.36). The Bangladeshi population showed a comparatively small sex difference in systolic (2.93 mm Hg, 95% CI: 1.20-4.66) and diastolic BP (0.68 mm Hg, 95% CI: -1.76 to 3.12) and prevalence of hypertension (RR 1.28, 95% CI: 0.66-2.46). Sex differences in BMI for the South Asian populations were greater than those in Europeans. The Indian population had similar sex differences in BP and hypertension compared with Europeans, but Pakistani and Bangladeshi had smaller sex differences. Sex differences in BMI might relate to the blunted sex differences in BP in Pakistani and Bangladeshi populations. Further research should focus on factors that underlie this intriguing sex difference among South Asian populations.

Cardiovascular disease, diabetes and established risk factors among populations of sub-Saharan African descent in Europe: a literature review

Background

Most European countries are ethnically and culturally diverse. Globally, cardiovascular disease (CVD) is the leading cause of death. The major risk factors for CVD have been well established. This picture holds true for all regions of the world and in different ethnic groups. However, the prevalence of CVD and related risk factors vary among ethnic groups.

Methods

This article provides a review of current understanding of the epidemiology of vascular disease, principally coronary heart disease (CHD), stroke and related risk factors among populations of Sub-Sahara African descent (henceforth, African descent) in comparison with the European populations in Europe.

Results

Compared with European populations, populations of African descent have an increased risk of stroke, whereas CHD is less common. They also have higher rates of hypertension and diabetes than European populations. Obesity is highly prevalent, but smoking rate is lower among African descent women. Older people of African descent have more favourable lipid profile and dietary habits than their European counterparts. Alcohol consumption is less common among populations of African descent. The rate of physical activity differs between European countries. Dutch African-Suriname men and women are less physically active than the White-Dutch whereas British African women are more physically active than women in the general population. Literature on psychosocial stress shows inconsistent results.

Conclusion

Hypertension and diabetes are highly prevalent among African populations, which may explain their high rate of stroke in Europe. The relatively low rate of CHD may be explained by the low rates of other risk factors including a more favourable lipid profile and the low prevalence of smoking. The risk factors are changing, and on the whole, getting worse especially among African women. Cohort studies and clinical trials are therefore needed among these groups to determine the relative contribution of vascular risk factors, and to help guide the prevention efforts. There is a clear need for intervention studies among these populations in Europe.