Social Determinants Hypertension: A Review of Studies from Jamaica Trevor S Ferguson, MBBS, DM, MSc, FACP Senior Lecturer (Epidemiology), Caribbean Institute for Health Research, UWI Honorary Consultant (General Internal Medicine), UHWI Caribbean Institute of Nephrology 11th Annual International Conference on Nephrology and Hypertension January 18 & 19, 2019

Introduction Social factors are now recognized as important contributors to the burden of HTN and elevated BP Over the last 2 -3 decades, a large body of literature has emerged, documenting associations between HTN and several social factors

Globally HTN Prevalence Highest in Low Income Countries Strong social gradient in global burden of HTN 28% in low income countries to 18% in high income countries Gradient similar in men and women Data source: WHO Global Health Observatory data repository

Social Factors and HTN in Epidemiological Studies Social factors associated with HTN include: Individual level socioeconomic status (SES) – income, education, and occupation Household SES – household assets (e.g. television, internet, motor vehicles, …) Neighbourhood SES - physical and social characteristics of communities in which persons live Levels of psychosocial stress

Socioeconomic status and hypertension Leng et al. – Meta-analysis Recent meta-analysis of 51 studies published in 2015 Overall increased risk of HTN with lower SES Income - pooled OR 1.19, 95% CI 0.96–1.48 1 Occupation - pooled OR 1.31, 95% CI 1.04–1.64 1 Education - pooled OR 2.02, 95% CI 1.55–2.63 1 Associations were significant in high-income countries Association more consistent among women 1Pooled OR – lowest vs highest SES groups Source: Leng et al. Socioeconomic status and hypertension: a meta-analysis; J Hypertens 33:221–229. DOI:10.1097/HJH.0000000000000428

Socioeconomic status and blood pressure Colhoun – Narrative Review Colhoun et al., 1998 – narrative review; 57 studies from developed countries, 13 studies from developing countries Overall, lower SES was associated with higher mean blood pressures in developed countries Stronger & more consistent association in women vs. men Substantial component of the SES gradient was explained by differences in BMI In developing countries, direction of association was often different - higher SES being associated with higher BP Journal of Human Hypertension volume 12, pages 91–110 (1998)

Potential pathways by which socioeconomic status may be associated with blood pressure Source: Colhoun et al. Journal of Human Hypertension (1998) 12, 91–110

Hypertension and socioeconomic status Grotto – Narrative Review, 2008 Reported associations between hypertension and several social determinants - occupation, education, urban or rural dwelling, among others In general, they found that lower SES was associated with higher BP Current Opinion in Cardiology: July 2008 - Volume 23 - Issue 4 - p 335–339; doi: 10.1097/HCO.0b013e3283021c70

Hypertension and socioeconomic status Grotto – Narrative Review, 2008 Suggested explanations for differences: Better awareness of HTN prevention and controls measures among higher SES groups Low birth weight and higher job strain among lower SES groups Current Opinion in Cardiology: July 2008 - Volume 23 - Issue 4 - p 335–339; doi: 10.1097/HCO.0b013e3283021c70

Hypertension and SES in Jamaica

SBP Spanish Town Cohort (1993-1998) Mendez and colleagues Mean SBP highest in men and women with higher income and lowest among those in the middle income groups J-shaped pattern in association between income and SBP Similar pattern for DBP DBP

SBP For education, distribution of mean SBP and DBP also J-shaped among men Among women those with college/university level education had lowest SBP Again, patterns for DBP were similar DBP

EDUCATION INCOME INCOME: Prevalence of hypertension showed similar J-shaped distribution by income category for both men and women and for education categories among men EDUCATION: For women prevalence of hypertension was again lowest among those with college/university education

Education and HTN Spanish Town Cohort vs. Jackson Heart Study

Education and HTN Spanish Town Cohort vs. Jackson Heart Study Prevalence of hypertension - adjusted for age and BMI STC - prevalence highest among men with better education and among women with lower education JHS – prevalence highest among those with less education for both men and women; statistically significant for women only

Educational Health Disparities in HTN from JHLS-II

Age-adjusted prevalence of hypertension among men in JHLS-II Prevalence of hypertension now lowest among those with post-secondary education Reversal of pattern seen in Spanish Town Cohort; possibly due to epidemiological transition – pattern now more similar to that seen in developed countries Differences were not statistically significant Ferguson et at. Frontiers in Cardiovasculat Medicine 2017; doi: 10.3389/fcvm.2017.00028

Age-specific prevalence of HTN by education category women for in JHLS-II Significant interaction by age In general, prevalence lower among those with better education; Highest prevalence varied by age-group – highest among persons with lowest education in the 40-59 age group, but among those with full secondary education for the 60-74 age group and those with junior secondary education among those 25-39 years

Early life SES and blood pressure Jamaica 1986 Birth Cohort Early life SES and blood pressure

Males whose mothers had lower occupation classification had higher SBP Maternal Occupation at time of birth and SBP at 18-20 years old in multi-level regression models in 1986 Birth Cohort Study Variable Males Females    (95% CI) Maternal occupation Highly Skilled/Skilled Reference Semi-skilled/Unskilled 3.67 (0.49, 6.85)* 1.81 (-0.65, 4.29) Unemployed 4.81 (1.99, 7.64)** 2.10 (-0.37, 4.39) Housewife 3.37 (0.64, 6.11)* 1.85 (-0.57, 4.26) * p<0.05; ** p<0.01; *** p<0.001 In the fully adjusted model, one standard deviation increase in BWT was associated with 1.16 mmHg reduction in SBP among men (95%CI 2.15 to 0.17; p=0.021) and 1.34 mmHg reduction in SBP among women (95%CI 2.21 to 0.47; p=0.003). Participants whose mothers had lower SEC had higher SBP compared to those with mothers of high SEC (β, 3.4-4.8 mmHg for men, p<0.05 for all SEC categories, and 1.8-2.1 for women, p>0.05) Males whose mothers had lower occupation classification had higher SBP Association for females not statistically significant Ferguson et al. (2015) Birth weight and maternal socioeconomic circumstances were inversely related to systolic blood pressure among Afro-Caribbean young adults. J Clin Epidemiol. 2015 Feb 12. doi: 10.1016/j.jclinepi.2015.01.026.

Predicted systolic blood pressure by birth weight and mothers occupation category Male Female These figures show predicted SBP by maternal occupation at birth and birth weight z-scores, based on the final SBP model. Among men, there was a consistent gradient in SBP by maternal occupation and birth weight SD distribution, with SBP consistently highest for those whose mothers were unemployed and lowest for those whose mothers were in a highly skilled/skilled occupation. Among women, the trend was less delineated by maternal occupation. SBP was lowest among whose mothers were in a highly skilled/skilled occupation category but there was little difference in SBP between the other groups. skilled/highly skilled semi-skilled/unskilled unemployed housewife Ferguson et al. (2015) Birth weight and maternal socioeconomic circumstances were inversely related to systolic blood pressure among Afro-Caribbean young adults. J Clin Epidemiol. 2015 Feb 12. doi: 10.1016/j.jclinepi.2015.01.026.

Household SES and blood pressure at age 18-20 years Jamaica 1986 Birth Cohort Household SES and blood pressure at age 18-20 years

Factors associated with elevated BP or HTN among males and females in multivariable logistic regression models Variable Odds Ratio 95% CI P-Value Household possessions   High (15-17 items) 1.0 - Moderate (10-14 items) 0.62 0.33 – 1.18 0.147 Low (0-9 items) 1.21 0.59 – 2.45 0.604 Variable Odds Ratio 95% CI P-Value Household possessions   High (15-17 items) 1.0 - Moderate (10-14 items) 4.63 1.31 – 16.4 0.017 Low (0-9 items) 2.61 0.70 – 9.77 0.154 Among females those from households with fewer household assets were more likely to have elevated blood pressure or hypertension Association among males not statistically significant

Neighbourhood SES and BP – Pooled Analysis 1986 Birth Cohort, JHLS-II, JYRRBS Sa1106

Methods A pooled analysis was conducted using data from 2 national surveys and a birth cohort; combined sample size = 2556 Data on neighbourhood SES were obtained from the Mona GeoInformatics Institute Community characteristics included poverty, unemployment, dependency ratio, population density, house size, and proportion with tertiary education Principal component analysis was used to derive community SES scores, then categorized into tertiles

Summary statistics for participant characteristics 1986 Birth Cohort n = 893 Youth Risk Survey n = 1200 JHLS-II n = 463 Age (years) *** 18.8 ± 0.44 16.5 ± 0.8 19.8 ± 1.9 BMI (kg/m2) *** 23.0 ± 3.0 22.3 ± 2.3 24.0 ± 5.4 SBP (mmHg) *** 110.4 ± 7.0 111.4 ± 7.1 113.9 ± 10.4 DBP (mmHg) *** 67.9 ± 5.9 70.4 ± 7.1 71.8 ± 7.8 Elevated BP / HTN *** 188 (21.1) 388 (32.3) 173 (37.4) *** P<0.001 Values are mean ± SD except for elevated BP/HTN which is number and percent Age range: 1986 Birth Cohort 18-20 years; Youth Risk 15-19 years; JHLS-II 15-24 years JHLS-II = Jamaica Health and Lifestyle Survey 2007-2008; BMI = body mass index; SBP = systolic blood pressure; DBP = diastolic blood pressure; BP = blood pressure; HTN = hypertension

Map of communities included in the analysis by study and socioeconomic status tertiles Communities coloured red represent those in the lowest socioeconomic status (SES) tertile, those coloured yellow are in the middle SES tertile and those coloured blue are in the upper SES tertile. Most upper tertile communities are from the urban areas in the parishes of Kingston, St Andrew and St Catherine.

Final multivariable models1 for association between SBP for individual and community characteristics Males -coefficient (95% CI) Females PCA SES Component 1   Lower Tertile Reference category Middle Tertile -2.41 (-4.05, -0.77) ** -1.43 (-2.91, 0.03) Upper Tertile -4.08 (-6.04, -2.11) *** -1.03 (-2.86, 0.80) PCA SES Component 2 0.11 (-1.73, 1.95) 2.59 (0.95, 4.21) ** 0.25 (-1.54, 2.05) 1.51 (-0.19, 3.21) Household Possessions -1.29 (-2.78, 0.20) -0.56 (-1.67, 0.55) -0.88 (-2.47, 0.72) -1.44 (-2.68, -0.19) * *p<0.05; **p<0.01; ***p<0.001 1Separate models computed for males and females PCA-SES1 – higher value = higher SES; Males with higher SES had lower SBP PCA-SES2 – higher value = lower SES; Females with lower SES had higher SBP

Spike plots with LOWESS mean-smoothing curve for predicted mean systolic blood pressure for each community ranked by PCA derived socioeconomic status (PCA SES component 1) suggest lower SBP with higher community SES PCA = principal component analysis; A SBP = systolic blood pressure; SES = socioeconomic status LOWESS = Locally Weighted Scatterplot Smoothing

Conclusion Higher neighbourhood SES was inversely associated with BP among Jamaican youth There were some significant gender differences in these associations Findings from this study suggest that the neighbourhood context may be an important factor in the aetiology of hypertension Interventions to address this growing public health challenges should include evaluation of neighbourhoods Key References 1. Arcaya MC, Tucker-Seeley RD, Kim R, Schnake-Mahl A, So M, Subramanian SV. Research on neighborhood effects on health in the United States: A systematic review of study characteristics. Social science & medicine (1982). 2016;168:16-29. 2. Diez Roux AV. Neighborhoods and Health: What Do We Know? What Should We Do? American journal of public health. 2016;106(3):430-1. 3. Diez Roux AV, Mair C. Neighborhoods and health. Annals of the New York Academy of Sciences. 2010;1186(1):125-45.

Summary and Implications Consistent evidence for a relationship between hypertension and SES Findings vary by sex and SES measure used More research needed to clarify associations and work out mechanisms Given general relationship between poor social circumstances and health, interventions to improve living conditions and social status are needed.

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