Trevor S. Ferguson

Prevalence of prehypertension and its relationship to risk factors for cardiovascular disease in Jamaica: Analysis from a cross-sectional survey

BackgroundRecent studies have documented an increased risk of cardiovascular disease (CVD) in persons with systolic blood pressures of 120–139 mmHg and/or diastolic blood pressures of 80–89 mmHg, classified as prehypertension in the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. In this paper we estimate the prevalence of prehypertension in Jamaica and evaluate the relationship between prehypertension and other risk factors for CVD.MethodsThe study used data from participants in the Jamaica Lifestyle Survey conducted from 2000–2001. A sample of 2012 persons, 15–74 years old, completed an interviewer administered questionnaire and had anthropometric and blood pressure measurements performed by trained observers using standardized procedures. Fasting glucose and total cholesterol were measured using a capillary blood sample. Analysis yielded crude, and sex-specific prevalence estimates for prehypertension and other CVD risk factors. Odds ratios for associations of prehypertension with CVD risk factors were obtained using logistic regression.ResultsThe prevalence of prehypertension among Jamaicans was 30% (95% confidence interval [CI] 27%–33%). Prehypertension was more common in males, 35% (CI 31%–39%), than females, 25% (CI 22%–28%). Almost 46% of participants were overweight; 19.7% were obese; 14.6% had hypercholesterolemia; 7.2% had diabetes mellitus and 17.8% smoked cigarettes. With the exception of cigarette smoking and low physical activity, all the CVD risk factors had significantly higher prevalence in the prehypertensive and hypertensive groups (p for trend < 0.001) compared to the normotensive group. Odds of obesity, overweight, high cholesterol and increased waist circumference were significantly higher among younger prehypertensive participants (15–44 years-old) when compared to normotensive young participants, but not among those 45–74 years-old. Among men, being prehypertensive increased the odds of having >/=3 CVD risk factors versus no risk factors almost three-fold (odds ratio [OR] 2.8 [CI 1.1–7.2]) while among women the odds of >/=3 CVD risk factors was increased two-fold (OR 2.0 [CI 1.3–3.8])ConclusionPrehypertension occurs in 30% of Jamaicans and is associated with increased prevalence of other CVD risk factors. Health-care providers should recognize the increased CVD risk of prehypertension and should seek to identify and treat modifiable risk factors in these persons.

Prevalence of the metabolic syndrome and its components in relation to socioeconomic status among Jamaican young adults: a cross-sectional study.

BackgroundThe metabolic syndrome has a high prevalence in many countries and has been associated with socioeconomic status (SES). This study aimed to estimate the prevalence of the metabolic syndrome and its components among Jamaican young adults and evaluate its association with parental SES.MethodsA subset of the participants from the 1986 Jamaica Birth Cohort was evaluated at ages 18-20 years between 2005 and 2007. Trained research nurses obtained blood pressure and anthropometric measurements and collected a venous blood sample for measurement of lipids and glucose. Prevalence of the metabolic syndrome and its components were estimated using the 2009 Consensus Criteria from the International Diabetes Federation, National Heart Lung and Blood Institute, American Heart Association, World Heart Federation, International Atherosclerosis Society, and International Association for the Study of Obesity. SES was assessed by questionnaire using occupation of household head, highest education of parent/guardian, and housing tenure of parent/guardian. Analysis yielded means and proportions for metabolic syndrome variables and covariates. Associations with levels of SES variables were obtained using analysis of variance. Multivariable analysis was conducted using logistic regression models.ResultsData from 839 participants (378 males; 461 females) were analyzed. Prevalence of the metabolic syndrome was 1.2% (95% confidence interval [95%CI] 0.5%-1.9%). Prevalence was higher in females (1.7% vs. 0.5%). Prevalence of the components [male: female] were: central obesity, 16.0% [5.3:24.7]; elevated blood pressure, 6.7% [10.8:3.3]; elevated glucose, 1.2% [2.1:0.4]; low HDL, 46.8% [28.8:61.6]; high triglycerides, 0.6% [0.5:0.6]. There were no significant differences in the prevalence of the metabolic syndrome for any of the SES measures used possibly due to lack of statistical power. Prevalence of central obesity was inversely associated with occupation (highly skilled 12.4%, skilled 13.5%, semi-skilled/unskilled 21.8%, p = 0.013) and education (tertiary 12.5%, secondary 14.1%, primary/all-age 28.4%, p = 0.002). In sex-specific multivariate logistic regression adjusted for hip circumference, central obesity remained associated with occupation and education for women only.ConclusionPrevalence of the metabolic syndrome is low, but central obesity and low HDL are present in 16% and 47% of Jamaican youth, respectively. Central obesity is inversely associated with occupation and education in females.

A continuum of admixture in the Western Hemisphere revealed by the African Diaspora genome

The African Diaspora in the Western Hemisphere represents one of the largest forced migrations in history and had a profound impact on genetic diversity in modern populations. To date, the fine-scale population structure of descendants of the African Diaspora remains largely uncharacterized. Here we present genetic variation from deeply sequenced genomes of 642 individuals from North and South American, Caribbean and West African populations, substantially increasing the lexicon of human genomic variation and suggesting much variation remains to be discovered in African-admixed populations in the Americas. We summarize genetic variation in these populations, quantifying the postcolonial sex-biased European gene flow across multiple regions. Moreover, we refine estimates on the burden of deleterious variants carried across populations and how this varies with African ancestry. Our data are an important resource for empowering disease mapping studies in African-admixed individuals and will facilitate gene discovery for diseases disproportionately affecting individuals of African ancestry.

Factors affecting study efficiency and item non-response in health surveys in developing countries: the Jamaica national healthy lifestyle survey

BackgroundHealth surveys provide important information on the burden and secular trends of risk factors and disease. Several factors including survey and item non-response can affect data quality. There are few reports on efficiency, validity and the impact of item non-response, from developing countries. This report examines factors associated with item non-response and study efficiency in a national health survey in a developing Caribbean island.MethodsA national sample of participants aged 15–74 years was selected in a multi-stage sampling design accounting for 4 health regions and 14 parishes using enumeration districts as primary sampling units. Means and proportions of the variables of interest were compared between various categories. Non-response was defined as failure to provide an analyzable response. Linear and logistic regression models accounting for sample design and post-stratification weighting were used to identify independent correlates of recruitment efficiency and item non-response.ResultsWe recruited 2012 15–74 year-olds (66.2% females) at a response rate of 87.6% with significant variation between regions (80.9% to 97.6%; p < 0.0001). Females outnumbered males in all parishes. The majority of subjects were recruited in a single visit, 39.1% required multiple visits varying significantly by region (27.0% to 49.8% [p < 0.0001]). Average interview time was 44.3 minutes with no variation between health regions, urban-rural residence, educational level, gender and SES; but increased significantly with older age category from 42.9 minutes in the youngest to 46.0 minutes in the oldest age category. Between 15.8% and 26.8% of persons did not provide responses for the number of sexual partners in the last year. Women and urban residents provided less data than their counterparts. Highest item non-response related to income at 30% with no gender difference but independently related to educational level, employment status, age group and health region. Characteristics of non-responders vary with types of questions.ConclusionInformative health surveys are possible in developing countries. While survey response rates may be satisfactory, item non-response was high in respect of income and sexual practice. In contrast to developed countries, non-response to questions on income is higher and has different correlates. These findings can inform future surveys.

Farming, reported pesticide use, and prostate cancer.

Prostate cancer is the leading cancer type diagnosed in American men and is the second leading cancer diagnosed in men worldwide. Although studies have been conducted to investigate the association between prostate cancer and exposure to pesticides and/or farming, the results have been inconsistent. We performed a meta-analysis to summarize the association of farming and prostate cancer. The PubMed database was searched to identify all published case–control studies that evaluated farming as an occupational exposure by questionnaire or interview and prostate cancer. Ten published and two unpublished studies were included in this analysis, yielding 3,978 cases and 7,393 controls. Prostate cancer cases were almost four times more likely to be farmers compared with controls with benign prostate hyperplasia (BPH; meta odds ratio [OR], crude = 3.83, 95% confidence interval [CI] = 1.96-7.48, Q-test p value = .352; two studies); similar results were obtained when non-BPH controls were considered, but with moderate heterogeneity between studies (meta OR crude = 1.38, 95% CI = 1.16-1.64, Q-test p value = .216, I2 = 31% [95% CI = 0-73]; five studies). Reported pesticide exposure was inversely associated with prostate cancer (meta OR crude = 0.68, 95% CI = 0.49-0.96, Q-test p value = .331; four studies), whereas no association with exposure to fertilizers was observed. Our findings confirm that farming is a risk factor for prostate cancer, but this increased risk may not be due to exposure to pesticides.

Diabetes mellitus in Jamaica: sex differences in burden, risk factors, awareness, treatment and control in a developing country

The objective of this study was to provide valid estimates of the burden of and risk factors for diabetes mellitus by sex in Jamaica, a predominantly Black, middle‐income and developing country.

Excess Cardiovascular Risk Burden in Jamaican Women Does Not Influence Predicted 10-Year CVD Risk Profiles of Jamaica Adults: An Analysis of the 2007/08 Jamaica Health and Lifestyle Survey.

Background Black Caribbean women have a higher burden of cardiovascular disease (CVD) risk factors than their male counterparts. Whether this results in a difference in incident cardiovascular events is unknown. The aim of this study was to estimate the 10 year World Health Organization/International Society for Hypertension (WHO/ISH) CVD risk score for Jamaica and explore the effect of sex as well as obesity, physical activity and socioeconomic status on these estimates. Methods and Findings Data from 40–74 year old participants in the 2007/08 Jamaica Health and Lifestyle Survey were used. Trained interviewers administered questionnaires and measured anthropometrics, blood pressure, fasting glucose and cholesterol. Education and occupation were used to assess socioeconomic status. The Americas B tables were used to estimate the WHO/ISH 10 year CVD risk scores for the population. Weighted prevalence estimates were calculated. Data from 1,432 (450 men, 982 women) participants were analysed, after excluding those with self-reported heart attack and stroke. The women had a higher prevalence of diabetes (19%W;12%M), hypertension (49%W;47%M), hypercholesterolemia (25%W;11%M), obesity (46%W;15%M) and physical inactivity (59%W;29%M). More men smoked (6%W;31%M). There was good agreement between the 10-year cardiovascular risk estimates whether or not cholesterol measurements were utilized for calculation (kappa –0.61). While 90% had a 10 year WHO/ISH CVD risk of less than 10%, approximately 2% of the population or 14,000 persons had a 10 year WHO/ISH CVD risk of ≥30%. As expected CVD risk increased with age but there was no sex difference in CVD risk distribution despite women having a greater risk factor burden. Women with low socioeconomic status had the most adverse CVD risk profile. Conclusion Despite women having a higher prevalence of CVD risk factors there was no sex difference in 10-year WHO/ISH CVD risk in Jamaican adults.

Laboratory-based and office-based risk scores and charts to predict 10-year risk of cardiovascular disease in 182 countries: a pooled analysis of prospective cohorts and health surveys.

BACKGROUND Worldwide implementation of risk-based cardiovascular disease (CVD) prevention requires risk prediction tools that are contemporarily recalibrated for the target country and can be used where laboratory measurements are unavailable. We present two cardiovascular risk scores, with and without laboratory-based measurements, and the corresponding risk charts for 182 countries to predict 10-year risk of fatal and non-fatal CVD in adults aged 40-74 years. METHODS Based on our previous laboratory-based prediction model (Globorisk), we used data from eight prospective studies to estimate coefficients of the risk equations using proportional hazard regressions. The laboratory-based risk score included age, sex, smoking, blood pressure, diabetes, and total cholesterol; in the non-laboratory (office-based) risk score, we replaced diabetes and total cholesterol with BMI. We recalibrated risk scores for each sex and age group in each country using country-specific mean risk factor levels and CVD rates. We used recalibrated risk scores and data from national surveys (using data from adults aged 40-64 years) to estimate the proportion of the population at different levels of CVD risk for ten countries from different world regions as examples of the information the risk scores provide; we applied a risk threshold for high risk of at least 10% for high-income countries (HICs) and at least 20% for low-income and middle-income countries (LMICs) on the basis of national and international guidelines for CVD prevention. We estimated the proportion of men and women who were similarly categorised as high risk or low risk by the two risk scores. FINDINGS Predicted risks for the same risk factor profile were generally lower in HICs than in LMICs, with the highest risks in countries in central and southeast Asia and eastern Europe, including China and Russia. In HICs, the proportion of people aged 40-64 years at high risk of CVD ranged from 1% for South Korean women to 42% for Czech men (using a ≥10% risk threshold), and in low-income countries ranged from 2% in Uganda (men and women) to 13% in Iranian men (using a ≥20% risk threshold). More than 80% of adults were similarly classified as low or high risk by the laboratory-based and office-based risk scores. However, the office-based model substantially underestimated the risk among patients with diabetes. INTERPRETATION Our risk charts provide risk assessment tools that are recalibrated for each country and make the estimation of CVD risk possible without using laboratory-based measurements. FUNDING National Institutes of Health.

Cohort Profile: The Jamaican 1986 Birth Cohort Study

Department of Community Health and Psychiatry, University of the West Indies, Mona, Jamaica, School of Graduate Studies and Research, University of the West Indies, Mona, Jamaica, Department of Child Health, University of the West Indies, Mona, Jamaica, Epidemiology Research Unit, Tropical Medicine Research Institute, University of the West Indies, Mona, Jamaica, Early Childhood Commission, Ministry of Education, Kingston, Jamaica and University Health Centre, University of the West Indies, Mona, Jamaica

Disparities in hypertension among black Caribbean populations: a scoping review by the U.S. Caribbean Alliance for Health Disparities Research Group (USCAHDR)

BackgroundDespite the large body of research on racial/ethnic disparities in health, there are limited data on health disparities in Caribbean-origin populations. This scoping review aimed to analyze and synthesize published and unpublished literature on the disparities in hypertension and its complications among Afro-Caribbean populations.MethodsA comprehensive protocol, including a thorough search strategy, was developed and used to identify potentially relevant studies. Identified studies were then screened for eligibility using pre-specified inclusion/exclusion criteria. An extraction form was developed to chart data and collate study characteristics including methods and main findings. Charted information was tagged by disparity indicators and thematic analysis performed. Disparity indicators evaluated include ethnicity, sex, socioeconomic status, disability, sexual orientation and geographic location. Gaps in the literature were identified and extrapolated into a gap map.ResultsA total of 455 hypertension related records, published between 1972 and 2012, were identified and screened. Twenty-one studies met inclusion criteria for detailed analysis. The majority of studies were conducted in the United Kingdom and utilized a cross-sectional study design. Overall, studies reported a higher prevalence of hypertension among Caribbean blacks compared to West African blacks and Caucasians. Hypertension and its related complications were highest in persons with low socioeconomic status. Gap analysis showed limited research data reporting hypertension incidence by sex and socioeconomic status. No literature was found on disability status or sexual orientation as it relates to hypertension. Prevalence and morbidity were the most frequently reported outcomes.ConclusionThe literature on hypertension health disparities in Caribbean origin populations is limited. Future research should address these knowledge gaps and develop approaches to reduce them.