M. Larissa Avilés-Santa

Prevalence of Major Cardiovascular Risk Factors and Cardiovascular Diseases Among Hispanic/Latino Individuals of Diverse Backgrounds in the United States

CONTEXT Major cardiovascular diseases (CVDs) are leading causes of mortality among US Hispanic and Latino individuals. Comprehensive data are limited regarding the prevalence of CVD risk factors in this population and relations of these traits to socioeconomic status (SES) and acculturation. OBJECTIVES To describe prevalence of major CVD risk factors and CVD (coronary heart disease [CHD] and stroke) among US Hispanic/Latino individuals of different backgrounds, examine relationships of SES and acculturation with CVD risk profiles and CVD, and assess cross-sectional associations of CVD risk factors with CVD. DESIGN, SETTING, AND PARTICIPANTS Multicenter, prospective, population-based Hispanic Community Health Study/Study of Latinos including individuals of Cuban (n = 2201), Dominican (n = 1400), Mexican (n = 6232), Puerto Rican (n = 2590), Central American (n = 1634), and South American backgrounds (n = 1022) aged 18 to 74 years. Analyses involved 15,079 participants with complete data enrolled between March 2008 and June 2011. MAIN OUTCOME MEASURES Adverse CVD risk factors defined using national guidelines for hypercholesterolemia, hypertension, obesity, diabetes, and smoking. Prevalence of CHD and stroke were ascertained from self-reported data. RESULTS Age-standardized prevalence of CVD risk factors varied by Hispanic/Latino background; obesity and current smoking rates were highest among Puerto Rican participants (for men, 40.9% and 34.7%; for women, 51.4% and 31.7%, respectively); hypercholesterolemia prevalence was highest among Central American men (54.9%) and Puerto Rican women (41.0%). Large proportions of participants (80% of men, 71% of women) had at least 1 risk factor. Age- and sex-adjusted prevalence of 3 or more risk factors was highest in Puerto Rican participants (25.0%) and significantly higher (P < .001) among participants with less education (16.1%), those who were US-born (18.5%), those who had lived in the United States 10 years or longer (15.7%), and those who preferred English (17.9%). Overall, self-reported CHD and stroke prevalence were low (4.2% and 2.0% in men; 2.4% and 1.2% in women, respectively). In multivariate-adjusted models, hypertension and smoking were directly associated with CHD in both sexes as were hypercholesterolemia and obesity in women and diabetes in men (odds ratios [ORs], 1.5-2.2). For stroke, associations were positive with hypertension in both sexes, diabetes in men, and smoking in women (ORs, 1.7-2.6). CONCLUSION Among US Hispanic/Latino adults of diverse backgrounds, a sizeable proportion of men and women had adverse major risk factors; prevalence of adverse CVD risk profiles was higher among participants with Puerto Rican background, lower SES, and higher levels of acculturation.

Prevalence of Diabetes Among Hispanics/Latinos From Diverse Backgrounds: The Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

OBJECTIVE We examine differences in prevalence of diabetes and rates of awareness and control among adults from diverse Hispanic/Latino backgrounds in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). RESEARCH DESIGN AND METHODS The HCHS/SOL, a prospective, multicenter, population-based study, enrolled from four U.S. metropolitan areas from 2008 to 2011 16,415 18–74-year-old people of Hispanic/Latino descent. Diabetes was defined by either fasting plasma glucose, impaired glucose tolerance 2 h after a glucose load, glycosylated hemoglobin (A1C), or documented use of hypoglycemic agents (scanned medications). RESULTS Diabetes prevalence varied from 10.2% in South Americans and 13.4% in Cubans to 17.7% in Central Americans, 18.0% in Dominicans and Puerto Ricans, and 18.3% in Mexicans (P < 0.0001). Prevalence related positively to age (P < 0.0001), BMI (P < 0.0001), and years living in the U.S. (P = 0.0010) but was negatively related to education (P = 0.0005) and household income (P = 0.0043). Rate of diabetes awareness was 58.7%, adequate glycemic control (A1C <7%, 53 mmol/mol) was 48.0%, and having health insurance among those with diabetes was 52.4%. CONCLUSIONS Present findings indicate a high prevalence of diabetes but considerable diversity as a function of Hispanic background. The low rates of diabetes awareness, diabetes control, and health insurance in conjunction with the negative associations between diabetes prevalence and both household income and education among Hispanics/Latinos in the U.S. have important implications for public health policies.

Prevalence of Hypertension, Awareness, Treatment, and Control in the Hispanic Community Health Study/Study of Latinos

BACKGROUND The prevention and control of hypertension is an essential component for reducing the burden of cardiovascular diseases. Here we describe the prevalence of hypertension in diverse Hispanic/Latino background groups and describe the proportion who are aware of their diagnosis, receiving treatment, and having their hypertension under control. METHODS The Hispanic Community Health Study/Study of Latinos is a longitudinal cohort study of 16,415 Hispanics/Latinos, aged 18-74 years from 4 US communities (Bronx, NY; Chicago, IL; Miami, FL; and San Diego, CA). At baseline (2008-2011) the study collected extensive measurements and completed questionnaires related to research on cardiovascular diseases. Hypertension was defined as measured blood pressure ≥140/90mm Hg or use of antihypertensive medication. RESULTS The total age-adjusted prevalence of hypertension in this study was 25.5% as compared with 27.4% in non-Hispanic whites in the National Health and Nutrition Examination Survey. Prevalence of hypertension increased with increasing age groups and was highest in Cuban, Puerto Rican, and Dominican background groups. The percent with hypertension who were aware, being treated with medication, or had their hypertension controlled was lower compared with US non-Hispanic whites with hypertension and it was lowest in those without health insurance. CONCLUSIONS These findings indicate a significant deficit in treatment and control of hypertension among Hispanics/Latinos residing in the United States, particularly those without health insurance. Given the relative ease of identification of hypertension and the availability of low-cost medications, enabling better access to diagnostic and treatment services should reduce the burden of hypertension in Hispanic populations.

Body Mass Index, Sex, and Cardiovascular Disease Risk Factors Among Hispanic/Latino Adults: Hispanic Community Health Study/Study of Latinos

Background All major Hispanic/Latino groups in the United States have a high prevalence of obesity, which is often severe. Little is known about cardiovascular disease (CVD) risk factors among those at very high levels of body mass index (BMI). Methods and Results Among US Hispanic men (N=6547) and women (N=9797), we described gradients across the range of BMI and age in CVD risk factors including hypertension, serum lipids, diabetes, and C‐reactive protein. Sex differences in CVD risk factor prevalences were determined at each level of BMI, after adjustment for age and other demographic and socioeconomic variables. Among those with class II or III obesity (BMI ≥35 kg/m2, 18% women and 12% men), prevalences of hypertension, diabetes, low high‐density lipoprotein cholesterol level, and high C‐reactive protein level approached or exceeded 40% during the fourth decade of life. While women had a higher prevalence of class III obesity (BMI ≥40 kg/m2) than did men (7% and 4%, respectively), within this highest BMI category there was a >50% greater relative prevalence of diabetes, hypertension, and hyperlipidemia in men versus women, while sex differences in prevalence of these CVD risk factors were ≈20% or less at other BMI levels. Conclusions Elevated BMI is common in Hispanic/Latino adults and is associated with a considerable excess of CVD risk factors. At the highest BMI levels, CVD risk factors often emerge in the earliest decades of adulthood and they affect men more often than women.

Local Ancestry Inference in a Large US-Based Hispanic/Latino Study: Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

We estimated local ancestry on the autosomes and X chromosome in a large US-based study of 12,793 Hispanic/Latino individuals using the RFMix method, and we compared different reference panels and approaches to local ancestry estimation on the X chromosome by means of Mendelian inconsistency rates as a proxy for accuracy. We developed a novel and straightforward approach to performing ancestry-specific PCA after finding artifactual behavior in the results from an existing approach. Using the ancestry-specific PCA, we found significant population structure within African, European, and Amerindian ancestries in the Hispanic/Latino individuals in our study. In the African ancestral component of the admixed individuals, individuals whose grandparents were from Central America clustered separately from individuals whose grandparents were from the Caribbean, and also from reference Yoruba and Mandenka West African individuals. In the European component, individuals whose grandparents were from Puerto Rico diverged partially from other background groups. In the Amerindian ancestral component, individuals clustered into multiple different groups depending on the grandparental country of origin. Therefore, local ancestry estimation provides further insight into the complex genetic structure of US Hispanic/Latino populations, which must be properly accounted for in genotype-phenotype association studies. It also provides a basis for admixture mapping and ancestry-specific allele frequency estimation, which are useful in the identification of risk factors for disease.

Challenges in Preventing Heart Disease in Hispanics: Early Lessons Learned from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

The challenge of preventing cardiovascular disease (CVD) in US Hispanics depends upon being able to understand and communicate about the diversity within this population in terms of environmental exposures, health behaviors, socio-cultural experiences and genetic background to CVD risk factor profiles and disease burdens. Recent publications from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) launched by the National Institutes of Health (NIH) have begun to accomplish this task. In this article we review some of the HCHS/SOL findings concerning cardiometabolic and other CVD risk factors and relate them to the need for increased access to health care and attention to lifestyle variables including nutrition. A major challenge that needs to be accomplished is to alert our lawmakers, public health officials, health care providers and the Hispanic population at large about how to lighten the CVD risk factor and disease burdens now carried by our Hispanic population.

Genetics of type 2 diabetes in U.S. Hispanic/Latino individuals: Results from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Few genome-wide association studies (GWAS) of type 2 diabetes (T2D) have been conducted in U.S. Hispanics/Latinos of diverse backgrounds who are disproportionately affected by diabetes. We conducted a GWAS in 2,499 T2D case subjects and 5,247 control subjects from six Hispanic/Latino background groups in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Our GWAS identified two known loci (TCF7L2 and KCNQ1) reaching genome-wide significance levels. Conditional analysis on known index single nucleotide polymorphisms (SNPs) indicated an additional independent signal at KCNQ1, represented by an African ancestry–specific variant, rs1049549 (odds ratio 1.49 [95% CI 1.27–1.75]). This association was consistent across Hispanic/Latino background groups and replicated in the MEta-analysis of type 2 DIabetes in African Americans (MEDIA) Consortium. Among 80 previously known index SNPs at T2D loci, 66 SNPs showed consistency with the reported direction of associations and 14 SNPs significantly generalized to the HCHS/SOL. A genetic risk score based on these 80 index SNPs was significantly associated with T2D (odds ratio 1.07 [1.06–1.09] per risk allele), with a stronger effect observed in nonobese than in obese individuals. Our study identified a novel independent signal suggesting an African ancestry–specific allele at KCNQ1 for T2D. Associations between previously identified loci and T2D were generally shown in a large cohort of U.S. Hispanics/Latinos.

Differences in hemoglobin a1cbetween hispanics/latinos and non-hispanic whites:An analysis of the hispanic community health study/study of latinos and the 2007-2012 national health and nutrition examination survey

OBJECTIVE To determine whether, after adjustment for glycemia and other selected covariates, hemoglobin A1c (HbA1c) differed among adults from six Hispanic/Latino heritage groups (Central American, Cuban, Dominican, Mexican, Puerto Rican, and South American) and between Hispanic/Latino and non-Hispanic white adults without self-reported diabetes. RESEARCH DESIGN AND METHODS We performed a cross-sectional analysis of data from 13,083 individuals without self-reported diabetes from six Hispanic/Latino heritage groups, enrolled from 2008 to 2011 in the Hispanic Community Health Study/Study of Latinos, and 2,242 non-Hispanic white adults enrolled during the 2007–2012 cycles of the National Health and Nutrition Examination Survey. We compared HbA1c levels among Hispanics/Latinos and between Hispanics/Latinos and non-Hispanic whites before and after adjustment for age, sex, fasting (FPG) and 2-h post–oral glucose tolerance test (2hPG) glucose, anthropometric measurements, and selected biochemical and hematologic variables and after stratification by diabetes status: unrecognized diabetes (FPG ≥7.1 mmol/L or 2hPG ≥11.2 mmol/L), prediabetes (FPG 5.6–7.0 mmol/L or 2hPG 7.8–11.1 mmol/L), and normal glucose tolerance (FPG <5.6 mmol/L and 2hPG <7.8 mmol/L). RESULTS Adjusted mean HbA1c differed significantly across all seven groups (P < 0.001). Non-Hispanic whites had significantly lower HbA1c (P < 0.05) than each individual Hispanic/Latino heritage group. Upon stratification by diabetes status, statistically significant differences (P < 0.001) in adjusted mean HbA1c persisted across all seven groups. CONCLUSIONS HbA1c differs among Hispanics/Latinos of diverse heritage groups and between non-Hispanic whites and Hispanics/Latinos after adjustment for glycemia and other covariates. The clinical significance of these differences is unknown.

Embedding clinical interventions into observational studies.

Novel approaches to observational studies and clinical trials could improve the cost-effectiveness and speed of translation of research. Hybrid designs that combine elements of clinical trials with observational registries or cohort studies should be considered as part of a long-term strategy to transform clinical trials and epidemiology, adapting to the opportunities of big data and the challenges of constrained budgets. Important considerations include study aims, timing, breadth and depth of the existing infrastructure that can be leveraged, participant burden, likely participation rate and available sample size in the cohort, required sample size for the trial, and investigator expertise. Community engagement and stakeholder (including study participants) support are essential for these efforts to succeed.

Factors Associated With Being Unaware of Having Diabetes

An improved understanding of which groups are more likely to be unaware of their diabetes may lead to more efficient screening, improved awareness, and overall better treatment for diabetes. Our objective was to investigate factors associated with being unaware of having diabetes among adults with diagnosed and undiagnosed diabetes. The 2011–2014 National Health and Nutrition Examination Survey (NHANES) is a stratified, multistage probability survey representative of the civilian, noninstitutionalized U.S. population (1). Data were collected during an in-home interview and a visit to a mobile examination center. We used data from 1,879 participants with either diagnosed or undiagnosed diabetes (based on a single measurement of A1C, fasting plasma glucose, or 2-h plasma glucose). Using logistic regression, we calculated odds ratios of being unaware of diabetes associated with age, race/ethnicity, sex, gestational diabetes mellitus (GDM), family history of diabetes, education, household income, smoking status, BMI, work-time activity, leisure-time activity, no health insurance, location of routine health …