Multiple independent genetic factors at NOS1AP modulate the QT interval in a multi-ethnic population.

Extremes of electrocardiographic QT interval are associated with increased risk for sudden cardiac death (SCD); thus, identification and characterization of genetic variants that modulate QT interval may elucidate the underlying etiology of SCD. Previous studies have revealed an association between a common genetic variant in NOS1AP and QT interval in populations of European ancestry, but this finding has not been extended to other ethnic populations. We sought to characterize the effects of NOS1AP genetic variants on QT interval in the multi-ethnic population-based Dallas Heart Study (DHS, n = 3,072). The SNP most strongly associated with QT interval in previous samples of European ancestry, rs16847548, was the most strongly associated in White (P = 0.005) and Black (P = 3.6 x 10(-5)) participants, with the same direction of effect in Hispanics (P = 0.17), and further showed a significant SNP x sex-interaction (P = 0.03). A second SNP, rs16856785, uncorrelated with rs16847548, was also associated with QT interval in Blacks (P = 0.01), with qualitatively similar results in Whites and Hispanics. In a previously genotyped cohort of 14,107 White individuals drawn from the combined Atherosclerotic Risk in Communities (ARIC) and Cardiovascular Health Study (CHS) cohorts, we validated both the second locus at rs16856785 (P = 7.63 x 10(-8)), as well as the sex-interaction with rs16847548 (P = 8.68 x 10(-6)). These data extend the association of genetic variants in NOS1AP with QT interval to a Black population, with similar trends, though not statistically significant at P<0.05, in Hispanics. In addition, we identify a strong sex-interaction and the presence of a second independent site within NOS1AP associated with the QT interval. These results highlight the consistent and complex role of NOS1AP genetic variants in modulating QT interval.

Characteristics of a spina bifida population including North American Caucasian and Hispanic individuals.

BACKGROUND: Meningomyelocele (MM) is a common human birth defect. MM is a disorder of neural development caused by contributions from genes and environmental factors that result in the NTD and lead to a spectrum of physical and neurocognitive phenotypes. METHODS: A multidisciplinary approach has been taken to develop a comprehensive understanding of MM through collaborative efforts from investigators specializing in genetics, development, brain imaging, and neurocognitive outcome. Patients have been recruited from five different sites: Houston and the Texas-Mexico border area; Toronto, Canada; Los Angeles, California; and Lexington, Kentucky. Genetic risk factors for MM have been assessed by genotyping and association testing using the transmission disequilibrium test. RESULTS: A total of 509 affected child/parent trios and 309 affected child/parent duos have been enrolled to date for genetic association studies. Subsets of the patients have also been enrolled for studies assessing development, brain imaging, and neurocognitive outcomes. The study recruited two major ethnic groups, with 45.9% Hispanics of Mexican descent and 36.2% North American Caucasians of European descent. The remaining patients are African-American, South and Central American, Native American, and Asian. Studies of this group of patients have already discovered distinct corpus callosum morphology and neurocognitive deficits that associate with MM. We have identified maternal MTHFR 667T allele as a risk factor for MM. In addition, we also found that several genes for glucose transport and metabolism are potential risk factors for MM. CONCLUSIONS: The enrolled patient population provides a valuable resource for elucidating the disease characteristics and mechanisms for MM development.

South Asian immigrant cardiovascular risk assessment in Houston, Texas 2005

Background. Heart disease is the leading cause of death and stroke is the third leading cause of deaths for all people in the United States. South Asian Americans have a higher risk of developing cardiovascular diseases than native United States residents. ^ Purpose. This study examines the cardiovascular risk factors in the South Asian immigrant community residing in Southwest Houston. This study also explores the level of health insurance available to the South Asian in Houston. ^ Methods. One hundred sixty-two South Asian patients aged 18 years and older received cardiovascular screening from January 1 st, 2005 to March 31st, 2005 at Ibn Sina Community Clinic; blood pressure was measured twice in both arms after resting five minutes. Height and weight were also recorded. Demographic data was collected through personal interview (questionnaire) and blood samples were drawn to collect laboratory data. ^ Results. There were 162 eligible South Asian patients, among whom 127 (78%) participated in the study. There were no significant differences between the responders and the non-responders in terms of demographics and clinical characteristics. Laboratory data revealed a mean total cholesterol of 201 ± 34 mg/dl, 54 percent had high total cholesterol above 200 mg/dl. The mean fasting glucose was 108 ± 43 mg/dl, and body mass index (BMI) was 28 ± 4 kg/m2. The prevalence of hypertension was comparable with the general U.S. population; 38 percent of the South Asian males and 29 percent of females had hypertension. The prevalence of diabetes was also compared; 21 percent of SA males (3% for white American males) and 7 percent of SA females (2% for white American females) were found to have undiagnosed diabetes. Of the sample 12 percent had both hypertension and diabetes; 21 percent had both hypertension and high BMI, and 19 percent had hypertension and high total cholesterol levels. ^ Conclusion. The present study shows that the South Asians in this sample are at greater risk of developing cardiovascular diseases than other ethnicities. The high prevalence of hypertension, type 2 diabetes, higher total cholesterol levels with overweight and obesity, and less leisure time physical activity are important cardiovascular risk factors for South Asians population. ^

Prevalence of HIV risk-related behaviors among undocumented Central American immigrant women in Houston, Texas, 2010

The primary aim of this dissertation research is to provide epidemiological data on HIV risk-related behaviors among undocumented Central American immigrant women living in Houston, Texas. Between February and May 2010, we used respondent driven sampling (RDS) to recruit 230 Guatemalan, Honduran, and El Salvadoran women, ages 18 to 50 years, living in Houston without a valid United States visa or residency papers. RDS is a probability-based sampling method that utilizes social networks to access members of hidden populations that lack a sampling frame. Participants completed an interview regarding their demographics, access to and utilization of healthcare services, HIV testing, and sexual behaviors. Data from this study were used 1) to describe the prevalence of sexual HIV risk-related behaviors among undocumented Central American immigrant women, comparing those who recently immigrated to the U.S. (within the past five years) to those with more established residency (of over five years); 2) to describe the prevalence of lifetime HIV testing and evaluate its associated factors in this target population; and 3) to describe the effectiveness of RDS to access members of this target population. ^ As described in Paper 1, there was a generally low prevalence of individual HIV risk-related behaviors (i.e., multiple, concurrent, convenience, and casual sexual partnerships) among the undocumented Central American immigrant women in this study. However, there was evidence of HIV risk due to unprotected sex with male partners who have concurrent sexual partnerships. We identified recent immigrants as the subpopulation at greatest risk, as they were significantly more likely than established immigrants to have multiple and/or concurrent sexual partners. As described in Paper 2, the lifetime prevalence of HIV testing was almost 70%. After adjusting for age, number of years living in the U.S., income security, and resource barriers, lifetime HIV testing was significantly associated with being from Honduras, having more than a sixth grade education, having a regular healthcare provider, and having knowledge of available healthcare resources. Finally, as described in Paper 3, RDS was an effective method for obtaining a diverse sample of Central American immigrant women in Houston. ^ This project is the first to use RDS to conduct an HIV behavioral survey among undocumented Central American immigrant women. Our results will inform the design of future research studies and the implementation of HIV prevention activities among undocumented Central American immigrants in the U.S.^

The prevalence of periodontal disease in Mexican American vs European American elderly in three distinct socio-economic communities in San Antonio, Texas

Purpose of the Study: This study evaluated the prevalence of periodontal disease between Mexican American elderly and European American elderly residing in three socio-economically distinct neighborhoods in San Antonio, Texas. ^ Study Group: Subjects for the original protocol were participants of the Oral Health: San Antonio Longitudinal Study of Aging (OH: SALSA), which began with National Institutes of Health (NIH) funding in 1993 (M.J. Saunders, PI). The cohort in the study was the individuals who had been enrolled in Phases I and III of the San Antonio Heart Study (SAHS). This SAHS/SALSA sample is a community-based probability sample of Mexican American and European American residents from three socio-economically distinct San Antonio neighborhoods: low-income barrio, middle-income transitional, and upper-income suburban. The OH: SALSA cohort was established between July 1993 and May 1998 by sampling two subsets of the San Antonio Heart Study (SAHS) cohort. These subsets included the San Antonio Longitudinal Study of Aging (SALSA) cohort, comprised of the oldest members of the SAHS (age 65+ yrs. old), and a younger set of controls (age 35-64 yrs. old) sampled from the remainder of the SAHS cohort. ^ Methods: The study used simple descriptive statistics to describe the sociodemographic characteristics and periodontal disease indicators of the OH: SALSA participants. Means and standard deviations were used to summarize continuous measures. Proportions were used to summarize categorical measures. Simple m x n chi square statistics was used to compare ethnic differences. A multivariable ordered logit regression was used to estimate the prevalence of periodontal disease and test ethnic group and neighborhood differences in the prevalence of periodontal disease. A multivariable model adjustment for socio-economic status (income and education), gender, and age (treated as confounders) was applied. ^ Summary: In the unadjusted and adjusted model, Mexican American elderly demonstrated the greatest prevalence for periodontitis, p < 0.05. Mexican American elderly in barrio neighborhoods demonstrated the greatest prevalence for severe periodontitis, with unadjusted prevalence rates of 31.7%, 22.3%, and 22.4% for Mexican American elderly barrio, transitional, and suburban neighborhoods, respectively. Also, Mexican American elderly had adjusted prevalence rates of 29.4%, 23.7%, and 20.4% for barrio, transitional, and suburban neighborhoods, respectively. ^ Conclusion: This study indicates that the prevalence of periodontal disease is an important oral health issue among the Mexican American elderly. The results suggest that the socioeconomic status of the residential neighborhood increased the risk for severe periodontal disease among the Mexican American elderly when compared to European American elderly. A viable approach to recognizing oral health disparities in our growing population of Mexican American elderly is imperative for the provision of special care programs that will help increase the quality of care in this minority population.^