Quantitative Genetics of Dehydroepiandrosterone Sulfate and Its Relation to Possible Cardiovascular Disease Risk Factors in Mexican Americans

Abstract

Dehydroepiandrosterone sulfate (DHEAS) is an adrenal steroid which has been inversely associated with development of atherosclerosis. We estimated heritability of serum DHEAS levels in 564 related Mexican Americans. We found a significant heritability for DHEAS (h² = 0.39, p < 0.001). Measures of alcohol consumption, reproductive status, body composition, and HDL₃ levels showed significant relationships with serum DHEAS levels. Sex and age were significantly associated with the mean, but not the genetic variance, of DHEAS levels. The results of this study demonstrate a significant genetic influence on steroid concentration and help to quantify the factors contributing to cardiovascular disease risk in Mexican Americans.

Hypertension and Stroke in Centenarians, Okinawa, Japan

“…In the Honolulu Heart Program, among Japanese-American men, hypertension continued to be significantly associated with an increased risk of hemorrhagic and thromboembolic stroke for all age groups up to 65–74 years, whereas a significant positive association was not found in the group from 75–93 years of age [14]. A prospective cohort study in the USA found that the relative risk of stroke in relation to hypertension decreased from 4.0 at the age of 50 years to unity at the age of 90 years [12]. On the other hand, another cohort study in Sweden showed that systolic but not diastolic blood pressure was significantly related to an increased risk of stroke in subjects aged 85–88 years [15].…”

“…Hypertension is a well-established risk factor for stroke in the middle-aged in both western and Asian countries [7,8,9,10,11]. Several studies in western countries indicated that the increased risk of stroke associated with hypertension weakened with advancing age [12,13,14,15]. The Framingham study demonstrated that systolic blood pressure was positively associated with the risk of stroke in a population ranging in age from 55 to 84 years at baseline [16].…”

“…In Japan, one cohort study showed a significant relationship between higher blood pressure and stroke in a general population of the elderly (aged 60 years or older) [18], whereas another cohort study showed that hypertension was not associated with the incidence of stroke in those 65 years or older in both sexes, irrespective of the quality of hypertension control [19]. Only a few prospective studies demonstrated the relationship between hypertension and stroke among those over 85 years of age in Western countries [12, 14, 15], but the findings were inconsistent. To our knowledge, there has been no study of the relationship between traditional risk factors such as hypertension and cigarette smoking and the development of stroke in subjects over the age of either 85 or 90 years in Asian countries.…”

Genomic Susceptibility Loci for Brain Atrophy in Hypertensive Sibships From the GENOA Study

“…Genetic and environmental correlations between the age-and sex-adjusted measures of brain anatomy and BPs were estimated by variance decomposition using maximum likelihood methods, 12 and phenotypic correlations between traits were calculated based on the genetic and environmental correlations. 13 Univariate and bivariate quantitative linkage analyses were performed using the Expectation Maximization Variance Components software program, 14 which uses a multivariate variance components approach that is an extension of the univariate approach described by Amos 15 and de Andrade et al 16 The multipoint identity-by-descent sharing among pairs of relatives were calculated using the SIM-WALK2 software program, which estimates multipoint identity-bydescent probabilities using an alternate Markov chain Monte Carlo algorithm that accommodates large sibships and provides estimates in agreement with deterministic methods. 17 Calculations were based on the pedigree relationships for 1413 of the original GENOARochester participants in whom measurements of genome-wide markers were available.…”

Genomic Susceptibility Loci for Brain Atrophy, Ventricular Volume, and Leukoaraiosis in Hypertensive Sibships

“…Adjustments for sex, age, and total intracranial volume (for brain atrophy and ventricular volume) or brain volume (for leukoaraiosis) were incorporated as co-variates in the genetic models. Genetic and environmental correlations between the adjusted (transformed) trait values were estimated by means of variance decomposition using maximum likelihood methods,13 and phenotypic correlations between traits were calculated on the basis of genetic and environmental correlations 14. Sibship structure was verified using the MERLIN software program 15.…”