Relationships among health factors and everyday problem solving in african americans.

This study examined whether measures of health status enhance the prediction of performance on everyday problem solving in adult African Americans. The sample consisted of 209 community-dwelling African American adults with a mean age of 66.82 years (SD=7.95). The following variables were included in the analysis: Everyday Problems Test (EPT), summary index of chronic illnesses (cardiovascular disease, hypertension, arthritis, stroke, and diabetes), self-rated health (current health, health in the past month, health compared with others, health compared with 5 years ago), and demographic information. Using hierarchical regression and follow-up communality analysis, the authors found that the number of chronic illnesses and self-rated health as compared with 5 years prior were significant and unique predictors of performance on the EPT but did not account for all of the demographic-related variance. The results indicate that health indices contribute to the variability in everyday cognition in this understudied population.

Genetic and environmental influences on forced expiratory volume in African Americans: the Carolina African-American Twin Study of Aging.

OBJECTIVES: Previous research found measures of pulmonary functioning to be strong predictors of cognitive functioning and mortality; however, there is considerable individual variability in performance on these measures. In the present analyses, the relative contribution of genetic and environmental influences to variability in average peak expiratory flow rate (APEFR) are examined in a sample of adult African-American twins. DESIGN: Birth records from North Carolina Register of Deeds offices were used to identify participants for the Carolina African-American Twin Study of Aging (CAATSA). Participants completed an in-person interview, which included measures of health status, cognition, and psychosocial measures. PARTICIPANTS: Data for the analysis come from 200 pairs of same sex twins (97 identical pairs, and 113 fraternal), with a mean age = 46.9 years (SD = 13.9), and with 39% of the sample being men. RESULTS: Phenotypic correlations between APEFR, age, gender, height, and cigarette consumption (measured in pack years), were all significant, ranging from -.63 to .43. After the affects of age, gender, height, and pack years were partialled out of APEFR, quantitative genetic analyses were conducted on the residuals. Model fitting demonstrated that variance in APEFR was accounted for by shared environmental effects (30%), genetic effects (14%), and non-shared environmental effects (56%). CONCLUSION: These results are discussed in relation to previous research conducted in other countries, and the importance of a complex systems approach to explanations of the impact of genes on central indices of health, such as APEFR.

Does intact pair status matter in the study of African American twins? The Carolina African American Twin Study of Aging.

In twin research, typically both members of a pair must participate. Survivorship of members of intact pairs compared to surviving members of nonintact twin pairs may reflect differences in psychosocial and health factors, and represent a potential selection bias relative to the general population. The purpose of the present study is to examine health, cognition, and well-being among members of African American intact twin pairs compared to individuals from nonintact twin pairs. Data from the Carolina African American Twin Study of Aging (CAATSA) were used for analyses. Subjects ranged in age from 25 to 89 years of age (mean = 59.78 years, SD = 12.84 years). CAATSA implements a 3-h protocol to collect data on demographics, health, cognition, and well-being. Data from one randomly selected member of each twin pair (N = 78) was compared to data from surviving members of nonintact twin pairs (N = 52). The results indicated significant differences on 11 of the 39 measures (i.e., age, education, forced expiratory volume, mean standing and sitting systolic and diastolic blood pressures, cognitive impairment score, alpha span, digit symbol, and logical memory). In each case, members of intact twin pairs performed better than surviving members of nonintact twin pairs. After controlling demographic variables, only blood pressures differed between the groups. It appears that using only pairs in research on older African American twins may represent a selection bias in estimating origins of individual variability in cognitive functioning and health but not psychological well-being.

Genetics and health disparities: fears and realities.

The development and testing of explanatory hypotheses about the underlying mechanisms that create health disparities among ethnic minorities will be crucial in identifying solutions for reducing the current differentials. This paper addresses the potential for using genetic information as a useful and necessary addition to approaches to measures of the "environment" in the study of the origins of health disparities. Approaches and theoretical perspectives on the integration of social science and genetic findings are discussed.

Genetic and environmental influences on blood pressure and pulse pressure among adult African Americans.

OBJECTIVE: The purpose of the present study was to identify sources of variability for systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP) in a sample of adult African-American twins. DESIGN: The classic twin design was employed to examine genetic and environmental sources of variance in the outcome measures of interest. PARTICIPANTS: Participants were 143 (71 MZ and 72 DZ) same-sex, intact twin pairs (mean age = 49.87 years; SD 13.62), who took part in the Carolina African-American Twin Study of Aging (CAATSA). MAIN OUTCOME MEASURES: Outcome measures of interest included SBP and DBP, and PP. RESULTS: For older twins, heritabilities were .52 for SBP, .36 for DBP, and .14 for PP. However, for younger twins, heritabilities were .44 for SBP, .27 for DBP, but no genetic influence on PP was observed. CONCLUSION: The results indicate that genetic factors are a significant source of variance in hemodynamic indices, and also suggest that, with advancing age, genetic factors play an increasing role in determining blood pressure and PP in this population.

The influence of social support and health on everyday problem solving in adult African Americans.

The purpose of this study was to examine the relationship between social support, health status, and everyday problem solving in African Americans. The sample included subjects recruited from Baltimore, Maryland. The sample consisted of 249 community-dwelling African American adults, 32% of whom were male, with a sample mean age of 67.8 years (SD = 8.47 years). Variables included: Everyday Problem Solving Test (EPT), social support given and received, physical limitations, counts of chronic illness, smoking, and demographic information. Using stepwise regression, age, education, physical limitations, and social support given were found to be significant predictors of performance on the EPT. Further analysis found support for a partial mediating effect of physical limitations on the relationship between social support and everyday problem solving. The results indicate that there may be differences in the cognitive abilities of those actively involved in social activities.

Sociocultural influences in genetic designs of aging: unexplored perspectives.

As the aging population continues to become more diverse, there is growing interest in understanding the similar and unique aspects of aging within and across people of different ethnic groups. The impact of culture on the sources of variation identified in quantitative genetic approaches has not been well discussed in the literature. The purpose of this paper is to review previous research pertinent to the cultural aspects of quantitative genetic approaches and methodologies, and provide conceptual and statistical approaches for advancing the science. To meet this objective, results from previously published studies as well as preliminary data analyses from the Carolina African American Twin Study of Aging will be presented. There are three themes to draw from the issues discussed in this paper: (1) avoiding genetic reductionism, (2) interpreting differential heritabilities, and (3) modeling cultural influences.

Genetic and environmental influences on body-fat measures among African-American twins.

OBJECTIVE: To investigate the genetic and environmental influences on body-fat measures including waist circumference (WC), waist-to-hip ratio (WHR), and body mass index (BMI) among African-American men and women. RESEARCH METHODS AND PROCEDURES: Measurements were taken as part of the Carolina African American Twin Study of Aging. This sample currently comprises 146 same-sex African-American twins with an average age of 50 years (range, 22 to 88 years). This analysis included 26 monozygotic and 29 dizygotic men and 45 monozygotic and 46 dizygotic women. Maximum likelihood quantitative genetic analysis was used. RESULTS: In men, additive genetic effects accounted for 77% of the variance in WC, 59% in WHR, and 89% in BMI. In women, additive genetic effects accounted for 76% of the variance in WC, 56% in WHR, and 73% in BMI. The remaining variance in both men and women was attributed to unique environmental effects (WC, 21%; WHR, 36%; BMI, 11% in men and WC, 22%; WHR, 38%; BMI, 27% in women) and age (WC, 2%; WHR, 5% in men and WC, 2%; WHR, 6% in women). When BMI was controlled in the analysis of WC and WHR, it accounted for a portion of the genetic and environmental variance in WHR and over one-half of the genetic and environmental variance in WC. DISCUSSION: There are both genetic and environmental influences on WC, WHR, and BMI, and independent of BMI, there are genetic and environmental effects on WC and WHR among both genders. The results from this African-American twin sample are similar to findings among white twin samples.