Obese African-American (AA) women are at high risk of hypertension (HT) and cardiovascular disease (CVD). Flow-mediated dilation (FMD) and arterial augmentation index (AI) are measures of endothelial function and arterial stiffness. Whether endothelial function and arterial stiffness predict risk of HT or CVD in obese African-American women with, versus without, parental histories of HT and whether aerobic exercise is an effective countermeasure remain unclear. The capacity for FMD is partly heritable. Therefore, we tested the hypotheses that less FMD and greater AI may be found in normotensive-obese, young-adult (18-26 year-old) AA women with hypertensive parents (n=10) than in a matched control group with normotensive parents (n=10) and that a single bout of aerobic exercise improves both endothelial function and arterial stiffness, with less improvement in the women with hypertensive parents. We studied each subject while at rest, 20 min before and 20 min after, 30 min of aerobic exercise. The exercise-induced changes and parental hypertension-related differences in AI were not significant. The exercise increased FMD in both of the groups with no significant difference in magnitude between the women with hypertensive and normotensive parents. FMD was significantly less in the women with hypertensive parents than in the women with normotensive parents after, but not before, the exercise (mean ±95% confidence interval of 11.3 ± 4.9% vs. 15.6 ± 4.9%, P=0.05). These findings suggest that a 30-min bout of aerobic exercise may improve FMD and unmask endothelial dysfunction in normotensive-obese, young-adult AA women with parental histories of HT. Future studies should determine whether regular aerobic exercise protects obese AA women from the endothelial dysfunction associated with diabetes and prevents CVD in this high-risk population.
The ontogeny of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] production and metabolic clearance rates (PR and MCR, respectively) was determined in chronically catheterized fetal (postconceptional age of 127 days; term = 145 days), neonatal (10 +/- 1 and again at 24 +/- 1 days postnatal), and adult (3 yr of age) sheep. Plasma concentrations of 1,25(OH)2D3 were more than twofold higher in fetuses than in adults and were increased by 78% during the 1st 24 days postnatally. In contrast, compared with values in fetuses, the MCR of 1,25(OH)2D3 was reduced by 40% in 10-day-old neonates and by 58% in 24-day neonates, although 24-day neonatal values were still 75% higher than adult values. In contrast, the PR of 1,25(OH)2D3 did not demonstrate an ontogenic change during development and remained at all times approximately ninefold the adult value. The finding, by regression analysis of an inverse relationship between the MCR and the plasma concentration of 1,25(OH)2D3, is interpreted to suggest that increased plasma concentrations are the result of a reduced MCR. We conclude that increases in plasma concentrations of 1,25(OH)2D3 in the perinatal period can occur by a mechanism that is independent of enhanced endogenous synthesis, namely a reduction in the MCR of the hormone.
Previous studies suggest that passive motion exercise (PME) may be useful for overcoming exercise limitations associated with a sedentary lifestyle, orthopedic disorders, and various other debilitating conditions. Negative mood response is one of the factors that limit a person’s ability to exercise. Therefore, this study tests the hypothesis that the mood response associated with PME is not different than the mood response associated with active motion exercise (AME). Eight women and seven men participated in the study and were administrated the Profile of Mood States (POMS) during modes of PME and AME in a randomized order. Outcome of the POMS consisted of the total mood disturbance score [(feelings of tension + depression + fatigue + anger + confusion) − vigor]. ANOVA was used to determine significance of differences in total mood disturbance, oxygen uptake (V.O2), and middle cerebral blood flow velocity (MCAv) at baseline and immediately after 30-minute conditions of PME and AME. Postexercise total mood disturbance score was significantly decreased for both conditions (PME baseline 29.2 ± 5.2 vs. postexercise 16.4 ± 6.8, P<0.05) and AME baseline 22.4 ± 4.4 vs. postexercise 13.1 ± 5.2, P<0.05). These senses of changes in feelings were associated with significant physiological increases in V.O2 and MCAv during both PME and AME (P<0.05). These results demonstrate that physiological and mood responses to passive and active motion cycling exercise are not different. Future studies should determine whether passive motion cycling exercise is a useful preventive medicine strategy for overcoming various disease-related exercise limitations and counteracting the adverse effects of sedentary lifestyles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.