245 research outputs found
Hemodynamics and Vascular Hypertrophy in African Americans and Caucasians With High Blood Pressure
BACKGROUND: Hypertension in African Americans is characterized by greater systemic vascular resistance (SVR) compared with Caucasian Americans, but the responsible mechanisms are not known. The present study sought to determine if peripheral vascular hypertrophy is a potential mechanism contributing to elevated SVR in African Americans with high blood pressure (BP).
METHODS: In a biracial sample of 80 men and women between the ages of 25 and 45 years, with clinic BP in the range 130/85-160/99mm Hg, we assessed cardiac output and SVR, in addition to BP. Minimum forearm vascular resistance (MFVR), a marker of vascular hypertrophy, also was assessed.
RESULTS: SVR was elevated in African Americans compared with Caucasians (P < 0.001). Regression models indicated that age, body mass index, 24-hour diastolic BP, and ethnicity were significant predictors of SVR. There was also a significant interaction between ethnicity and MFVR in explaining SVR in the study sample. In particular, there was a significant positive association between MFVR and SVR among African Americans (P = 0.002), whereas the association was inverse and not statistically significant among Caucasians (P = 0.601).
CONCLUSION: Hypertrophy of the systemic microvasculature may contribute to the elevated SVR that is characteristic of the early stages of hypertension in African American compared with Caucasians
Effects of Exercise and Sertraline on Measures of Coronary Heart Disease Risk in Patients With Major Depression: Results From the SMILE-II Randomized Clinical Trial
To assess the effects of supervised and home-based aerobic exercise training, and antidepressant pharmacotherapy (sertraline) on coronary heart disease (CHD) risk factors in a sample of participants with major depressive disorder (MDD)
Examination of Several Physiological and Psychosocial Factors Potentially Associated With Masked Hypertension Among Low-Risk Adults
We examined the association of factors in addition to prehypertensive office blood pressure (BP) level that might improve detection of masked hypertension (MH, defined as non-elevated office BP with elevated out-of-office BP average) among those otherwise at low-risk. This sample of 340 untreated adults 30 years and older with office BP average <140/90 mmHg all had two sets of paired office BP measurements and 24-hour ambulatory BP monitoring (ABPM) sessions one week apart. Other than BP levels, the only factors that were associated (at P<0.10) with MH at both sets were male sex (75% vs 66%) and working outside the home (72% vs 59% first set; 71% vs 45% second set). Adding these variables to BP level in the model did not appreciably improve detection of MH. We found no demographic, clinical, or psychosocial measures that improved upon prehypertension as a potential predictor of MH in this sample
Ethnic Differences in the Effects of the DASH Diet on Nocturnal Blood Pressure Dipping in Individuals with High Blood Pressure
Ethnic differences in nocturnal blood pressure (BP) dipping may contribute to the increased risk for adverse cardiovascular events noted in African Americans (AAs). The DASH (Dietary Approaches to Stop Hypertension) diet has been shown to be efficacious in lowering clinic and ambulatory BP; however, the effect of the DASH diet on BP dipping is unclear
The DASH Diet and Insulin Sensitivity
Lifestyle modifications, including adoption of the Dietary Approaches to Stop Hypertension (DASH) dietary pattern, weight loss in individuals who are overweight or obese, and physical activity, are effective in the prevention and treatment of hypertension. A healthy lifestyle may also have beneficial effects on metabolic abnormalities, such as insulin resistance, that are associated with high blood pressure. This review examines the independent and combined effects of the DASH diet and weight loss plus exercise on blood pressure and insulin sensitivity, with a focus on recently published results from the ENCORE study. Our data suggest that the DASH eating plan alone lowers blood pressure in overweight individuals with higher than optimal blood pressure, but significant improvements in insulin sensitivity are observed only when the DASH diet is implemented as part of a more comprehensive lifestyle modification program that includes exercise and weight loss
Effect of Glycemic Load on Peptide-YY Levels in a Biracial Sample of Obese and Normal Weight Women
Black women suffer a disproportionately higher rate of obesity than their white counterparts. Reasons for this racial disparity may reflect underlying differences in the appetite suppressing peptide-YY (PYY). The PYY response to food is differentially influenced by macronutrient content but the effect of glycemic load on PYY response is unknown. This study examined whether glycemic load influences fasting and postprandial PYY levels and whether fasting and postprandial PYY levels are lower in obese black women compared to normal weight black women and to white women. Data were collected from 40 women (20 black, 20 white; 10 each normal weight vs. obese) at the University of North Carolina Clinical and Translational Research Center (CTRC). Participants completed in counterbalanced order two 4½-day weight-maintenance, mixed macronutrient high vs. low glycemic load diets followed by a test meal of identical composition. Total PYY levels were assessed before and after each test meal. Results show no differences in fasting PYY levels but significantly less postprandial PYY area under the curve (PYYAUC) in the group of obese black women compared to each other group (race × obesity interaction, P 0.27). These findings indicate that postprandial PYY secretion is not affected by glycemic load but is blunted in obese black women compared with normal weight black women and with white women; additionally, they begin to address whether blunted PYY secretion contributes uniquely to the pathogenesis of obesity in black women
The effect of job strain on nighttime blood pressure dipping among men and women with high blood pressure
Blunted nighttime blood pressure dipping is an established cardiovascular risk factor. This study examined the effect of job strain on nighttime blood pressure dipping among men and women with high blood pressure
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Levels of Office Blood Pressure and Their Operating Characteristics for Detecting Masked Hypertension Based on Ambulatory Blood Pressure Monitoring
BACKGROUND Masked hypertension (MH)—nonelevated office blood pressure (BP) with elevated out-of-office BP average—conveys cardiovascular risk similar to or approaching sustained hypertension, making its detection of potential clinical importance. However, it may not be feasible or cost-effective to perform ambulatory BP monitoring (ABPM) on all patients with a nonelevated office BP. There likely exists a level of office BP below which ABPM is not warranted because the probability of MH is low.
METHODS We analyzed data from 294 adults aged ≥30 years not on BP-lowering medication with office BP <140/90mm Hg, all of whom underwent 24-hour ABPM. We calculated sensitivity, false-positive rate, and likelihood ratios (LRs) for the range of office BP cutoffs from 110 to 138mm Hg systolic and from 68 to 88mm Hg diastolic for detecting MH.
RESULTS The systolic BP cutoff with the highest +LR for detecting MH (1.8) was 120mm Hg, and the diastolic cutoff with the highest +LR (2.4) was 82mm Hg. However, the systolic level of 120mm Hg had a false-positive rate of 42%, and the diastolic level of 82mm Hg had a sensitivity of only 39%.
CONCLUSIONS The cutoff of office BP with the best overall operating characteristics for diagnosing MH is approximately 120/82mm Hg. However, this cutoff may have an unacceptably high false-positive rate. Clinical risk tools to identify patients with nonelevated office BP for whom ABPM should be considered will likely need to include factors in addition to office BP
GENDER DIFFERENCES IN THE ENDOTHELIAL FUNCTION OF UNTREATED HYPERTENSION
Vascular endothelial dysfunction is associated with increased risk for adverse cardiovascular (CV) events. However, less is known about sex differences in the endothelial function of untreated hypertensive individuals. The purpose of this study was to assess endothelial function in women and men with untreated hypertension. Ninety participants (35 women, 55 men), aged 40 to 60 years (mean age, 46.1±8.2 years), with untreated stage 1 hypertension (systolic blood pressure 140-159 mm Hg and/or diastolic blood pressure 90-99 mm Hg) underwent brachial artery endothelial-dependent flow-mediated dilation and endothelial-independent glyceryl trinitrate dilation. Women had a smaller flow-mediated dilation response than men (adjusted mean±standard error of the mean [SEM]; 1.8±0.6% vs 3.9±0.4%, P=.036), adjusting for baseline arterial diameter (P=.004), age (P=.596), ethnicity (P=.496), log shear stress ratio (P<.001), body mass index (P=.009), 24-hour diastolic blood pressure (P=.169), high-density lipoprotein (P=.225), log creatinine (P=.927), and log physical activity (P=.682). Glyceryl trinitrate dilation did not differ by sex in adjusted models. Women between the ages of 40 and 60 years with untreated stage 1 hypertension exhibited a greater impairment of endothelial function compared with their male counterparts. These findings raise the possibility that female sex may impart a greater risk of CV events in patients with untreated stage 1 hypertension potentially due to poorer endothelial function
Low-Glycemic Load Decreases Postprandial Insulin and Glucose and Increases Postprandial Ghrelin in White but Not Black Women
Alterations in appetite hormones favoring increased postprandial satiety have been implicated in both the glycemic control and potential weight-loss benefits of a low-glycemic diet. Racial differences exist in dietary glycemic load and appetite hormone concentrations. This study examined the impact of glycemic load on appetite hormones in 20 black women [10 normal weight, BMI = 22.8 ± 1.42 (mean ± SD); 10 obese, BMI = 35.1 ± 2.77] and 20 white women (10 normal weight, BMI = 22.9 ± 1.45; 10 obese, BMI = 34.3 ± 2.77). Each woman completed two 4.5-d weight-maintenance, mixed-macronutrient, high-glycemic vs. low-glycemic load diets that concluded with a test meal of identical composition. Blood samples collected before and serially for 3 h after each test meal were assayed for plasma ghrelin and serum insulin and glucose concentrations. Compared with the high-glycemic load meal, the low-glycemic load meal was associated with lower insulinAUC (P = 0.02), glucoseAUC (P = 0.01), and urge to eat ratings (P = 0.05) but with higher ghrelinAUC (P = 0.008). These results suggest the satiating effect of a low-glycemic load meal is not directly linked to enhanced postprandial suppression of ghrelin. Notably, these effects were significant among white but not black women, suggesting that black women may be less sensitive than white women to the glucoregulatory effects of a low-glycemic load. These findings add to a growing literature demonstrating racial differences in postprandial appetite hormone responses. If reproducible, these findings have implications for individualized diet prescription for the purposes of glucose or weight control in women
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