Rebecca Din-Dzietham

High Blood Pressure Trends in Children and Adolescents in National Surveys, 1963 to 2002

Background— Secular trend data on hypertension in children and adolescents are scarce and inconsistent. In the face of growing obesity, we sought to assess high blood pressure (HBP) secular trends in children and adolescents enrolled in national surveys and to determine whether the HBP trend reversed its course with the rise in obesity. Methods and Results— National survey data obtained from multistage probability sampling of the US noninstitutionalized population from 1963 to 2002 were examined; 8- to 17-year-old non-Hispanic blacks and whites and Mexican Americans were included. HBP ascertainment was based on age-, gender-, and height percentile–specific systolic and diastolic BPs. Weighted analyses were performed to account for the complex design. The BP, pre-HBP, and HBP trends were downward from 1963 to 1988 and upward thereafter. Pre-HBP and HBP increased 2.3% (P=0.0003) and 1% (P=0.17), respectively, between 1988 and 1999. Obesity increase, more so abdominal than general obesity, partially explained the rise in HBP and pre-HBP from 1988 to 1999. BP and HBP reversed their downward trends 10 years after the increase in the prevalence of obesity. Additionally, an ethnic and gender gap appeared in 1988 for pre-HBP and in 1999 for HBP; non-Hispanic blacks and Mexican Americans had a greater prevalence of HBP and pre-HBP than non-Hispanic whites, and males had a greater prevalence than females. Conclusions— HBP and pre-HBP in children and adolescents are on the rise. These new findings have implications for the cardiovascular disease public health burden, particularly the risk of a new cardiovascular disease transition. They reinforce the urgent call for early prevention of obesity and HBP and illustrate racial/ethnic disparities in this age group.

Perceived stress following race-based discrimination at work is associated with hypertension in African-Americans. The metro Atlanta heart disease study, 1999-2001

There is increasing evidence of an association between stress related to job strain and hypertension. However little data exist on stress from racism and race-based discrimination at work (RBDW). The objective of this study was to investigate whether blood pressure (BP) outcomes are positively associated with stressful racism towards African-Americans from non-African-Americans as well as RBDW from other African-Americans. The metro Atlanta heart disease study was a population-based study which included 356 African-American men and women, aged >/=21 years, residing in metropolitan Atlanta, Georgia during 1999-2001. Perceived stress was self-reported by 197 participants for racism from non-African-Americans and 95 for RBDW from other African-Americans. Sitting systolic (SBP) and diastolic (DBP) BP were taken at a clinic visit and was the average of the last two of three BP measures. Hypertension was self-reported as physician-diagnosed high BP on 2 or more visits. Logistic and least-squares linear regression models were fit accordingly and separately for each type of stress, adjusting for age, gender, body mass index, and coping abilities. The likelihood of hypertension significantly increased with higher levels of perceived stress following racism from non-African-Americans, but not from RBDW from other African-Americans; adjusted odd ratios (95% CI) were 1.4 (1.0, 1.9) and 1.2 (0.8, 1.5) per unit increment of stress. The adjusted magnitude of SBP and DBP increase between low and very high level of stress, conversely, was greater when RBDW originated from African-Americans than racism from non-African-Americans. Stressful racism and RBDW encounters are associated with increased SBP and DBP and increased likelihood of hypertension in African-Americans. Future studies with a larger sample size are warranted to further explore these findings for mechanistic understanding and occupational policy consideration regarding stress risk reduction.

Racial differences in arterial stiffness and microcirculatory function between Black and White Americans.

Background Compared with whites, black Americans suffer from a disproportionate burden of cardiovascular disease (CVD). We hypothesized that racial differences in the prevalence of CVD could be attributed, in part, to impaired vascular function in blacks after adjustment for differences in risk factor burden. Methods and Results We assessed vascular function in 385 black and 470 white subjects (mean age, 48±11 years; 45% male). Using digital pulse amplitude tonometry (EndoPAT) we estimated the reactive hyperemia index (RHI), a measure of microvascular endothelial function, and peripheral augmentation index (PAT‐AIx). Central augmentation index (C‐AIx) and pulse‐wave velocity (PWV) were measured as indices of wave reflections and arterial stiffness, respectively, using applanation tonometry (Sphygmocor). Compared with whites, blacks had lower RHI (2.1±0.6 versus 2.3±0.6, P<0.001), greater arterial wave reflections assessed as both PAT‐AIx (20.4±21.5 versus 17.0±22.4, P=0.01) and CAIx (20.8±12.3 versus 17.5±13.3, P=0.001), and greater arterial stiffness, measured as PWV (7.4±1.6 versus 7.1±1.6 m/s, P=0.001). After adjustment for traditional CVD risk factors, black race remained a significant predictor of lower RHI and higher PAT‐AIx and CAIx (all P<0.001) in all subjects and of higher PWV in men (P=0.01). Furthermore, these associations persisted in a subgroup analysis of “healthy” individuals free of CVD risk factors. Conclusion Black race is associated with impaired microvascular vasodilatory function, and greater large arterial wave reflections and stiffness. Because impairment in these vascular indices may be associated with worse long‐term outcomes, they may represent underlying mechanisms for the increased CVD risk in blacks.

Interaction of sleep quality and psychosocial stress on obesity in African Americans: the Cardiovascular Health Epidemiology Study (CHES)

BackgroundCompared with whites, sleep disturbance and sleep deprivation appear more prevalent in African Americans (AA). Long-term sleep deprivation may increase the risk of obesity through multiple metabolic and endocrine alterations. Previous studies have reported contradictory results on the association between habitual sleep duration and obesity. Accordingly, we aimed to assess whether sleep quality and duration are inversely associated with body mass index (BMI) and obesity and test whether these associations are modified by psychosocial stress, known to influence sleep quality.MethodsA sample of 1,515 AA residents of metropolitan Atlanta, aged 30-65 years, was recruited by a random-digit-dialing method in 2007-08. The outcome obesity was defined by BMI (kg/m2) continuously and categorically (BMI ≥ 30 versus BMI < 30). Global sleep quality (GSQ) score was computed as the sum of response values for the seven components of the Pittsburgh Sleep Quality Index (PSQI) scale. GSQ score was defined as a continuous variable (range 0-21) and as tertiles. The general perceived stress (GPS), derived from the validated Cohen scale, was categorized into tertiles to test the interaction. Chi-square tests, correlation coefficients and weighted multiple linear and logistic regression were used to assess the associations of GSQ, GPS and obesity.ResultsThe mean (standard deviation) age was 47.5 (17.0) years, and 1,096 (72%) were women. GSQ score categorized into tertiles was associated with BMI. Among women, after multivariable adjustment that included age, gender, physical activity, smoking status, education, total family income, financial stress and history of hypertension, hypercholesterolemia, diabetes and myocardial infarction, obesity was associated with sleep quality as assessed by GSQ continuous score, [odds ratio, OR (95% C.I.): 1.08 (1.03 - 1.12)], and with a worse sleep disturbance subcomponent score [OR (95% C.I.): 1.48 (1.16 - 1.89)]. Among all participants, stress modified the association between obesity and sleep quality; there was an increased likelihood of obesity in the medium stress category, OR (95% C.I.): 1.09 (1.02 - 1.17).ConclusionSleep quality was associated with obesity in women. The association of sleep quality with obesity was modified by perceived stress. Our results indicate the need for simultaneous assessment of sleep and stress.

Association between Depression and Inflammation - Differences by Race and Sex: The META-Health Study

Objective: To test whether the association between depression and inflammation differs by race and sex. Depressive symptoms have been associated with higher levels of C-reactive protein (CRP). However, few studies have examined this association in samples including a significant number of African Americans, or examined whether the association differs by race and sex. Methods: Depressive symptoms and CRP were assessed in 512 African American and white participants, age 30 to 65 years, as part of the community-based Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) Study. Depression was determined by responses to the Beck Depression Inventory II (BDI-II). Multivariable linear regression models were used to adjust for demographic and metabolic risk factors. Results: African American men had higher total BDI-II scores than white men (p =.03), whereas there was no difference in women. There was a significant race-sex-depression interaction in predicting CRP levels (p =.02). White women with mild to severe depressive symptoms had higher levels of CRP compared with those with minimal to no depressive symptoms (p <.05). There were no differences in levels of CRP by severity of depressive symptoms in white men or African Americans of either sex. Higher BDI-II scores were related to higher CRP levels in white women after adjusting for age and level of education (&bgr; = 0.227, p =.006). However, the association was eliminated after further adjustment for metabolic risk factors (&bgr; = 0.077, p =.35). Conclusions: Although depressive symptoms are associated with inflammation, the association varies by race and sex.CVD = cardiovascular disease; BDI-II = Beck Depression Inventory II; CRP = C-reactive protein; BMI = body mass index; HDL-C = high-density lipoprotein cholesterol

The Association between Depression and Leptin is Mediated by Adiposity

Objective Animal models suggest that impaired leptin production, or leptin resistance despite increased leptin levels, may contribute to depression. The link between leptin and depression could be mediated by obesity, which is more common in depression and increases leptin production. Methods We administered the Beck Depression Inventory–II (BDI-II) to 537 participants (mean [standard deviation (SD)] age = 51 [9] years; female, 61%) enrolled in the Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) study. Leptin levels were examined as continuous log-transformed values. Results Participants with moderate to severe depression had higher levels of leptin (median [interquartile range] 37.7 [17.6–64.9] ng/mL) than those with mild depression (22.9 [7.0–57.9] ng/mL) or minimal to no depression (19.8 ng/mL [7.8–39.1], p = .003). Participants with moderate to severe depression had higher body mass index (BMI) than those with mild or minimal depression (mean [SD] = 33 [8] versus 31 [9] versus 29 [7] kg/m2, p = .001). After multivariate adjustment for age, sex, race, smoking status, hypertension, diabetes, blood pressure, lipids, and C-reactive protein, the BDI-II score remained a significant predictor of leptin levels (&bgr; = 0.093, p = .01). Further adjustment for BMI eliminated the association between the BDI-II score and leptin (&bgr; = 0.03, p = .3). Adjusting for waist circumference in place of BMI revealed similar findings. Conclusions The association between depression and leptin seems to be mediated by increased adiposity in depressed individuals. Abbreviations BDI-II = Beck Depression Inventory–II BMI = body mass index HDL-C = high-density lipoprotein cholesterol

Differences in weight perception among blacks and whites.

BACKGROUND The prevalence of obesity is higher in blacks than whites, especially in black women, and is known to be associated with major cardiovascular disease risk factors, which are also more prevalent in blacks than whites. Weight perception may contribute to these differences if blacks are more likely to underestimate their weight. We explored race and gender differences in underestimation of weight using body mass index (BMI) and waist circumference (WC), after adjusting for other cardiovascular risk factors. METHODS AND RESULTS We studied 219 white and 240 black women and men as part of the META-Health Study. Perceived weight was assessed over the phone and categorized into three categories: underweight or normal weight, overweight, or obesity. Height, weight, and WC were measured at a subsequent visit, and BMI was calculated. Logistic regression was used to compare the likelihood of underestimating actual weight category by race, before and after adjusting for sociodemographic, lifestyle factors, and medical history. In multivariate analysis, the odds of underestimating BMI category was greater than threefold in blacks compared with whites (OR 3.1, 95% CI 1.9-4.8) and was larger for black women than for black men (p<0.01 for interaction). When abdominal adiposity was taken into account by utilizing WC as a measure of weight, the observed difference in weight underestimation remained. CONCLUSION Our data reveal a significant misperception of weight among blacks, particularly black women, who have the highest burden of obesity. A multifaceted approach with efficient identification of social, cultural, and environmental factors that give rise to obesity tolerance in blacks will provide potential targets for intervention, which may ameliorate weight misperception and the prevalence of excess weight in the black population.

Differences in Systemic Oxidative Stress Based on Race and the Metabolic Syndrome: The Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) Study

BACKGROUND Classification schema such as metabolic syndrome may underestimate cardiovascular disease (CVD) risk in African Americans, despite a higher burden of CVD in African Americans. Oxidative stress results from an imbalance of prooxidants and antioxidants and leads to endothelial dysfunction that promotes vascular inflammation and atherosclerosis. Aminothiol markers of oxidative stress are associated with CVD risk factors and metabolic syndrome; however, little is known about racial differences in levels of oxidative stress. We sought to investigate whether oxidative stress would be higher in African Americans compared to whites independently of traditional risk factor burden. METHODS We assessed oxidative stress in a biracial, community-based cohort. In 620 subjects (59% female, 52% African American) in the Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) study, we measured plasma levels of glutathione, an intracellular antioxidant, and its redox potential as a ratio of reduced and oxidized glutathione (E(h) glutathione). RESULTS African Americans had lower glutathione levels (P<0.001) compared to whites. There was a trend toward more oxidized E(h) glutathione (P = 0.07) in African Americans; however, this did not reach statistical significance. After adjustment for demographics and CVD risk factors, African-American race remained a significant correlate of lower glutathione levels (P<0.001) and a more oxidized E(h) glutathione (P = 0.04). After further adjustment for high-sensitivity C-reactive protein (hsCRP), glutathione remained significantly lower in African Americans (P = 0.001). African Americans with or without metabolic syndrome had lower glutathione levels compared to whites with or without metabolic syndrome, respectively (both P ≤ 0.001), and African Americans without metabolic syndrome had a more oxidized E(h) glutathione compared to whites without metabolic syndrome (P = 0.003). CONCLUSIONS African Americans have higher levels of oxidative stress than whites, even after adjustment for differences in CVD risk factors and inflammation. Racial differences in oxidative stress may play a key role in understanding observed racial disparities in CVD.

Association of Adiponectin With Left Ventricular Mass in Blacks The Jackson Heart Study

Background— Blacks have a higher prevalence of left ventricular hypertrophy than whites. Several population-based studies have reported an inverse association between adiponectin and left ventricular mass (LVM); however, the relationship between adiponectin levels and LVM has yet to be defined in blacks. The Jackson Heart Study cohort provides an opportunity to test the hypothesis that the inverse association between adiponectin and LVM may be modified by risk factors common among blacks. Methods and Results— The study population included 2649 black Jackson Heart Study participants (mean age 51±12 years, 63% women, 51% obese, 54% with hypertension, and 16% with diabetes). Multiple linear and spline regression was used to assess the association, with adjustment for demographic, clinical, and behavioral covariates. Among all the participants, there was a statistically significant but modest inverse association between adiponectin and LVM index. Hypertension and insulin resistance emerged as statistically significant effect modifiers of this relationship. The inverse association present among the normotensive participants was explained by obesity measures such as the body mass index. Among participants with both hypertension and insulin resistance, there was a significant direct association between adiponectin and the LVM index after multivariable adjustment (&bgr;=1.55, P=0.04, per 1-SD increment in the adiponectin log value). Conclusions— The association between serum adiponectin and LVM among blacks in the Jackson Heart Study cohort was dependent on hypertension and insulin resistance status. Normotensive blacks exhibited an inverse adiponectin-LVM association, whereas participants with hypertension and insulin resistance had a direct association.

Association of Adiponectin With Left Ventricular Mass in BlacksClinical Perspective

Background— Blacks have a higher prevalence of left ventricular hypertrophy than whites. Several population-based studies have reported an inverse association between adiponectin and left ventricular mass (LVM); however, the relationship between adiponectin levels and LVM has yet to be defined in blacks. The Jackson Heart Study cohort provides an opportunity to test the hypothesis that the inverse association between adiponectin and LVM may be modified by risk factors common among blacks. Methods and Results— The study population included 2649 black Jackson Heart Study participants (mean age 51±12 years, 63% women, 51% obese, 54% with hypertension, and 16% with diabetes). Multiple linear and spline regression was used to assess the association, with adjustment for demographic, clinical, and behavioral covariates. Among all the participants, there was a statistically significant but modest inverse association between adiponectin and LVM index. Hypertension and insulin resistance emerged as statistically significant effect modifiers of this relationship. The inverse association present among the normotensive participants was explained by obesity measures such as the body mass index. Among participants with both hypertension and insulin resistance, there was a significant direct association between adiponectin and the LVM index after multivariable adjustment (&bgr;=1.55, P=0.04, per 1-SD increment in the adiponectin log value). Conclusions— The association between serum adiponectin and LVM among blacks in the Jackson Heart Study cohort was dependent on hypertension and insulin resistance status. Normotensive blacks exhibited an inverse adiponectin-LVM association, whereas participants with hypertension and insulin resistance had a direct association.