Healthy African American Adults Research Articles

Adversity type and timing predict temporal summation of pain in African-American adults.

African Americans are disproportionately exposed to adversity across the lifespan, which includes both stressful and traumatic events. Adversity, in turn, is associated with alterations in pain responsiveness. Racial differences in pain responsiveness among healthy adults are well established. However, the extent to which adversity type and timing are associated with alterations in pain responsiveness among healthy African-American adults is not well understood. The present study included 160 healthy African-American adults (98 women), ages 18 to 45. Outcome measures included pain tolerance and temporal summation of pain to evoked thermal pain. Composite scores were created for early-life adversity (childhood trauma, family adversity) and recent adversity (perceived stress, chronic stress burden). A measure of lifetime racial discrimination was also included. Higher levels of recent adversity were associated with higher temporal summation of pain, controlling for gender, age, and education. Neither early-life adversity nor lifetime racial discrimination were associated with temporal summation of pain. The present findings suggest that heightened temporal summation of pain among healthy African-American adults is associated with exposure to recent adversity events. Improved understanding of how recent adversity contributes to heightened temporal summation of pain in African Americans could help to mitigate racial disparities in pain experiences by identifying at-risk individuals who could benefit from early interventions.

Cognitive-Affective-Behavioral Pathways Linking Adversity and Discrimination to Daily Pain in African-American Adults.

The tendency to ruminate, magnify, and experience helplessness in the face of pain - known as pain catastrophizing - is a strong predictor of pain outcomes and is associated with adversity. The ability to maintain functioning despite adversity - referred to as resilience - also influences pain outcomes. Understanding the extent to which pain catastrophizing and resilience influence relations between adversity and daily pain in healthy African-American adults could improve pain risk assessment and mitigate racial disparities in the transition from acute to chronic pain. This study included 160 African-American adults (98 women). Outcome measures included daily pain intensity (sensory, affective) and pain impact on daily function (pain interference). Adversity measures included childhood trauma exposure, family adversity, chronic burden from recent stressors, and ongoing perceived stress. A measure of lifetime racial discrimination was also included. Composite scores were created to capture early-life adversity (childhood trauma, family adversity) versus recent-life adversity (perceived stress, chronic burden). Increased pain catastrophizing was correlated with increased adversity (early and recent), racial discrimination, pain intensity, and pain interference. Decreased pain resilience was correlated with increased recent-life adversity (not early-life adversity or racial discrimination) and correlated with increased pain intensity (not pain-related interference). Bootstrapped multiple mediation models revealed that relationships between all adversity/discrimination and pain outcomes were mediated by pain catastrophizing. Pain resilience, however, was not a significant mediator in these models. These findings highlight opportunities for early interventions to reduce cognitive-affective-behavioral risk factors for persisting daily pain among African-American adults with greater adversity exposure by targeting pain catastrophizing.

Abstract D044: Age and sex effects on quantitative sensory testing values in healthy African American adults

Abstract Introduction: Only a few studies have reported quantitative sensory testing (QST) reference values for healthy African Americans, and those studies are limited in sample size and range of age of participants. The intent of our study was to fill a gap in the understanding of pain and somatosensory function in African Americans by generating QST values for healthy African American adults. In a large cohort of pain-free, healthy African American adults whose past pain experiences and current psychological status were known, our study aim was to determine thermal and mechanical QST values and compare those values at the anterior forearm by age and sex. We also determined the values for 5 other body sites and compared the values for differences by testing site location (upper body versus lower body). Methodology: In this cross-sectional study, 124 pain-free African American adults (age 18 to 69 years, 49% female) completed demographic and self-reported pain, fatigue and psychosocial measures. QST included obtaining thermal and mechanical responses and associated pain intensity levels. We applied the Benjamini-Hochberg procedure to adjust the p values to account for the multiple t tests. Results: We found thermal detection values at the anterior forearm were (29.2°C±1.6) for cool detection (CD) and (34.5°C±1.2) for warm detection (WD). At that site, pain thresholds were: cold pain threshold (CPTh) (26.3°C±5.0), heat pain threshold (HPTh) (37.8°C±3.6), and mechanical pain thresholds (MPTH) (16.7±22.2 grams of force, gF). There was a significant between sex difference for WD, with women being more sensitive (q=0.027). Lower body sites were less sensitive than upper body sites across all thermal modalities (q<0.003), but not for the mechanical modality. Mean pain intensity scores rated immediately after the CPTh and HPTh were 1.9 ± 1.3 to 2.2 ± 1.2 on the 0-10 pain intensity scale. Similarly, after the MPTh tests the mean pain intensity scores were 0.5 ± 0.5 to 0.8 ± 0.6. These scores did not differ significantly by sex or age group and clearly indicate that the participants reported pain threshold at an appropriately low perceptual intensity. Pain intensity values for past pain experiences and low ratings for fatigue, depression and anxiety indicated that these factors were unlikely contributors to their pain threshold reports. Conclusion: The QST values from this protocol at the anterior forearm indicate that healthy African American adults had average thermal pain thresholds within 6°C of the temperature of adaptation and average MPTh under 20 gF. Differences in responses to thermal and mechanical stimuli for upper verses lower body were consistent with prior research. These findings add to the body of literature confirming that African American adults indeed have lower pain thresholds than those reported for White adults. These QST values can be used as controls for African Americans with cancer to understand the neuropathic pain syndromes associated with tumor progression and cancer treatments. Citation Format: Keesha L. Powell-Roach, Starja Q. Booker, Yingwei Yao, Marie L. Suarez, Miriam O. Ezenwa, Roger B. Fillingim, Zaijie J. Wang, Robert E. Molokie, Diana J. Wilkie. Age and sex effects on quantitative sensory testing values in healthy African American adults [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D044.

Thermal and mechanical quantitative sensory testing values among healthy African American adults.

PurposeOnly a few studies have reported quantitative sensory testing (QST) reference values for healthy African Americans, and those studies are limited in sample size and age of participants. The study purpose was to characterize QST values in healthy, pain-free African American adults and older adults whose prior pain experiences and psychological status were also measured. We examined the QST values for differences by sex, age, and body test site.Patients and methodsA cross-sectional sample of 124 pain-free African American adults (age 18–69 years, 49% female) completed demographic and self-reported pain, fatigue and psychosocial measures. QST was performed to obtain thermal and mechanical responses and associated pain intensity levels.ResultsWe found thermal detection values at the anterior forearm were (29.2 °C±1.6) for cool detection (CD) and (34.5 °C±1.2) for warm detection (WD). At that site the sample had cold pain threshold (CPTh) (26.3 °C±5.0), heat pain threshold (HPTh) (37.8 °C±3.6), and mechanical pain thresholds (MPTH) (16.7±22.2 grams of force, gF). There was a significant between sex difference for WD, with women being more sensitive (q=0.027). Lower body sites were less sensitive than upper body sites across all thermal modalities (q<0.003), but not for the mechanical modality.ConclusionThe QST values from this protocol at the anterior forearm indicate that the healthy African American adults had average thermal pain thresholds close to the temperature of adaptation and average MPTh under 20 gF. Differences in responses to thermal and mechanical stimuli for upper verses lower body were consistent with prior research.

Erythrocyte Cytochrome b Reductase 1 Protein Levels and Structure in Sickle Cell Patients

In humans, vitamin C (ascorbic acid) is required as substrate or cofactor in a number of important cellular processes. Patients with sickle cell disease (SCD) often are deficient in vitamin C and thus potentially adversely affected. A major determinant of the cellular availability of ascorbate is the plasma level of the vitamin. This reflects the balance between dietary supply, uptake by tissues, excretion, oxidative reactions in the plasma, and RBC dependent recycling or irreversible decomposition of oxidized ascorbate. The mechanisms for depressed plasma ascorbate levels in SCD patients have not been identified, and the effectiveness and safety of dietary ascorbate supplements have not been established. As RBC dysfunction is central to SCD, we have focused on the possibility that SCD patients' RBC membranes have an altered level, structure or function of CYBRD1, a key enzyme in recycling oxidized plasma ascorbate (Fig. 1A).Materials and methods:Blood samples were collected in EDTA tubes from adult SCD patients at routine ambulatory clinic visits and from healthy African American adults. Protocols were approved by institutional review. RBC were isolated by centrifugation and lysed in hypotonic buffer; membranes were isolated by centrifugation and stored at -80 C.Electrophoretic and western blot analyses: RBC membrane proteins were separated by SDS-PAGE, stained with Coomassie Blue and analyzed by densitometry to quantitate total membrane protein (standard: BSA). Alternatively, separated proteins were transferred to nitrocellulose or PVDF and probed with antibodies against CYBRD1. Immunoreactive bands were visualized colorimetrically and quantitated by densitometry (standard: recombinant human CYBRD1 (rCYBRD1)).Mass spectroscopic analyses: CYBRD1 was extracted from RBC membranes with dodecyl maltoside, and further enriched by immunoprecipitation. The immunopurified mixture was separated by SDS-PAGE and stained with Coomassie Blue. Gel pieces containing the CYBRD1 monomers were subjected to in-gel digestion and MS analysis of the tryptic peptides.Results and conclusions:Detailed dose-response analyses found unsuspected positively cooperative behavior between 0 and ~2 ng CYBRD1 in both rCYBRD1 and RBC membrane samples. This invalidated calculations of RBC CYBRD1 content based on linear response to rCYBRD1. However, selected RBC membrane samples were routinely included as quality controls on many blots. Further, the dose-response curves for RBC membrane samples had a consistent shape that fit a simple saturable model with an x-axis offset parameter. It was thus possible to estimate the CYBRD1 content for 36 of the RBC samples using one of them (V7) as reference (Fig. 1B). This permitted our ongoing comparison of CYBRD1 content in patients and controls, and in SCD subtypes.RBC CYBRD1 content in 4 homozygous SCD subjects sampled at 5 regular clinic visits changed little over 7-9 months (averages: 0.32 ± 0.05; 0.25 ± 0.05; 0.41 ± 0.04; and 0.37 ± 0.04 ng CYBRD1/µg RBC membrane protein). This suggests that patients' RBC CYBRD1 contents are relatively stable despite the short RBC half-life, and that a single sampling is sufficient for cross sectional studies.There was no significant difference in CYBRD1 level among ambulatory HbSC (N=6) and HbSS (N=8) patientsand healthy controls (N=8)(Fig. 1C, top). However, there were notable differences in CYBRD1 protein modification, with significantly less modification in CYBRD1 from HbSS patients than either HbSC patients or healthy controls (Fig. 1C, bottom).Similar isoform banding patterns are seen for patient and control CYBRD1 with antibodies against either the N- and C-terminal peptides (Fig. 1D). Retention of epitopes at both ends of CYBRD1 in the isoforms argues against differential proteolysis being involved. The mass spectrometric analyses found extensive oxidative modification of multiple methionine residues, but similar patterns were seen in RBC CYBRD1 from an SCD patient and a healthy control. Phosphorylation was found at multiple sites in residues 200-285 of CYBRD1 from both patient and control, but the fraction phosphorylated appeared much too low to account for the large proportion of CYBRD1 in individual isoforms. Thus, the structural basis for the isoforms' differential gel mobility remains to be identified.Support: American Heart Association, 16GRNT29170013 (R. Kulmacz); NIH 5T35DK007676 (B. Kone) [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

A preliminary experimental examination of worldview verification, perceived racism, and stress reactivity in African Americans.

According to worldview verification theory, inconsistencies between lived experiences and worldviews are psychologically threatening. These inconsistencies may be key determinants of stress processes that influence cardiovascular health disparities. This preliminary examination considers how experiencing injustice can affect perceived racism and biological stress reactivity among African Americans. Guided by worldview verification theory, it was hypothesized that responses to receiving an unfair outcome would be moderated by fairness of the accompanying decision process, and that this effect would further depend on the consistency of the decision process with preexisting justice beliefs. A sample of 118 healthy African American adults completed baseline measures of justice beliefs, followed by a laboratory-based social-evaluative stressor task. Two randomized fairness manipulations were implemented during the task: participants were given either high or low levels of distributive (outcome) and procedural (decision process) justice. Glucocorticoid (cortisol) and inflammatory (C-reactive protein) biological responses were measured in oral fluids, and attributions of racism were also measured. The hypothesized 3-way interaction was generally obtained. Among African Americans with a strong belief in justice, perceived racism, cortisol, and C-reactive protein responses to low distributive justice were higher when procedural justice was low. Among African Americans with a weak belief in justice however, these responses were higher when a low level of distributive justice was coupled with high procedural justice. Biological and psychological processes that contribute to cardiovascular health disparities are affected by consistency between individual-level and contextual justice factors. (PsycINFO Database Record

Blood Antioxidant Defenses and Sickle Cell Disease: Analyzing Cytochrome b Reductase 1 Protein Levels and Structure in Erythrocyte Membranes

Introduction: The pathology of sickle cell disease (SCD) includes ischemia / reperfusion events in the vasculature, compromised blood antioxidant defenses and elevated risk of cardiovascular complications. Vitamin C (ascorbate) is a major blood antioxidant; ascorbate inside red blood cells (RBC) furnishes an electron (e-) to recycle plasma ascorbate to its active, reduced state (Fig. 1). A key step, transmembrane e- transfer, involves cytochrome b reductase 1 (CYBRD1). Thus, a deficiency or defect in red cell CYBRD1 could plausibly increase oxidative stress and interconnected inflammatory processes, contributing to cardiovascular complications in SCD patients. Testing for CYBRD1 deficiency requires a quantitative assay for the protein in RBC, so we developed a suitable assay and used it to screen a small number of SCD patients and healthy individuals.Materials and methods: Blood samples were collected from steady state adult SCD patients, healthy African American adults, and steady state pediatric SCD patients before and 2-5 months on hydroxyurea (HU) therapy. Protocols were approved by institutional review.The CYBRD1 assay workflow is shown in Fig. 2. RBC membrane proteins were separated on two SDS-PAGE gels, along with a mixed standard (1.0 µg bovine serum albumin (BSA) + 1.9 ng of His6-tagged recombinant human CYBRD1 (rCYBRD1; PMID 21501687)). One gel was Coomassie-stained for quantitation of total membrane protein minus membrane-bound hemoglobin (Hb) (standard: BSA). Proteins in the other gel were transferred to a nitrocellulose filter, probed with CYBRD1 antibody (GeneTex #104793) and visualized with secondary antibody and chromogenic substrate for quantitation of CYBRD1 (standard: rCYBRD1), which was normalized to membrane protein. Gels, blots and calibrated density step tablets were scanned (transmittance mode) with an Epson V550; digitized images were analyzed using ImageJ. Two independent samples and paired t tests were used to compare between- and within-group mean differences in RBC CYBRD1 levels, respectively.Results: The Coomassie-stained gels exhibited the usual profile of RBC membrane proteins (Fig. 2). In the immunoblots, the rCYBRD1 standard showed the expected narrow monomer band at ~30 kDa and faint dimer band at ~60 kDa (Fig. 2). However, RBC membrane samples revealed several CYBRD1 monomer bands, indicating the presence of previously unsuspected isoforms of CYBRD1. Further, the CYBRD1 isoform pattern in RBC from healthy controls was quite different from those seen in SCD patients. The functional impact of these differences remains to be investigated.Assay of progressively diluted control RBC membranes produced a linear response for CYBRD1 from 0.7-7.2 ng (r2 = 0.975) and for total protein from 1 to 10 µg (r2 = 0.993). The sub-nanogram detection of CYBRD1 protein makes the assay usable with as little as 0.25 ml of blood. The coefficient of variation was ~15%, quite reasonable precision for quantitative immunoblotting.CYBRD1 levels in RBC from healthy African American adults averaged 0.68 ± 0.13 ng/µg membrane protein (N1 = 10; Fig. 3). CYBRD1 levels in RBC of adult SCD patients averaged 0.35 ± 0.14 ng/µg membrane protein (N2=7). This difference in means was highly statistically significant by two-tailed t-test (p < 0.0002), supporting our hypothesis that a deficiency in RBC CYBRD1 contributes to elevated oxidative stress in SCD patients.RBC CYBRD1 levels in pediatric SCD patients not on HU therapy averaged 0.27 ± 0.14 ng/µg protein (N3=12; Fig. 3). Pediatric patients on HU therapy averaged 0.41 ± 0.18 ng CYBRD1/µg membrane protein (N4=7). For the five pediatric patients examined both before and during HU therapy there was a marginally significant increased mean CYBRD1 level on HU (p < 0.099 by paired, two-tailed t test).Conclusions: Our newly developed assay allows quantitation of the RBC CYBRD1 protein level and analysis of the CYBRD1 isoform pattern using a small blood sample. The pilot screening results suggest that adult SCD patients have lower levels of CYBRD1 in their RBC, and a different pattern of CYBRD1 isoforms. Analysis of the CYBRD1 protein may be useful in assessing the state of individual SCD patients' blood antioxidant defenses and the antioxidant effects of HU. Thus, it will be worthwhile to examine the RBC CYBRD1 protein and activity in larger numbers of patients and controls, and to explore the origins of any differences between the groups. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Distance and Interference in the Reference Management of African American Adults

The purpose of this study was to examine the effect of distance and interference on the adequacy of reference management in 2 contrasting narrative conditions among age-defined groups of healthy African American adults. Twenty middle-aged (M = 51 years) and 20 older (M = 72 years) women produced a complex story retelling and a personal narrative of a childhood experience. All narratives were transcribed orthographically, parsed into terminal units (T-units), and analyzed for surface structure markings of referents. Results varied on the basis of task complexity and specific dependent variables. Older adults produced shorter T-unit distances between nouns and pronouns in story retelling compared with middle-aged adults. Middle-aged adults, but not older adults, exhibited longer T-unit distances between referents on story retelling than on personal narratives. Both groups performed similarly in the management of intervening information between referents. The presence of African American English features was related to interference but not to referential distance. Older adults demonstrated an effective age-related strategy for simplifying complex story retelling by producing shorter T-unit distances and, thus, less intervening information between referents. These findings suggest that referential distance may be a more important factor in mediating story recall. (For a summary and guidelines for therapy, see Bunce, 1991.).

Chronic cocaine use and its association with myocardial steatosis evaluated by 1H magnetic resonance spectroscopy in African Americans.

Cardiac steatosis is a manifestation of ectopic fat deposition and is associated with obesity. The impact of chronic cocaine use on obesity measures and on the relationship between obesity measures and cardiac steatosis is not well-characterized. The objectives of this study were to compare obesity measures in chronic cocaine users and nonusers, and to explore which factors, in addition to obesity measures, are associated with myocardial triglyceride in African Americans, using noninvasive magnetic resonance spectroscopy. Between June 2004 and January 2014, 180 healthy African American adults without HIV infection, hypertension, and diabetes were enrolled in an observational proton magnetic resonance spectroscopy and imaging study investigating factors associated with cardiac steatosis. Among these 180 participants, 80 were chronic cocaine users and 100 were nonusers. The median age was 42 (interquartile range, 34-47) years. Obesity measures trended higher in cocaine users than in nonusers. The median myocardial triglyceride was 0.6% (interquartile range, 0.4%-1.1%). Among the factors investigated, years of cocaine use, leptin, and visceral fat were independently associated with myocardial triglyceride. Body mass index and visceral fat, which were significantly associated with myocardial triglyceride in noncocaine users, were not associated with myocardial triglyceride content in cocaine users. This study shows (1) cocaine users may have more fat than nonusers and (2) myocardial triglyceride is independently associated with duration of cocaine use, leptin, and visceral fat in all subjects, whereas leptin and high-density lipoprotein cholesterol, but not visceral fat or body mass index, in cocaine users, suggesting that chronic cocaine use may modify the relationships between obesity measures and myocardial triglyceride.

Theta frequency activity during rapid eye movement (REM) sleep is greater in people with resilience versus PTSD

Emotional memory consolidation has been associated with rapid eye movement (REM) sleep, and recent evidence suggests that increased electroencephalogram spectral power in the theta (4-8Hz) frequency range indexes this activity. REM sleep has been implicated in posttraumatic stress disorder (PTSD) as well as in emotional adaption. In this cross-sectional study, thirty young healthy African American adults with trauma exposure were assessed for PTSD status using the Clinician Administered PTSD Scale. Two consecutive night polysomnographic (PSG) recordings were performed and data scored for sleep stages. Quantitative electroencephalographic spectral analysis was used to measure theta frequency components sampled from REM sleep periods of the second-night PSG recordings. Our objective was to compare relative theta power between trauma-exposed participants who were either resilient or haddeveloped PTSD. Results indicated higher right prefrontal theta power during the first and last REM periods in resilient participants compared with participants with PTSD. Right hemisphere prefrontal theta power during REM sleep may serve as a biomarker of the capacity for adaptive emotional memory processing among trauma-exposed individuals.

Abstract 273: Levels Of Vcam-1 Are Associated With Flow-mediated Dilation In Healthy African American Adults

Background: Vascular cell adhesion molecule-1 (VCAM-1) mediates the adhesion of monocytes to vascular endothelium, which play a role in the development of endothelial dysfunction and atherosclerosis. Flow-mediation dilation (FMD) is an endothelium-dependent response, which is mediated by nitric oxide and closely related to endothelial function. The purpose of the study was to test whether levels of VCAM-1 were associated the endothelial-dependent (FMD) in normotensive African Americans. Normotensives were studied in order to eliminate the influence of hypertension. Methods and Results: Blood was collected in 22 subjects aged 41-62 yrs with normal blood pressure (125.0 ± 9.1 mmHg) after 12 hr fast. Plasma was obtained by centrifugation within 15 min after collection in 4 degree. A commercially available solid phase sandwich enzyme linked immuno-sorbent assay kit was used to detect VCAM-1 levels in plasma. FMD was measured after 5-min cuff occlusion using Doppler ultrasound. The maximum FMD diameters were calculated. In the entire study population, levels of VCAM-1 (556.92 ± 154.20 ng/mL) were negatively correlated with the true peak FMD (FMD: 7.81 ± 2.22 %, r=-0.484, P=0.023). Conclusion: Levels of VCAM-1 were associated with endothelial responsiveness in healthy African Americans with normal blood pressure. These results suggest that the level of VCAM-1 may be a predictive of endothelial dysfunction in the unique healthy populations.

Abstract 425: High Sodium Excretion is not Associated with Reduced Vasodilation in Healthy African American Adults

Background: High dietary sodium (Na) intake has been shown to be related to the development of endothelial dysfunction and hypertension. Urinary sodium excretion in people with normal renal function can indirectly reflect the level of dietary sodium intake. The purpose of the study was to test whether high urine Na excretion was independent from other risk factors and related to the compromised endothelial-dependent (fiow-mediated dilation [FMD]) and/or endothelium-independent (nitroglycerin-induced dilation [NMD]) in normotensive African Americans. Normotensives were studied in order to eliminate the influence of hypertension. METHODS: Urine was collected for 24 hr in 30 subjects aged 41-63 yrs with normal blood pressure (125.7 ± 9.7/81 ± 7.1 mmHg). 16 subjects had Na excretion &lt;150 mmol (99.6 ± 24.8 mmol) and were classified as the Normal Na excretion group and 14 subjects had Na excretion ≥150 mmol/g (186.5 ± 27.1 mmol) and were classified as the High Na excretion group. FMD was measured after 5-min cuff occlusion and NMD was measured after application of 0.8 mg nitroglycerin using Doppler ultrasound. The maximum FMD- and NMD-diameters and FMD/NMD ratio were calculated. Results: There were no differences in other dietary factors, age, body mass index, blood pressure, or physical activity levels between the groups. Plasma concentrations of cholesterol, glucose, antioxidant status and inflammatory markers did not differ between groups. FMD (Normal: 7.4 ± 2.9% vs. High: 9.5 ± 3.6%; p=0.09) and NMD (Normal: 17.9 ± 6.3% vs. High: 27.8 ± 18.1%; p=0.07) and true peak FMD/NMD ratio (Normal: 0.45 ± 0.22 vs. High: 0.38 ± 0.11; p=0.26) were not different between groups. No significant correlations were found between 24hr Na excretion and FMD (r=0.332; p=0.073), NMD (r=0.356; p=0.053) or FMD/NMD ratio(r=0.112; p=0.554) in the entire study group. Conclusion: High Na excretion was not associated with reduced endothelial responsiveness in healthy African Americans with normal blood pressure. These results suggest that high Na intake may not be predictive of endothelial dysfunction in putatively healthy populations.

Low vitamin D levels, prediabetes and prehypertension in healthy African American adults

AimsTo determine if customary lower serum vitamin D concentrations in healthy African American (AA) adults are associated with modest elevations in fasting plasma glucose (FPG) and/or resting blood pressure (BP). Numerous health disparities between African American (AA) and Caucasian American (CA) adults, especially those which increase cardiovascular morbidity and mortality, have been attributed to lower serum vitamin D concentrations in the AA. Prediabetes (PreDM) and prehypertension (PreHTN) are significantly more prevalent in healthy disease free CA adults with serum vitamin D concentrations below the 75th percentile for the Caucasian cohort. We hypothesized that despite overall lower serum vitamin D concentrations in AA, an increase in the prevalence for PreDM and PreHTN would be seen in those with low vitamin D levels. Methods and resultsDisease free AA adults in the National Health and Nutrition Examination Survey 2001–2006 were assessed. PreDM and PreHTN were diagnosed using the ADA and JNC 7 criteria: (FPG) 100–125 mg/dL and resting systolic (SBP) 120–139 and/or diastolic (DBP) 80–89 mm Hg, respectively. Logistic regression was employed to assess effects of low vitamin D concentrations on the odds for PreDM and PreHTN (n = 621). Age, gender and BMI adjusted odds ratio for co-morbid PreDM and PreHTN in AA men (n = 343) and women (n = 278) with vitamin D levels ≤45.4 versus >45.4 nmol/L was 2.02 (1.11, 3.68), (p < 0.021). ConclusionsEvaluating serum vitamin D levels, with consideration for supplementation in seemingly healthy AA adults with prediabetes, prehypertension, or co-existing prediabetes and prehypertension, has merit.

Determinants of Exhaled Nitric Oxide Levels in Healthy Non-Smoking African American Adults

Asthma is a significant cause of morbidity and mortality for African Americans. Exhaled nitric oxide (FeNO) levels are elevated in asthma and airway levels of NO metabolites regulate airway inflammation and airway diameter. More needs to be known about the factors that regulate FeNO. There is a need for FeNO reference values for African Americans. The objective of this study was to establish reference values and identify factors associated with FeNO levels in healthy African American adults. FeNO was measured in 895 healthy, non-smoking, African Americans between the ages of 18 and 40. FeNO measurements were repeated in 84 subjects. Factors potentially associated with FeNO were measured including blood pressure, height, weight, serum total IgE, ECP, CRP and nitrate. Data on respiratory symptoms including upper respiratory infection (URI) symptoms were collected. Univariate and multivariate analyses of the relationship between these variables and FeNO were performed. In healthy, non-smoking African Americans, FeNO was stable during repeated measurements (rI = 0.81). Gender (p < 0.0001), serum total IgE (p < 0.0001) and current URI symptoms (p = 0.0002) contributed significantly to FeNO variability but together accounted for less than 50% of the variation in FeNO. The high correlation between repeated measurements of FeNO and the low correlation coefficients of known factors associated with FeNO suggest that other factors may contribute substantially to FeNO variability in African Americans. Gender, elevated serum total IgE and current URI symptoms should be considered when evaluating FeNO levels in adults. Importantly, these studies provide FeNO reference values for healthy African American adults.

Validation of the Detroit Area Study Discrimination Scale in a community sample of older African American adults: the Pittsburgh healthy heart project.

This study examined the construct validity of the Detroit Area Study Discrimination Questionnaire (DAS-DQ) in 49 healthy African American adults, with respect to its association with global measures and daily experiences of psychological demand. Daily experiences of psychological demand were obtained using ecological momentary assessment (EMA) methods. Everyday Mistreatment, as measured by the DAS-DQ, was significantly related to global reports of perceived stress and depression but was unrelated to measures of hostility and social desirability. Everyday Mistreatment was significantly related to average EMA score measures of Negative Affect and Social Conflict but was unrelated to daily experiences of Task Demand or Decisional Control. Negative Affect mediated the relation between Everyday Mistreatment and global reports of perceived stress. In contrast, Lifetime History of Discrimination, as measured by the DAS-DQ, was unrelated to global measures or daily experiences of stress. Thus, this study lends support to the construct validity of the DAS-DQ.

Age, working memory, figurative language type, and reading ability: influencing factors in African American adults' comprehension of figurative language.

This study investigated the cognitive and linguistic factors presumed to be associated with adult comprehension of figurative language, including age, working memory (WM), figurative language type, and reading comprehension (RC). Forty younger (M = 22 years) and 40 older (M = 63 years) healthy African American adults completed WM and reading tasks, and the 60-item forced-choice multiple-category (20 idioms, 20 metaphors, and 20 metonyms) Figurative Language Comprehension Test. After controlling for WM and RC, the older adults outperformed the younger adults on idioms and metonyms. Metaphor comprehension was comparable between the groups. Findings demonstrate that WM and RC underlie adults' comprehension of figurative language and should be considered when interpreting performance on tests assessing figurative language competence in this population.