Feasibility and Performance of Hemoglobin A1C Self-Testing During COVID-19 Among African Americans With Type 2 Diabetes

PURPOSE

The purpose of the study was to determine the feasibility of implementing A1C self-testing at home using the A1CNow® Self Check and to compare the accuracy of the A1CNow to a reference standard in African Americans with type 2 diabetes (T2D).

METHODS

African American adults with T2D were recruited from 13 different churches (N = 123). Phase 1, conducted during the early phase of the COVID-19 pandemic, examined the feasibility of A1C assessment using the A1CNow performed at home by untrained participants. Phase 2, conducted when in-person research resumed, compared A1C values concurrently measured using the A1CNow and the DCA Vantage™ Analyzer (reference standard) collected by research staff at church testing sites.

RESULTS

In Phase 1, 98.8% of participants successfully completed at least 1 at-home A1C test; the overall failure rate was 24.7%. In Phase 2, the failure rate of staff-performed A1CNow testing was 4.4%. The Bland-Altman plot reveals that A1CNow values were 0.68% lower than DCA values, and the mean differences (A1CNow minus DCA) ranged from -2.6% to 1.2% with a limit of agreement between -1.9% to 0.5%.

CONCLUSIONS

A1C self-testing is feasible for use in community settings involving African American adults with T2D. The A1CNow Self-Check underestimated A1C values when compared with the reference standard. Ongoing improvements in point-of-care devices have the potential to expand research and clinical care, especially in underserved communities.

Diabetes Self-Management Education and Support Culturally Tailored for African Americans: COVID-19-Related Factors Influencing Restart of the TX STRIDE Study

Purpose

The purpose of this substudy was to determine the most acceptable way to restart the Texas Strength Through Resilience in Diabetes Education (TX STRIDE) study safely using remote technologies. Following the emergence of COVID-19, all in-person TX STRIDE intervention and data collection sessions were paused.

Methods

Qualitative descriptive methods using telephone interviews were conducted during the research pause. A structured interview guide was developed to facilitate data collection and coding. Forty-seven of 59 Cohort 1 participants were interviewed (mean age = 60.7 years; 79% female; mean time diagnosed with type 2 diabetes = 11 years).

Results

Data categories and subcategories were generated from the interview responses and included: personal experiences with COVID-19, effects of COVID-19 on diabetes self-management, psychosocial and financial effects of COVID-19, and recommendations for program restart. Although some participants lacked technological knowledge, they expressed eagerness to learn how to use remote meeting platforms to resume intervention and at-home data-collection sessions. Six months after the in-person intervention was paused, TX STRIDE restarted remotely with data collection and class sessions held via Zoom. A majority of participants (72.9%) transitioned to the virtual platform restart.

Conclusions

Qualitative findings guided the appropriate implementation of technology for the study, which facilitated a successful restart. High retention of participants through the study transition provides evidence that participants are invested in learning how to manage their diabetes despite the challenges and distractions imposed by COVID-19.

Race moderates the association of perceived everyday discrimination and hair cortisol concentration

The influence of discrimination on hypothalamic-pituitary-adrenal (HPA) axis function is considered to be more pronounced for racial minority versus majority groups, although empirical support for this argument is not strong. This study examined whether the association of perceived discrimination was more strongly associated with long-term, retrospective cortisol output (as measured by hair cortisol concentration [HCC]) among African American compared to White adults. Participants included 141 community-dwelling adults (72 White, 69 African American; mean age 45.8 years; 67% females). The Everyday Discrimination Scale assessed perceived discrimination. The first 3 cm of proximal scalp hair was analyzed for HCC using enzyme-linked immunoassay. Associations between race, perceived discrimination and HCC were examined using hierarchical multiple regression. African Americans had higher HCC than Whites, but both groups reported perceived discrimination with similar frequency. Race moderated the association between perceived discrimination and HCC (R2 interaction = 0.03, p = 0.007) such that perceived discrimination was positively associated with HCC among African Americans (β = 0.28, p = 0.007), but not Whites (β = -0.11, p = 0.274). Perceived discrimination did not mediate the association between race and HCC (β for indirect effect = 0.025, 95% CI [-.003, 0.087]). Although perceived discrimination did not differ between races, perceived discrimination was positively associated with retrospective levels of cortisol in scalp hair among African Americans but not Whites. This may suggest that characteristics of discrimination other than frequency are particularly salient to HPA axis function among African Americans (e.g. attribution, severity, historical context).LAY SUMMARYThis study found that greater perceived discrimination frequency was associated with greater long-term cortisol secretion (i.e. hair cortisol concentration) among African American compared to White adults. Both groups reported similar discrimination frequency, so the uniqueness of African Americans' experience with discrimination may be salient to HPA axis upregulation for this population.

Perceived stress, psychological resilience, hair cortisol concentration, and metabolic syndrome severity: A moderated mediation model

BACKGROUND

Psychological resilience is considered to protect against detrimental effects of perceived stress on cardiovascular and metabolic health, but few studies have tested biological mechanisms underlying these relationships.

PURPOSE

This study examined whether psychological resilience moderated the indirect association of perceived stress with Metabolic Syndrome (MetS) severity via hair cortisol concentration (HCC), a retrospective index of hypothalamic pituitary adrenal (HPA) axis activity.

METHOD

Participants included 228 adults (73 White, 86 Hispanic, 69 African American; mean age 45.29 years; 68% females). Participants completed questionnaires assessing perceived stress (Perceived Stress Scale) and resilience (Brief Resilience Scale). The first 3 cm of scalp-near hair were analyzed for cortisol concentration using enzyme-linked immunoassay analysis. Cardiometabolic risk factors including blood glucose, lipids, blood pressure, and waist circumference were assessed, from which a sex- and race/ethnicity-specific continuous MetS severity score was calculated. A moderated mediation model was tested using path analysis.

RESULTS

Psychological resilience moderated the association of perceived stress with HCC (R² change for interaction = 0.014, p =  0.043), such that the association of perceived stress and HCC decreased as resilience scores increased. Resilience also moderated the indirect association of perceived stress with MetS severity via HCC (b = -0.039, 95% CI [-0.001; -0.100]), such that HCC mediated the association of greater perceived stress with greater MetS severity only for individuals reporting Brief Resilience Scale scores 3 or below (range: 1.17-5.00). Psychological resilience was also associated with lower MetS severity (β = -0.227, p =  0.014) independent of perceived stress and HCC.

CONCLUSION

Findings suggest that psychological resilience may serve as both a stress buffer and as a direct determinant of cardiometabolic health. These results extend literature on psychological resilience to measures of retrospective HPA axis function and MetS severity in a diverse sample.

Resilience-based Diabetes Self-management Education: Perspectives From African American Participants, Community Leaders, and Healthcare Providers

Purpose The purpose of this qualitative, focus group study was to further refine the Resilience-based Diabetes Self-management Education (RB-DSME) recruitment process and intervention, build greater trust in the community, and identify strategies to enhance its sustainability as a community-based intervention in African American church settings. Methods Six 2-hour focus groups (N = 55; 10 men and 45 women) were led by a trained moderator with a written guide to facilitate discussion. Two sessions were conducted with individuals diagnosed with type 2 diabetes mellitus (T2DM) who participated in previous RB-DSME pilot interventions and their family members, two sessions with local church leaders, and two sessions with community healthcare providers who care for patients with T2DM. Two independent reviewers performed content analysis to identify major themes using a grounded theory approach. The validity of core themes was enhanced by external review and subsequent discussions with two qualitative methods consultants. Results There was expressed interest and acceptability of the RB-DSME program. Church connection and pastor support were noted as key factors in building trust and enhancing recruitment, retention, and sustainability of the program. Core themes across all groups included the value of incentives, the need for foundational knowledge shared with genuine concern, teaching with visuals, dealing with denial, balancing the reality of adverse consequences with hope, the importance of social support, and addressing healthcare delivery barriers. Conclusion Focus groups documented the feasibility and potential effectiveness of RB-DSME interventions to enhance diabetes care in the African American community. In clinical practice, inclusion of these core themes may enhance T2DM self-care and treatment outcomes.

Hair cortisol concentration and glycated hemoglobin in African American adults

BACKGROUND

African Americans have higher diabetes prevalence compared to Whites. They also have elevated cortisol levels - indicating possible HPA axis dysregulation - which may raise blood glucose as part of the biological response to physiological and psychosocial stress. Little is known about chronic cortisol levels in African Americans, and even less about the role of chronically elevated cortisol in type 2 diabetes development in this racial group.

PURPOSE

We used analysis of cortisol in hair to examine associations of long-term (∼3months) cortisol levels with glycated hemoglobin (HbA1c) in a group of African American adults. In exploratory analyses, we also studied the relationship of hair dehydroepiandrosterone (DHEA) with HbA1c.

METHOD

Participants were 61 community-dwelling African American adults (85% female; mean age 54.30 years). The first 3cm of scalp-near hair were analyzed for cortisol and DHEA concentration using enzyme-linked immunoassay analysis. Glycated hemoglobin was assessed, and regression analyses predicting HbA1c from hair cortisol and DHEA were performed in the full sample and in a subsample of participants (n=20) meeting the National Institute of Diabetes and Digestive Kidney Disease (NIDDK) criteria for type 2 diabetes (HbA1c≥6.5%).

RESULTS

In the full sample, HbA1c increased with hair cortisol level (β=0.22, p=0.04, f(2)=0.10), independent of age, sex, chronic health conditions, diabetes medication use, exercise, and depressive symptoms. In the subsample of participants with an HbA1c≥6.5%, hair cortisol was also positively related to HbA1c (β=0.45, p=0.04, f(2)=0.32), independent of diabetes medication use. Glycated hemoglobin was unrelated to hair DHEA in both the full sample and HbA1c≥6.5% subsample.

CONCLUSION

Long-term HPA axis dysregulation in the form of elevated hair cortisol is associated with elevated HbA1c in African American adults.

A resilience intervention in African-American adults with type 2 diabetes

OBJECTIVES

To explore the feasibility and outcomes of a resilience-based diabetes self-management education (RB-DSME) program to improve psychological and physiological health in African-American adults with type 2 diabetes.

METHODS

An experimental group (N = 32) received RB-DSME and a comparison group (N = 33) received standard DSME. Psychological and physiological measures were taken at baseline and 6 months. ANCOVAs assessed whether the experimental group improved its overall outcome relative to the comparison group, while controlling for baseline scores.

RESULTS

The experimental group's outcomes were significantly improved vis-à-vis the comparison group for diabetes knowledge, positive meaning, HDL cholesterol, and fasting blood glucose.

CONCLUSIONS

The RB-DSME shows feasibility and promise for enhancing health; a full-scale randomized trial is warranted.

Positivity and indicators of health among African Americans with diabetes

OBJECTIVES

To examine the utility of the positivity ratio to distinguish differences in psychological and physiological health in African Americans with type 2 diabetes.

METHODS

Study participants (N = 93) were recruited through radio and church announcements and grouped by their positivity ratio.

RESULTS

Multivariate analyses showed flourishing individuals had the highest resilience and lowest depressive symptoms and HbA1c (A1C), whereas depressed individuals recorded the lowest resilience and highest depressive symptoms and A1C. Small to large effect sizes were reported.

CONCLUSIONS

Further support for the utility and generalizability of the positivity ratio was provided. Cultivating positive emotions may improve the health of individuals with type 2 diabetes.

The molecular basis of hypertension

More than 50 million Americans display blood pressures outside the safe physiological range. Unfortunately for most individuals, the molecular basis of hypertension is unknown, in part because pathological elevations of blood pressure are the result of abnormal expression of multiple genes. This review identifies a number of important blood pressure regulatory genes including their loci in the human, mouse, and rat genome. Phenotypes of gene deletions and overexpression in mice are summarized. More detailed discussion of selected gene products follows, beginning with proteins involved in ion transport, specifically the epithelial sodium channel and sodium proton exchangers. Next, proteins involved in vasodilation/natriuresis are discussed with emphasis on natriuretic peptides, guanylin/uroguanylin, and nitric oxide. The renin angiotensin aldosterone system has an important role antagonizing the vasodilatory cyclic GMP system.

A genetic model defines the importance of the atrial natriuretic peptide receptor (guanylyl cyclase-A) in the regulation of kidney function

Disruption of the atrial natriuretic peptide (ANP) receptor [guanylyl cyclase-A (GC-A)] gene yields mice with a salt-resistant form of hypertension, raising fundamental questions on the role of ANP in acute regulation of the kidney. Here, we show that water intake, food consumption, stool weight, urine volume, and sodium excretion are not significantly different between wild-type and GC-A null mice on standard rodent chow (0.7% NaCl) or a high-salt diet (8% NaCl). In conscious mice with an indwelling catheter, the infusion of a physiological saline solution containing 4% BSA resulted in a marked natriuresis/diuresis in wild-type mice but no response in GC-A null animals. When physiological saline was given by gavage, however, the kidney response of wild-type and null mice was equivalent, raising the possibility that the gastrointestinal tract can directly regulate kidney function. However, administration of 0.9% saline through an intraperitoneal route also resulted in equal kidney responses in wild-type and null mice. When 0.9% NaCl lacking protein was infused i.v., wild-type and null mice both responded at the kidney level. Thus, GC-A appears dispensable for regulation of sodium/water excretion in response to changes in dietary sodium concentration, but likely becomes critical in volume expansions where the isooncotic pressure remains constant, such as head-out immersion or the initial and correctable stages of congestive heart failure.

Magnetic resonance imaging accurately estimates LV mass in a transgenic mouse model of cardiac hypertrophy

Transgenic mice with a dysfunctional guanylyl cyclase A gene (GCA -/-) are unable to transduce the signals from atrial naturetic peptide and develop hypertension and cardiac hypertrophy. Magnetic resonance imaging (MRI) was performed to assess cardiac hypertrophy in these animals, using wild-type siblings as controls. Anesthetized mice were studied by gated multislice, multiphase cine MRI at 1.5 T. Simpson's rule was used to estimate left ventricle (LV) mass and volumes from short-axis images. Correlation between LV mass evaluated by MRI and at necropsy was excellent, with LVnecropsy = 1.04 x LVMRI + 4.69 mg (r2 = 0.95). By MRI, GCA -/- LV mass was significantly different when compared with isogenic controls [GCA -/-, 226 +/- 43 mg (n = 14) vs. controls, 156 +/- 14 mg (n = 10); P < 0.0001]. LV volumes and ejection fraction in the two groups were not significantly different. MRI provides an accurate means for the noninvasive assessment of murine cardiac phenotype and may be useful in following the effects of genetic modification.

The heart communicates with the kidney exclusively through the guanylyl cyclase-A receptor: acute handling of sodium and water in response to volume expansion

Disruption of guanylyl cyclase-A (GC-A) results in mice displaying an elevated blood pressure, which is not altered by high or low dietary salt. However, atrial natriuretic peptide (ANP), a proposed ligand for GC-A, has been suggested as critical for the maintenance of normal blood pressure during high salt intake. In this report, we show that infusion of ANP results in substantial natriuresis and diuresis in wild-type mice but fails to cause significant changes in sodium excretion or urine output in GC-A-deficient mice. ANP, therefore, appears to signal through GC-A in the kidney. Other natriuretic/diuretic factors could be released from the heart. Therefore, acute volume expansion was used as a means to cause release of granules from the atrium of the heart. That granule release occurred was confirmed by measurements of plasma ANP concentrations, which were markedly elevated in both wild-type and GC-A-null mice. After volume expansion, urine output as well as urinary sodium and cyclic GMP excretion increased rapidly and markedly in wild-type mice, but the rapid increases were abolished in GC-A-deficient animals. These results strongly suggest that natriuretic/diuretic factors released from the heart function exclusively through GC-A.

Prevention of hypercalciuria and stone-forming propensity during prolonged bedrest by alendronate

The bone loss and hypercalciuria induced by immobilization or the decreased gravitational forces of space are well described. Using a model of bedrest immobilization, the ability of a potent aminobisphosphonate, alendronate, to avert hypercalciuria and stone-forming propensity was tested. Sixteen male subjects participated in a randomized, placebo-controlled trial in which they received either 20 mg of alendronate or placebo 2 weeks prior to and during 3 weeks of strict bedrest. Parameters of bone and calcium metabolism and urinary crystallization of stone-forming salts were measured before and at the end of bedrest. In the placebo group, bedrest increased urinary calcium (209 +/- 47 to 267 +/- 60 mg/day, p < 0.01) and the saturation of calcium phosphate. Before bedrest, the alendronate group had a significantly lower serum calcium (8.8 +/- 0.4 vs. 9.6 +/- 0.5 mg/dl, p < 0.01) and higher serum PTH (62.4 +/- 33.1 vs. 23.1 +/- 7.5 pg/ml, p < 0.01) compared with the placebo group. Moreover, the alendronate group had a lower urinary calcium (75 +/- 41 mg/day) and saturation of calcium oxalate and calcium phosphate. These effects of alendronate were sustained during bedrest. Following bedrest in the alendronate group, urinary calcium rose to 121 +/- 50 mg/day, a value less than that in the placebo group before or during bedrest. Similarly, urinary saturation of calcium oxalate and calcium phosphate rose with bedrest in the alendronate-treated patients but remained lower than values obtained in placebo-treated patients before or during bedrest. Alendronate inhibits bone mineral loss and averts the hypercalciuria and increased propensity for the crystallization of stone-forming calcium salts which occurs during 3 weeks of strict bedrest.