How to treat hypertension in blacks: review of the evidence

Risk Factors for Diabetic Retinopathy in Latin America (Mexico) and the World: A Systematic Review and Meta-Analysis

Diabetic retinopathy (DR) is one of the main complications of diabetes, and the management of the main control parameters explains only an 11% reduction in the risk of progressing to DR, leaving 89% to be explained by other factors or correlations between the usual factors that are currently unknown. The objective of this systematic review and meta-analysis is to evaluate the similarities and differences between the possible risk factors for developing DR when comparing the world to Latin American populations. The search was performed first for Latin American (LA) populations and a second search for non-Latin American (Non-LA) populations. Using the PRISMA guidelines, five articles were found to be relevant for each of the groups. The patients who had elevated systolic blood pressure (SBP) developed DR more frequently than the patients without retinopathy (Z = 2.1, p = 0.03), an effect measured in the population at a global level (GL), behavior that becomes not significant when the LA and non-LA populations are grouped separately; relevant to this is that the diagnosis of hypertension (HBP) grouped globally and stratified does not present a risk factor for DR (Z = 0.79, p = 0.42). This indicates that SBP is a risk factor for the world population and that, by separating it into different regions, the omission could cause it not to be considered a possible risk factor. In conclusion, the relationship between the increase in DR associated with the risk factors present in different populations, the limited research conducted in Latin America, and the cultural, social, economic, and genetic differences makes for a complex condition, which reflects the necessity of researching in a more integrated way.

Real-World Effectiveness and Safety of Two-Drug Single Pill Combinations of Antihypertensive Medications for Blood Pressure Management: A Follow-Up on Daily Cardiology Practice in Douala, Cameroon

INTRODUCTION

Hypertension is the leading cause of morbidity and mortality in sub-Saharan Africa (SSA). Current guidelines recommend using two or more antihypertensive agents in single pill combinations (SPCs) to treat hypertension, but data from African patients that support these recommendations are lacking. We assessed the effectiveness and tolerance of three SPCs in lowering blood pressure (BP) amongst hypertensive patients in Douala.

METHOD

All patients included in the hypertension registry of the Douala General Hospital and the Douala Cardiovascular Center between January 2010 and May 2020, and receiving a two-drug SPCs (renin-angiotensin system inhibitors (RAASi) + diuretics (DIU), calcium channel blockers (CCB) + RAASi, or DIU + CCB) were tracked from baseline through 16 weeks. Our primary outcome was a decrease in systolic BP (SBP) from baseline up to 16 weeks after initiation of treatment. A mixed linear repeated model was used to evaluate the change of SBP from baseline to week 16, while controlling for age, gender, and baseline SBP. Statistical significance was set at p < 0.05.

RESULTS

Of 377 participants on two-drug SPCs, 123 were on CCB + DIU, 96 on RAASi + CCB, and 158 on RAASi + DIU. The mean age was 54.6 (± 11.2) years. At baseline, participants on RAASi + CCB presented with slightly higher SBP compared to the other two groups. Overall, the SBP decreased by 34.3 (± 14.2) mmHg from baseline values and this was comparable across the three groups of SPCs (p = 0.118). The control rate after 16 weeks of follow-up was 62.3% with no significant difference between groups. The occurrence of adverse events was 3.4% and was comparable among the three groups.

CONCLUSION

The three two-drug SPCs were highly effective in reducing and controlling BP with low and similar rates of adverse effects. Long-term data documenting safety and whether these agents exert a differential cardiovascular effect in addition to and independent of their BP-lowering effect are needed for SSA populations.

Genomic ancestry as a risk factor for diabetic retinopathy in patients with type 1 diabetes from an admixed population: a nested case-control study in Brazil

AIMS

The influence of genetic factors on the development and progression of diabetic retinopathy is still unclear. Previous studies showed controversial results. We aimed to characterize the relationship between genomic ancestry and self-reported color/race with severe diabetic retinopathy in patients with type 1 diabetes belonging to a highly admixed population.

METHODS

This study was a nested case-control based on data collected from a large cross-sectional, nationwide survey conducted in clinics from all five geographic regions of Brazil. For the present study, we included 414 individuals. Cases (n = 176) were considered if they had severe non-proliferative or proliferative diabetic retinopathy, and controls (n = 238) were type 1 diabetes patients without retinopathy, matched for diabetes duration by a range of 5 years. Indirect ophthalmoscopy was performed, and individual genomic ancestry was inferred using a panel of 46 ancestry informative markers.

RESULTS

The backward stepwise logistic regression analysis showed that African genomic ancestry (OR 3.9, p = 0.045), HbA1c (OR 1.24, p = 0.001), glomerular filtration rate (OR 0.98, p < 0.001) and hypertension (OR 2.52, p < 0.001) were associated with severe diabetic retinopathy after adjusting for clinical and demographic data. Self-reported color/race was not statistically associated with diabetic retinopathy.

CONCLUSIONS

Genomic ancestry, as well as clinical variables such as hypertension, impaired glomerular filtration rate and poor diabetes control (HbA1c), was important risk factor for the development of severe diabetic retinopathy. Further studies are needed, especially in highly admixed populations, to better understand the role of genomic ancestry and possible genes that might be associated with the development and/or progression of diabetic retinopathy.

Sympathetic neural reactivity to mental stress differs in black and non-Hispanic white adults

Black adults have a higher risk of hypertension compared with non-Hispanic white (NHW) adults, but physiological mechanisms underlying this predisposition remain unclear. This study compared muscle sympathetic nerve activity (MSNA) responses to mental stress in a group of young black and NHW participants. We hypothesized that the sympathoexcitation associated with mental stress would be greater in black adults compared with NHW participants. Thirty-five male adults (19 black, 23 ± 1 yr; 16 NHW, 22 ± 1 yr) were examined during 5-min supine baseline and 5 min of mental stress (via mental arithmetic). Baseline mean arterial pressure (80 ± 2 vs. 82 ± 1 mmHg), heart rate (61 ± 4 vs. 61 ± 2 beats/min), MSNA (13 ± 1 vs. 15 ± 2 bursts/min), and sympathetic baroreflex sensitivity (-1.1 ± 0.4 vs. -1.5 ± 0.3 bursts·100 heart beats^-1·mmHg^-1) were not significantly different between NHW and black adults ( P > 0.05), respectively. MSNA reactivity to mental stress was significantly higher in NHW compared with black adults (time × race, P = 0.006), with a particularly divergent responsiveness during the first minute of mental stress in NHW (Δ4 ± 1 burst/min) and black (Δ-2 ± 2 burst/min; P = 0.022) men. Blood pressure and heart rate reactivity to mental stress were similar between groups. In summary, black participants demonstrated a lower MSNA responsiveness to mental stress compared with NHW adults. These findings suggest that, despite a higher prevalence of hypertension, black subjects do not appear to have higher neural and cardiovascular responsiveness to mental stress compared with NHW. NEW & NOTEWORTHY Black men have a blunted muscle sympathetic nerve activity response to mental stress compared with non-Hispanic white (NHW) men, especially at the onset of mental stress when muscle sympathetic nerve activity decreased in blacks and increased in NHW men. Thus, despite a high prevalence of hypertension in blacks, normotensive NHW men display a greater peripheral sympathetic neural reactivity to mental stress than black men.

Triple-Combination therapy with olmesartan, amlodipine, and hydrochlorothiazide in black and non-black study participants with hypertension: the TRINITY randomized, double-blind, 12-week, parallel-group study

BACKGROUND

Although awareness of hypertension in Black patients has increased, blood pressure (BP) is frequently inadequately controlled.

OBJECTIVE

This prespecified subgroup analysis of the TRINITY study evaluated the efficacy and safety of olmesartan medoxomil (OM) 40 mg, amlodipine besylate (AML) 10 mg, and hydrochlorothiazide (HCTZ) 25 mg triple-combination treatment compared with the component dual-combination treatments in Black and non-Black study participants.

STUDY DESIGN

TRINITY was a 12-week, randomized, double-blind, parallel-group evaluation. The first patient was enrolled in May 2008 and the last patient completed the study in February 2009. The study consisted of a 3-week washout period for participants receiving antihypertensive therapy and a 12-week double-blind treatment period. For the treatment phase, all study participants were stratified by age, race, and diabetes mellitus status and randomized to a treatment sequence that led to their final treatment assignment, which they received from weeks 4 to 12 (OM 40 mg/AML 10 mg/HCTZ 25 mg, OM 40 mg/AML 10 mg, OM 40 mg/HCTZ 25 mg, or AML 10 mg/HCTZ 25 mg). In the first 2 weeks of the double-blind treatment period, all participants received either dual-combination treatment or placebo. Participants assigned to dual-combination treatment continued treatment until week 4, and participants receiving placebo were switched at week 2 to receive one of the dual-combination treatments until week 4. At week 4, participants either continued dual-combination treatment or randomly received triple-combination treatment until week 12.

SETTING

317 clinical sites in the USA and Puerto Rico were included in the study.

PATIENTS

Study participants eligible for randomization (N = 2492) were ≥18 years of age with mean seated blood pressure (SeBP) ≥140/100 mmHg or ≥160/90 mmHg (off antihypertensive medication).

INTERVENTION

The intervention was with dual- or triple-combination antihypertensive treatment: OM 40 mg/AML 10 mg/HCTZ 25 mg, OM 40 mg/AML 10 mg, OM 40 mg/HCTZ 25 mg, or AML 10 mg/HCTZ 25 mg.

MAIN OUTCOME MEASURE

The primary efficacy variable was the change in least squares (LS) mean seated diastolic BP (SeDBP) from baseline to week 12. Secondary efficacy variables included the LS mean change in seated systolic BP (SeSBP), percentage of study participants reaching BP goal, and safety parameters.

RESULTS

In both Black and non-Black participants, triple-combination treatment resulted in significant and similar mean reductions in SeDBP and SeSBP (p ≤ 0.0001 vs each dual-combination treatment) with a greater proportion of participants reaching BP goal compared with dual-combination treatments, regardless of race. Most treatment-emergent adverse events were mild or moderate in severity and no new safety concerns were identified.

CONCLUSION

Triple-combination treatment provided greater BP reductions than dual-combination treatments regardless of race.

CLINICAL TRIAL REGISTRATION

Registered at ClinicalTrials.gov as NCT00649389.

Prevalence of diabetic retinopathy in various ethnic groups: a worldwide perspective

The alarming rise in diabetes prevalence is a global public health and economic problem. Diabetic retinopathy is the most common complication of diabetes and the leading cause of blindness among working-age populations in the Western world. Screening and prompt treatment of diabetic retinopathy are not top priorities in many regions of the world, because the impacts of other causes of preventable blindness remain an issue. Ethnicity is a complex, independent risk factor for diabetic retinopathy. Observations from white populations cannot be extrapolated fully to other ethnic groups. The prevalence of diabetic retinopathy, sight-threatening diabetic retinopathy, and clinically significant macular edema are higher in people of South Asian, African, Latin American, and indigenous tribal descent compared to the white population. Although all ethnic groups are susceptible to the established risk factors of diabetic retinopathy-such as length of exposure and severity of hyperglycemia, hypertension, and hyperlipidemia-ethnic-specific risk factors also may influence these rates. Such risk factors may include differential susceptibility to conventional risk factors, insulin resistance, differences in anthropometric measurements, truncal obesity, urbanization, variations in access to healthcare systems, genetic susceptibility, and epigenetics. The rates of nonproliferative diabetic retinopathy appear to be declining in the United States, supporting the observation that better medical management of diabetes and prompt treatment of sight-threatening diabetic retinopathy substantially improve the long-term diabetic retinopathy incidence; studies from other parts of the world are limited and do not mirror this finding, however. We examine the ethnicity and region-based prevalence of diabetic retinopathy around the world and highlight the need to reinforce ethnicity-based screening and treatment thresholds in diabetic retinopathy.

Stroke: a realistic approach to a growing problem in sub-Saharan Africa is urgently needed

Stroke is an increasing problem in sub-Saharan Africa, even in children. High rates of hypertension, diabetes, alcohol abuse, smoking, insufficient fruit and vegetable consumption, sickle cell disease, HIV infection, antiretroviral use and race are likely contributing factors. Although often considered as related to increasing wealth, stroke is more strongly related to poverty, and in turn increases it. Case-fatality rates are high and premature death and years of life lost are a major problem. We propose an approach to stroke prevention and treatment that takes into account the real situation on the ground and can be applied in sub-Saharan Africa, an area where stroke units are largely not feasible and many patients do not reach hospitals. Involvement of community and faith-based organisations, use of simple diagnostic tests, emphasis on clinical examination to differentiate between haemorrhagic and ischaemic stroke, prompt initiation of aspirin therapy and training of community nurses on essential management of stroke should be urgently implemented.