Comparison of Dual Therapies for Lowering Blood Pressure in Black Africans.

BACKGROUND: The prevalence of hypertension among black African patients is high, and these patients usually need two or more medications for blood-pressure control. However, the most effective two-drug combination that is currently available for blood-pressure control in these patients has not been established. METHODS: In this randomized, single-blind, three-group trial conducted in six countries in sub-Saharan Africa, we randomly assigned 728 black patients with uncontrolled hypertension (≥140/90 mm Hg while the patient was not being treated or was taking only one antihypertensive drug) to receive a daily regimen of 5 mg of amlodipine plus 12.5 mg of hydrochlorothiazide, 5 mg of amlodipine plus 4 mg of perindopril, or 4 mg of perindopril plus 12.5 mg of hydrochlorothiazide for 2 months. Doses were then doubled (10 and 25 mg, 10 and 8 mg, and 8 and 25 mg, respectively) for an additional 4 months. The primary end point was the change in the 24-hour ambulatory systolic blood pressure between baseline and 6 months. RESULTS: The mean age of the patients was 51 years, and 63% were women. Among the 621 patients who underwent 24-hour blood-pressure monitoring at baseline and at 6 months, those receiving amlodipine plus hydrochlorothiazide and those receiving amlodipine plus perindopril had a lower 24-hour ambulatory systolic blood pressure than those receiving perindopril plus hydrochlorothiazide (between-group difference in the change from baseline, -3.14 mm Hg; 95% confidence interval [CI], -5.90 to -0.38; P = 0.03; and -3.00 mm Hg; 95% CI, -5.8 to -0.20; P = 0.04, respectively). The difference between the group receiving amlodipine plus hydrochlorothiazide and the group receiving amlodipine plus perindopril was -0.14 mm Hg (95% CI, -2.90 to 2.61; P=0.92). Similar differential effects on office and ambulatory diastolic blood pressures, along with blood-pressure control and response rates, were apparent among the three groups. CONCLUSIONS: These findings suggest that in black patients in sub-Saharan Africa, amlodipine plus either hydrochlorothiazide or perindopril was more effective than perindopril plus hydrochlorothiazide at lowering blood pressure at 6 months. (Funded by GlaxoSmithKline Africa Noncommunicable Disease Open Lab; CREOLE ClinicalTrials.gov number, NCT02742467.).

High prevalence of non-dipping patterns among Black Africans with uncontrolled hypertension: a secondary analysis of the CREOLE trial.

BACKGROUND: Dipping of blood pressure (BP) at night is a normal physiological phenomenon. However, a non-dipping pattern is associated with hypertension mediated organ damage, secondary forms of hypertension and poorer long-term outcome. Identifying a non-dipping pattern may be useful in assessing risk, aiding the decision to investigate for secondary causes, initiating treatment, assisting decisions on choice and timing of antihypertensive therapy, and intensifying salt restriction. OBJECTIVES: To estimate the prevalence and factors associated with non-dipping pattern and determine the effect of 6 months of three antihypertensive regimens on the dipping pattern among Black African hypertensive patients. METHODS: This was a secondary analysis of the CREOLE Study which was a randomized, single blind, three-group trial conducted in 10 sites in 6 Sub-Saharan African countries. The participants were 721 Black African patients, aged between 30 and 79 years, with uncontrolled hypertension and a baseline 24-h ambulatory blood pressure monitoring (ABPM). Dipping was calculated from the average day and average night systolic blood pressure measures. RESULTS: The prevalence of non-dipping pattern was 78% (564 of 721). Factors that were independently associated with non-dipping were: serum sodium > 140 mmol/l (OR = 1.72, 95% CI 1.17-2.51, p-value 0.005), a higher office systolic BP (OR = 1.03, 95% CI 1.01-1.05, p-value 0.003) and a lower office diastolic BP (OR = 0.97, 95% CI 0.95-0.99, p-value 0.03). Treatment allocation did not change dipping status at 6 months (McNemar's Chi2 0.71, p-value 0.40). CONCLUSION: There was a high prevalence of non-dipping among Black Africans with uncontrolled hypertension. ABPM should be considered more routinely in Black Africans with uncontrolled hypertension, if resources permit, to help personalise therapy. Further research is needed to understand the mechanisms and causes of non-dipping pattern and if targeting night-time BP improves clinical outcomes. Trial registration ClinicalTrials.gov (NCT02742467).

The importance of the epithelial sodium channel in determining salt sensitivity in people of African origin.

Hypertension is highly prevalent in Black Africans and has been found to be associated with worse blood pressure (BP) control and more cardiovascular disease. Black Africans are more salt sensitive with low renin and aldosterone levels. This can be explained in part by variants in the epithelial sodium channel (ENaC) causing an increase in channel activity resulting in sodium and water retention. These variants in the ENaC are increased in the Black African populations presumably due to selective pressure for sodium retention in traditionally low-salt diets. Furthermore, increased endothelial sodium channel activity contributes to the risk of vascular stiffness, which may also result in more difficult to control hypertension. Patients with increased activity of the ENaC are more likely to respond to amiloride (a selective sodium channel antagonist), which has implications for the management of severe and resistant hypertension in Black Africans. A large-scale controlled trial on the use of amiloride compared to usual care is warranted in Blacks with severe or resistant hypertension.

The relevance of performing 24-hour ambulatory blood pressure and pulse wave analysis in kidney transplant recipients.

Hypertension guidelines recommend out-of-office blood pressure (BP) measurement especially 24-hour ambulatory measurement (ABPM), to diagnose and manage hypertension but this is not routinely performed in kidney transplant units. This study was to determine if 24-hour ABPM, compared with office BP in kidney transplant recipients, would be more informative regarding BP management, and if pulse wave analysis (PWA) would assist in risk stratification. This study included patients older than 18 years, with working graft kidney for > 12 months, and without problems affecting BP measurement and interpretation. After performing office BP measurements, a 24-hour ABPM with additional capability of calculating pulse wave velocity (PWV), augmentation index and central BP was undertaken. Patients were assessed for controlled hypertension, uncontrolled hypertension, masked hypertension, nocturnal hypertension, white coat hypertension, and dipping BP status. Data were analyzed using standard statistical tests. Of 30 patients, 15 were Black Africans and 15 were of Mixed Ancestry with a mean age of 48.9 years. 17 patients were males and 36.7% had controlled hypertension, 30% uncontrolled hypertension, 6.7% white coat hypertension, and 33.3% masked hypertension, of whom 70% had isolated nocturnal hypertension. 70% had a non-dipping, 26.7% a reverse dipping and only 3.3% had a normal dipping BP pattern. The mean difference between brachial systolic BP and central systolic BP was 10.4 mmHg, whereas PWV and augmentation index were similar to healthy populations. Conclusion: In kidney transplant recipients, 24-hour ABPM was superior to office BP in defining hypertensive status that qualified for modification of therapy, but PWA did not contribute to risk assessment.

The impact of vascular calcification among dialysis-dependent South African patients: A 5-year follow-up study
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BACKGROUND: Vascular calcification is a major risk factor for cardiovascular morbidity and mortality in patients with end-stage renal disease (ESRD). In Western countries, Blacks appear to have lesser degrees of vascular calcification compared to non-Blacks. However, there is no published data from sub-Saharan Africa. MATERIALS AND METHODS: This study assessed the 5-year change in vascular calcification and mortality in a previously published cohort of patients with ESRD. Vascular calcification was assessed by abdominal aortic calcification score and vascular stiffness by pulse wave velocity (PWV). RESULTS: 66 of the original 74 participants studied at baseline were identified. The median age was 46.6 years (37.6 - 59.2), and 57.6% were women. Abdominal aortic calcification showed no progression among Blacks (baseline range 0 - 5, follow-up range 0 - 8 (p = 1.00)), but a trend to progression among non-Blacks (baseline range 0 - 19, follow up range 0 - 22 (p = 0.066)). Black participants did not display a survival advantage (p = 0.870). Non-Blacks had higher parathyroidectomy rates than Blacks with 9/30 cases compared to 2/36 (p = 0.036). After adjustment for parathyroidectomy at follow-up, the odds ratio of having abdominal vascular calcification score of ≥ 1 amongst non-Blacks was 8.6-fold greater compared to Blacks (p = 0.03). A positive correlation (r = 0.5) was observed between PWV and abdominal aortic calcification (p = 0.047). Elevated baseline coronary artery calcification score and FGF-23 level at baseline were not associated with a difference in mortality. CONCLUSION: There was no significant progression in vascular calcification among Blacks. After adjusting for increased parathyroidectomy rates, there was a greater progression of vascular calcification amongst non-Blacks compared to Blacks.

A Multicenter, Cross-Sectional Quality Improvement Project: The Perioperative Implementation of a Hypertension Protocol by Anesthesiologists.

BACKGROUND: Hypertension is a common risk factor for cardiovascular morbidity and mortality, with a high prevalence in patients presenting for elective surgery. In limited resource environments, patients have poor access to primary care physicians, limiting the efficacy of lifestyle modification for the management of hypertension. In these circumstances, the perioperative period presents a unique opportunity for diagnosis and initiation and/or modification of pharmacotherapy of hypertension. Anesthesiologists are ideally placed to lead this aspect of perioperative medicine. The study objective was for anesthesiologists to identify patients at the preoperative visit with previously undiagnosed or poorly controlled chronic hypertension and follow a simple management algorithm. METHODS: In collaboration with expert physicians, we designed and implemented an algorithm for the diagnosis and management of chronic hypertension. This was a multicenter, cross-sectional quality improvement project in 7 hospitals in the Western Cape, South Africa. On the day before scheduled elective surgery, adult in-patients had 2 sets of blood pressure (BP) readings taken, one by nurses and the other by anesthesiologists, using a noninvasive automated BP device. These were averaged on an electronic database, to diagnose hypertension. Patients with normal BP or well-controlled hypertension required no further management. Those with borderline BP received educational pamphlets. Patients with stage 1 or 2 hypertension were managed with medication according to the algorithm, starting 1 day postoperatively, and provided with educational pamphlets. Patients with stage 3 disease had their surgery postponed and were referred to a physician. The primary outcome was adherence by the anesthesiologist to the algorithm in the diagnosis and management of hypertension. An 80% adherence rate was considered successful implementation. The secondary outcome was the adherence to the algorithm at discharge. RESULTS: Two hundred ninety-eight patients were screened for hypertension. One hundred six patients were eligible for the quality improvement project. Thirty-seven (34.9%) had borderline BP readings, 43 (40.6%) had stage 1, 22 (20.8%) stage 2, and 4 (3.8%) stage 3 hypertension, respectively. The adherence rate by the anesthesiologist in initiating treatment according to the algorithm was 89 of 106 (84.0%; 95% confidence interval [CI, 77.0-91.0). There was full adherence to the algorithm in 59 of 106 (55.5%; 95% CI, 46.2-65.1) at the time of discharge from hospital. CONCLUSIONS: Anesthesiologists successfully implemented a quality improvement project for diagnosis and management of hypertension in the perioperative period. This has the potential to reduce the public health burden of hypertension in limited resource environments. Successful ongoing prescription and follow-up requires cooperation within a multidisciplinary team.

Body weight and eGFR during dulaglutide treatment in type 2 diabetes and moderate-to-severe chronic kidney disease (AWARD-7).

In patients with type 2 dibetes and moderate-to-severe chronic kidney disease, dulaglutide treatment led to body weight (BW) loss and lesser eGFR decline compared to insulin glargine. As BW may affect muscle mass, creatinine-based eGFR can be altered independently of kidney function. Cystatin C-based eGFR is not affected by muscle mass. The objective of this post-hoc analysis was to determine whether the lesser eGFR decline with dulaglutide was related to BW loss. Baseline characteristics were similar between treatments ([mean ± SD] age, 64.6 ± 8.6 years; women, 48%; BW, 89.1 ± 17.7 kg; eGFR [CKD-EPI-cystatin C] 38 ± 14 mL/min/1.73m2 ). BW decreased with dulaglutide 1.5 and 0.75 mg and increased with insulin glargine ([LSM change (SE)], -2.66 [0.47] kg and -1.71 [0.45] vs 1.57 [0.43] kg; P < 0.001). Changes in eGFR were not significant with dulaglutide 1.5 and 0.75 mg, but eGFR significantly decreased with insulin glargine (eGFR-CKD-EPI-cystatin C [LSM change (95%CI)], -0.7 [-2.5, 1.0] and -0.7 [-2.4, 1.1] vs -3.3 [-5.1, -1.6] mL/min/1.73 m2 ; P ≤ 0.037 vs glargine). Changes in BW did not correlate with changes in eGFR-CKD-EPI-cystatin C (r = -0.041; n = 471; P = 0.379) or eGFR-CKD-EPI-creatinine (r = -0.074; n = 473; P = 0.106). In conclusion, the lesser decline in eGFR observed with dulaglutide was not influenced by BW loss.

The effects of add-on corticosteroids on renal outcomes in patients with biopsy proven HIV associated nephropathy: a single centre study from South Africa.

BACKGROUND: The aim of this study was to assess, the efficacy and safety of add-on corticosteroids to antiretroviral therapy [ART] in patients with biopsy proven HIV associated nephropathy. METHODS: All included patients had histological evidence of either collapsing or non-collapsing focal segmental glomerulosclerosis (FSGS) or podocyte and/or parietal cell hypertrophy or hyperplasia. All patients had evidence of tubulointerstitial inflammation with microcysts. Patients were randomized to ART with the addition of 1 mg/kg of corticosteroids [ART+C] or remained in the group [ART Alone] and followed for 2 years. A repeat biopsy was performed at 6 months. RESULTS: Twenty-one patients were randomized to [ART+C] and 17 to [ART Alone]. The baseline estimated glomerular filtration rate (eGFR) was significantly lower in the [ART+C] vs. [ART Alone] group [35mls/min/1.73m2 vs. 47 mls/min/1.73m2, p = 0.015]. The [ART+C] cohort had a statistically significant improvement in median (eGFR) from baseline to last follow up compared with [ART Alone] i.e. [Δ = 25mls/min (IQR: 15;51) vs 9 mls/min (IQR: 0-24), p = 0.008]. There were no statistically significant differences between the groups when proteinuria and histology were analyzed. There were 8 deaths during the trial period, 7 from [ART+C] (Log rank p = 0.071). CONCLUSIONS: In the [ART+C] cohort there was a significant improvement in eGFR over 2-years with increased mortality. Routine corticosteroid use cannot currently be recommended. Further investigation to define which subgroup of this cohort would safely benefit from the positive effects is required. TRIAL REGISTRATION: ISRCTN study ID ( 56112439 ] was retrospectively registered on the 5 September 2018.

Mobile Phone Text Messages to Support Treatment Adherence in Adults With High Blood Pressure (SMS-Text Adherence Support [StAR]): A Single-Blind, Randomized Trial.

BACKGROUND: We assessed the effect of automated treatment adherence support delivered via mobile phone short message system (SMS) text messages on blood pressure. METHODS AND RESULTS: In this pragmatic, single-blind, 3-arm, randomized trial (SMS-Text Adherence Support [StAR]) undertaken in South Africa, patients treated for high blood pressure were randomly allocated in a 1:1:1 ratio to information only, interactive SMS text messaging, or usual care. The primary outcome was change in systolic blood pressure at 12 months from baseline measured with a validated oscillometric device. All trial staff were masked to treatment allocation. Analyses were intention to treat. Between June 26, 2012, and November 23, 2012, 1372 participants were randomized to receive information-only SMS text messages (n=457), interactive SMS text messages (n=458), or usual care (n=457). Primary outcome data were available for 1256 participants (92%). At 12 months, the mean adjusted change in systolic blood pressure compared with usual care was -2.2 mm Hg (95% confidence interval, -4.4 to -0.04) with information-only SMS and -1.6 mm Hg (95% confidence interval, -3.7 to 0.6) with interactive SMS. Odds ratios for the proportion of participants with a blood pressure <140/90 mm Hg were 1.42 (95% confidence interval, 1.03-1.95) for information-only messaging and 1.41 (95% confidence interval, 1.02-1.95) for interactive messaging compared with usual care. CONCLUSIONS: In this randomized trial of an automated adherence support program delivered by SMS text message in a general outpatient population of adults with high blood pressure, we found a small reduction in systolic blood pressure control compared with usual care at 12 months. There was no evidence that an interactive intervention increased this effect. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02019823. South African National Clinical Trials Register, number SANCTR DOH-27-1212-386; Pan Africa Trial Register, number PACTR201411000724141.

Clinical profile and outcome of patients with biopsy-proven acute interstitial nephritis in Cape Town: a 10-year review
.

BACKGROUND: Acute interstitial nephritis (AIN) is a common cause of acute kidney injury that has not been adequately characterized in Sub-Saharan Africa (SSA) despite an increasing use of potentially inciting agents for the treatment of human immunodeficiency virus (HIV) and tuberculosis in the region. METHODS: A retrospective audit of records of patients with biopsy-proven AIN diagnosed at Groote Schuur Hospital, Cape Town from the 1st of January, 2006, to the 31st of December, 2015. RESULTS: 54 patients with biopsy-proven AIN were reviewed. The majority were of black African origin (59.2%), with HIV (42.8%) and HIV-tuberculosis coinfection (30.5%) as the most common comorbidities. Drug-related AIN was seen in 38 (67.9%) patients, with rifampicin as the most often implicated medication. Probable drug-related AIN was seen in 3 (5.4%) patients, infection-related AIN in 8 (14.3%), and unspecified causes in 4 (7.4%). AIN was suspected in 44.6% of patients before biopsy. 18 patients (34%) received hemodialysis, while 19 (35.2%) were treated with corticosteroids. Complete renal recovery at 30 and 90 days was seen in 23 (42.6%) patients and 24 (45.3%) patients, respectively, with the majority seen among those with drug-induced AIN. Six (11.1%) patients died; 4 (10.5%) of the patients were in the drug-related group. There was no correlation between degree of interstitial inflammation and severity of renal failure (p = 0.10). On multivariate logistic regression, drug-related causes of AIN were predictive of complete recovery at day 30 (OR 16.63; 95% CI: 1.71 - 161.6, p = 0.02), and presence of interstitial fibrosis reduced likelihood of recovery (OR 0.03; 95% CI 0.002 - 0.46, p = 0.012). Steroid use did not influence partial recovery (OR 0.59, 95% CI 0.17 - 1.77; p = 0.32) or complete recovery (OR 3.38, 95% CI 0.38 - 30.39, p = 0.28). CONCLUSIONS: AIN is common in patients with HIV or those on treatment for tuberculosis. Drug-related AIN is often associated with improved outcomes. This is particularly reassuring in the SSA region where the use of potentially-inciting medications is rife from a high burden of HIV and tuberculosis.
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Mortality risk factors in intensive care unit patients with acute kidney injury requiring renal replacement therapy: a retrospective cohort study
.

BACKGROUND: Mortality of critically-ill patients with acute kidney injury (AKI) requiring renal replacement therapy (RRT) in an intensive-care setting continues to remain high. There is still uncertainty as to which factors should guide clinical judgement. METHODS: A cohort of 155 patients admitted to an intensive-care unit and necessitating RRT due to AKI were retrospectively analyzed. Demographic and clinical parameters at the time of RRT initiation were retrieved. Multi- and univariate analyses were performed to determine the impact of different risk factors on mortality. RESULTS: The most common causes of AKI were sepsis (39.3%) and cardiac events (32%). The majority of patients were treated by continuous (67.3%), the others by intermittent RRT. After 30 days, 51.0% of patients survived. Nonsurvivors were older (73 vs. 69 years), had a higher APACHEE II score (30.1 ± 5.6 vs. 26.5 ± 7.1), and were more likely to be vasopressor dependent, mechanically ventilated, or treated by continuous RRT. Multivariate analysis revealed that higher age, higher APACHEE II score, and lower serum creatinine at baseline were independent predictors for mortality, whereas histories of diabetes mellitus, arterial hypertension, coronary heart disease, or stroke were not. CONCLUSION: Critically-ill patients with AKI requiring RRT continue to have a high mortality. Age and APACHE II score showed an impact on mortality whereas traditional cardiovascular risk factors did not. Higher BUN and creatinine levels do not have a negative impact on mortality. Our findings support the current practice that RRT initiation should primarily be guided by clinical decision.
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The importance of G protein-coupled receptor kinase 4 (GRK4) in pathogenesis of salt sensitivity, salt sensitive hypertension and response to antihypertensive treatment.

Salt sensitivity is probably caused by either a hereditary or acquired defect of salt excretion by the kidney, and it is reasonable to consider that this is the basis for differences in hypertension between black and white people. Dopamine acts in an autocrine/paracrine fashion to promote natriuresis in the proximal tubule and thick ascending loop of Henle. G-protein receptor kinases (or GRKs) are serine and threonine kinases that phosphorylate G protein-coupled receptors in response to agonist stimulation and uncouple the dopamine receptor from its G protein. This results in a desensitisation process that protects the cell from repeated agonist exposure. GRK4 activity is increased in spontaneously hypertensive rats, and infusion of GRK4 antisense oligonucleotides attenuates the increase in blood pressure (BP). This functional defect is replicated in the proximal tubule by expression of GRK4 variants namely p.Arg65Leu, p.Ala142Val and p.Val486Ala, in cell lines, with the p.Ala142Val showing the most activity. In humans, GRK4 polymorphisms were shown to be associated with essential hypertension in Australia, BP regulation in young adults, low renin hypertension in Japan and impaired stress-induced Na excretion in normotensive black men. In South Africa, GRK4 polymorphisms are more common in people of African descent, associated with impaired Na excretion in normotensive African people, and predict blood pressure response to Na restriction in African patients with mild to moderate essential hypertension. The therapeutic importance of the GRK4 single nucleotide polymorphisms (SNPs) was emphasised in the African American Study of Kidney Disease (AASK) where African-Americans with hypertensive nephrosclerosis were randomised to receive amlodipine, ramipril or metoprolol. Men with the p.Ala142Val genotype were less likely to respond to metoprolol, especially if they also had the p.Arg65Leu variant. Furthermore, in the analysis of response to treatment in two major hypertension studies, the 65Leu/142Val heterozygote predicted a significantly decreased response to atenolol treatment, and the 65Leu/142Val heterozygote and 486Val homozygote were associated in an additive fashion with adverse cardiovascular outcomes, independent of BP. In conclusion, there is considerable evidence that GRK4 variants are linked to impaired Na excretion, hypertension in animal models and humans, therapeutic response to dietary Na restriction and response to antihypertensive drugs. It may also underlie the difference in hypertension between different geographically derived population groups, and form a basis for pharmacogenomic approaches to treatment of hypertension.

Efficacy of a text messaging (SMS) based intervention for adults with hypertension: protocol for the StAR (SMS Text-message Adherence suppoRt trial) randomised controlled trial.

BACKGROUND: Interventions to support people with hypertension in attending clinics and taking their medication have potential to improve outcomes, but delivery on a wide scale and at low cost is challenging. Some trials evaluating clinical interventions using short message service (SMS) text-messaging systems have shown important outcomes, although evidence is limited. We have developed a novel SMS system integrated with clinical care for use by people with hypertension in a low-resource setting. We aim to test the efficacy of the system in improving blood pressure control and treatment adherence compared to usual care. METHODS/DESIGN: The SMS Text-message Adherence suppoRt trial (StAR) is a pragmatic individually randomised three-arm parallel group trial in adults treated for hypertension at a single primary care centre in Cape Town, South Africa. The intervention is a structured programme of clinic appointment, medication pick-up reminders, medication adherence support and hypertension-related education delivered remotely using an automated system with either informational or interactive SMS text-messages. Usual care is supplemented by infrequent non-hypertension related SMS text-messages. Participants are 1:1:1 individually randomised, to usual care or to one of the two active interventions using minimisation to dynamically adjust for gender, age, baseline systolic blood pressure, years with hypertension, and previous clinic attendance. The primary outcome is the change in mean systolic blood pressure at 12-month follow-up from baseline measured with research staff blinded to trial allocation. Secondary outcomes include the proportion of patients with 80% or more of days medication available, proportion of participants achieving a systolic blood pressure less than 140 mmHg and a diastolic blood pressure less than 90 mmHg, hospital admissions, health status, retention in clinical care, satisfaction with treatment and care, and patient related quality of life. Anonymised demographic data are collected on non-participants. DISCUSSION: The StAR trial uses a novel, low cost system based on widely available mobile phone technology to deliver the SMS-based intervention, manage communication with patients, and measure clinically relevant outcomes. The results will inform implementation and wider use of mobile phone based interventions for health care delivery in a low-resource setting. TRIAL REGISTRATION: NCT02019823.

Genetic Factors Contributing to the Pathogenesis of Essential Hypertension in Two African Populations.

The African continent has the highest prevalence of hypertension globally, with South Africa reporting the highest prevalence in Southern Africa. While the influence of genetic variability in the pathogenesis of hypertension is well described internationally, limited reports are available for African populations. This study aimed to assess the association of genetic variants and essential hypertension in a cohort of two ethnic South African population groups. Two hundred and seventy-seven hypertensive and one hundred and seventy-six normotensive individuals were genotyped for 78 variants. Genotyping was performed using the Illumina GoldenGate Assay and allele-specific polymerase chain reaction. The association of variants was assessed using the Fisher Exact test under the additive and allelic genetic models, while multivariate logistic regression was used to predict the development of hypertension. Five variants (CYP11B2 rs179998, AGT rs5051 and rs699, AGTR1 rs5186, and ACE rs4646994) were significantly associated with essential hypertension in the cohort under study. Furthermore, AGTR1 rs5186 and AGT rs699 were identified as risk factors for the development of hypertension in both ethnic groups. In two ethnic South African populations, an association was observed between renin-angiotensin-aldosterone system (RAAS)-related genes and the development of hypertension.

Dialysis initiation: what's the rush?

The recent trend to early initiation of dialysis (at eGFR >10 ml/min/1.73 m(2) ) appears to have been based on conventional wisdoms that are not supported by evidence. Observational studies using administrative databases report worse comorbidity-adjusted dialysis survival with early dialysis initiation. Although some have concluded that the IDEAL randomized controlled trial of dialysis start provided evidence that patients become symptomatic with late dialysis start, there is no definitive support for this view. The potential harms of early start of dialysis, including the loss of residual renal function (RRF), have been well documented. The rate of RRF loss (renal function trajectory) is an important consideration for the timing of the dialysis initiation decision. Patients with low glomerular filtration rate (GFR) may have sufficient RRF to be maintained off dialysis for years. Delay of dialysis start until a working arterio-venous access is in place seems prudent in light of the lack of harm and possible benefit of late dialysis initiation. Prescribing frequent hemodialysis is not recommended when dialysis is initiated early. The benefits of early initiation of chronic dialysis after episodes of congestive heart failure or acute kidney injury require further study. There are no data to show that early start benefits diabetics or other patient groups. Preemptive start of dialysis in noncompliant patients may be necessary to avoid complications. The decision to initiate dialysis requires informed patient consent and a joint decision by the patient and dialysis provider. Possible talking points for obtaining informed consent are provided.

Kidney disease in elderly South Africans.

BACKGROUND: Life expectancy is low in many African countries due to several factors including the ongoing HIV epidemic. However, the global increase in life expectancy has translated to more elderly patients living with chronic kidney disease (CKD). The patterns of kidney disease in the elderly have never been described from sub-Saharan Africa. METHODS: This study was a retrospective study of 111 elderly patients (age ≥ 60 years) who had a renal biopsy performed at the Groote Schuur Hospital in Cape Town between 1st January 2000 and 31st December 2009. RESULTS: The mean age of patients at time of biopsy was 66.3 ± 5.7 years (males: 66.4 ± 5.6; females: 66.3 ± 5.9 years). Primary glomerular diseases were seen in 38.7%, secondary glomerular diseases in 36.0%, tubulointerstitial diseases in 17.1% and diseases classified as miscellaneous in 8.1% of all patients. Nephrotic syndrome was the most common indication for the performance of a renal biopsy (48.6%). Membranous lomerulonephritis (MGN) was the most common type of disease observed (14.4%) and was significantly more frequent in males than in females (p = 0.029). Other common histological diagnoses included diabetes nephropathy (12.6%), chronic glomerulonephritis (5.4%), and lupus nephritis (4.5%). HIV associated nephropathy (HIVAN) was only seen in 1 patient (0.9%). CONCLUSION: The patterns of renal disease currently seen in elderly South Africans closely resembles that reported from other countries but is at complete variance with the pattern reported in the general population of South Africa in which HIV plays a significant role.

Changes in blood pressure after catheter-based renal denervation in South Africa.

BACKGROUND: Renal denervation (RDN) is an interventional treatment for patients with uncontrolled hypertension. The Global SYMPLICITY Registry (GSR) is a prospective, all-comer, world-wide registry designed to assess the safety and efficacy of RDN. We evaluated the outcomes in South African patients in the GSR over 12 months. METHODS: Eligible patients with hypertension had a daytime mean blood pressure (BP) > 135/85 mmHg or night-time mean BP > 120/70 mmHg. Office and 24-hour ambulatory systolic BP reduction and adverse events over 12 months were evaluated. RESULTS: South African patients (n = 36) in the GSR had a mean age of 54.4 ± 9.9 years with a median of four prescribed antihypertensive medication classes. At 12 months, mean changes in office and 24-hour ambulatory systolic BP were -16.9 ± 24.2 and -15.3 ± 18.5 mmHg, respectively, with only one adverse event recorded. CONCLUSIONS: RDN safety and efficacy in South African patients were consistent with world-wide GSR results.

Primary Sjögren's syndrome with renal tubular acidosis and central pontine myelinolysis: An unusual triad.

Primary Sjögren's syndrome (pSS) is a complex, multisystem autoimmune disorder. It is characterized by lymphocytic infiltration of the exocrine glands. In the setting of pSS, the presence of systemic disease is an important prognostic determinant, but involvement of the kidney is uncommon. The triad of pSS, distal renal tubular acidosis (dRTA), and central pontine myelinolysis (CPM) is rare and potentially fatal. A 42-year-old woman presented with dRTA, profound hypokalemia, and CPM characterized by progressive global quadriparesis, ophthalmoplegia, and encephalopathy. Sjögren's syndrome was diagnosed based on sicca symptoms, clinical features, and strongly positive anti-SSA/Ro and anti-SSB/La autoantibodies. The patient responded well to electrolyte replacement, acid-base correction, corticosteroids, and subsequent cyclophosphamide therapy. Early recognition and appropriate treatment resulted in good kidney and neurological outcomes in this case. This report highlights the need to consider the diagnosis of pSS in unexplained dRTA and CPM, as it has a favorable prognosis if recognized and managed timeously.