Brief Report: Identification of Elite and Viremic Controllers From a Large Urban HIV Ambulatory Center in Kampala, Uganda.

BACKGROUND: Throughout the world, there are antiretroviral therapy-naive HIV+ individuals who maintain elevated peripheral CD4 T-cell counts, historically referred to as long-term nonprogressors (LTNPs). With recent improvements in viral load (VL) detection methods to levels as low as 20 copies per milliliter, 2 subsets of LTNPs have been defined: elite controllers (ECs), with undetectable VLs for at least 6-12 months, and viremic controllers (VCs), with VLs between 200 and 2000 copies per milliliter. ECs and VCs have been extensively studied in the developed world to determine underlying mechanisms responsible for virologic control. In sub-Saharan Africa, most studies have characterized LTNPs based on immunologic criteria making it difficult to compare findings with the Western cohorts, which use virologic criteria. Here, we describe a cohort of Uganda ECs and VCs attending a large HIV ambulatory center in Kampala, Uganda, based initially on CD4 counts and confirmed by repeated VL measurements. METHODS: A cross-sectional study was conducted among 14,492 HIV-infected, antiretroviral therapy-naive individuals aged 18 years and older under care for at least 5 years with serial peripheral CD4 counts ≥500 cells/μL. Among those, we determined the frequency of individuals with VLs <2000 copies per milliliter for at least 6 months. RESULTS: We report a prevalence of 0.26% (38/14,492) of HIV controllers in the clinic. We identified 36 ECs and 2 VCs. These individuals were middle-aged with an average CD4 count of 858 ± 172 (mean ± SD, 95% confidence interval: 795 to 921). Their average duration in HIV care was 7.4 ± 2.1 years (mean ± SD, 95% confidence interval: 6.6 to 8.1). The majority of EC/VCs were women (87%, 33/38), reflecting the demographics of the urban clinic. CONCLUSIONS: For the first time, this study demonstrates the frequency of EC/VCs in a large urban clinic in Uganda. Further study of these East African subjects may provide insights into how some individuals are able to control HIV in the absence of medications

Association between Blood Pressure and HIV Status in Rural Uganda: Results of Cross-Sectional Analysis.

Introduction: The association between HIV status and hypertension is not well described within sub-Saharan Africa. We examined prevalence and risk factors for hypertension among HIV positive and negative individuals living in a rural district of Uganda. Methods: We conducted a cross-sectional analysis in two concurrent cohorts of 600 HIV negative and 721 HIV seropositive individuals aged ≥35 years. Results: Of the 721 HIV positive participants, 59.8% were women and the median age was 44.3 years, while for HIV negative individuals, 55% were women and the median age was 47.8 years. Over 90% of HIV positive individuals were on antiretroviral treatment. The prevalence of hypertension (≥140/≥90 mmHg) was 33.5% in HIV negative individuals and 23.9% in HIV positive individuals. Age (adjusted OR = 1.05, 95% CI 1.03 to 1.06) and BMI (adjusted OR = 1.08, 95% CI 1.05 to 1.12) were associated with higher odds of hypertension. Having HIV was associated with lower odds of hypertension (adjusted OR = 0.66, 95% CI 0.50 to 0.88), lower systolic blood pressure (-5.1 mmHg, 95% CI: -7.4 to -2.4) and lower diastolic blood pressure (-4.0 mmHg, 95% CI: -5.6 to -2.5). We did not observe differences in the odds of hypertension by CD4 count, viral load or ART among HIV positive individuals in this sample. Conclusions: Hypertension was prevalent in one third of HIV negative individuals and in one fourth of HIV positive patients. While access to health information among individuals attending HIV clinics may explain observed differences, more research is needed to understand plausible biological and social mechanisms that could explain lower blood pressure among people living with HIV in Uganda

Blood pressure levels among children in rural Uganda: results from 1913 children in a general population survey.

Despite increasing levels of adult hypertension in sub-Saharan Africa (SSA), there is limited information on elevated blood pressure among children in SSA. We described the distribution of blood pressure among children in rural Uganda and estimated hypertension prevalence. We conducted a cross-sectional study in south-western Uganda, collecting demographic, anthropometric and blood pressure measurements from children aged 6-12 years. Children with elevated blood pressure (systolic and/or diastolic blood pressure greater or equal to the 95th percentile for age, height and sex) were invited for two further assessments 6-18 months later. We described blood pressure distribution at first assessment, assessed associations with demographic and anthropometric characteristics and estimated prevalence of hypertension as defined by having elevated blood pressure on three separate occasions months apart. Blood pressure (BP) was measured in 1913 children (50% male, 3% overweight or obese, 22% stunted) at the first assessment. Mean (SD) systolic and diastolic BP at first assessment was 113.4 mmHg (±10.8) and 69.5 mmHg (±8.3), respectively, and 44.2% had elevated BP. Older age, higher BMI, and being female were associated with higher BP, and stunted height was associated with lower BP. An estimated 7.8% [95% CI:(6.6-9.1)], (males: 6.8%, females: 9.0%), had elevated BP on three separate occasions, and were considered hypertensive. High blood pressure levels among adults in SSA may be set early in life. In this study, obesity (a common lifestyle modifiable risk factor in other settings) was largely irrelevant. More research is needed to understand the main drivers for elevated blood pressure in SSA further

Alternative pre-analytic sample handling techniques for glucose measurement in the absence of fluoride tubes in low resource settings.

INTRODUCTION: Sodium fluoride (NaF) tubes are the recommended tubes for glucose measurements, but these are expensive, have limited number of uses, and are not always available in low resource settings. Alternative sample handling techniques are thus needed. We compared glucose stability in samples collected in various tubes exposed to different pre-analytical conditions in Uganda. METHODS: Random (non-fasted) blood samples were drawn from nine healthy participants into NaF, Ethylenediaminetetraacetic acid (EDTA), and plain serum tubes. The samples were kept un-centrifuged or centrifuged with plasma or serum pipetted into aliquots, placed in cool box with ice or at room temperature and were stored in a permanent freezer after 0, 2, 6, 12 and 24 hours post blood draw before glucose analysis. RESULTS: Rapid decline in glucose concentrations was observed when compared to baseline in serum (declined to 64%) and EDTA-plasma (declined to 77%) after 6 hours when samples were un-centrifuged at room temperature whilst NaF-plasma was stable after 24 hours in the same condition. Un-centrifuged EDTA-plasma kept on ice was stable for up to 6 hours but serum was not stable (degraded to 92%) in the same conditions. Early centrifugation prevented glucose decline even at room temperature regardless of the primary tube used with serum, EDTA-plasma and NaF-plasma after 24 hours. CONCLUSION: In low resource settings we recommend use of EDTA tubes placed in cool box with ice and analysed within 6 hours as an alternative to NaF tubes. Alternatively, immediate separation of blood with manual hand centrifuges will allow any tube to be used even in remote settings with no electricity

HbA1c performs well in monitoring glucose control even in populations with high prevalence of medical conditions that may alter its reliability: the OPTIMAL observational multicenter study

INTRODUCTION: The utility of HbA1c (glycosylated hemoglobin) to estimate glycemic control in populations of African and other low-resource countries has been questioned because of high prevalence of other medical conditions that may affect its reliability. Using continuous glucose monitoring (CGM), we aimed to determine the comparative performance of HbA1c, fasting plasma glucose (FPG) (within 5 hours of a meal) and random non-fasting glucose (RPG) in assessing glycemic burden. RESEARCH DESIGN AND METHODS: We assessed the performance of HbA1c, FPG and RPG in comparison to CGM mean glucose in 192 Ugandan participants with type 2 diabetes. Analysis was undertaken in all participants, and in subgroups with and without medical conditions reported to affect HbA1c reliability. We then assessed the performance of FPG and RPG, and optimal thresholds, in comparison to HbA1c in participants without medical conditions thought to alter HbA1c reliability. RESULTS: 32.8% (63/192) of participants had medical conditions that may affect HbA1c reliability: anemia 9.4% (18/192), sickle cell trait and/or hemoglobin C (HbC) 22.4% (43/192), or renal impairment 6.3% (12/192). Despite high prevalence of medical conditions thought to affect HbA1c reliability, HbA1c had the strongest correlation with CGM measured glucose in day-to-day living (0.88, 95% CI 0.84 to 0.91), followed by FPG (0.82, 95% CI 0.76 to 0.86) and RPG (0.76, 95% CI 0.69 to 0.81). Among participants without conditions thought to affect HbA1c reliability, FPG and RPG had a similar diagnostic performance in identifying poor glycemic control defined by a range of HbA1c thresholds. FPG of ≥7.1 mmol/L and RPG of ≥10.5 mmol/L correctly identified 78.2% and 78.8%, respectively, of patients with an HbA1c of ≥7.0%. CONCLUSIONS: HbA1c is the optimal test for monitoring glucose control even in low-income and middle-income countries where medical conditions that may alter its reliability are prevalent; FPG and RPG are valuable alternatives where HbA1c is not available

Continuous glucose monitoring demonstrates low risk of clinically significant hypoglycemia associated with sulphonylurea treatment in an African type 2 diabetes population: results from the OPTIMAL observational multicenter study.

INTRODUCTION: People living with diabetes in low-resource settings may be at increased hypoglycemia risk due to food insecurity and limited access to glucose monitoring. We aimed to assess hypoglycemia risk associated with sulphonylurea (SU) and insulin therapy in people living with type 2 diabetes in a low-resource sub-Saharan African setting. RESEARCH DESIGN AND METHODS: This study was conducted in the outpatients' diabetes clinics of two hospitals (one rural and one urban) in Uganda. We used blinded continuous glucose monitoring (CGM) and self-report to compare hypoglycemia rates and duration in 179 type 2 diabetes patients treated with sulphonylureas (n=100) and insulin (n=51) in comparison with those treated with metformin only (n=28). CGM-assessed hypoglycemia was defined as minutes per week below 3mmol/L (54mg/dL) and number of hypoglycemic events below 3.0 mmol/L (54 mg/dL) for at least 15 minutes. RESULTS: CGM recorded hypoglycemia was infrequent in SU-treated participants and did not differ from metformin: median minutes/week of glucose <3 mmol/L were 39.2, 17.0 and 127.5 for metformin, sulphonylurea and insulin, respectively (metformin vs sulphonylurea, p=0.6). Hypoglycemia risk was strongly related to glycated haemoglobin (HbA1c) and fasting glucose, with most episodes occurring in those with tight glycemic control. After adjusting for HbA1c, time <3 mmol/L was 2.1 (95% CI 0.9 to 4.7) and 5.5 (95% CI 2.4 to 12.6) times greater with sulphonylurea and insulin, respectively, than metformin alone. CONCLUSIONS: In a low-resource sub-Saharan African setting, hypoglycemia is infrequent among people with type 2 diabetes receiving sulphonylurea treatment, and the modest excess occurs predominantly in those with tight glycemic control

24-hour ambulatory blood pressure monitoring and hypertension related risk among HIV-positive and HIV-negative individuals: cross sectional study findings from rural Uganda

Hypertension is diagnosed and treated based on blood pressure (BP) readings obtained in the clinic setting. Positive HIV status is associated with a higher prevalence of abnormal diurnal BP patterns, diagnosed with ambulatory BP monitoring rather than the conventional method of BP measurement. Little is known about ambulatory BP profiles in people living with HIV (PLHIV) in low-income countries, especially within sub-Saharan Africa. In this study, we compared 24-h ambulatory BP profiles of 140 HIV-positive individuals vs. profiles in 166 HIV negative individuals living in rural Uganda. HIV was well-controlled, with all HIV seropositive participants reporting use of anti-retroviral therapy, and ~123 (88%) having undetectable viral load. Most participants reported ART use duration of less than 10 years. Compared to HIV negative participants, HIV positive participants had lower median 24-h systolic BP (110.4 mmHg (IQR: 105.7, 118.7) vs 117.7 mmHg (IQR: 110.8, 129.8), p < 0.001), and 24-h diastolic BP (69.2 mmHg (IQR: 65.0, 74.9) vs. 71.9 mmHg (IQR: 67.2, 78.1), p = 0.004). Adjusted results showed greater percentage systolic nocturnal dipping among PLHIV compared to HIV negative individuals (difference = 2.70 (IQR: 0.94, 4.47), p < 0.05). Results of the adjusted Poisson regression suggested lower prevalence of 24-h and night hypertension among HIV positives compared to HIV negative, but were not statistically significant. Our data suggest that continuous 24-h BP measurements are lower in PLHIV on ART compared to HIV negative individuals

Identification and characterisation of diabetes in Uganda: protocol for the nested, population-based ‘Diabetes in low-resource Populations’ (DOP) Study

Introduction Sub-Saharan Africa is experiencing an increasing burden of diabetes, but there are little reliable data, particularly at the community level, on the true prevalence or why this condition affects young and relatively lean individuals. Moreover, the detection of diabetes in Africa remains poor, not only due to a lack of resources but because the performance of available diagnostic tests is unclear.Methods This research aims to (1) determine the prevalence and risk factors of diabetes in a rural Ugandan population, (2) use clinical and biochemical markers to define different diabetes phenotypes and (3) study the progression of diabetes in this population. We will also assess the utility of the widely used tests (glycated haemoglobin (HbA1c), oral glucose tolerance test (OGTT) and fasting glucose) in diagnosing diabetes.Design This is a population-based study nested within the longstanding general population cohort in southwestern Uganda. We will undertake a population survey to identify individuals with diabetes based on fasting glucose, HbA1c, OGTT results or history of pre-existing diabetes.Participants The study intends to enrol up to 11 700 individuals aged 18 years and above, residing within the study area and not pregnant or within 6 months post-delivery date. All participants will have detailed biophysical and biochemical/metabolic measurements. Individuals identified to have diabetes and a random selection of controls will have repeat tests to test reproducibility before referral and enrolment into a diabetic clinic. Participants will then be followed up for 1 year to assess the course of the disease, including response to therapy and diabetes-related complications.Conclusions These data will improve our understanding of the burden of diabetes in Uganda, the risk factors that drive it and underlying pathophysiological mechanisms, as well as better ways to detect this condition. This will inform new approaches to improve the prevention and management of diabetes.Ethics and dissemination This study protocol was approved by the Uganda Virus Research Institute Research Ethics Committee (REC) (number: G.C./127/21/09/858), the London School of Hygiene and Tropical Medicine REC (number: 26638) and the Uganda National Council for Science and Technology (protocol number: HS1791ES). Written informed consent will be obtained from all participants before being enrolled on to the study and conducting study-related procedures. Research findings will be disseminated in policy briefs, seminars, local and international conferences and publications in peer-reviewed open-access journals. As part of the dissemination plans, findings will also be disseminated to patient care groups and to clinicians.Trial registration number NCT05487079