Characterization of kidney disease in sub-Saharan Africa

Background: Chronic kidney disease (CKD) is an established cause of morbidity and mortality worldwide. While methods to determine kidney function are well established in Western populations, there are good reasons to believe these methods may not translate well to sub-Saharan Africa (sSA), meaning the overall burden of CKD is uncertain. The aim of this thesis was to determine the prevalence and mortality associated with renal impairment using conventional estimated glomerular filtration rate (eGFR) approaches, we also compared performance of measured GFR (mGFR) to eGFR and used mGFR based model to impute CKD prevalence in sSA. Methods: We determined the prevalence and all-cause mortality from impaired renal function [defined as eGFR) <60mls/min/1.73m2 within a population-based cohort among adults of 18 years and above in rural Uganda. Working with the African Research on Kidney Disease Network (ARK) a consortium of three community-based cohorts from Malawi, Uganda and South Africa, we stratified participants by level of renal function. We intravenously injected 5millilitres bolus of exogenous iohexol and drew venous samples from the contralateral arm at 5, 120, 180 and 240- minute time points to determine the mGFR. We compared the performance of existing equations to mGFR and used a model to impute kidney function based on mGFR. Results: In Uganda, among 5,979 participants, we found an overall prevalence of eGFR <60 ml/min per 1.73 m2 of 1.6% (95% CI 1.34–1.99) with up to 1,089 (18.2%) having an eGFR <90 ml/min per 1.73 m2 in a predominantly young population. Older age, hypertension and anemia were independently associated with impaired renal function. In adjusted analyses, participants with baseline eGFR ≤45mls/min/1.73m2 had six-fold higher mortality compared to those with eGFR ≥90mls/min/1.73m2 (HR 6.12 (95% CI 2.27-16.45)) with strong evidence of a linear trend for risk of mortality as renal function declined (p<0.001). Among the 2,578 participants with mGFR and 2433 with cystatin C eGFR from the ARK study, we found that that all eGFR equations overestimate GFR compared to mGFR or cystatin C across the three countries and this was worsened by use of ethnicity coefficient. Using a model to impute kidney function based on mGFR, we estimated CKD prevalence to be two to three-fold higher compared to creatinine-based estimates in populations across six countries in sSA. Conclusion: Based on existing creatinine-based methods to estimate GFR, we found a relatively low prevalence of impaired renal function in the general population. We also demonstrated that eGFR <45mls/min/1.73m2 are associated with an increased all-cause mortality. However, using iohexol clearance, we showed that these creatinine-based measures over-estimate GFR and under-estimate CKD. This means a substantial proportion of people with kidney disease are missed by current eGFR equations which may have adverse effects on the health and care of patients with CKD in sSA

Diagnostic accuracy of fine needle aspiration cytology in providing a diagnosis of cervical lymphadenopathy among HIV-infected patients

Background: Opportunistic infections and malignancies cause lymphadenopathy in HIV-infected patients. The use and accuracy of fine needle aspiration cytology in diagnosing of cervical lymphadenopathy among HIV-infected patients is not well studied in Uganda.Objective: The aim of this study was to determine the diagnostic accuracy of fine needle aspiration cytology in providing a diagnosis of cervical lymphadenopathy among HIV-infected patients in Uganda.Methods: We consecutively recruited adult HIV-infected patients with cervical lymphadenopathy admitted to Mulago Hospital medical wards. Clinical examination, fine needle aspiration and lymph node biopsy were performed. We estimated the sensitivity, specificity; negative and positive predictive values using histology as the gold standard.Results: We enrolled 108 patients with a mean age of 33 years (range, 18-60), 59% were men and mean CD4 was 83(range, 22-375) cells/mm3. The major causes of cervical lymphadenopathy were: tuberculosis (69.4%), Kaposi's sarcoma-KS (10.2%) and reactive adenitis (7.4%). Overall fine needle aspiration cytology accurately predicted the histological findings in 65 out of 73 cases (89%) and missed 7 cases (9.5%). With a sensitivity of 93.1%, specificity of 100%, positive predictive value of 100% and negative predictive value of 78.7% for tuberculosis and 80%; 98.4%;88.9% and 98.9% for KS respectively. No fine needle aspiration complications were noted.Conclusions: Fine needle aspiration cytology is safe and accurate in the diagnosis of tuberculosis and KS cervical lymphadenopathy among HIV-positive patients.Keywords: Fine needle aspiration cytology, cervical lymphadenopathy, HI

Validation of the Saint George's Respiratory Questionnaire in Uganda.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) will soon be the third leading global cause of death and is increasing rapidly in low/middle-income countries. There is a need for local validation of the Saint George's Respiratory Questionnaire (SGRQ), which can be used to identify those experiencing lifestyle impairment due to their breathing. METHODS: The SGRQ was professionally translated into Luganda and reviewed by our field staff and a local pulmonologist. Participants included a COPD-confirmed clinic sample and COPD-positive and negative members of the community who were enrolled in the Lung Function in Nakaseke and Kampala (LiNK) Study. SGRQs were assembled from all participants, while demographic and spirometry data were additionally collected from LiNK participants. RESULTS: In total, 103 questionnaires were included in analysis: 49 with COPD from clinic, 34 community COPD-negative and 20 community COPD-positive. SGRQ score varied by group: 53.5 for clinic, 34.4 for community COPD-positive and 4.1 for community COPD-negative (p<0.001). The cross-validated c statistic for SGRQ total score predicting COPD was 0.87 (95% CI 0.75 to 1.00). SGRQ total score was associated with COPD severity (forced expiratory volume in 1 s per cent of predicted), with an r coefficient of -0.60 (-0.75, -0.39). SGRQ score was associated with dyspnoea (OR 1.05/point; 1.01, 1.09) and cough (1.07; 1.03, 1.11). CONCLUSION: Our Luganda language SGRQ accurately distinguishes between COPD-positive and negative community members in rural Uganda. Scores were correlated with COPD severity and were associated with odds of dyspnoea and cough. We find that it can be successfully used as a respiratory questionnaire for obstructed adults in Uganda

Geographic differences in the prevalence of hypertension in Uganda: Results of a national epidemiological study.

BACKGROUND: Hypertension accounts for more than 212 million global disability-adjusted life-years, and more than 15 million in sub-Saharan Africa. Identifying factors underlying the escalating burden of hypertension in sub-Saharan Africa may inform delivery of targeted public health interventions. METHODS: As part of the cross-sectional nationally representative Uganda National Asthma Survey conducted in 2016, we measured blood pressure (BP) in the general population across five regions of Uganda. We defined hypertension as systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg, or on-going use of medications for the purpose of lowering BP among adults (≥18 years of age); pre-hypertension as systolic BP between 120 and 140 mmHg and/or diastolic BP bteween 80 and 90 mmHg among adolescents and adults (≥12 years of age). FINDINGS: Of 3416 participants who met inclusion criteria, 38.9% were male, and mean age ± SD was 33.8 ± 16.9 years. The age- and sex-adjusted prevalence of hypertension was 31.5% (95% confidence interval [CI] 30.2 to 32.8). The adjusted prevalence of hypertension was highest in the Central Region (34.3%; 95% CI 32.6 to 36.0), and it was comparable to that in the West and East Regions. However, compared with the Central Region, hypertension was significantly less prevalent in the North (22.0%; 95 CI 19.4 to 24.6) and West Nile Regions (24.1%; 95% CI 22.0 to 26.3). Adjustment for demographic characteristics (occupation, monthly income, and educational attainment) of participants did not account for the significantly lower prevalence of hypertension in the North and West Nile Regions. The prevalence of pre-hypertension was 38.8% (95% CI 37.7 to 39.8), and it was highly prevalent among young adults (21-40 years of age: 42.8%; 95% CI 41.2-44.5%) in all regions. CONCLUSIONS: Hypertension is starkly prevalent in Uganda, and numerous more people, including young adults are at increased risk. The burden of hypertension is highest in the Central, Western, and Eastern regions of the country; demographic characteristics did not fully account for the disparate regional burden of hypertension. Future studies should explore the potential additional impact of epidemiological shifts, including diet and lifestyle changes, on the development of hypertension

Kidney disease in Uganda: a community based study.

BACKGROUND: Chronic kidney disease (CKD) is a major cause of morbidity and mortality in Sub-Saharan Africa (SSA). The majority of studies on CKD in SSA have been conducted among HIV-infected populations and mainly from large health facilities. We determined the prevalence of CKD and its predictors among populations in communities in central Uganda. METHODS: A cross-sectional study was conducted in Wakiso district using multi-stage sampling. Data was collected on age, sex, socio-economic status, history of alcohol intake, diabetes mellitus, hypertension and smoking. Measurement of blood pressure, weight and height to determine body mass index (BMI) and investigations including HIV testing, fasting blood sugar, creatinine and urinalysis were conducted. Logistic regression was used to estimate the strength of the association between variables and the presence of CKD estimated using the Cockcroft Gault formula. RESULTS: A total of 955 participants aged 18-87 years were enrolled into the study. The median age was 31 years (Interquartile range 24-42) and majority (67%) were female. Up to 21.4% (204/955) had abnormal renal function with CKD stage 1 in 6.2% (59/955), stage 2 in 12.7% (121/955), stage 3 in 2.4% (23/955), CKD stage 4 in 0% and CKD stage 5 in 0.1% (1/995). Female gender OR 1.8 (95% Confidence Interval [CI] 1.2-2.8), age >30 years OR 2.2(95% CI 1.2-3.8) and high social economic status OR 2.1 (95% CI 1.3-3.6) were associated with increased risk of CKD while BMI > 25Kg/m2 was protective against CKD OR 0.1 (95% CI 0.04-0.2). Traditional risk factors such as HIV-infection, diabetes mellitus, smoking and alcohol intake were not found to be significantly associated with CKD. CONCLUSION: We found a high prevalence of kidney disease in central Uganda. Interestingly the traditional risk factors associated with CKD previously documented, were not associated with CKD

Effectiveness of low-dose theophylline for the management of biomass-associated COPD (LODOT-BCOPD): study protocol for a randomized controlled trial

BACKGROUND: COPD is a leading cause of death globally, with the majority of morbidity and mortality occurring in low- and middle-income country (LMIC) settings. While tobacco-smoke exposure is the most important risk factor for COPD in high-income settings, household air pollution from biomass smoke combustion is a leading risk factor for COPD in LMICs. Despite the high burden of biomass smoke-related COPD, few studies have evaluated the efficacy of pharmacotherapy in this context. Currently recommended inhaler-based therapy for COPD is neither available nor affordable in most resource-limited settings. Low-dose theophylline is an oral, once-a-day therapy, long used in high-income countries (HICs), which has been proposed for the management of COPD in LMICs in the absence of inhaled steroids and/or bronchodilators. The Low-dose Theophylline for the Management of Biomass-Associated COPD (LODOT-BCOPD) trial investigates the clinical efficacy and cost-effectiveness of low-dose theophylline for the management of biomass-related COPD in a low-income setting. METHODS: LODOT-BCOPD is a randomized, double-blind, placebo-controlled trial to test the efficacy of low-dose theophylline in improving respiratory symptoms in 110 participants with moderate to severe COPD in Central Uganda. The inclusion criteria are as follows: (1) age 40 to 80 years, (2) full-time resident of the study area, (3) daily biomass exposure, (4) post-bronchodilator FEV1/FVC below the 5th percentile of the Global Lung Initiative mixed ethnic reference population, and (5) GOLD Grade B-D COPD. Participants will be randomly assigned to receive once daily low-dose theophylline (200 mg ER, Unicontin-E) or placebo for 52 weeks. All participants will receive education about self-management of COPD and rescue salbutamol inhalers. We will measure health status using the St. George's Respiratory Questionnaire (SGRQ) and quality of life using the EuroQol-5D (EQ-5D) at baseline and every 6 months. In addition, we will assess household air pollution levels, serum inflammatory biomarkers (fibrinogen, hs-CRP), and theophylline levels at baseline, 1 month, and 6 months. The primary outcome is change in SGRQ score at 12 months. Lastly, we will assess the cost-effectiveness of the intervention by calculating quality-adjusted life years (QALYs) from the EQ-5D. TRIAL REGISTRATION: ClinicalTrials.gov  NCT03984188 . Registered on June 12, 2019 TRIAL ACRONYM: Low-dose Theophylline for the Management of Biomass-Associated COPD (LODOT-BCOPD)

Validation of the Saint George's Respiratory Questionnaire in Uganda

Introduction: Chronic obstructive pulmonary disease (COPD) will soon be the third leading global cause of death and is increasing rapidly in low/middle-income countries. There is a need for local validation of the Saint George's Respiratory Questionnaire (SGRQ), which can be used to identify those experiencing lifestyle impairment due to their breathing. Methods: The SGRQ was professionally translated into Luganda and reviewed by our field staff and a local pulmonologist. Participants included a COPD-confirmed clinic sample and COPD-positive and negative members of the community who were enrolled in the Lung Function in Nakaseke and Kampala (LiNK) Study. SGRQs were assembled from all participants, while demographic and spirometry data were additionally collected from LiNK participants. Results: In total, 103 questionnaires were included in analysis: 49 with COPD from clinic, 34 community COPD-negative and 20 community COPD-positive. SGRQ score varied by group: 53.5 for clinic, 34.4 for community COPD-positive and 4.1 for community COPD-negative (p<0.001). The cross-validated c statistic for SGRQ total score predicting COPD was 0.87 (95% CI 0.75 to 1.00). SGRQ total score was associated with COPD severity (forced expiratory volume in 1 s per cent of predicted), with an r coefficient of -0.60 (-0.75, -0.39). SGRQ score was associated with dyspnoea (OR 1.05/point; 1.01, 1.09) and cough (1.07; 1.03, 1.11). Conclusion: Our Luganda language SGRQ accurately distinguishes between COPD-positive and negative community members in rural Uganda. Scores were correlated with COPD severity and were associated with odds of dyspnoea and cough. We find that it can be successfully used as a respiratory questionnaire for obstructed adults in Uganda

A Novel Case-Finding Instrument for Chronic Obstructive Pulmonary Disease in Low- and Middle-Income Country Settings

Background: Low- and middle-income countries (LMICs) account for >90% of deaths and illness episodes related to COPD; however, this condition is commonly underdiagnosed in these settings. Case-finding instruments for COPD may improve diagnosis and identify individuals that need treatment, but few have been validated in resource-limited settings. Methods: We conducted a population-based cross-sectional study in Uganda to assess the diagnostic accuracy of a respiratory symptom, exposure and functional questionnaire in combination with peak expiratory flow for COPD diagnosis using post-bronchodilator FEV1/FVC z-score below the 5th percentile as the gold standard. We included locally relevant exposure questions and statistical learning techniques to identify the most important risk factors for COPD. We used 80% of the data to develop the case-finding instrument and validated it in the remaining 20%. We evaluated for calibration and discrimination using standard approaches. The final score, COLA (COPD in LMICs Assessment), included seven questions, age and pre-bronchodilator peak expiratory flow. Results: We analyzed data from 1,173 participants (average age 47 years, 46.9% male, 4.5% with COPD) with acceptable and reproducible spirometry. The seven questions yielded a cross-validated area-under-the-curve [AUC] of 0.68 (95% CI 0.61–0.75) with higher scores conferring greater odds of COPD. The inclusion of peak expiratory flow and age improved prediction in a validation sample (AUC=0.83, 95% CI 0.78–0.88) with a positive predictive value of 50% and a negative predictive value of 96%. The final instrument (COLA) included seven questions, age and pre-bronchodilator peak expiratory flow. Conclusion: COLA predicted COPD in urban and rural settings in Uganda has high calibration and discrimination, and could serve as a simple, low-cost screening tool in resource-limited settings