Angiotensin II status and sympathetic activation among hypertensive patients in Uganda: a cross-sectional study.

BACKGROUND: Sympathetic activation and renin-angiotensin system are essential for development and sustenance of hypertension. However, the status of these systems has not been well evaluated among patients in an African setting. This study therefore set out to assess the angiotensin II status and sympathetic activation among hypertensive patients in Uganda. METHODS: In this cross sectional study conducted at Mulago, the national referral hospital, blood samples were taken to measure angiotensin II, metanephrines and normetanephrines. Urine samples were also taken for measuring urine creatinine and sodium. The angiotensin II categories were defined using the Mosby's Diagnostic and Laboratory Test References. 9th ed while the metanephrines and normetanephrine categories were defined using the Makerere University Biosafety II Immunology Laboratory reference values. RESULTS: 162 patients were consented and enrolled into the study, of these 136 (84 %) had low, 15 (9 %) had normal, while, 11 (7 %) had high angiotensin II levels. 142 (88 %) participants had normal levels of metanephrine, while 20 (12 %) had high levels. Only 88 were assessed for metanephrines and of these 85 (97 %) had normal, while 3 (3 %) had raised levels. Urine sodium was associated with low and normal angiotensin II levels (P value 0.007). Female gender and diastolic blood pressure were associated with a protective effect against high normetanephrines (OR 0.29, P value 0.015), 80-89 mmHg (OR 0.19, p value 0.053), above 100 mmHg (OR 0.27, p value 0.022). Current smoking status was associated with high risk for abnormal normetanephrines (OR 17.6, P value -0.022) while former smoking was associated with high risk for abnormal metanephrines (OR 18.7, p value 0.022). After multivariate analysis, all the significant variables at bivariate analysis were still significant except those who stopped smoking and those with a BP at 80-89 which were not significant. CONCLUSIONS: Hypertensive patients in this setting have predominantly low angiotensin II hypertension as a result of high salt intake. Sympathetic activation is not a significant mechanism of hypertension in this study population, more so in the females, with the exception of smokers who have a highly activated sympathetic system. Therefore, the use of agents targeting renin angiotensin and sympathetic systems as single first line antihypertensive agents in this setting should be re-evaluated if such patients are to be treated effectively.

Vitamin D deficiency and its characteristics among patients with acute stroke at a national referral hospital in Kampala Uganda.

BACKGROUND: Vitamin D deficiency has been associated with acute stroke and other cardiovascular diseases in the developed world. Low 25-hydroxyvitamin D (25OHD) has been described in some populations in Sub-Saharan Africa (SSA) in spite of adequate sunshine all year round. There is no information on the magnitude of vitamin D deficiency among patients with stroke and other cardiovascular diseases in Uganda or SSA. The aim of this study was to determine the burden and characteristics of vitamin D deficiency among patients with acute stroke, the most common form of cardiovascular events in SSA. METHODS: We conducted a cross-sectional study between October 2012 and March 2013. We consecutively recruited 142 subjects with acute stroke admitted to the medical wards of Mulago hospital. We administered a pre-tested questionnaire to the study participants, and did a detailed physical examination and laboratory evaluation. Serum levels of 25OHD were determined using an electrochemiluminescence assay. Data were analyzed using STATA version 12 software. RESULTS: The prevalence of vitamin D deficiency (25OHD < 20 ng/ml) was 15 %. Longer hours of sunshine exposure decreased the likelihood vitamin D deficiency significantly (adjusted OR 0.85, p = 0.03). Higher HDL cholesterol had a significant inverse association with vitamin D deficiency (adjusted OR 0.15, p = 0.02). In addition, the likelihood of vitamin D deficiency increased with rising age (adjusted OR 1.03, p = 0.05). CONCLUSIONS: There was a relatively low burden of vitamin D deficiency among patients with acute stroke in Uganda. With increasing longevity and indoor lifestyles vitamin D deficiency may assume a greater role in stroke and other cardiovascular diseases in tropical sub Saharan Africa. Future studies on the mechanisms of vitamin D deficiency and its relationship to outcomes among patients with stroke may be necessary.

Cardiovascular risk factors among patients with chronic kidney disease attending a tertiary hospital in Uganda.

INTRODUCTION: Chronic kidney disease (CKD) is a risk factor for the development of cardiovascular disease, which is the primary cause of morbidity and mortality in patients with CKD. Local data about cardiovascular risk factors among CKD patients is generally scanty. OBJECTIVE: To determine the prevalence of the common cardiovascular risk factors among patients with CKD attending the nephrology out-patient clinic in Mulago national referral hospital in Uganda. METHODS: This was a cross-sectional study in which 217 patients with a mean age of 43 years were recruited over a period of nine months. Data on demographic characteristics, risk factors for cardiovascular disease, complete blood count, renal function tests/electrolytes, and lipid profiles were collected using a standardised questionnaire. RESULTS: One hundred and eleven (51.2%) of the participants were male. Hypertension was reported in 90% of participants while cigarette smoking was present in 11.5%. Twenty-two participants (10.2%) were obese and 16.1% were diabetic. A total of 71.9% had a haemoglobin concentration < 11 g/dl, with the prevalence of anaemia increasing with advancing renal failure (p < 0.001); 44.7% were hypocalcaemic and 39.2% had hyperphosphataemia. The prevalence of abnormal calcium and phosphate levels was found to increase with declining renal function (p = 0.004 for calcium and p < 0.001 for phosphate). CONCLUSION: This study demonstrated that both traditional and non-traditional cardiovascular risk factors occurred frequently in patients with CKD attending the nephrology out-patient clinic at Mulago Hospital.

Pattern and presentation of cardiac diseases among patients with chronic kidney disease attending a national referral hospital in Uganda: a cross sectional study.

BACKGROUND: Chronic kidney disease is a risk factor for development of cardiovascular diseases. Cardiovascular diseases are the primary cause of morbidity and mortality in patients with chronic kidney disease. There is limited data on cardiovascular diseases among chronic kidney disease patients in resource limited settings including Uganda. We determined the prevalence and patterns of cardiac diseases among patients with chronic kidney disease attending the nephrology outpatient clinic in Mulago National Referral Hospital in Uganda. METHODS: This was a cross sectional study in which two hundred seventeen patients with chronic kidney disease were recruited over a period of 9 months. Data on demographic characteristics and risk factors for cardiovascular diseases were collected using a standardized questionnaire. Cardiac evaluation was done using resting electrocardiography and transthoracic echocardiography performed for all study participants and findings entered into a data sheet. RESULTS: One hundred eleven (51.2 %) of the 217 participants were male. Mean age was 42.8 years. One hundred eighteen (54.4 %) of patients had either eccentric or concentric left ventricular hypertrophy. Patients with left ventricular hypertrophy were more likely to be hypertensive (p < 0.001) or anemic (p = 0.034). Up to 9.2 % of study subjects had valvular heart disease (rheumatic or degenerative) and 22 % had pericarditis. Forty one patients (18.9 %) had left ventricular systolic failure (Ejection fraction < 50 %). There was a higher prevalence of systolic failure in patients with left ventricular hypertrophy (21 % vs. 16 %) although this was not statistically significant, p = 0.346. Thirty eight participants (17.5 %) had diastolic failure while 2 % had cardiac rhythm abnormalities. CONCLUSION: Cardiac abnormalities are common in a predominantly young African population with CKD. Clinicians should routinely screen and manage cardiovascular disease in CKD patients.

Benzathine penicillin adherence for secondary prophylaxis among patients affected with rheumatic heart disease attending Mulago Hospital.

INTRODUCTION: Rheumatic heart disease (RHD) frequently occurs following recurrent episodes of acute rheumatic fever (ARF). Benzathine penicillin (benzapen) is the most effective method for secondary prophylaxis against ARF whose efficacy largely depends on adherence to treatment. Various factors determine adherence to therapy but there are no data regarding current use of benzapen in patients with RHD attending Mulago Hospital. The study aims were (1) to determine the levels of adherence with benzapen prophylaxis among rheumatic heart disease patients in Mulago Hospital, and (2) establish the patient factors associated with adherence and, (3) establish the reasons for missing monthly benzathine penicillin injections. METHODS: This was a longitudinal observational study carried out in Mulago Hospital cardiac clinics over a period of 10 months; 95 consecutive patients who satisfied the inclusion criteria were recruited over a period of four months and followed up for six months. Data on demographic characteristics and disease status were collected by means of a standardised questionnaire and a card to document the injections of benzapen received. RESULTS: Most participants were female 75 (78.9%). The age range was five to 55 years, with a mean of 28.1 years (SD 12.2) and median of 28 years. The highest education level was primary school for most patients (44, 46.3%) with eight (8.4%) of the patients being illiterate. Most were either NYHA stage II (39, 41.1%) or III (32, 33.7%). Benzathine penicillin adherence: 44 (54%) adhered to the monthly benzapen prophylaxis, with adherence rates ≥ 80%; 38 (46%) patients were classified as non-adherent to the monthly benzapen, with rates less than 80%. The mean adherence level was 70.12% (SD 29.25) and the median level was 83.30%, with a range of 0-100%; 27 (33%) patients had extremely poor adherence levels of ≤ 60%. Factors associated with adherence: higher education status, residing near health facility favoured high adherence, while painful injection was a major reason among poor performers. CONCLUSION: The level of non-adherence was significantly high (46%). Residence in a town/city and having at least a secondary level of education was associated with better adherence, while the painful nature of the benzapen injections and lack of transport money to travel to the health centre were the main reasons for non-adherence among RHD patients in Mulago.

Cardiovascular complications in newly diagnosed rheumatic heart disease patients at Mulago Hospital, Uganda.

BACKGROUND: Complications of rheumatic heart disease are associated with severe morbidity and mortality in developing countries where the disease prevalence remains high. Due to lack of screening services, many patients present late, with severe valve disease. In Uganda, the disease and its complications are still not well studied. OBJECTIVE: To profile and describe cardiovascular complications in newly diagnosed rheumatic heart disease patients attending the Mulago National Referral Hospital in Uganda. METHODS: This was a cross-sectional study where consecutive, newly diagnosed rheumatic heart disease patients were assessed and followed up for complications, such as heart failure, pulmonary hypertension, atrial fibrillation, recurrence of acute rheumatic fever, and stroke. RESULTS: A total of 309 (115 males and 196 females) definite rheumatic heart disease patients aged 15-60 years were enrolled in the study and analysed. Complications occurred in 49% (152/309) of the newly diagnosed rheumatic heart disease cases, with heart failure (46.9%) the most common complication, followed by pulmonary arterial hypertension (32.7%), atrial fibrillation (13.9%), recurrence of acute rheumatic fever (11.4%), infective endocarditis (4.5%) and stroke (1.3%). Atrial fibrillation and acute rheumatic fever were the most common complications associated with heart failure. CONCLUSION: In this study we found that about 50% of newly diagnosed rheumatic heart disease patients in Uganda presented with complications. Heart failure and pulmonary arterial hypertension were the most commonly observed complications.

Presenting features of newly diagnosed rheumatic heart disease patients in Mulago Hospital: a pilot study.

INTRODUCTION: Rheumatic heart disease (RHD) continues to cause gross distortions of the heart and the associated complications of heart failure and thromboembolic phenomena in this age of numerous high-efficacy drugs and therapeutic interventions. Due to the lack of contemporary local data, there is no national strategy for the control and eradication of the disease in Uganda. This study aimed to describe the presenting clinical features of newly diagnosed patients with RHD, with particular reference to the frequency of serious complications (atrial fibrillation, systemic embolism, heart failure and pulmonary hypertension) in the study group. METHODS: One hundred and thirty consecutive patients who satisfied the inclusion criteria were recruited over a period of eight months from June 2011 to January 2012 at the Mulago Hospital, Uganda. Data on demographic characteristics, disease severity and presence of complications were collected by means of a standardised questionnaire. RESULTS: Seventy-one per cent of the patients were female with a median age of 33 years. The peak age of the study group was 20 to 39 years, with the commonest presenting symptoms being palpitations, fatigue, chest pain and dyspnoea. The majority of the patients presented with moderate-to-severe valvular disease. Pure mitral regurgitation was the commonest valvular disease (40.2%), followed by mitral regurgitation plus aortic regurgitation (29%). Mitral regurgitation plus aortic regurgitation plus mitral stenosis was found in 11% of patients. There was only one case involving the tricuspid valve. The pulmonary valves were not affected in all patients; 45.9% of patients presented in severe heart failure in NYHA class III/IV, 53.3% had pulmonary hypertension, 13.9% had atrial fibrillation and 8.2% had infective endocarditis. All patients presented with dilated atria (> 49 mm). CONCLUSION: A significant proportion of RHD patients present to hospital with severe disease associated with severe complications of advanced heart failure, pulmonary hypertension, infective endocarditis and atrial fibrillation. There is a need to improve awareness of the disease among the population, and clinical suspicion in primary health workers, so that early referral to specialist management can be done before severe damage to the heart ensues.

Socioeconomic and environmental risk factors among rheumatic heart disease patients in Uganda.

BACKGROUND: Although low socioeconomic status, and environmental factors are known risk factors for rheumatic heart disease in other societies, risk factors for rheumatic heart disease remain less well described in Uganda. AIMS AND OBJECTIVE: The objective of this study was to investigate the role of socio-economic and environmental factors in the pathogenesis of rheumatic heart disease in Ugandan patients. METHODS: This was a case control study in which rheumatic heart disease cases and normal controls aged 5-60 years were recruited and investigated for socioeconomic and environmental risk factors such as income status, employment status, distance from the nearest health centre, number of people per house and space area per person. RESULTS: 486 participants (243 cases and 243 controls) took part in the study. Average age was 32.37+/-14.6 years for cases and 35.75+/-12.6 years for controls. At univariate level, Cases tended to be more overcrowded than controls; 8.0+/-3.0 versus 6.0+/-3.0 persons per house. Controls were better spaced at 25.2 square feet versus 16.9 for cases. More controls than cases were employed; 45.3% versus 21.1%. Controls lived closer to health centers than the cases; 4.8+/-3.8 versus 3.3+/-12.9 kilometers. At multivariate level, the odds of rheumatic heart disease was 1.7 times higher for unemployment status (OR = 1.7, 95% CI = 1.05-8.19) and 1.3 times higher for overcrowding (OR = 1.35, 95% CI = 1.1-1.56). There was interaction between overcrowding and longer distance from the nearest health centre (OR = 1.20, 95% CI = 1.05-1.42). CONCLUSION: The major findings of this study were that there was a trend towards increased risk of rheumatic heart disease in association with overcrowding and unemployment. There was interaction between overcrowding and distance from the nearest health center, suggesting that the effect of overcrowding on the risk of acquiring rheumatic heart disease increases with every kilometer increase from the nearest health center.