Trends in coronary artery disease and associated risk factors in sub-Saharan Africans.

It has been suggested that the prevalence of coronary artery disease (CAD) is steadily increasing in sub-Saharan Africa. To address this issue, we conducted a Medline search of English language articles on cardiovascular diseases-and specifically CAD in Africa- from 1966 to 1997. The prevalence of CAD and related complications is relatively low in most regions in Africa compared to that obtained in the economically developed countries, although the situation is rapidly changing due to trends in urbanization, changes in lifestyle, acquisition of technology and the increasing numbers of tertiary care institutions. There are variations in reported prevalence rates within the different regions, but there is an upward trend in all the regions of the sub-Saharan Africa. This trend is believed to be related to the increasing frequencies of CAD risk factors in the subcontinent.

The viability of hemodialysis as a treatment option for renal failure in a developing economy.

The viability of hemodialysis as a treatment option for renal failure in a developing economy like Nigeria was assessed in this study to determine whether committing huge capital in establishing such centres all over the country is justifiable. A total of 158 patients dialysed at the Owena Dialysis Centre over a period of 3 years (January 1991-December 1993) were studied. There were 112 males and 46 females, ranging in age between 15 and 81 years. 17 of patients had acute renal failure (ARF), while 141 had chronic renal failure (CRF). During the period of study, a total of 1,452 dialysis sessions were carried out ranging between 8 and 77 sessions per month (mean 40 sessions/month). Dialysis sessions ranged between 1 and 101 sessions per patient. A progressive increase in the number of dialysis sessions between 1991 and 1993 was noted, and new patients who required dialysis were being seen at a rate of between 1 and 10 per month. 112 patients (70.8%) could afford dialysis for less than one month while only 3 (1.9%) could afford to continue dialysis for over 12 months. All cases of ARF (except one) recovered normal renal function after dialysis, while 116 CRF patients were discharged home after less than 10 sessions of dialysis due to financial constraints. The study shows that hemodialysis is a relevant treatment option for renal failure even in a developing economy like Nigeria subject to adequate health planning. The major limitations to its profitable utilization under the present health care dispensations are highlighted.

The effect of anti-hypertensive therapy on urinary albumin excretion in Nigerian hypertensives.

The effect of blood pressure control on urinary protein excretion was assessed in 24 benign essential hypertensive subjects (12 males and 12 females). There were 23 controls (11 males and 12 females). Mean ages were 55 and 53 years respectively. Twenty-four hours urine was collected from each subject before and after control of blood pressure, while the controls had only one 24 h urine sample collected. 24 h urinary albumin excretion was assessed using the Bromocresol Green Method. Control of blood pressure in the subjects took an average of eight weeks. Subjects were either given hydroflumethiazide, alpha-methyldopa and/or prazosin as required. Blood pressure was measured in the right arm at each visit and pill counting was used to assess the compliance with therapy. The average urinary albumin excretion was significantly higher in the hypertensive subjects than the normotensive controls (P < 0.05). The average urinary albumin excretion after control of blood pressure was also significantly lower than, before control of blood pressure (P < 0.02). There was no correlation between SBP, DBP, MAP, and 24 h urinary albumin excretion in both subjects and controls. This study has shown that control of blood pressure can reduce or reverse urinary albumin excretion in Nigerian hypertensives.

Blood pressure, hypertension and correlates in urbanised workers in Ibadan, Nigeria: a revisit.

To provide an update on blood pressure (BP) levels and hypertension correlates in urban workers in Ibadan, Nigeria, we administered a questionnaire to, and measured the BP in, 608 men and 309 women, age range 18-64 years. Systolic BP (SBP) rose in men and women after the age of 25, but the rise in diastolic BP (DBP) started earlier dropping in women only after the age of 44. SBP and DBP were higher in men than women (P < 0.001). The prevalence of hypertension was 9.3% in the population, being 10.4% in men and 7.1% in women; age-adjusted rates were 9.8% and 8.0% respectively. The prevalence of hypertension increased with age in both genders. Body mass index was correlated to SBP (r = 0.142, P = 0.022) and DBP (r = 0.149, P = 0.032) in men, and with SBP (r = 0.1501, P = 0.013) and DBP (r = 0.1569, P = 0.0085) in women. BP was correlated to years of education (P < 0.001) and income (P < 0.001) in men, but not in women. Regular and moderate alcohol consumption was associated with hypertension (chi2 = 4.8, P < 0.05). Awareness of BP status was generally low, 7.7% in men and 8.7% in women, but was significantly higher in the hypertensives than the normotensives (chi2 = 241, P < 0.0001). The hypertension prevalence rates are not too different from figures obtained in the last four decades, which generally have not exceeded 15%, inspite of the apparent influence of the modernisation indices of education and income.

The Nigerian hypertension programme.

The developing world is an economic entity arbitrarily characterised by a gross national product (GNP) of US $7910 per capita, and below. It is further categorised into low and middle-income economies with a GNP of US $635 as the dividing line. The bulk of low-income economies, often referred to as the Third World, are in sub-Saharan Africa, Asia and China, and are either impoverished by very limited resources both human and material, or with large populations. Nigeria is affected by both situations.

Hemodialysis in Ibadan: a preliminary report on the first 100 dialysis.

The experience with the first 100 hemodialysis sessions at the Owena Dialysis Centre of the University College Hospital, Ibadan (UCH) is hereby presented. A total of 9 patients were dialysed during a 7-month period. The femoral vein was the most often utilised vascular access route (53 episodes in 5 patients) while a forearm fistula was functional in only one patient. The dialyzer and blood lines were reused for each patient for a maximum of 5 times. Technical problems encountered were: power failure (12 episodes), ruptured dialyzer (3), water-pipe leakage (4) machine breakdown (2) and heparin pump failure (2). Clinical problems were: failure of fistula access (2), thrombosed femoral veins (2), clotted cannula (3), low arterial pressure (20); nausea and vomiting (2), pruritus (46), muscle cramps (5), Sepsis (8) and hypotension (2). Six patients discontinued treatment after less than 10 dialyses due to financial constraints. The high cost of hemodialysis remains the major setback to its use in the treatment of end-stage renal disease in developing countries; there is the need for acceptable improvisation to reduce the overhead cost so as to make it available to most patients requiring dialysis.

The problems of peritoneal dialysis in the management of chronic uraemia in Nigeria.

The problems encountered in the use of peritoneal dialysis (PD) in the initial management of patients with chronic renal failure in Nigeria were highlighted, studying 23 patients (13 males and 10 females) aged between 15 and 68 years (mean age 36.4 years). Peritonitis was the most common complication, occurring in 16 (70%) of patients; effluent drainage obstruction in 11 patients (48%); haemorrhagic effluent in 10 patients (44%); fluid leak from catheter site infection in 7 patients (30%); accidental disconnection of line/catheter joint in 5 patients (22%); and catheter site infection in 2 patients (9%). A positive effluent culture was found in only 4 out of 18 cultured samples, with Klebsiella and Staphylococcus aureus being the organisms isolated. Dialysis was terminated in patients for the following reasons: financial constraints (8 patients), unresolving peritonitis (7 patients), drainage problems (3 patients), and clinical improvement (5 patients). The study concludes that PD in the management of chronic uraemia in developing countries, while producing clinical benefits in the majority of patients, is still not generally acceptable as a long-term treatment modality in view of the number of problems.

The diagnostic accuracy of resident doctors in the Department of Medicine University College Hospital, Ibadan.

A study has been undertaken of 52 "charts review" cases (postmortem) formally discussed by Resident Staff of the Department of Medicine, University College Hospital, Ibadan at meetings over a period of 24 months. The senior registrars' diagnosis were correct in 39 (75%) cases while the registrars diagnosis were correct in 34 (64.4%) cases. The senior registrars were correct more often than the registrars; though the difference between them was not statistically significant (x2-1.14, P = n.s).

Glomerular function in sickle cell disease patients during crisis.

An 8 month prospective study was carried out in 20 adult sickle cell disease (SCD) patients 16 sickle cell anaemia (Hbss) and 4 sickle cell Hbc disease (Hbsc); who had vaso-occlusive crises within the study period to determine the extent of the effect of sickle cell crisis on glomerular function in SCD patients during crisis. The male: female ratio was 1:57 and their mean age was 21.1 +/- 7.9 years. Creatinine clearance (CCr), as an index of glomerular function, was determined at the pre-crisis, crisis, 2 and 4 weeks post-crisis and at the end of the study period. The mean values of their CCr dropped from 113.37 +/- 33.80mls/min at pre-crisis stage to 96.39 +/- 30.13mls/min during crisis (p < 0.001) indicating glomerular dysfunction. It improved significantly to 107.75 +/- 30.20mls/min at 4 weeks post-crisis (p < 0.001). There was no significant differences in the mean values of CCr at the end of the study (116.20 +/- 31.43mls/min) compared to the pre-crisis stage (p > 0.05). It is concluded that glomerular dysfunction in SCD patients during crisis is potentially reversible.

Chronic diarrhoea due to strongyloidiasis in a Nigerian with chronic renal failure: a case report.

A case of chronic diarrhoea due to infection with Strongyloides stercoralis in a Nigerian patient with chronic renal failure is presented. Due to the potential for fatal outcome in this infection, strongyloidiasis should be kept in mind as a cause of chronic diarrhoea in chronic renal failure patients in endemic areas.

The causes and course of acute tubular necrosis in Nigerians.

To characterize the precipitating factors and course of acute tubular necrosis (ATN) in Nigerians, we studied the clinical course of ATN in 40 consecutive patients (22 male) seen in the Renal Unit of the University College Hospital, Ibadan, between June 1986 and July 1989. Nephrotoxicity resulting from the use of traditional herbal remedies (15 patients, (37.5%)) and septicaemia (7 patients (17.5%)) were the most commonly identified precipitating factors. The mean duration of the oliguric phase was 9 +/- 3.8 days, while that of the diuretic phase was 17.5 +/- 7.1 days. Majority (26 patients (65%)) were anuric at presentation. The mean urine output during the oliguric phase was 16.7 +/- 36.5 ml, whereas it was 3622 +/- 2159 ml during the diuretic phase. Transient hypertension occurred in 8.5% of cases. A total of 10 patients (25%) died. Six deaths occurred in non-dialysed patients while 5 were associated with encephalopathy. Of the 15 patients in whom ATN resulted from the use of herbal remedies, only 1 died. Nephrotoxicity from traditional herbal remedies is an important cause of ATN in Ibadan. The exact pathogenesis is unclear and warrants further investigation.

Blood pressure and educational level among factory workers in Ibadan, Nigeria.

An epidemiological survey of blood pressure was carried out among men employed at a single factory in Ibadan, Nigeria. All available employees participated, with only four persons excluded at the time of analysis for missing data. Hypertension was uncommon (blood pressure greater than or equal to 160/95 = 8%) and little rise in mean blood pressure was observed with age. Obesity was likewise uncommon, although body mass index was related to blood pressure (r = 0.22; P less than 0.01). Contrary to reports from Western industrialised countries, education was found to have a significant positive association with blood pressure, and this finding was independent of age, body mass index, pulse, and alcohol consumption. The process of modernisation is associated with rising blood pressure in West Africa at the present time, but the absolute risk remains low.

Heart disease in blacks of Africa and the Caribbean.

Cardiovascular pathology in African and Afro-Caribbean blacks features three major conditions: hypertension, rheumatic heart disease, and the cardiomyopathies. Ischemic heart disease is as yet distinctly uncommon in these societies but the adoption of Western lifestyle and its inevitable risk factors for atherosclerosis makes it likely that coronary artery disease will emerge ultimately. Hypertension poses special problems in these regions--its prevalence rate is high both in rural and urban settings, its consequences devastating in its severity of target organ involvement, and its management strategy complicated by the high cost of drugs, poor patient compliance, and the lack of clinical resources for effective monitoring of detected and referred cases. Rheumatic heart disease remains an eminently preventable condition. The ultimate strategy lies in improving the quality of life in these communities through adequate housing, sanitation, and health education, and integrating primary prophylaxis into national health care programs to forestall the development of rheumatic fever. Cardiomyopathy poses the greatest challenge as its etiology remains elusive. Its dilated form has been linked with Toxoplasma and with Coxsackie B viruses, but hard evidence of a cause-effect relationship is still lacking.

Intracellular sodium and blood pressure in Nigerians.

In examining the relationship between erythrocyte sodium, potassium, and blood pressure in Nigerians, we measured the erythrocyte sodium and potassium in 25 hypertensive and 34 normotensive subjects. Of the normotensive subjects, 15 had positive family histories of hypertension and 19 did not. The hypertensive subjects were older (50.1 +/- 1.7 years) than the normotensive subjects (25.4 +/- 0.7 years) (mean +/- SEM; P < .001). The mean arterial pressure in hypertensive subjects was higher (108.8 +/- 2.3 mm Hg), as expected, compared with normotensive subjects (86.98 +/- 1.62 mm Hg) (P < .001). The mean duration of hypertension in hypertensive subjects was 5.60 +/- 0.75 years. Erythrocyte sodium was higher in hypertensive subjects (9.57 +/- 0.19 mmol/L) compared with normotensive subjects (7.96 +/- 0.19 mmol/L) (P < .001). Among normotensive subjects, erythrocyte sodium was higher in those with a positive family history of hypertension (8.59 +/- 0.31 mmol/L) compared to those without such a history (7.47 +/- 0.18 mmol/L), and this was also statistically significant (P = .027). Erythrocyte potassium levels were similar in the hypertensive subjects (83.51 +/- 0.71 mmol/L), in normotensive subjects (81.86 +/- 0.81 mmol/L), and in those without a family history of hypertension (80.20 +/- 0.51 mmol/L) (P = .675). We observed a significant (P < .001) positive correlation between erythrocyte sodium and systolic (r = 0.99) and diastolic (r = 0.39) blood pressures. Our findings support the hypothesis that erythrocyte sodium is closely related to blood pressure and its nonracial genetic determinants.

Epidemiology of cardiovascular disease in developing countries.

As infection and malnutrition are steadily overcome in the developing world, cardiovascular disease loom large in the profile of morbidity and mortality in these societies. Hypertension, rheumatic heart disease and the cardiomyopathies are already taking their toll and atherosclerosis is certain to pose public health problems soon unless steps are taken now, through attention to known risk factors, to pre-empt or at least minimize its consequences. There are populations in developing countries among whom blood pressure does not appear to rise with age and in whom the prevalence of hypertension is very low. Studies of these communities and of migrant groups indicate that salt has an important effect on blood pressure. In spite of these observations, however, it is well known that black communities tend, on the whole, to show a higher prevalence of hypertension and more severe target-organ damage than white communities. Other distinguishing features are lower cholesterol, triglyceride and low-density lipoprotein fractions and a delayed response to a sodium load in black populations. Economic constraints limit the effective application of stepped-care therapy in the management of moderate to severe hypertension. Beta-blockers and angiotensin converting enzyme (ACE) inhibitors are not so effective in black communities unless combined with diuretics.

Current aspects of high blood pressure research in Africa.

Hypertension in Africa represents a challenge and an opportunity. As the two epidemics of infection and malnutrition are increasingly brought under control, increasing morbidity and mortality from hypertension have been documented and offer a challenge for prevention. Heterogeneity within and between African populations offers opportunities for detecting clues to the etiology and pathogenesis of hypertension. For example, populations in urban areas have already shown a greater prevalence of obesity, hypertension, and hypertensive heart and kidney disease than those in rural areas. The generally better lipid profiles in African blacks compared with whites is associated not only with low rates of coronary heart disease, but also with low prevalences of hypertensive retinopathy, despite substantial prevalences of hypertension in African blacks. Areas of Africa with a natural abundance of salt, such as Gambia and Senegal, tend to have indigenes with less tendency to retain a salt load than those from areas that are traditionally salt poor.

Prolonged prednisolone therapy in adult nephrotic syndrome: a preliminary study.

Twenty-five adult Nigerian patients suffering from the nephrotic syndrome with normocomplementaemic mesangiocapillary glomerulonephritis were studied. Twelve of these were treated with prednisolone at a dose of 1.5 mg/kg body weight/day, with maximum dose of 90 mg/day initially for 2 weeks. Thereafter, a quarter of the daily dose was given on alternate days for a period varying from 6 to 12 months. The 13 others were similarly followed up on a dietary and diuretic regime alone. Oedema disappeared completely in all the steroid group except one, whilst it persisted in five of the controls. Proteinuria persisted in all the controls but remitted in five of the test patients. Renal function deteriorated with rising plasma creatinine in five of the controls, in contrast with one of the test patients. The beneficial effect of prednisolone observed here calls for further long-term studies.