Stroke mortality in urban and rural Tanzania. Adult Morbidity and Mortality Project.

BACKGROUND: Most data for stroke mortality in sub-Saharan Africa are hospital based. We aimed to establish the contribution of cerebrovascular disease to all-cause mortality and cerebrovascular disease mortality rates in adults aged 15 years or more in one urban and two rural areas of Tanzania. METHODS: Regular censuses of the three surveillance populations consisting of 307,820 people (125,932 aged below 15 years and 181,888 aged 15 or more) were undertaken with prospective monitoring of all deaths arising in these populations between June 1, 1992 and May 31, 1995. Verbal autopsies were completed with relatives or carers of the deceased to assess, when possible, the cause of death. FINDINGS: During the 3-year observation period 11,975 deaths were recorded in the three surveillance areas, of which 7629 (64%) were in adults aged 15 years or more (4088 [54%] of these in men and 3541 [46%] in women). In the adults, 421 (5.5%) of the deaths were attributed to cerebrovascular disease, 225 (53%) of these in men and 196 (47%) in women. The yearly age-adjusted rates per 100,000 in the 15-64 year age group for the three project areas (urban, fairly prosperous rural, and poor rural, respectively) were 65 (95% CI 39-90), 44 (31-56), and 35 (22-48) for men, and 88 (48-128), 33 (22-43), and 27 (16-38) for women, as compared with the England and Wales (1993) rates of 10.8 (10.0-11.6) for men and 8.6 (7.9-9.3) for women. INTERPRETATION: We postulate that the high rates in Tanzania were due to untreated hypertension. Our study assessed mortality over a single time period and therefore it is not possible to comment on trends with time. However, ageing of the population is likely to lead to a very large increase in mortality from stroke in the future.

Age specific prevalence of impairment and disability relating to hemiplegic stroke in the Hai District of northern Tanzania. Adult Morbidity and Mortality Project.

OBJECTIVES: To determine the age specific prevalence of impairment and disability relating to hemiplegic stroke in one rural area of Tanzania. METHODS: During the yearly house to house census of the study population of 148 135 (85 152 aged 15 and over) in August 1994, specific questions were asked to identify those who might be disabled from stroke. People thus identified were subsequently interviewed and examined by one investigator. In those in whom the clinical diagnosis of stroke was confirmed a more detailed interview and examination relating to risk factors and recovery was carried out. RESULTS: One hundred and eight patients, 61 men and 47 women, were identified with a median age of 70 (range 18-100). Median age at first stroke was 65 years. The age specific rates in this study were lower than previous studies in developed countries. All were cared for at home although 23 (21%) were bedbound. CONCLUSIONS: Although prevalence of impairment and disability related to stroke in this population as a whole was low this is mainly explained by the age structure, with less than 6% being aged 65 and over. Age standardised rates for stroke with residual disability were about half those found in previous studies in developed countries. Death from stroke in Africa may be higher but data are limited. With the demographic transition stroke is likely to become a more important cause of disability in sub-Saharan Africa.

Insulin resistance and hypertension in non-obese Africans in Tanzania.

Insulin sensitivity was assessed using a glucose-insulin infusion test in 15 newly diagnosed non-obese hypertensive black Tanzanians with normal glucose tolerance and in 15 normotensive control subjects matched for age, sex, and body mass index. The steady-state blood glucose and metabolic clearance rate of glucose (MCR) were used as measures of insulin sensitivity. The mean MCR (glucose) was significantly reduced (7.12+/-0.57 versus 9.50+/-0.69 micromol/kg per minute; P<.05) and mean steady-state blood glucose was significantly elevated (5.0+/-0.3 versus 3.7+/-0.3 mmol/L; P<.01) in subjects with hypertension compared with the normotensive group. For all subjects there was a significant inverse correlation between MCR (glucose) and systolic (P=.003) and diastolic (P=.005) blood pressure; and a positive correlation was found between fasting serum insulin levels and systolic (P=.005) and diastolic (P=.004) blood pressure. These observations were independent of body mass index and serum lipid levels. These data indicate a strong association between insulin mediated glucose uptake and blood pressure in this population of normal weight untreated urban Africans.

The relationship of concentrations of insulin and proinsulin-like molecules with coronary heart disease prevalence and incidence. A study of two ethnic groups.

OBJECTIVE: To define the potential role of proinsulin-like molecules as risk factors for cardiovascular disease. RESEARCH DESIGN AND METHODS: Fasting concentrations of proinsulin, des-31,32-proinsulin, and insulin, and of insulin 2 h after a 75-g glucose load, were measured in 1,034 nondiabetic europid subjects and 257 south Asian subjects and related to prevalent coronary heart disease (Minnesota-coded electrocardiographic criteria or ischemic chest pain). In 137 south Asian subjects, the fasting concentrations were related to incident coronary heart disease over a 6.5-year follow-up. RESULTS: The standardized odds ratios for prevalent coronary heart disease were as follows: fasting insulin, 1.29 (1.11-1.49), P = 0.0006; 2-h insulin, 1.25 (1.08-1.45), P = 0.003; proinsulin, 1.23 (0.99-1.53), P = 0.058; and des-31,32-proinsulin, 1.32 (1.03-1.69), P = 0.026. The odds ratios were similar in the two ethnic groups. These relationships became insignificant when controlling for age, sex, and BMI. The standardized odds ratios for incident coronary heart disease were as follows: fasting insulin, 0.99 (0.63-1.55), P = 0.97; proinsulin, 1.13 (0.72-1.78), P = 0.59; and des-31,32-proinsulin, 1.00 (0.61-1.63), P = 1.00. CONCLUSIONS: We have found similar relationships between concentrations of proinsulin-like molecules and prevalent coronary heart disease, as are observed for insulin in these nondiabetic subjects, although these molecules comprise only approximately 10% of all insulin-like molecules. It appears biologically implausible that these relationships represent cause and effect.

Diabetes mellitus as a cause of death in sub-Saharan Africa: results of a community-based study in Tanzania. The Adult Morbidity and Mortality Project.

The aim of this study was to determine the contribution of diabetes mellitus to all-cause mortality and diabetes mortality rates in adults 15 years and above living in one urban and two rural areas of Tanzania (Dar es Salaam, Hai and Morogoro Rural Districts). The three surveillance populations comprised 307,912 persons. Prospective monitoring of all deaths between 1 June 1992 and 31 May 1995 was carried out. Cause of death was determined by verbal 'autopsy' conducted with relatives of the deceased. In total, 4299 deaths were recorded in children (aged < 15 years) and 8054 in adults. In children there were no reported deaths associated with diabetes (due to or in children with diabetes). The adult male mortality rates associated with diabetes were 34, 30, and 15 per 100,000 per year in Dar es Salaam, Hai and Morogoro Rural Districts respectively. The figures in women were 21, 18, and 4 per 100,000 per year, respectively. The percentages of all adult male deaths associated with diabetes were 2.6%, 2.1% and 0.7% respectively. In women the percentages were 1.7%, 1.8%, and 0.2% respectively. Acute metabolic complications, infection, and stroke each accounted for approximately 30% of all diabetic deaths. Thus diabetes mortality rates varied between the three surveillance areas, being lowest in the poorest rural area. Rates were higher in men in all areas. While care is required in the comparison of mortality rates between countries, it was noteworthy that Tanzania, a country with a low diabetes prevalence, had diabetes mortality rates which were higher than or comparable to rates in Mauritius and the United States. Most patients died from preventable causes, indicating a need for improved case-management of diabetic emergencies as well as better detection and treatment of hypertension.

Utilisation of government and private health services in Dar es Salaam.

Following the liberalisation of medical practice in Tanzania since the early 1990's, and the introduction of user fees in public hospitals in 1993, a household survey evaluated utilisation of health care in Dar es Salaam. A sample of 6,589 inhabitants was interviewed in April 1995 by means of a two-stage cluster sampling technique. Of the respondents, 32% reported some use of health care within the previous two weeks. Among these respondents, 35% had used government health services, 41% had used private services and self-treatment was chosen by 27%. The user patterns identified reveal that adults aged 15-49 years used government health service least often. Use of government services clearly decreased as the level of education, socioeconomic class and wealth status of the zone of residence of the ill person increased. Conversely in the study sample, there was an apparent tendency for people with a high level of education or belonging to a rich socio-economic class to use private facilities more often. The data also indicate that already after two years the private sector plays an important role in providing medical care and that a two-tier system of health care delivery is developing. In order to render the private sector complementary to public services, there is need for a coherent policy on legislation, development, regulation and control of private sector health services as well as a monitoring system to reinforce the policies.

Outlook for survivors of childhood in sub-Saharan Africa: adult mortality in Tanzania. Adult Morbidity and Mortality Project.

OBJECTIVE: To measure age and sex specific mortality in adults (15-59 years) in one urban and two rural areas of Tanzania. DESIGN: Reporting of all deaths occurring between 1 June 1992 and 31 May 1995. SETTING: Eight branches in Dar es Salaam (Tanzania's largest city), 59 villages in Morogoro rural district (a poor rural area), and 47 villages in Hai district (a more prosperous rural area). SUBJECTS: 40,304 adults in Dar es Salaam, 69,964 in Hai, 50,465 in Morogoro rural. MAIN OUTCOME MEASURES: Mortality and probability of death between 15 and 59 years of age (45Q15). RESULTS: During the three year observation period a total of 4929 deaths were recorded in adults aged 15-59 years in all areas. Crude mortalities ranged from 6.1/1000/year for women in Hai to 15.9/1000/year for men in Morogoro rural. Age specific mortalities were up to 43 times higher than rates in England and Wales. Rates were higher in men at all ages in the two rural areas except in the age group 25 to 29 years in Hai and 20 to 34 years in Morogoro rural. In Dar es Salaam rates in men were higher only in the 40 to 59 year age group. The probability of death before age 60 of a 15 year old man (45Q15) was 47% in Dar es Salaam, 37% in Hai, and 58% in Morogoro; for women these figures were 45%, 26%, and 48%, respectively. (The average 45Q15s for men and women in established market economies are 15% and 7%, respectively.) CONCLUSION: Survivors of childhood in Tanzania continue to show high rates of mortality throughout adult life. As the health of adults is essential for the wellbeing of young and old there is an urgent need to develop policies that deal with the causes of adult mortality.

Blood pressure changes in diabetes in urban Tanzania.

Little is known of the natural history of blood pressure (BP) levels in diabetic patients from sub-Saharan Africa. BP levels were therefore recorded in such patients in Dar es Salaam, Tanzania, over 2, 5, and 7 years. Hypertension was found in 5% of insulin-treated diabetes mellitus (IDDM) and 29.2% of non-insulin-dependent diabetes mellitus (NIDDM) patients at presentation with diabetes. Hypertension developed in a further 2 IDDM (3.7%) and 27 NIDDM (15.6%) patients at 2 years, and in 3 IDDM (13.0%) and 9 NIDDM (9.8%) patients at 5 years. Seven NIDDM (18.4%) patients had developed hypertension by 7 years. In NIDDM patients with normal BP initially, the mean systolic BP rose from 131 to 141 mmHg (P < 0.001) 2 years later (n = 146); from 131 to 138 mmHg (P < 0.001) for those followed for 5 years (n = 82); and from 131 to 138 mmHg (P < 0.05) for those followed for 7 years (n = 31). The mean diastolic BP was 83 mmHg initially and 84 mmHg (NS) for those followed for 2 years (n = 146). There was no observed rise in mean diastolic BP at 5 or 7 years of follow-up. In IDDM patients without hypertension, only the systolic BP rose significantly by 5 years, from 124 to 132 mmHg (P < 0.001; n = 20). These changes were independent of age, sex, body mass index, and proteinuria.(ABSTRACT TRUNCATED AT 250 WORDS)

IDDM susceptibility associated with polymorphisms in the insulin gene region. A study of blacks, Caucasians and orientals.

Previous studies have suggested an association between polymorphisms in the insulin gene region and insulin-dependent diabetes mellitus (IDDM). Most of the studies so far have been performed in Caucasoid populations. We have investigated 418 random IDDM patients and 422 healthy control subjects from three different ethnic groups; Tanzanian blacks, Norwegian Caucasians and Japanese orientals. Our data suggest that polymorphisms in the insulin gene region confer susceptibility to IDDM in Caucasians, and that a similar tendency though not statistically significant is observed among Tanzanian blacks, while no significant contribution is seen among Japanese orientals. We further demonstrate that the disease-associated genotype INS +/+ confers susceptibility independently of HLA class II alleles associated with IDDM. Compared to the contribution of particular HLA-DQ alleles in IDDM susceptibility, the additional risk conferred by the insulin gene region polymorphism is, however, small. Genotyping of the insulin gene region will therefore most probably not be a useful tool in the prediction of IDDM.

Perinatal mortality in rural Tanzania.

In 1987, as part of the World Health Organization's Inter-Health Programme, we carried out a noncommunicable diseases survey in six rural villages in Tanzania. Each women completed a questionnaire, part of which was concerned with obstetric history, and underwent a physical examination. Our findings of unacceptably high perinatal mortality and abortion rates are described below.

PIP: Within the framework of the World Health Organization's [WHO] Inter- Health Program, a noncommunicable diseases survey was carried out in 6 villages located in 2 regions of Tanzania in 1987. A total of 3565 women were queried about their viable pregnancies, still-births, perinatal deaths (death within the first week of life), and abortions (loss of conceptus within 28 weeks of gestation). The overall abortion rate was 119/1000 pregnancies (range of 89/1000-170/1000 pregnancies). In the Kilimanjaro region, the abortion rate was 97/1000 compared to 145/1000 in the Morogoro region. The overall perinatal mortality rate was 73/1000 births (range of 49/1000-124/1000 births). In the Kilimanjaro region, the perinatal mortality rate was 58/1000 births vs. 91/1000 in the Morogoro region. The overall abortion rate for the 6 villages was 12% of pregnancies, while the range culled from the literature was 10-25%. The rate of miscarriage before 20 weeks of gestation has been estimated at 36-43%. In the Morogoro region, miscarriage rates were highest in the older age groups, which is indicative of improved health care. The difference in perinatal mortality rates between the 2 regions may be attributable to the relatively higher level of development of the Kilimanjaro region. This difference in socioeconomic development was also reflected in the infant mortality rate: 70/1000 births in the Kilimanjaro compared to 140/1000 in the Morogoro region. Other studies in east Africa showed perinatal mortality rates of 46/1000 births in Kenya's Machakos region during 1975-78, and a rate of 124/1000 births in Tanzania near the Morogoro region during 1984-85. Community-based studies focusing on women's health and care during pregnancy and childbirth are needed to investigate the causes of perinatal deaths, because hospital-based studies give a disjointed picture of both rates and the causes.

Schistosomiasis prevalence after administration of praziquantel to school children in Melela village, Morogoro region, Tanzania.

A study of the prevalence of schistosomiasis was carried out in 253 school children in Melela, Tanzania, one year after a single dose of praziquantel, 40 mg/kg body weight. The cure rate was 90.4%. However the new incidence estimate was 21.2% in children who were initially negative. The use of reagent strips in urine tests for the detection of urinary schistosomiasis was also evaluated. The presence of blood in the urine was highly sensitive (> 96%) and specific (87%). The sensitivity of proteinuria was less, but it was highly specific (94%). This study shows that chemotherapy will have to be combined with other measures to achieve lasting benefits and raises the question as to how often the population should be treated. It also confirms the value of urine test strips as an indirect diagnostic test for urinary schistosomiasis in an endemic area. Further follow-up is necessary to make useful predictions concerning incidence and reinfection rates in the community. This will also help in deciding how often chemotherapy should be given to the population.

Coronary heart disease risk factors in sub-Saharan Africa: studies in Tanzanian adolescents.

STUDY OBJECTIVE: To assess the level of cardiovascular risk factors in young people in sub-Saharan Africa living in rural and urban settings. DESIGN: Cross sectional survey of the population aged 15 to 19 years. SETTING: Eight rural Tanzanian villages in three regions, and two districts in Dar es Salaam. PARTICIPANTS: 664 males and 803 females in rural villages and 85 males and 121 females in the city. Response rates for total population were 74% to 94% in the rural areas and 60% in the city. MEASUREMENTS AND RESULTS: Measurements included blood pressure, body mass index, serum lipids, and blood glucose concentrations (fasting and two hours after 75 g glucose). Blood pressure was slightly but significantly higher in young women than in young men (115/67 mmHg versus 113/65 mmHg) and increased significantly with age. Only 0.4% subjects had blood pressure greater than 140 and/or 90 mmHg. There were no urban-rural differences. Body mass index was higher in females (mean (SD) 20.3 (2.8) kg/m2) than males (18.5 (2.1)). Overweight was found in only 0.6% at age 15 years but 5.4% at age 19 years. Serum cholesterol concentrations were low at 3.5 mmol/l in males and 3.7 mmol/l in females. Only 7% had values above 5.2 mmol/l. The highest concentrations were found in the city and in Kilimanjaro, the most prosperous rural region. Serum triglycerides were 1.0 (0.5) mmol/l in males and 1.1 (0.5) mmol/l in females, and were highest in the city dwellers. Diabetes was rare (0.28% males, 0.12% females) but impaired glucose tolerance was present in 4.7% and 4.1% respectively. Drinking alcohol was equally prevalent in males and females, reaching 30% at age 19 years. Only 0.4% of females smoked compared with 7.3% of males. Smoking was commoner in rural areas that in the city. CONCLUSIONS: Several risk factors for cardiovascular disease were found in Tanzanian adolescents, but levels were much lower than in studies reported from developed nations. The challenge is to maintain these low levels as the population becomes more urbanised and more affluent.

Low prevalence of risk factors for coronary heart disease in rural Tanzania.

A community-based survey was used to assess the prevalence of risk factors for coronary heart disease (CHD) in rural Tanzanians. In all, 8581 subjects (3705 men, 4876 women) aged > or = 15 years in eight villages in three regions in rural Tanzania representing a range of socioeconomic deprivation were studied. The main outcome measures were serum cholesterol and triglyceride level, blood pressure and prevalence of dyslipidaemia, hypertension, smoking, overweight, impaired glucose tolerance (IGT) and diabetes; as well as ECG changes. Mean serum cholesterol levels in men were 4.2, 3.4 and 3.7 mmol/l, and in women 4.4 3.6 and 3.9 mmol/l in Kilimanjaro, Morogoro and Mara regions respectively. In Kilimanjaro region 17.4% of men and 19.0% of women had values above 5.2 mmol/l compared with only 5.0% and 6.7% in Morogoro region and 4.8% and 6.9% respectively in Mara region. Systolic and diastolic blood pressures increased with age in both men and women in all three regions with the most marked increase in Kilimanjaro region and the smallest rise in Mara region. Mean age-adjusted values were highest in Kilimanjaro region (124/75 mm Hg, and 125/76 mm Hg in men and women respectively) and lowest in Mara region (120/70 mm Hg in men and 118/68 mm Hg in women). Hypertension was found in 6.6% of men and 7.5% of women in Kilimanjaro region, 3.3% and 4.7% in Morogoro, and 2.6% and 3.4% in Mara region. Cigarette smoking was found in 42.6% of men in Kilimanjaro region, 28.2% of Morogoro region and 8.6% in Mara region. Less than 4% of women smoked in all three regions.(ABSTRACT TRUNCATED AT 250 WORDS)