Anti-diabetic drugs in the private and public sector in Dar es Salaam, Tanzania

OBJECTIVES

To compare availability, cost, affordability and sources of anti-diabetic drugs between private and public health facilities in Dar es Salaam, Tanzania.

DESIGN

Cross sectional descriptive study.

SETTING

Diabetic clinics in private and public health facilities in Dar es Salaam, Tanzania.

SUBJECTS

Eighty patients randomly selected and 45 health facility personnel staff working in the diabetic clinics. Semi-structured questionnaires and a checklist were used to collect the information.

RESULTS

Oral hypoglycaemic agents were available in all seven private and three public facilities that were studied. Private facilities stocked more types of oral hypoglycaemic agents than public facilities, which stocked only chlorpropamide and tolbutamide, based on the National Essential Drugs List. The cost of chlorpropamide was five times higher in private facilities compared to public facilities. Insulin was also available in all the facilities. The price of animal insulin in private health facilities was ten times that in public health facilities. Human insulin, which is generally more expensive than animal insulin, was only available in private facilities. Although prices were much lower in public facilities, affordability emerged as a common issue in both private and public facilities.

CONCLUSIONS

Urban private health facilities offer a wider choice for the needs of diabetic patients but this advantage is compromised by higher prices as compared to public facilities as well as inconsistent supply across facilities. Public health facilities offer only a limited selection of essential oral hypoglycaemics and insulin but at a lower price and across all facilities. Twenty six per cent and 10% of patients in public and private facilities respectively are unable to afford anti-diabetic drugs. The need for intervention to increase affordability of anti-diabetic drugs is evident. Financing and cost of drugs needs to be addressed, either by means of health insurance or other mechanisms, in this era of increasing prevalence of diabetes mellitus among developing countries.

A sub-Saharan African perspective of diabetes

Diabetes mellitus is an important and increasing cause of morbidity and mortality in sub-Saharan Africa. Accurate epidemiological studies are often logistically and financially difficult, but processes of rural-urban migration and epidemiological transition are certainly increasing the prevalence of type 2 diabetes. Type 1 disease is relatively rare, although this may be related to high mortality. This diabetic subgroup appears to present at a later age (by about a decade) than in Western countries. Variant forms of diabetes are also described in the continent; notably 'atypical, ketosis-prone' diabetes, and malnutrition-related diabetes mellitus. These types sometimes make the distinction between type 1 and type 2 diabetes difficult. Interestingly, this is also a current experience in the developed world. As more detailed and reliable complication studies emerge, it is increasingly apparent that African diabetes is associated with a high complication burden, which is both difficult to treat and prevent. More optimistically, a number of intervention studies and twinning projects are showing real benefits in varying locations. Future improvements depend on practical and sustainable support, coupled with local acceptance of diabetes as a major threat to the future health and quality of life of sub-Saharan Africans.

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, impaired glucose tolerance and cardiovascular disease risk factors in the Asian Indian Bhatia community living in Tanzania and in the United Kingdom

A population-based cross-sectional survey was carried out to study potential environmental risk factors contributing to diabetes and cardiovascular risk in the same homogeneous group in the United Kingdom and in Dar es Salaam, Tanzania. In Dar es Salaam, 222 members of the Bhatia community aged 15 years and over were studied. In the UK, 180 randomly selected subjects aged 15 years and over participated. Age, sex, and body mass index adjusted mean levels of fasting glucose (5.5 mmol l-1 vs 5.1 mmol l-1 (p < 0.001)) and 2 h glucose (6.8 mmol l-1 vs 6.0 mmol l-1 (p < 0.001)) were significantly higher in Tanzanian subjects than in UK subjects. Mean levels of serum triglycerides (1.5 mmol l-1 vs. 1.3 mmol l-1 (p < 0.05)) and systolic blood pressure (135 mmHg vs 127 mmHG (p < 0.05) were significantly higher in subjects in the UK. The age and sex adjusted prevalence of impaired glucose tolerance (28.4% vs 11.4% (p < 0.001)), newly diagnosed diabetes (8.6 % vs 1.5% (p < 0.01)), hypercholesterolaemia (9.9% vs 1.5% (p < 0.001)), and smoking (12.1% vs 3.9% (p < 0.01)) were significantly higher in subjects in Tanzania compared to subjects in the UK. The prevalence of known diabetes, hypertriglyceridaemia, hypertension, and obesity did not show significant differences between subjects in Tanzania and those in the UK. Within the same homogeneous community with the same likely genetic predisposition, there are substantial geographical differences in cardiovascular risk factors, the causes of which remain to be determined.

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)

Impaired glucose tolerance and diabetes mellitus in Hindu Indian immigrants in Dar es Salaam

The prevalence of Impaired Glucose Tolerance (IGT) and diabetes mellitus was studied in a migrant Hindu Indian community in Dar es Salaam, Tanzania. Using 1985 WHO criteria, 75 g oral glucose tolerance tests (OGTT) were performed on 1147 (583 men; 564 women) subjects aged 15 years and over. The age-standardized prevalence of IGT in men and women was 15.2 and 17.2%, and that of diabetes was 9.1% (6.5% known; 2.6% previously undiagnosed) and 9.0% (3.7% known; 5.3% previously undiagnosed), respectively. Diabetes was present in 12.9% of men and 12.8% of women aged 35 years and above. The overall age- and sex-standardized prevalence of IGT was 16.2% and of diabetes 9.1%. The major risk factors associated with diabetes in both men and women were age, family history of diabetes, and physical inactivity, and in women body mass index (BMI). Age and BMI contributed to the higher frequency of IGT in women as compared with men while in men, age was the only contributory factor. Despite overweight and obesity being more frequent in women than men, age-standardized prevalence rates of IGT and diabetes were similar between men and women. The decreased prevalence of diabetes in men and women performing moderate/heavy physical activity was independent of age and BMI.

Prevalences of diabetes and cardiovascular disease risk factors in Hindu Indian subcommunities in Tanzania

OBJECTIVES

To seek differences in the prevalence of diabetes mellitus and other coronary heart disease risk factors, and to identify factors associated with these differences within a Hindu Indian community.

DESIGN

Population based cross sectional survey.

SETTING

Dar-es-Salaam, Tanzania.

SUBJECTS

Of 20 Hindu subcommunities categorised by caste in Dar-es-Salaam, seven were randomly selected. 1147 (76.7%) of 1495 subjects aged 15 or over participated.

MAIN OUTCOME MEASURES

Blood glucose concentrations (fasting and two hours after oral glucose loading), serum total cholesterol and serum triglyceride concentrations, blood pressure, and height and weight.

RESULTS

The subcommunities differed substantially in socioeconomic characteristics and lifestyle. Overall, 9.8% of subjects (109/1113) had diabetes, 17.0% (189/1113) impaired glucose tolerance, 14.5% (166/1143) hypertension, and 13.3% (151/1138) were obese. The mean fasting blood glucose concentration was 4.9 mmol/l, the blood glucose concentration two hours after oral loading (75 g) 6.0 mmol/l, the total cholesterol concentration 4.9 mmol/l, the serum triglyceride concentration 1.4 mmol/l, and body mass index (weight/height: kg/m2) 24.3. Systolic and diastolic blood pressures were 121 and 77 mm Hg respectively. There were important intercommunity differences even after standardisation for age, sex, and body mass index--for example, in mean fasting blood glucose concentration (range 4.5 (Jains) to 5.9 mmol/l (Patels)), serum total cholesterol concentration (range 4.5 (Jains) to 6.2 mmol/l (Suthars)), systolic blood pressure (range 110 (Limbachias) to 127 mm Hg (Bhatias)), and prevalences of diabetes (range 3.4% (3/87 Limbachias) to 18% (20/111 Navnats)) and hypertension (range 5.7% (5/87 Limbachias) to 19.4% (43/222 Bhatias). Variables which showed significant linear correlation with subcommunity variations were entered into a multiple regression model. Intercommunity variations persisted. The Limbachia and Jain communities had the lowest prevalence of and mean values for coronary heart disease risk factors and the Bhatia and Patel communities had the highest.

CONCLUSIONS

In this series intercommunity variations in disease and risk factors might have been related to genetic, dietary, socioeconomic, and lifestyle differences but could not be explained by the characteristics studied. Studies of Indian subcommunities are warranted to confirm and extend these descriptive findings and explore the genetic basis of diabetes. Communities of Indian origin should not be perceived as homogeneous.

Epidemiology of diabetes in Asians of the Indian subcontinent

Asians from the Indian subcontinent have received greater attention in diabetes studies because of their migration in large numbers. The prevalence of non-insulin-dependent diabetes mellitus (NIDDM) in migrant Indians is higher than that in the population residing in the Indian subcontinent and is also usually higher than in the other racial groups in the host country. However, before drawing any conclusions with reference to the high prevalence of NIDDM in the migrant Indians, careful comparisons are required with more up-to-date information available from the Indian subcontinent itself. Recent data from India indeed indicate that the prevalence rates have either been underestimated in the past or are rising. The problem is compounded by the different diagnostic criteria used for defining diabetes. Some of the possible factors which cause variations in the rates of NIDDM in this population are discussed.

Improvement in glucose tolerance after one year of follow-up in a Hindu community in Africa

Oral glucose tolerance was studied following a 75 g glucose load in 108 (82.4%) of 131 male and 110 (79.1%) of 139 female members of a Hindu subcommunity aged 15 years and over in Dar es Salaam. One year later, the glucose tolerance tests were repeated in 93 (86.1%) and 93 (84.5%) of the 108 male, and 110 of the female subjects, respectively. In the first survey, 25 (26.9%) of the 93 male and 24 (25.8%) of the 93 female subjects had impaired glucose tolerance (IGT), 6 (6.4%) and 15 (16.1%), respectively, had diabetes mellitus; and 62 (66.7%) and 54 (58.1%), respectively, had normal glucose tolerance. In the repeat survey, of the 93 male and 93 female subjects, 8 (8.6%) and 7 (7.5%) had IGT, 4 (4.3%) and 10 (10.8%) had diabetes; and 81 (87.1%) and 76 (81.7%) were normal, respectively. Of the 21 subjects diagnosed as having diabetes in the first survey, 13 (61.9%) continued to show diabetic glucose tolerance; 4 (19%) IGT and 4 (19%) had normal glucose tolerance with no gender difference. One (1.6%) of the 62 male subjects and none of the 54 females with normal glucose tolerance in the first survey progressed to IGT, while the remainder retained normal glucose tolerance. Diabetes and IGT rates in both surveys were higher for the older than the younger persons. A significant fall in mean fasting and post-75 g blood glucose levels, and in mean systolic and diastolic pressure levels was observed between the first and second surveys in both genders. There was, however, no significant difference in body mass index (BMI), serum total cholesterol and triglyceride levels between surveys, suggesting that major dietary changes had not taken place. Male subjects who showed persistent IGT had significantly lower mean level of body mass index (kg/m2) than subjects who reverted to normal, whilst for the whole group those who had persistent IGT were older. It is tempting to speculate that these changes were due to community action. However, in view of the lack of change in weight and lipids and similar results in other communities in Tanzania when retested at 1 week, further studies are needed to establish the significance of the findings.