Diabetes in Africa

Type 2 diabetes mellitus in sub-Saharan Africa: challenges and opportunities

Type 2 diabetes mellitus (T2DM), which was once thought to be rare in sub-Saharan Africa (SSA), is now well established in this region. The SSA region is undergoing a rapid but variable epidemiological transition fuelled by the pace of urbanization, with disease burden profiles shifting from communicable diseases to non-communicable diseases (NCDs). Information on the epidemiology of T2DM has increased, but wide variations in study methods, diagnostic biomarkers and criteria hamper analytical comparison, and data from high-quality studies are limited. The prevalence of T2DM is still low in some rural populations but moderate or high rates are reported in many countries/regions, with evidence for an increase in some. In addition, the proportion of undiagnosed T2DM is still high. The prevalence of T2DM is highest in African people living in urban areas, and the gradient between African people living in urban areas and people in the African diaspora is rapidly fading. However, data from longitudinal studies are lacking and there is limited information on chronic complications and the genetics of T2DM. The large unmet needs for T2DM care call for greater investment of resources into health systems to manage NCDs in SSA. Proposed health-system paradigms are being developed in some countries/regions. However, national NCD programmes need to be adequately funded and coordinated to stem the tide of T2DM and its complications.

Diabetic foot ulcer disease in African continent: 'From clinical care to implementation' - Review of diabetic foot in last 60 years - 1960 to 2020

The prevalence of diabetes mellitus is increasing globally and the greatest potential increases in diabetes will occur in Africa. Data suggest that these increases is associated with rapid demographic, sociocultural and economic transitions. There will be a parallel increase in the complications of diabetes and among the various complications those related to diabetic foot disease are associated with the highest morbidity and mortality. Diabetic Peripheral neuropathy (DPN) is the most common cause of diabetic foot complications in African countries; however, peripheral arterial disease (PAD) appears to increase, possibly a result of rising urbanization. Search done for the past six decades (1960 to 2020) on all foot complications. Rates of complications of diabetic foot in last six decades varied by country as follow: DPN: 4-90%; PAD: 0-77%; foot ulcers: 4-61%; amputation rates: 3-61% and high mortality rates reaching to 55%, patients who presented late with infection and gangrene. Educational and prevention programmes are required to curb the growing complications of diabetic foot ulcers in Africa among patients and health care workers. Secondly, it is imperative that governments across the African continent recognise the clinical and public health implications of diabetic foot disease in persons with diabetes.

EADSG Guidelines: Insulin Therapy in Diabetes

A diagnosis of diabetes or hyperglycemia should be confirmed prior to ordering, dispensing, or administering insulin (A). Insulin is the primary treatment in all patients with type 1 diabetes mellitus (T1DM) (A). Typically, patients with T1DM will require initiation with multiple daily injections at the time of diagnosis. This is usually short-acting insulin or rapid-acting insulin analogue given 0 to 15 min before meals together with one or more daily separate injections of intermediate or long-acting insulin. Two or three premixed insulin injections per day may be used (A). The target glycated hemoglobin A1c (HbA1c) for all children with T1DM, including preschool children, is recommended to be < 7.5% (< 58 mmol/mol). The target is chosen aiming at minimizing hyperglycemia, severe hypoglycemia, hypoglycemic unawareness, and reducing the likelihood of development of long-term complications (B). For patients prone to glycemic variability, glycemic control is best evaluated by a combination of results with self-monitoring of blood glucose (SMBG) (B). Indications for exogenous insulin therapy in patients with type 2 diabetes mellitus (T2DM) include acute illness or surgery, pregnancy, glucose toxicity, contraindications to or failure to achieve goals with oral antidiabetic medications, and a need for flexible therapy (B). In T2DM patients, with regards to achieving glycemic goals, insulin is considered alone or in combination with oral agents when HbA1c is ≥ 7.5% (≥ 58 mmol/mol); and is essential for treatment in those with HbA1c ≥ 10% (≥ 86 mmol/mol), when diet, physical activity, and other antihyperglycemic agents have been optimally used (B). The preferred method of insulin initiation in T2DM is to begin by adding a long-acting (basal) insulin or once-daily premixed/co-formulation insulin or twice-daily premixed insulin, alone or in combination with glucagon-like peptide-1 receptor agonist (GLP-1 RA) or in combination with other oral antidiabetic drugs (OADs) (B). If the desired glucose targets are not met, rapid-acting or short-acting (bolus or prandial) insulin can be added at mealtime to control the expected postprandial raise in glucose. An insulin regimen should be adopted and individualized but should, to the extent possible, closely resemble a natural physiologic state and avoid, to the extent possible, wide fluctuating glucose levels (C). Blood glucose monitoring is an integral part of effective insulin therapy and should not be omitted in the patient's care plan. Fasting plasma glucose (FPG) values should be used to titrate basal insulin, whereas both FPG and postprandial glucose (PPG) values should be used to titrate mealtime insulin (B). Metformin combined with insulin is associated with decreased weight gain, lower insulin dose, and less hypoglycemia when compared with insulin alone (C). Oral medications should not be abruptly discontinued when starting insulin therapy because of the risk of rebound hyperglycemia (D). Analogue insulin is as effective as human insulin but is associated with less postprandial hyperglycemia and delayed hypoglycemia (B). The shortest needles (currently the 4-mm pen and 6-mm syringe needles) are safe, effective, and less painful and should be the first-line choice in all patient categories; intramuscular (IM) injections should be avoided, especially with long-acting insulins, because severe hypoglycemia may result; lipohypertrophy is a frequent complication of therapy that distorts insulin absorption, and therefore, injections and infusions should not be given into these lesions and correct site rotation will help prevent them (A). Many patients in East Africa reuse syringes for various reasons, including financial. This is not recommended by the manufacturer and there is an association between needle reuse and lipohypertrophy. However, patients who reuse needles should not be subjected to alarming claims of excessive morbidity from this practice (A). Health care authorities and planners should be alerted to the risks associated with syringe or pen needles 6 mm or longer in children (A).

Readiness of Sub-Saharan Africa Healthcare Systems for the New Pandemic, Diabetes: A Systematic Review

Background

Effective health systems are needed to care for the coming surge of diabetics in sub-Saharan Africa (SSA).

Objective

We conducted a systematic review of literature to determine the capacity of SSA health systems to manage diabetes.

Methodology

We used three different databases (Embase, Scopus, and PubMed) to search for studies, published from 2004 to 2017, on diabetes care in SSA.

Results

Fifty-five articles met the inclusion criteria, covering the different aspects related to diabetes care such as availability of drugs and diagnostic tools, the capacity of healthcare workers, and the integration of diabetes care into HIV and TB platforms.

Conclusion

Although chronic care health systems in SSA have developed significantly in the last decade, the capacity for managing diabetes remains in its infancy. We identified pilot projects to enhance these capacities. The scale-up of these pilot interventions and the integration of diabetes care into existing robust chronic disease platforms may be a feasible approach to begin to tackle the upcoming pandemic in diabetes. Nonetheless, much more work needs to be done to address the health system-wide deficiencies in diabetes care. More research is also needed to determine how to integrate diabetes care into the healthcare system in SSA.

The 30-year cardiovascular risk profile of South Africans with diagnosed diabetes, undiagnosed diabetes, pre-diabetes or normoglycaemia: the Bellville, South Africa pilot study

Abstract

The aim of this pilot study was to assess the 30-year risk for cardiovascular disease (CVD) in the South Africa population of mixed-ancestry in individuals with non-diabetic hyperglycaemia, and undiagnosed and self-reported diabetes. Participants were drawn from an urban community of the Bellville South suburb of Cape Town. In total, 583 subjects without a history of CVD were eligible for lifetime CVD risk estimation. Gender-specific prediction for CVD risk was calculated using the 30-year CVD interactive risk calculator. High CVD risk (> 20%) was evident in normoglycaemic and younger subjects (under 35 years). The significant predictors of CVD were sibling history of diabetes, and triglyceride, low-density lipoprotein cholesterol and glycated haemoglobin levels (p < 0.001). The high lifetime risk in normoglycaemic and younger subjects may be considered a warning that CVD might take on epidemic proportions in the near future in this country. We recommend the inclusion of education on CVD in school and university curricula.

[Contribution of arterial Doppler ultrasound of the lower limbs in the treatment of diabetic foot at Saint-Jean de Dieu Hospital in Thies (Senegal)]

Introduction

Le pied diabétique se définit comme l'ensemble des manifestations trophiques du pied survenant chez le diabétique par atteinte nerveuse, artérielle et ou infectieuse. Le pied diabétique est un problème majeur de santé publique à l’échelle mondiale avec un taux d'amputation de membres inférieurs très élevé. L’écho-doppler artériel des membres inférieurs est de nos jours incontournable dans la prise en charge du pied diabétique. Le but de cette étude est de montrer la place prépondérante qu'occupe l’écho-doppler artériel dans le bilan lésionnel du pied diabétique.

Méthodes

Nous avons mené une étude rétrospective monocentrique incluant 46 patients sur une période de 24 mois, de mars 2012 à mars 2014 à l'hôpital Saint-Jean de Dieu, un des deux hôpitaux de référence de la région de Thiès, doté depuis juillet 2011 d'un centre moderne de traitement du diabète et des maladies cardio-métaboliques (Diabcarmet). Dans les critères d'inclusion, nous avons sélectionné tous les patients diabétiques adressés pour un écho-doppler artériel des membres inférieurs dans le cadre d'une prise en charge du pied diabétique. Etaient exclus de l’étude, les patients artéritiques non-diabétiques et les patients diabétiques asymptomatiques référés pour un bilan écho-doppler de routine.

Résultats

Le sex-ratio était de 1.42 (27 hommes pour 19 femmes). L’âge moyen des patients était de 62,86 ans avec des extrêmes de 23 et 88 ans. 60% des patients (n=28) étaient âgés entre 50 et 70 ans. Le diabète de type 2 était retrouvé chez 95% des patients (n=44) alors que le diabète de type 1 représentait 5% (n=2). La moyenne d’évolution du diabète était estimée à 8 ans, avec des extrêmes de 2 et 20 ans. On notait une atteinte du pied droit chez 24 patients, une atteinte du pied gauche chez 18 patients et une atteinte bilatérale chez 4 patients. La plupart du temps, les lésions du pied diabétique survenaient sur un terrain de diabète déséquilibré (95%). Cliniquement, ces lésions étaient dominées par la gangrène infectieuse du pied (43.47%), l'abolition des pouls tibiaux et pédieux (17.4%), la gangrène infectieuse des orteils (13.07%), la gangrène mixte du pied (4.34%) et le mal perforant plantaire (4.34%). Sur le plan échographique, vingt-six patients ne présentaient aucune anomalie hémodynamique significative, même si sur le plan morphologique la médiacalcose était retrouvée chez tous nos patients (n=46). Les autres lésions morphologiques et hémodynamiques artérielles étaient dominées par la sténose serrée de l'artère fémorale superficielle chez 6 patients soit 13.04%, les sténoses des artères tibiales antérieures et postérieures chez 4 patients (6.52%) et l'association de plusieurs lésions artérielles chez 4 patients (8.7%). Le taux d'amputation, dans notre série, était de 21.7%.

Conclusion

Le pied diabétique est une complication potentiellement grave du diabète, en Afrique sub-saharienne du fait d'un fort taux d'amputation de membre. L’écho-doppler artériel des membres inférieurs est un moyen d'imagerie non irradiant et non invasif indispensable dans la prise de décision thérapeutique du pied diabétique.

Prevalence and correlates of diabetes mellitus in Uganda: a population-based national survey

OBJECTIVE

We analysed fasting blood glucose (FBG) and other data collected as part of a population-based nationwide non-communicable disease risk factor survey, to estimate the prevalence of impaired fasting glycaemia (IFG) and diabetes mellitus and to identify associated factors in Uganda.

METHODS

The nationwide cross-sectional survey was conducted between April and July 2014. Participants were adults aged 18-69 years. A multistage stratified sample design was used to produce a national representative sample. Fasting capillary glucose was measured to estimate glycaemia. Data were managed with WHO e-STEPs software and Epi Info. Stata(®) survey procedures were used to account for the sampling design, and sampling weights were used to account for differential probability of selection between strata.

RESULTS

Of the 3689 participants, 1467 (39.8%) were males, and 2713 (73.5%) resided in the rural areas. The mean age was 35.1 years (standard deviation = 12.6) for males and 35.8 years (13.2) for females. The overall prevalence of IFG was 2.0% (95% confidence interval (CI) = 1.5-2.5%), whereas that of diabetes mellitus was 1.4% (95% CI 0.9-1.9%). The prevalence of IFG was 2.1% (95% CI 1.3-2.9%) among males and 1.9% (95% CI 1.3-2.6%) among females, whereas that of diabetes mellitus was 1.6% (95% CI 0.8-2.6%) and 1.1% (95% CI 0.6-1.7%), respectively. The prevalence of IFG was 2.6% (95% CI 1.4-3.8%) among urban and 1.9% (95% CI 1.3-2.4%) among rural residents, whereas that of diabetes mellitus was 2.7% (95% CI 1.4-4.1) and 1.0% (95% 0.5-1.6%), respectively. The majority of participants identified with hyperglycaemia (90.5% IFG and 48.9% diabetes) were not aware of their hyperglycaemic status. Factors associated with IFG were region of residence, body mass index and total cholesterol; factors associated with diabetes mellitus were age, sex, household floor finish and abdominal obesity.

CONCLUSION

The prevalence of IFG and of diabetes mellitus is low in the Ugandan population, providing an opportunity for the prevention of diabetes. The majority of persons with hyperglycaemia were not aware of their hyperglycaemic status, which implies a likelihood of presenting late with complications.

Prevalence and Risk Factors for Overweight and Obesity among HIV-Infected Adults in Dar es Salaam, Tanzania

BACKGROUND

Overweight and obesity are increasingly prevalent among HIV-infected populations. We describe their prevalence and associated risk factors among HIV-infected adults in Dar es Salaam, Tanzania.

METHODS

A cross-sectional study was conducted to determine the proportion of patients who were overweight or obese at enrollment to care and treatment centres from 2004 to 2011. Multivariate relative risk regression models were fit to identify risk factors.

RESULTS

A total of 53 825 patients were included in the analysis. In all, 16% of women and 8% of men were overweight, while 7% and 2% were obese, respectively. In multivariate analyses, older age, higher CD4 count, higher hemoglobin levels, female sex, and being married were associated with obesity and overweight. World Health Organization HIV disease stage, tuberculosis history, and previous antiretroviral therapy were inversely associated with obesity and overweight.

CONCLUSION

Overweight and obesity were highly prevalent among HIV-infected patients. Screening for overweight and obesity and focused interventions should be integrated into HIV care.

The rising burden of diabetes and hypertension in southeast asian and african regions: need for effective strategies for prevention and control in primary health care settings

Aim. To review the available literature on burden of diabetes mellitus (DM) and hypertension (HTN) and its coexistence in Southeast Asian (SEA) and the African (AFR) regions and to suggest strategies to improve DM and HTN prevention and control in primary health care (PHC) in the two regions. Methods. A systematic review of the papers published on DM, HTN, and prevention/control of chronic diseases in SEA and AFR regions between 1980 and December 2012 was included. Results. In the year 2011, SEA region had the second largest number of people with DM (71.4 million), while the AFR region had the smallest number (14.7 million). Screening studies identified high proportions (>50%) of individuals with previously undiagnosed HTN and DM in both of the SEA and AFR regions. Studies from both regions have shown that DM and HTN coexist in type 2 DM ranging from 20.6% in India to 78.4% in Thailand in the SEA region and ranging from 9.7% in Nigeria to 70.4% in Morocco in the AFR region. There is evidence that by lifestyle modification both DM and HTN can be prevented. Conclusion. To meet the twin challenge of DM and HTN in developing countries, PHCs will have to be strengthened with a concerted and multipronged effort to provide promotive, preventive, curative, and rehabilitative services.

The metabolic syndrome in Africa: Current trends

Metabolic syndrome is a clustering of several cardiovascular risk factors. Contrary to earlier thoughts, metabolic syndrome is no longer rare in Africa. The prevalence is increasing, and it tends to increase with age. This increase in the prevalence of metabolic syndrome in the continent is thought to be due to departure from traditional African to western lifestyles. In Africa, it is not limited to adults but is also becoming common among the young ones. Obesity and dyslipidemia seem to be the most common occurring components. While obesity appears more common in females, hypertension tends to be more predominant in males. Insulin resistance has remained the key underlying pathophysiology. Though pharmacologic agents are available to treat the different components of the syndrome, prevention is still possible by reverting back to the traditional African way of life.

Diabetes in Sub Saharan Africa 1999-2011: epidemiology and public health implications. A systematic review

Background

Diabetes prevalence is increasing globally, and Sub-Saharan Africa is no exception. With diverse health challenges, health authorities in Sub-Saharan Africa and international donors need robust data on the epidemiology and impact of diabetes in order to plan and prioritise their health programmes. This paper aims to provide a comprehensive and up-to-date review of the epidemiological trends and public health implications of diabetes in Sub-Saharan Africa.

Methods

We conducted a systematic literature review of papers published on diabetes in Sub-Saharan Africa 1999-March 2011, providing data on diabetes prevalence, outcomes (chronic complications, infections, and mortality), access to diagnosis and care and economic impact.

Results

Type 2 diabetes accounts for well over 90% of diabetes in Sub-Saharan Africa, and population prevalence proportions ranged from 1% in rural Uganda to 12% in urban Kenya. Reported type 1 diabetes prevalence was low and ranged from 4 per 100,000 in Mozambique to 12 per 100,000 in Zambia. Gestational diabetes prevalence varied from 0% in Tanzania to 9% in Ethiopia. Proportions of patients with diabetic complications ranged from 7-63% for retinopathy, 27-66% for neuropathy, and 10-83% for microalbuminuria. Diabetes is likely to increase the risk of several important infections in the region, including tuberculosis, pneumonia and sepsis. Meanwhile, antiviral treatment for HIV increases the risk of obesity and insulin resistance. Five-year mortality proportions of patients with diabetes varied from 4-57%. Screening studies identified high proportions (> 40%) with previously undiagnosed diabetes, and low levels of adequate glucose control among previously diagnosed diabetics. Barriers to accessing diagnosis and treatment included a lack of diagnostic tools and glucose monitoring equipment and high cost of diabetes treatment. The total annual cost of diabetes in the region was estimated at US$67.03 billion, or US$8836 per diabetic patient.

Conclusion

Diabetes exerts a significant burden in the region, and this is expected to increase. Many diabetic patients face significant challenges accessing diagnosis and treatment, which contributes to the high mortality and prevalence of complications observed. The significant interactions between diabetes and important infectious diseases highlight the need and opportunity for health planners to develop integrated responses to communicable and non-communicable diseases.

Diabetes in Sub Saharan Africa 1999-2011: epidemiology and public health implications. A systematic review

BACKGROUND

Diabetes prevalence is increasing globally, and Sub-Saharan Africa is no exception. With diverse health challenges, health authorities in Sub-Saharan Africa and international donors need robust data on the epidemiology and impact of diabetes in order to plan and prioritise their health programmes. This paper aims to provide a comprehensive and up-to-date review of the epidemiological trends and public health implications of diabetes in Sub-Saharan Africa.

METHODS

We conducted a systematic literature review of papers published on diabetes in Sub-Saharan Africa 1999-March 2011, providing data on diabetes prevalence, outcomes (chronic complications, infections, and mortality), access to diagnosis and care and economic impact.

RESULTS

Type 2 diabetes accounts for well over 90% of diabetes in Sub-Saharan Africa, and population prevalence proportions ranged from 1% in rural Uganda to 12% in urban Kenya. Reported type 1 diabetes prevalence was low and ranged from 4 per 100,000 in Mozambique to 12 per 100,000 in Zambia. Gestational diabetes prevalence varied from 0% in Tanzania to 9% in Ethiopia. Proportions of patients with diabetic complications ranged from 7-63% for retinopathy, 27-66% for neuropathy, and 10-83% for microalbuminuria. Diabetes is likely to increase the risk of several important infections in the region, including tuberculosis, pneumonia and sepsis. Meanwhile, antiviral treatment for HIV increases the risk of obesity and insulin resistance. Five-year mortality proportions of patients with diabetes varied from 4-57%. Screening studies identified high proportions (> 40%) with previously undiagnosed diabetes, and low levels of adequate glucose control among previously diagnosed diabetics. Barriers to accessing diagnosis and treatment included a lack of diagnostic tools and glucose monitoring equipment and high cost of diabetes treatment. The total annual cost of diabetes in the region was estimated at US$67.03 billion, or US$8836 per diabetic patient.

CONCLUSION

Diabetes exerts a significant burden in the region, and this is expected to increase. Many diabetic patients face significant challenges accessing diagnosis and treatment, which contributes to the high mortality and prevalence of complications observed. The significant interactions between diabetes and important infectious diseases highlight the need and opportunity for health planners to develop integrated responses to communicable and non-communicable diseases.

Type 2 diabetes mellitus and obesity in sub-Saharan Africa

While communicable diseases such as human immunodeficiency virus/acquired immune deficiency syndrome, malaria, and tuberculosis have continued to pose greater threats to the public health system in sub-Saharan Africa (SSA), it is now apparent that non-communicable diseases such as diabetes mellitus are undoubtedly adding to the multiple burdens the peoples in this region suffer. Type 2 diabetes mellitus (T2DM) is the most common form of diabetes (90-95%), exhibiting an alarming prevalence among peoples of this region. Its main risk factors include obesity, rapid urbanization, physical inactivity, ageing, nutrition transitions, and socioeconomic changes. Patients in sub-Saharan Africa also show manifestations of beta-cell dysfunction and insulin resistance. However, because of strained economic resources and a poor health care system, most of the patients are diagnosed only after they have overt symptoms and complications. Microvascular complications are the most prevalent, but metabolic disorders and acute infections cause significant mortality. The high cost of treatment of T2DM and its comorbidities, the increasing prevalence of its risk factors, and the gaps in health care system necessitate that solutions be planned and implemented urgently. Aggressive actions and positive responses from well-informed governments appear to be needed for the conducive interplay of all forces required to curb the threat of T2DM in sub-Saharan Africa. Despite the varied ethnic and transitional factors and the limited population data on T2DM in sub-Saharan Africa, this review provides an extensive discussion of the literature on the epidemiology, risk factors, pathogenesis, complications, treatment, and care challenges of T2DM in this region.

Diabetes in sub-Saharan Africa

In Sub-Saharan Africa, prevalence and burden of type 2 diabetes are rising quickly. Rapid uncontrolled urbanisation and major changes in lifestyle could be driving this epidemic. The increase presents a substantial public health and socioeconomic burden in the face of scarce resources. Some types of diabetes arise at younger ages in African than in European populations. Ketosis-prone atypical diabetes is mostly recorded in people of African origin, but its epidemiology is not understood fully because data for pathogenesis and subtypes of diabetes in sub-Saharan African communities are scarce. The rate of undiagnosed diabetes is high in most countries of sub-Saharan Africa, and individuals who are unaware they have the disorder are at very high risk of chronic complications. Therefore, the rate of diabetes-related morbidity and mortality in this region could grow substantially. A multisectoral approach to diabetes control and care is vital for expansion of socioculturally appropriate diabetes programmes in sub-Saharan African countries.

A prospective evaluation of lower extremity ulcers in a Zimbabwean population

Aetiological factors and their frequencies, causes, level and impact of immunosuppression on outcome of lower extremity ulcers were prospectively recorded. A total of 100 patients were evaluated. Consent for HIV testing was given by 68 patients and 31 (46%) of these were HIV infected. Thirty patients were diabetic. CD 4+ T-lymphocyte count was assessed in 41 patients. Eleven were HIV infected with a mean CD 4+ count of 229 +/- 137 cells/microl. Six had non insulin-dependent diabetes mellitus (NIDDM) with a mean CD 4+ count 430 +/- 308 cells/microl. Five had both HIV infection and NIDDM with a mean CD 4+ count of 299 +/- 120 cells/microl. All three groups differed from the normal 707 +/- 285 cells/microl found in 17 non HIV-infected non diabetic patients (P < 0. 05). The main aetiologies were bacterial infection, arterial disease, trauma and neuropathy. Ulcer healing and limb salvage were noted in 71%. Mortality was 10%; seven in HIV-infected and three in non HIV-infected non diabetic patients (P = 0. 06). Amputation rate was 9%. Persisting ulcers were noted in 8% and 2% were lost to follow-up. Our evaluation shows that wound aetiologies in Zimbabwe differ from those in the West. Immunosuppression because of HIV infection and NIDDM was noted in more than half of the patients. HIV infection may increase mortality in this group of patients.

Epidemiology of heart failure in sub-Saharan Africa

Heart failure has emerged as a dominant form of cardiovascular disease in Africa, and has great social and economic relevance owing to its high prevalence, mortality and impact on young, economically active individuals. The causes of heart failure in Africans remain largely nonischemic. Hypertension, cardiomyopathy, rheumatic heart disease, chronic lung disease and pericardial disease are the main contributors to the etiology of cardiac failure in sub-Saharan Africa, accounting for over 90% of cases. Hypertensive heart disease complications occur more frequently in Africans and the majority of affected patients are younger. Endemic cardiomyopathies include dilated cardiomyopathy, peripartum cardiomyopathy and endomyocardial fibrosis. Nonendemic cardiomyopathies apparently occur with the same frequency as in other parts of the world, and include hypertrophic cardiomyopathy and arrhythmogenic right ventricular dysplasia/cardiomyopathy. Coronary artery disease and its complications remain uncommon in Africa, but the situation is changing due to modifications in lifestyle, risk-prone behavior, diet, cultural attitudes and other consequences of rapid urbanization. As the prevalence of heart failure is expected to rise substantially in sub-Saharan Africa, the authors call for population-based studies and registries of the epidemiology of heart failure in Africans and the urgent study of interventions that will decrease morbidity and mortality from the causes of heart failure, with a focus both on nonischemic and ischemic risk factors.

Diabetic foot ulcers and ethnicity in Tanzania: a contrast between African and Asian populations

To characterise the role of ethnicity in the occurrence of foot ulcer disease in persons with diabetes, we analysed prospectively collected data for persons attending the diabetes clinic at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania. A case was defined as any adult presenting to MNH with an ulcer at or below the ankle joint during July 1998-June 2005. We documented clinical and epidemiologic characteristics, progress, interventions and outcome. Seven hundred and eight persons met the case definition - 570 (80%) ethnic Africans and 138 (20%) Asian Indians. Ethnic Africans were more likely to present with gangrene (P < 0.01); Indians were more likely to be obese (P < 0.001) or have large vessel disease (P < 0.001). For Africans, intrinsic complications (neuro-ischaemia or macrovascular disease) delayed ulcer healing; for Asian Indians, mode of intervention (e.g. sloughectomy or glycaemic control with insulin or oral agents) determined the same outcome. Indigenous ethnic African and Asian Indian populations with diabetes display contrasting foot ulcer epidemiology. Peripheral vascular disease and gangrene are playing a larger role in ulcer pathogenesis and outcomes for both ethnic groups than was previously thought. Preventive efforts and interventions should be tailored to the two ethnic groups to achieve complete ulcer healing.

Diabetes and other disorders of glycemia in a rural South African community: prevalence and associated risk factors

OBJECTIVE

The purpose of this study was to determine the prevalence of diabetes, impaired glucose tolerance (IGT), impaired fasting glycemia (IFG), and associated risk factors in a rural South African black community.

RESEARCH DESIGN AND METHODS

This was a cross-sectional survey conducted by random cluster sampling of adults aged >15 years. Participants had a 75-g oral glucose tolerance test using the 1998 World Health Organization criteria for disorders of glycemia.

RESULTS

Of 1,300 subjects selected, 1,025 subjects (815 women) participated (response rate 78.9%). The overall age-adjusted prevalence of diabetes was 3.9%, IGT 4.8%, and IFG 1.5%. The prevalence was similar in men and women for diabetes (men 3.5%; women 3.9%) and IGT (men 4.6%; women 4.7%) but higher in men for IFG (men 4.0%; women 0.8%). The prevalence of diabetes and IGT increased with age both in men and women, with peak prevalence in the 55- to 64-year age-group for diabetes and in the >or=65-year age-group for IGT. Of the cases of diabetes, 84.8% were discovered during the survey. In multivariate analysis, the significant independent risk factors associated with diabetes included family history (odds ratio 3.5), alcohol ingestion (2.8), waist circumference (1.1), systolic blood pressure (1.0), serum triglycerides (2.3), and total cholesterol (1.8); hip circumference was protective (0.9).

CONCLUSIONS

There is a moderate prevalence of diabetes and a high prevalence of total disorders of glycemia, which suggests that this community, unlike other rural communities in Africa, is well into an epidemic of glucose intolerance. There is a low proportion of known diabetes and a significant association with potentially modifiable risk factors.

Pregnancy complicated by type 2 diabetes: an emerging problem

The prevalence of type 2 diabetes in pregnancy has increased everywhere in recent years. A number of studies have suggested that adverse maternal and fetal outcomes in these women have approached the figures for type 1 diabetic pregnancies. A low rate of planned pregnancies, suboptimal metabolic control and obesity have emerged as significant factors contributing towards poor outcome in these women, so efforts should be made to monitor these patients more carefully in order to improve this situation.

A time bomb of cardiovascular risk factors in South Africa: results from the Heart of Soweto Study "Heart Awareness Days"

BACKGROUND

There is strong anecdotal evidence that many urban communities in Sub-Saharan Africa are in epidemiologic transition with the subsequent emergence of more affluent causes of heart disease. However, data to describe the risk factor profile of affected communities is limited.

METHODS

During 9 community screening days undertaken in the predominantly Black African community of Soweto, South Africa (population 1 to 1.5 million) in 2006-2007, we examined the cardiovascular risk factor profile of volunteers. Screening comprised a combination of self-reported history and a clinical assessment that included calculation of body mass index (BMI), blood pressure and random blood glucose and total cholesterol levels.

RESULTS

In total, we screened a total of 1691 subjects (representing almost 0.2% of the total population). The majority (99%) were Black African, there were more women (65%) than men and the mean age was 46+/-14 years. Overall, 78% of subjects were found to have >or=1 major risk factor for heart disease. By far the most prevalent risk factor overall was obesity (43%) with significantly more obese women than men (23% versus 55%: OR 1.76 95% CI 1.62 to 1.91: p<0.001). A further 33% of subjects had high blood pressures (systolic or diastolic) and 13% an elevated (non-fasting) total blood cholesterol level: no statistically significant differences between the sexes were found. There was a positive correlation between increasing BMI and other risk factors including elevated systolic (r(2)=0.046, p<0.001) and diastolic blood pressure (r(2)=0.032, p<0.001) with overweight subjects three times more likely to have concurrent hypercholesterolemia (OR 3.3, 95% CI 2.1 to 5.3: p<0.01).

CONCLUSIONS

These unique pilot data strongly suggest a high prevalence of related risk factors for heart disease in this urban black African population in epidemiologic transition. Further research is needed to confirm our findings and to determine their true causes and potential consequences.

Challenges for management of the diabetic foot in Africa: doing more with less

Diabetes mellitus reached epidemic proportions in much of the less-developed world over a decade ago. In Africa, incidence and prevalence rates of diabetes are increasing and foot complications are rising in parallel. The predominant risk factor for foot complications is underlying peripheral neuropathy, although there is a body of evidence that confirm the increasing role of peripheral vascular disease. Gangrene and infections are two of the more serious sequelae of diabetic foot ulcer disease that cause long-standing disability, loss of income, amputation or death. Unfortunately, diabetes imposes a heavy burden on the health services in many African countries, where resources are already scarce or cut back. Reasons for poor outcomes of foot complications in various less-developed countries include the following: lack of awareness of foot care issues among patients and health care providers alike; very few professionals with an interest in the diabetic foot or trained to provide specialist treatment; non existent podiatry services; long distances for patients to travel to the clinic; delays among patients in seeking timely medical care, or among untrained health care providers in referring patients with serious complications for specialist opinion; lack of the concept of a team approach; absence of training programs for health care professionals; and finally lack of surveillance activities. There are ways of improving diabetic foot disease outcomes that do not require an exorbitant outlay of financial resources. These include implementation of sustainable training programmes for health care professionals, focusing on the management of the complicated diabetic foot and educational programmes that include dissemination of information to other health care professionals and patients; sustenance of working environments that inculcate commitment by individual physicians and nurses through self growth; rational optimal use of existing microbiology facilities and prescribing through epidemiologically directed empiricism, where appropriate; and using sentinel hospitals for surveillance activities. Allied with the golden rules of prevention (i.e. maintenance of glycaemic control to prevent peripheral neuropathy, regular feet inspection, making an effort not to walk barefooted or cut foot callosities with razors or knives at home and avoidance of delays in presenting to hospital at the earliest onset of a foot lesion), reductions in the occurrence of adverse events associated with the diabetic foot is feasible in less-developed settings.

Tropical diabetic hand syndrome. Epidemiology, pathogenesis, and management

The tropical diabetic hand syndrome (TDHS) is a complication affecting patients with diabetes mellitus in the tropics. The syndrome encompasses a localized cellulitis with variable swelling and ulceration of the hands, to progressive, fulminant hand sepsis, and gangrene affecting the entire limb. TDHS is less well recognized than foot infections and not generally classified as a specific diabetes complication. Hand infection was first described in Nigeria in 1984. Since then, the majority of cases have been reported in the African continent and more recently in India. There is often a history of antecedent minor hand trauma (e.g. scratches or insect bites). Presentation to hospital is often delayed due to the patients' unawareness of the potential risks, lack of concern because the initiating trauma might have been trivial, or decision to seek initial help from traditional healers. The first analytic study was done in Dar es Salaam, Tanzania, to characterize the epidemiology, clinical characteristics and risk factors of TDHS. Independent risk factors for TDHS include poorly controlled diabetes, neuropathy, insulin treatment or malnutrition. Clinicians should be aware of these complications and be prepared to immediately admit TDHS patients to hospital for aggressive surgical intervention (i.e. debridement, pus drainage or amputation) and high-dose, intravenous, broad-spectrum antibacterial therapy that includes anti-anaerobic activity. Without prompt, aggressive treatment TDHS can lead to permanent disability, limb amputation (13% of TDHS patients require major upper limb amputation), or death. Prevention strategies include patient and staff education that focuses on proper hand care, nutrition, and the importance of seeking medical attention immediately following hand trauma regardless of the severity of the injury, or at the earliest onset of hand-related symptoms, such as redness or swelling. Prevention of permanent disability and death due to TDHS will require improved management of glycemic levels in resource-limited countries, and surgical intervention during less severe stages of the condition.

Decreased serum magnesium and zinc levels: atherogenic implications in type-2 diabetes mellitus in Nigerians

Serum magnesium, zinc and total cholesterol were evaluated in 40 Nigerian patients suffering from type-2 diabetes mellitus (21M, 19F) and 20 (14M, 6F) apparently normal non diabetic control subjects. The mean age of the diabetic patients was similar to that of controls (p > 0.05). The mean duration of the disease was (4.7 + 0.7 SEM) in these patients. Fasting blood glucose and total cholesterol were significantly higher in diabetics than in non diabetic control subjects (p > 0.001). The serum total cholesterol showed inter-group variation when the patients were classified into four different age groups. In contrast, the serum level of magnesium (Mg) and zinc (Zn) were significantly lower in diabetics than in controls (p > 0.001). There were no significant correlation between glucose and the minerals, Mg. and Zn. Serum total cholesterol showed a significant positive correlation with magnesium (r = 0.6: p > 0.001), while the correlation with zinc was not significant. In type-2 diabetic mellitus the concentration of both Mg and Zn levels were significantly reduced, probably suggesting lower antioxidant status in this condition. The implication is the greater susceptibility to LDL-cholesterol oxidation. The attendant risk of development of premature Coronary Heart Disease is discussed. Magnesium and zinc are nutritional minerals that play crucial roles in the regulation of carbohydrate and lipid metabolism.

Factors affecting perinatal morbidity and mortality in pregnancies complicated by diabetes mellitus in Sudan

To investigate the influence of obstetric factors and indices of maternal metabolic control on perinatal morbidity and mortality, 88 diabetic pregnant Sudanese women (type 1, n=38; type 2, n=31; gestational diabetes, n=19) and 50 non-diabetic pregnant control women were studied. The mean fasting blood glucose was 11.1+/-2.8 mmol/l and the mean HbA(1c) at booking interview was 8.8+/-2.1% in the diabetic women. Pregnancy complications such as Caesarean sections, urinary tract infections, pregnancy-induced hypertension and intrauterine foetal death were higher among diabetic compared with control women (P<0.0001) and varied with the type of diabetes. Infants of diabetic mothers had a higher incidence of neonatal complications than those of non-diabetic women (54.4% vs. 20.0%; P<0.0001). Infants without complications and who were born to diabetic mothers had better Apgar scores at 5 min (9.8+/-0.5 vs. 8.9+/-1.6; P<0.01) and lower cord C-peptide when compared to infants with complications (P<0.05). In conclusion, the prevalence of maternal and neonatal complications among Sudanese diabetic women and their infants is high. Maternal hyperglycaemia is an important factor affecting maternal wellbeing and neonatal morbidity and mortality.

The epidemiology of diabetic limb sepsis: an African perspective

We review the epidemiology of foot and hand sepsis in adult diabetes patients in Africa. Limb sepsis in these patients is associated with significant morbidity and mortality. The pathogenesis of diabetic foot infections in these patient populations appears to be similar to that for patients in industrialized countries -ulcers and underlying peripheral neuropathy being the most important risk factors. Prevention of peripheral neuropathy through aggressive glycaemic control may be the most important primary control measure for foot infections. The tropical diabetic hand syndrome (TDHS) is being increasingly seen in diabetes patients in certain parts of Africa. The syndrome is acute, usually follows minor trauma to the hand, and is associated with a progressive synergistic form of gangrene. The major risk factors for TDHS are unknown but recent data suggest poor glycaemic control is associated with poor outcome. Treatment of TDHS requires aggressive surgery. Hence, preventive efforts for both foot and hand sepsis include aggressive glucose control, and education on hand and foot care and the importance of seeking medical attention promptly at the earliest onset of symptoms

Diabetes trends in Africa

Diabetes is an important cause of morbidity and mortality in Africa. Although a dramatic increase in disease burden is projected, it remains to be seen what effect the ongoing devastation of HIV disease will have on the epidemiology of such chronic diseases as diabetes. Recent data on type 2 diabetes prevalence indicate low rates in some rural populations, moderate rates similar to those in developed areas in some countries, and alarmingly high rates in others. The frequent observation of moderate to high prevalence of impaired glucose tolerance, particularly in populations with a low prevalence of diabetes, may indicate the early stage of a diabetes epidemic. Risk factors include urbanization, age, and family history of disease, as well as such modifiable risk factors as adiposity and physical inactivity. For type 1 diabetes, limited data indicate that the prevalence is low in sub-Saharan Africa and that onset occurs later in life there than in other parts of the world. Mortality associated with diabetes is unacceptably high and is disproportionately due to preventable acute metabolic and infective causes. With long duration of disease, there is a high frequency of hypertension and microvascular complications. The apparent low frequency of chronic macrovascular complications needs fuller documentation - as does the apparent high frequency of hypertension even in the non-diabetic population. Efforts to prevent this disease and its complications in Africa are impeded by inadequate health care infrastructure, inadequate supply of medications, absence of educational programs, and lack of available health care facilities and providers.

Clinical outcome of diabetes patients hospitalized with foot ulcers, Dar es Salaam, Tanzania

AIMS

To determine the prevalence rate, clinical features, risk factors, and clinical outcome of foot ulcers in diabetes patients admitted to Muhimbili National Hospital, Dar es Salaam, Tanzania.

METHODS

A prospective cohort study of newly hospitalized, adult diabetes patients with foot ulcers was conducted during January 1997 to December 1998 (study period). Detailed clinical and epidemiological data were recorded for each patient, followed by a comprehensive physical examination. Clinical outcome was documented.

RESULTS

Of 627 diabetes patients evaluated during the study period, 92 (15%) had foot ulcers. Of these 92 patients, 30 (33%) were selected for surgery (minor and major amputations); the rest were managed conservatively. Patients who underwent surgery were more likely than those who did not to have gangrene (P < 0.001) or neuropathy (P < 0.01). On stratification by severity of ulcers, patients with Wagner score > or = 4 were significantly more likely than those < 4 to have neuroischaemic foot lesions (P < 0.001) or delayed presentation to hospital (P < 0.001). The overall mortality rates for amputees and non-amputees were similar (29%); the highest in-patient mortality rate (54%) was observed among patients with severe (Wagner grade > or = 4) ulcers who did not undergo surgery.

CONCLUSIONS

Diabetic foot ulcers are associated with significant morbidity and mortality in Tanzania. Mortality rates among patients with severe ulcers remain high despite surgery. Thus, surgery undertaken during the less severe stages of ulcers may improve patient outcome. Education of patients should underscore the importance of foot care and consulting a doctor during the early stages of foot ulcer disease.

Gestational diabetes mellitus and fetal death in Mozambique: an incident case-referent study

BACKGROUND

Third trimester fetal death is a common problem in Mozambique, occurring in approximately 5% of parturient women.

OBJECTIVE

To elucidate the magnitude of the gestational diabetes mellitus problem, and to estimate its prevalence in a group of women with unexplained late fetal deaths and in women with live fetuses (referents).

METHODS

An incident case-referent study of 109 pregnant Mozambican women with fetal deaths and 110 women delivering liveborns, regarding fasting B-glucose, oral glucose tolerance test and glycosylated hemoglobin.

RESULT

The difference in gestational diabetes mellitus prevalence in the two groups is not significant. The prevalence of gestational diabetes mellitus was high in both groups: 11% and 7%, respectively.

Where does the black population of South Africa stand on the nutrition transition?

OBJECTIVE

To review data on selected risk factors related to the emergence of noncommunicable diseases (NCDs) in the black population of South Africa.

METHODS

Data from existing literature on South African blacks were reviewed with an emphasis placed on changes in diet and the emergence of obesity and related NCDs.

DESIGN

Review and analysis of secondary data over time relating to diet, physical activity and obesity and relevant to nutrition-related NCDs.

SETTINGS

Urban, peri-urban and rural areas of South Africa. National prevalence data are also included.

SUBJECTS

Black adults over the age of 15 years were examined.

RESULTS

Shifts in dietary intake, to a less prudent pattern, are occurring with apparent increasing momentum, particularly among blacks, who constitute three-quarters of the population. Data have shown that among urban blacks, fat intakes have increased from 16.4% to 26.2% of total energy (a relative increase of 59.7%), while carbohydrate intakes have decreased from 69.3% to 61.7% of total energy (a relative decrease of 10.9%) in the past 50 years. Shifts towards the Western diet are apparent among rural African dwellers as well. The South African Demographic and Health Survey conducted in 1998 revealed that 31.8% of African women (over the age of 15 years) were obese (body mass index (BMI) > or = 30kg m(-2)) and that a further 26.7% were overweight (BMI > or = 25 to <30 kg m(-2)). The obesity prevalence among men of the same age was 6.0%, with 19.4% being overweight. The national prevalence of hypertension in blacks was 24.4%, using the cut-off point of 140/90 mmHg. There are limited data on the population's physical activity patterns. However, the effects of the HIV/AIDS epidemic will become increasingly important.

CONCLUSIONS

The increasing emergence of NCDs in black South Africans, compounded by the HIV/AIDS pandemic, presents a complex picture for health workers and policy makers. Increasing emphasis needs to be placed on healthy lifestyles.

A Tanzanian perspective on the nutrition transition and its implications for health

OBJECTIVE

The purpose of this paper is to describe social and economic changes related to shifts in diet and activity and to present prevalences for chronic diseases associated with the nutrition transition.

DESIGN

Observations about social changes are descriptive, based on published reports and personal observations. Prevalence and trends data are based on a Ministry of Health published report and, for infants and toddlers, on primary data.

SETTING

Disease prevalences for diabetes mellitus and hypertension are taken from four sites, representing underdeveloped, semi-developed and well-developed rural communities and Dar es Salaam, the largest city in Tanzania. The prevalences of underweight and overweight for infants and toddlers are taken from a small periurban clinic in Tanzania.

SUBJECTS

Adults over 15 years of age are included in the prevalence data for chronic disease. The urban sample is stratified by occupation and ethnicity. The data for infants and toddlers include newborns to those aged 23 months.

RESULTS

An increase in the prevalence of diabetes and hypertension was observed. Simultaneously, there have been rapid changes in diet and physical activity related to urbanisation and modernisation. The highest prevalences for diabetes and hypertension were among high-ranking executives.

CONCLUSION

The increase in chronic disease could be related to the rise in the number of high-ranking executives. Simultaneously, per capita income has gone down, and malnutrition prevalence has risen. Programmes are being developed to simultaneously monitor trends in overweight while preventing protein-energy malnutrition and micronutrient deficiency.

Tropical diabetic hand syndrome: risk factors in an adult diabetes population

OBJECTIVES

To determine risk factors for the tropical diabetic hand syndrome, a condition associated with significant morbidity and mortality in Africa.

METHODS

This was a case-control study of a Tanzanian diabetes population presenting with the syndrome during February 1998 to March 2000. A case patient was defined as any patient with diabetes presenting with hand cellulitis, ulceration, or gangrene. Control patients were randomly selected patients with diabetes who had no hand symptoms.

RESULTS

Thirty-one case patients and 96 control patients were identified. The median age of case patients was 52 years (range, 28--76 y); 58% were male; 4 patients (16%) died. Precipitating events included papule (n = 6), insect bites (n = 6), boils (n = 5), burns (n = 2), or trauma (n = 3). Case and control patients were similar for presence of micro- and macrovascular disease and occupation. On logistic regression analysis, independent risk factors were body mass index of 20 or less (odds ratio [OR] = 18.0; 95% confidence interval [CI] = 4.3--97.0; P < 0.001), peripheral neuropathy (OR = 23.0; 95% CI = 5.3--124.0; P < 0.001), or type I diabetes, (OR = 6.7; 95% CI = 2.0--24.0, P < 0.01).

CONCLUSION

The major risk factors for the tropical diabetic hand syndrome are intrinsically related to the underlying disease. Thus, prevention of hand infections may require aggressive glucose control, and education on hand care and the importance of seeing a doctor promptly at the onset of symptoms.

Nutritional consequences of the African diaspora

Along with their foods and dietary customs, Africans were carried into diaspora throughout the Americas as a result of the European slave trade. Their descendants represent populations at varying stages of the nutrition transition. West Africans are in the early stage, where undernutrition and nutrient deficiencies are prevalent. Many Caribbean populations represent the middle stages, with undernutrition and obesity coexisting. African-Americans and black populations in the United Kingdom suffer from the consequences of caloric excess and diets high in fat and animal products. Obesity, non-insulin-dependent diabetes mellitus, hypertension, coronary heart disease, and certain cancers all follow an east-to-west gradient of increasing prevalence. Public health efforts must focus not only on eradicating undernutrition in West Africa and the Caribbean but also on preventing obesity, hypercholesterolemia, and their consequences. Fortunately, a coherent and well-supported set of recommendations exists to promote better nutrition. Implementation of it founders primarily as a result of the influence of commercial and political interests.

Clinical classification of diabetes in tropical west Africa

The objective of this work was to classify and describe the different types of diabetic patients detected in West Africa. In four health centres (three in Ivory Coast, one in Niger) 310 new cases were detected and followed up over 1 year. Classification was based on age at diagnosis, BMI, ketonuria, basal and stimulated C-peptide levels at inclusion, and response to antidiabetic therapy. In this population, males were predominant (sex ratio = 2.40), and random blood glucose levels very high at screening (mean +/- SE, 18.6 +/- 0.4 mmol/l). Only one case of fibrocalculous pancreatic diabetes and one possible case of diabetes mellitus related to malnutrition were detected. IDDM was diagnosed in 11.3% of the patients, half of them above 35 years. Leanness was observed in 59% of the patients with NIDDM. A dramatic decrease of fasting blood glucose was observed in all groups after 2 months of treatment, especially in NIDDM. As IDDM and non-obese NIDDM presented great similarities before treatment, even for C-peptide levels, a point score system is proposed to classify these two groups at baseline. In conclusion, it is confirmed that the form of diabetes previously defined as related to malnutrition is a very rare entity in black African populations. In contrast, African diabetes is characterised by the high proportion of NIDDM patients with low BMI, and reduced beta-cell function, rarely associated to ketonuria. This form of diabetes seems to be adequately controlled with oral hypoglycaemic drugs and/or diet in the year following diagnosis.

Monitoring diabetic control in developing countries: a review of glycated haemoglobin and fructosamine assays

Measurement of glycated proteins, especially haemoglobins, is now a routine procedure for monitoring previous glycaemic control in diabetic patients in the developed world. Until recently, however, the assays were sophisticated and costly and, therefore, were only rarely used in developing countries. With easier and cheaper tests now available, the measurement of glycaemic control could be also introduced into regional hospitals in developing countries. This paper reviews feasible methods for clinical laboratories with limited resources. Recent experiences from African countries are included.

Decreased insulin-mediated but not non-insulin-dependent glucose disposal rates in glucose intolerance and type II diabetes in African (Ghanaian) immigrants

The authors evaluated the significance of beta cell function, non-insulin-dependent glucose disposal (glucose effectiveness [Sg]), and insulin-dependent glucose disposal (insulin sensitivity) in African immigrants with varying degrees of glucose tolerance. Thirty-two African immigrants residing in Franklin County, Ohio, were studied. There were 16 subjects with normal glucose tolerance (NGT), 11 with intermediate glucose tolerance (IGT), and 5 with type II diabetes mellitus (DM). Insulin sensitivity index and Sg were measured by an insulin-modified, frequently sampled intravenous glucose tolerance test. The mean fasting and post-glucose serum glucose levels were lowest in the NGT, intermediate in the IGT group, and highest in the DM group. Mean serum insulin and c-peptide responses rose briskly by threefold to a peak in the NGT and the IGT groups. In the DM group, mean serum insulin and c-peptide responses were severely blunted to glucose stimulation. The sensitivity index was highest in the NGT (3.09 +/- 0.27), intermediate in the IGT (1.81 +/- 0.47), and lowest in the DM (0.48 +/- 0.28 x 10(-2).mins-1 (microU/ml)-1). The Sg was identical in the NGT (2.78 +/- 0.22) and IGT (2.78 +/- 0.27) groups but was slightly but not significantly lower in the DM (2.20 +/- 0.35 x 10(-2).mins-1). In addition, the glucose decay constant was not statistically different in the NGT (3.00 +/- 0.38) and IGT (2.25 +/- 0.19) group, but the mean values were significantly greater than in the patients with diabetes (0.78 +/- 0.15 percent/mins). The mean disposition index (sensitivity index X beta cell function as assessed by both insulin and c-peptide) was significantly greater in NGT than in the IGT (P<0.05) and in the diabetic group (P<0.001). In summary, the authors demonstrate that, in native African immigrants, type II diabetes is associated with significant reduction in beta cell function, insulin sensitivity, and glucose decay constant, but not in Sg. In patients with intermediate or impaired glucose tolerance, there is moderate insulin resistance and evidence of inadequate compensation by beta cell, but the Sg, the Sg at theoretical insulin concentration, and glucose decay constant remain normal. They conclude that, unlike other ethnic and racial groups, in glucose intolerant native African patients, alterations in Sg or non-insulin dependent glucose disposal (ie, tissue glucose sensitivity) do not appear to play a significant role in the impairment of glucose tolerance and type II diabetes in African immigrants.

Metabolic characteristics of African descendants: a comparative study of African-Americans and Ghanaian immigrants using minimal model analysis

We have previously demonstrated that glucose-tolerant American blacks manifest significantly higher insulin concentrations and a lower insulin sensitivity than native African blacks who reside in their respective countries. It is, however, unknown whether the serum glucose, beta-cell function and insulin sensitivity are different in native Africans and African-Americans who reside in the same environments. We have studied 68 healthy American blacks and age- and weight-matched 30 African blacks recently immigrated from Ghana residing in Franklin County, Ohio, USA. Each subject underwent a standard oral glucose tolerance test to determine glucose tolerance status. Insulin sensitivity index (Si) and glucose effectiveness (Sg) were measured by the insulin-modified, frequently-sampled intravenous glucose tolerance test. The body composition variables were measured by the bioelectrical impedance analyser and body fat distribution pattern by the waist-hip ratio. The clinical characteristics were identical in the African-American and the African blacks; the mean fasting serum glucose, insulin and C-peptide levels were not different. Following the oral and intravenous glucose administration, the mean peak and incremental areas of serum glucose, insulin and C-peptide were not different in the two groups. The mean Si (3.1 +/- 0.7 vs 2.4 +/- 0.3 x 10(-4).(min/microU.1-1)-1 and Sg (2.5 +/- 0.3 vs 2.7 +/- 0.2 x 10(-2).min-1) were not significantly different in the American and African blacks, respectively. In summary, the metabolic parameters measured in the American blacks and recent African immigrants were identical.(ABSTRACT TRUNCATED AT 250 WORDS)

Mortality and outcome of insulin-dependent diabetes in Soweto, South Africa

Sixty-four insulin-dependent (Type 1) diabetic patients (IDDM) in Soweto, South Africa were followed over a 10-year period. Patients were assessed in 1982 and again in 1992. There were 10 deaths (16%), half of which were due to renal failure. Ketoacidosis, hypoglycaemia, and sepsis accounted for the rest. At the 10-year follow-up mean age (+/- SD) was 32.4 +/- 5.0 years and diabetes duration 13.6 +/- 2.6 years. Retinopathy affected 52%, peripheral neuropathy 42%, and nephropathy 28% (all significantly increased from the 1982 assessment). Microalbuminuria and autonomic neuropathy were also common. Serum cholesterol was over 6.5 mmol l-1 in 19%, hypertension affected 22%, and 28% were cigarette smokers; though no patient had evidence of macroangiopathy. We conclude that IDDM in South Africa is associated with excess mortality, a significant proportion of which is related to nephropathy. Diabetes of long duration is now not uncommon in South Africa, and although diabetic complications frequently occur, most patients have good life quality and freedom from large vessel disease.

Outcome of pregnancy in diabetic women in Soweto, South Africa 1983-1992

A specialized service for pregnant diabetic women of African ethnic origin from Soweto was introduced in May 1983 at Baragwanath Hospital. Modern methods of management were used, including home blood glucose monitoring. A total of 354 pregnancies (147 gestational, 207 pregestational) were managed over an 8 1/2 year period. All but 12 women were treated with insulin. Mean capillary blood glucose (+/- SD) ranged from 5.8 +/- 0.8 mmol l-1 in the insulin-dependent group to 6.2 mmol l-1 in the gestational group (p < 0.01). Although maternal hypoglycaemia was common (14.4%) in the insulin-dependent patients, no ill effects were noted. The highest Caesarean section rate was in the gestational group (56%), the lowest in the insulin-dependent group (39.8%) (p < 0.01). Mean (+/- SD) neonatal weights were similar in the insulin-dependent and non-insulin-dependent groups (3131 +/- 627.9 g and 3236 +/- 674.3 g resp. p = NS); offspring of the gestational group were heavier than the insulin-dependent group (3384.4 +/- 657.5 g) (p < 0.01). Neonatal hypoglycaemia occurred in less than 5% of offspring overall. The combined perinatal mortality was 6.1%, stillbirths accounting for the majority (63.6%) of deaths. Major congenital abnormalities occurred in 6(1.7%) of the offspring. The perinatal mortality of the 'control' group of 146 women was 26.1%. Glucose intolerance persisted in at least 34.7% of gestational diabetic women postpartum. This study suggests that a specialized service for pregnant diabetic women from a Third World community can be implemented with good effect and limited expense. Late presentation of pregestational diabetic women is a problem.

Is diabetes mellitus related to undernutrition in rural Tanzania?

OBJECTIVE

To investigate the relation between undernutrition and diabetes.

DESIGN

Survey of glucose tolerance in rural Tanzania.

SETTING

Eight villages in three widely separated regions of Tanzania.

SUBJECTS

8581 people aged 15 and above: 3705 men and 4876 women.

MAIN OUTCOME MEASURES

Oral glucose tolerance, body mass index, height, and low haemoglobin and cholesterol concentrations.

RESULTS

In the eight villages 42.7-56.9% of all men and 30.0-45.2% of all women had a body mass index below 20 kg/m2; the lowest quintile was 18.2 kg/m2 in men and 18.6 kg/m2 in women. The prevalence of diabetes did not change significantly from the lowest to the highest fifths of body mass index in men (lowest 1.6% (95% confidence interval 0.8% to 2.9%) v highest 1.3% (0.7% to 2.5%)) or women (1.1% (0.6% to 2.1%) v 0.5% (0.2% to 1.2%)). In men and in women prevalence of impaired glucose tolerance was greater in the lowest fifths of height (8.2% (6.3% to 10.6%), and 11.1% (9.2% to 13.3%)) respectively and body mass index (9.6% (7.5% to 12.1%), and 8.4% (6.7% to 10.5%)) than in the highest fifths (impaired glucose tolerance 4.7% (3.4% to 6.5%); and 5.1% (3.9% to 6.7%); body mass index 5.1% (3.7% to 7.0%), and 7.7% (6.2% to 9.6%).

CONCLUSION

Rates of diabetes were not significantly associated with low body mass index or height, but overall rates were much lower than those in well nourished Western populations. Increased impaired glucose tolerance in the most malnourished people may reflect the larger glucose load per kilogram weight. The role of undernutrition in the aetiology of diabetes must be questioned.

A genetic marker at the glucokinase gene locus for type 2 (non-insulin-dependent) diabetes mellitus in Mauritian Creoles

The prevalence of Type 2 (non-insulin-dependent) diabetes mellitus is high in Mauritius, a multiethnic island nation in the southwestern Indian Ocean. Evaluation of candidate genes in the different ethnic groups represents a means of assessing the genetic component. As glucokinase is known to be a key regulator of glucose homeostasis in liver and pancreatic Beta-cells, the human gene was isolated and a dinucleotide repeat (CA)n marker was identified at this locus. A polymerase chain reaction assay was developed, and alleles differing in size were observed in individuals, according to the number of repeats in the amplified fragment. Eighty-five Creoles and 63 Indians of known glucose tolerance status were typed by amplification of genomic DNA for this dinucleotide (CA)n repeat marker. Four different alleles were observed including Z, the most common allele, and Z + 2, Z + 4, and Z + 10, which differed from Z by 2, 4, and 10 nucleotides respectively. In Mauritian Creoles, the frequency of the Z + 2 allele was greater in Type 2 diabetic subjects than in control subjects (23.8% vs 8.9%, p = 0.008), and the frequency of the Z allele was lower in Type 2 diabetic subjects (60% vs 75.6%, p = 0.03). Analysis with univariate logistic regression models indicated that the Z + 2 allele had the highest odds ratio, 3.08 (95% confidence interval 1.14-8.35, p = 0.0416), among the other risk factors (age, sex, body mass index, and waist/hip ratio). The multivariate odds ratio for Type 2 diabetes was 2.88 (95% confidence interval 0.98-8.50, p = 0.0551).(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of diabetes and obesity in the adult population of the Seychelles

The prevalence of diabetes and obesity were assessed in an age- and sex-stratified sample of 1078 individuals living in Mahé, The Republic of Seychelles. Presence or absence of diabetes mellitus was assessed by measuring glucose concentration in fasting venous blood. Prevalence of obesity (standardized for age) was elevated five-fold in women compared with men (20.9 vs 4.2%). In women, it increased from 8.9% at age 25-34 years to 29.4% at age 35-44 years and plateaued thereafter, whereas it did not change with age in men. Prevalence of diabetes (standardized for age) was 3.4% for men and 4.6% for women. It increased markedly with age, from 0.0 and 0.8% at age 25-34 years to 8.8 and 13.4% at age 55-64 years in men and women, respectively. A strong association of diabetes with excess body weight was observed. Most cases of diabetes can be attributed to Type 2 (non-insulin-dependent) diabetes. Fifty-five percent of diabetic individuals were unaware of their disease at the time of the survey.