Point-of-care glycated hemoglobin a1c testing for the identification of hyperglycemia severity among individuals with dual tuberculosis and diabetes mellitus in Tanzania

Background

Poor glycemic control during tuberculosis (TB) treatment is challenging, as the optimum treatment strategy remains unclear. We assessed hyperglycemia severity using glycated hemoglobin (HbA1c) test and predictors of severe hyperglycemia at the time of TB diagnosis in three resources-diverse regions in Tanzania.

Methods

This was a substudy from a large cohort study implemented in three regions of Tanzania. TB individuals with diabetes mellitus (DM) (prior history of DM or newly diagnosed DM) were assessed for hyperglycemic levels using HbA1c test and stratified as mild (<53 mmol/mol), moderate (≥53-<86 mmol/mol), and severe (≥86 mmo/mol).

Results

From October 2019 to September 2020, 1344 confirmed TB individuals were screened for DM and 105 (7.8%) individuals had dual TB/DM and were assessed for glycemic levels. Of these, 69 (67.7%) had a prior history of DM and 26 (24.8%) were living with human immunodeficiency virus. Their mean age was 49.0 (±15.0) years and 56.2% were male. The majority (77.1%) had pulmonary TB, and 96.2% were newly diagnosed TB individuals. HbA1c test identified 41(39.0%), 37 (35.2%), and 27 (25.7%) individuals with severe, moderate, and mild the hyperglycaemia respectively. Female sex (odds ratio [OR]: 3.55, 95% confidence interval [CI]: 1.06-11.92, P = 0.040) and previous history of DM (OR: 3.71, 95% CI: 1.33-10.33, P = 0.013) were independent risk factors for severe hyperglycemic at the time of TB diagnosis.

Conclusion

By integrating early HbA1c testing, a substantial proportion of individuals with severe hyperglycemia were identified. HbA1c testing can be recommended to identify and triage patients requiring personalized intensified DM management in resource-limited programmatic settings.

Energy expenditure and intensity of ritual jumping-dancing in male Maasai

OBJECTIVES

Traditional jumping-dance rituals performed by Maasai men involve prolonged physical exertion that may contribute significantly to overall physical activity level. We aimed to objectively quantify the metabolic intensity of jumping-dance activity and assess associations with habitual physical activity and cardiorespiratory fitness (CRF).

METHODS

Twenty Maasai men (18-37 years) from rural Tanzania volunteered to participate in the study. Habitual physical activity was monitored using combined heart rate (HR) and movement sensing over 3 days, and jumping-dance engagement was self-reported. A 1-h jumping-dance session resembling a traditional ritual was organized, during which participants' vertical acceleration and HR were monitored. An incremental, submaximal 8-min step test was performed to calibrate HR to physical activity energy expenditure (PAEE) and assess CRF.

RESULTS

Mean (range) habitual PAEE was 60 (37-116) kJ day-1  kg-1 , and CRF was 43 (32-54) mL O2  min-1  kg-1 . The jumping-dance activity was performed at an absolute HR of 122 (83-169) beats·min-1 , and PAEE of 283 (84-484) J min-1  kg-1 or 42 (18-75)% when expressed relative to CRF. The total PAEE for the session was 17 (range 5-29) kJ kg-1 , ~28% of the daily total. Self-reported engagement in habitual jumping-dance frequency was 3.8 (1-7) sessions/week, with a total duration of 2.1 (0.5-6.0) h/session.

CONCLUSIONS

Intensity during traditional jumping-dance activity was moderate, but on average sevenfold higher than habitual physical activity. These rituals are common, and can make a substantial contribution to overall physical activity in Maasai men, and thus be promoted as a culture-specific activity to increase energy expenditure and maintain good health in this population.

Implementing Innovative Approaches to Improve Health Care Delivery Systems for Integrating Communicable and Non-Communicable Diseases Using Tuberculosis and Diabetes as a Model in Tanzania

Background: Many evidence-based health interventions, particularly in low-income settings, have failed to deliver the expected impact. We designed an Adaptive Diseases Control Expert Programme in Tanzania (ADEPT) to address systemic challenges in health care delivery and examined the feasibility, acceptability and effectiveness of the model using tuberculosis (TB) and diabetes mellitus (DM) as a prototype. Methods: This was an effectiveness-implementation hybrid type-3 design that was implemented in Dar es Salaam, Iringa and Kilimanjaro regions. The strategy included a stepwise training approach with web-based platforms adapting the Gibbs' reflective cycle. Health facilities with TB services were supplemented with DM diagnostics, including glycated haemoglobin A1c (HbA1c). The clinical audit was deployed as a measure of fidelity. Retrospective and cross-sectional designs were used to assess the fidelity, acceptability and feasibility of the model. Results: From 2019-2021, the clinical audit showed that ADEPT intervention health facilities more often identified median 8 (IQR 6-19) individuals with dual TB and DM, compared with control health facilities, median of 1 (IQR 0-3) (p = 0.02). Likewise, the clinical utility of HbA1c on intervention sites was 63% (IQR:35-75%) in TB/DM individuals compared to none in the control sites at all levels, whereas other components of the standard of clinical management of patients with dual TB and DM did not significantly differ. The health facilities showed no difference in screening for additional comorbidities such as hypertension and malnutrition. The stepwise training enrolled a total of 46 nurse officers and medical doctors/specialists for web-based training and 40 (87%) attended the workshop. Thirty-one (67%), 18 nurse officers and 13 medical doctors/specialists, implemented the second step of training others and yielded a total of 519 additional front-line health care workers trained: 371 nurses and 148 clinicians. Overall, the ADEPT model was scored as feasible by metrics applied to both front-line health care providers and health facilities. Conclusions: It was feasible to use a stepwise training and clinical audit to support the integration of TB and DM management and it was largely acceptable and effective in differing regions within Tanzania. When adapted in the Tanzania health system context, the model will likely improve quality of services.

Skeletal muscle fibre type and enzymatic activity in adult offspring following placental and peripheral malaria exposure in foetal life

Background

Maternal malaria may restrict foetal growth. Impaired utero-placental blood flow due to malaria infection may cause hypoxia-induced altered skeletal muscle fibre type distribution in the offspring, which may contribute to insulin resistance and impaired glucose metabolism. This study assessed muscle fibre distribution 20 years after placental and/or peripheral in-utero malaria exposure compared to no exposure, i.e., PPM+, PM+, and M-, respectively.

Methods

We traced 101 men and women offspring of mothers who participated in a malaria chemosuppression study in Muheza, Tanzania. Of 76 eligible participants, 50 individuals (29 men and 21 women) had skeletal muscle biopsy taken from m. vastus lateralis in the right leg. As previously reported, fasting and 30 min post-oral glucose challenge plasma glucose values were higher, and insulin secretion disposition index was lower, in the PPM+ group. Aerobic capacity (fitness) was estimated by an indirect VO₂max test on a stationary bicycle. Muscle fibre sub-type (myosin heavy chain, MHC) distribution was analysed, as were muscle enzyme activities (citrate synthase (CS), 3-hydroxyacyl-CoA dehydrogenase, myophosphorylase, phosphofructokinase, lactate dehydrogenase, and creatine kinase activities. Between-group analyses were adjusted for MHC-I %.

Results

No differences in aerobic capacity were found between groups. Despite subtle elevations of plasma glucose levels in the PPM+ group, there was no difference in MHC sub-types or muscle enzymatic activities between the malaria-exposed and non-exposed groups.

Conclusion

The current study did not show differences in MHC towards glycolytic sub-types or enzymatic activity across the sub-groups. The results support the notion of the mild elevations of plasma glucose levels in people exposed to placental malaria in pregnancy being due to compromised pancreatic insulin secretion rather than insulin resistance.

Experiences and perceptions of participants on the pathway towards clinical management of dual tuberculosis and diabetes mellitus in Tanzania

BACKGROUND

Diabetes mellitus (DM) is a common comorbidity among people with tuberculosis (TB). Despite the availability of guidelines on how to integrate dual TB/DM in Tanzania, the practice of integration at various healthcare levels is unclear.

OBJECTIVE

To explore the participants' experiences and perceptions on the pathway towards clinical management of dual TB/DM.

METHOD

The research was carried out in Dar es Salaam, Iringa, and Kilimanjaro regions between January and February 2020. A qualitative, in-depth interview approach was used to collect participants' experiences and perspectives on the acquisition of dual TB/DM services at various levels of healthcare facilities. The information gathered were coded and classified thematically.

RESULTS

The participants' perception of TB services within the healthcare facilities was positive due to the support they received from the healthcare providers. On the other hand, participants reported difficulty receiving management in various health facilities for each condition in terms of access to dual TB/DM care and access to DM medication. This was viewed as a significant challenge for the participants with dual TB/DM.

CONCLUSIONS

The current disjunction and disruption in healthcare for people with dual TB/DM makes it difficult to access services at various levels of health facilities. For optimal clinical management for people with dual TB/DM, patient-centered strategies and integrated approaches are urgently needed.

Directly measured aerobic fitness in male Maasai of Tanzania

OBJECTIVES

The agro-pastoralist Maasai of East Africa are highly physically active, but their aerobic fitness has so far only been estimated using heart rate (HR) response to submaximal exercise and not directly measured. Thus, we aimed to measure aerobic fitness directly using respiratory gas analysis in a group of Maasai, and habitual physical activity energy expenditure (PAEE) as explanatory variable.

METHODS

In total, 21 (10 rural, 11 semi-urban) of 30 volunteering Tanzanian Maasai men were eligible to participate. Respiratory gas exchange was measured during a graded exercise test until exhaustion on a stationary bicycle to determine aerobic fitness. Maximal effort criteria were at least two of the following (1) leveling off, (2) respiratory exchange ratio (RER) >1.10, and (3) maximum HR within 10 bpm of age-estimated maximum HR. Habitual PAEE was estimated using combined accelerometry and HR monitoring. Anthropometry, biochemistry, blood pressure, resting HR, and dietary intake information were collected for background information.

RESULTS

Mean age was 43.2 (range 26-60) years, and hemoglobin was higher in the rural versus semi-urban Maasai (16.9 vs. 15.4 g/dl, p = .02). Mean aerobic fitness (34.4 vs. 33.3 mlO2 /min/kg, p = .79), and mean PAEE (58.5 vs. 52.9 kJ/day/kg, p = .64) were similar in rural and semi-urban Maasai, respectively.

CONCLUSIONS

Aerobic fitness was low to moderate in male rural and semi-urban Maasai. This may be explained by relatively low PAEE in comparison to previous objectively measured activity levels in Maasai, which indicates recent lifestyle changes.

Where can Tanzania health system integrate clinical management of patients with dual tuberculosis and diabetes mellitus? A cross-sectional survey at varying levels of health facilities

Objective

Study design

Methods

Results

Conclusion

Diabetes in developing countries

There has been a rapid escalation of type 2 diabetes (T2D) in developing countries, with varied prevalence according to rural vs urban habitat and degree of urbanization. Some ethnic groups (eg, South Asians, other Asians, and Africans), develop diabetes a decade earlier and at a lower body mass index than Whites, have prominent abdominal obesity, and accelerated the conversion from prediabetes to diabetes. The burden of complications, both macro- and microvascular, is substantial, but also varies according to populations. The syndemics of diabetes with HIV or tuberculosis are prevalent in many developing countries and predispose to each other. Screening for diabetes in large populations living in diverse habitats may not be cost-effective, but targeted high-risk screening may have a place. The cost of diagnostic tests and scarcity of health manpower pose substantial hurdles in the diagnosis and monitoring of patients. Efforts for prevention remain rudimentary in most developing countries. The quality of care is largely poor; hence, a substantial number of patients do not achieve treatment goals. This is further amplified by a delay in seeking treatment, "fatalistic attitudes", high cost and non-availability of drugs and insulins. To counter these numerous challenges, a renewed political commitment and mandate for health promotion and disease prevention are urgently needed. Several low-cost innovative approaches have been trialed with encouraging outcomes, including training and deployment of non-medical allied health professionals and the use of mobile phones and telemedicine to deliver simple health messages for the prevention and management of T2D.

Gestational diabetes mellitus risk score: A practical tool to predict gestational diabetes mellitus risk in Tanzania

BACKGROUND

Universal screening for hyperglycemia during pregnancy may be in-practical in resource constrained countries. Therefore, the aim of this study was to develop a simple, non-invasive practical tool to predict undiagnosed Gestational diabetes mellitus (GDM) in Tanzania.

METHODS

We used cross-sectional data of 609 pregnant women, without known diabetes, collected in six health facilities from Dar es Salaam city (urban). Women underwent screening for GDM during ante-natal clinics visit. Smoking habit, alcohol consumption, pre-existing hypertension, birth weight of the previous child, high parity, gravida, previous caesarean section, age, MUAC ≥ 28 cm, previous stillbirth, haemoglobin level, gestational age (weeks), family history of type 2 diabetes, intake of sweetened drinks (soda), physical activity, vegetables and fruits consumption were considered as important predictors for GDM. Multivariate logistic regression modelling was used to create the prediction model, using a cut-off value of 2.5 to minimise the number of undiagnosed GDM (false negatives).

RESULTS

Mid-upper arm circumference (MUAC) ≥ 28 cm, previous stillbirth, and family history of type 2 diabetes were identified as significant risk factors of GDM with a sensitivity, specificity, positive predictive value, and negative predictive value of 69%, 53%, 12% and 95%, respectively. Moreover, the inclusion of these three predictors resulted in an area under the curve (AUC) of 0.64 (0.56-0.72), indicating that the current tool correctly classifies 64% of high risk individuals.

CONCLUSION

The findings of this study indicate that MUAC, previous stillbirth, and family history of type 2 diabetes significantly predict GDM development in this Tanzanian population. However, the developed non-invasive practical tool to predict undiagnosed GDM only identified 6 out of 10 individuals at risk of developing GDM. Thus, further development of the tool is warranted, for instance by testing the impact of other known risk factors such as maternal age, pre-pregnancy BMI, hypertension during or before pregnancy and pregnancy weight gain.

Capacity and capability of Tanzania health facilities to diagnose and manage diabetes mellitus in pregnancy

AIMS

Gestational Diabetes Mellitus (GDM) remains a neglected cause of maternal and foetal morbidity and mortality in developing countries exacerbated by limited screening and management strategies. This study aimed to understanding how the RCH health system works in Tanzania, so as to provide opportunity for improving GDM screening and management.

METHODS

A questionnaire was administered to facility staff and physical performance observed in 30 randomly selected public RCH facilities.

RESULTS

Deficiencies identified included limited understaffing, late booking at ANC, and limited screening for GDM due to lack of equipment and supplies. Most women (96%) attending ANCs and postnatal care (87%) were managed at respective facilities with only 12% and 22% respectively being referred to higher levels of care. Facility staff were less trained or received fewer refresher courses in diabetes (0-5%), hypertension (4-6%), and other NCDs (0-16%) compared to training in PMCTC (39%), management of postpartum bleeding (31%) and HIV/AIDs (31%).

CONCLUSION

Diabetes during pregnancy is rarely sought in public health facilities and its management is suboptimal. Training and refresher courses of staff in diabetes and hypertension should be uplifted and health systems should be strengthened to improve capacity and capability of facilities for better quality of care.

Hyperglycaemia is inversely correlated with live M. bovis BCG-specific CD4+ T cell responses in Tanzanian adults with latent or active tuberculosis

Introduction

The rising prevalence of Diabetes mellitus (DM) in high TB‐endemic countries may adversely affect sustainability of TB control since DM constitutes a risk factor for development of active tuberculosis (TB). The impact of DM on TB specific adaptive immune responses remains poorly addressed, particularly in people living in Sub‐Saharan countries. We performed a functional characterization of TB specific cellular immune response in Tanzanian subjects with active or latent Mycobacterium tuberculosis (Mtb) infection stratified by their diabetic status.

Methods

HIV negative active TB patients (≥18 years) with Xpert MTB/RIF positive pulmonary TB were included before starting TB treatment in Dar es Salaam, Tanzania between April and December 2013. HIV negative healthy controls latently infected with TB but without past TB history were also included. Active and latent TB patients were stratified in two groups according to their diabetic status. Peripheral Blood Mononuclear cells were stimulated with either live M. bovis BCG or Mtb‐specific peptide pools and analyzed by intracellular cytokine staining and polychromatic flow cytometry.

Results

Our results show a lower frequency of IFN‐γ CD4⁺ T cells in patients with active TB and DM compared to patients with active TB only after live M. bovis BCG (p = 0.04) but not after Mtb peptide pools re‐stimulation. Irrespective of TB status, level of glycaemia is selectively inversely correlated with IFN‐γ and TNF‐α CD4⁺ T cell production (p = 0.02 and p = 0.03) after live M. bovis BCG stimulation.

Conclusions

These results support the hypothesis that hyperglycaemia negatively impacts antigen processing and/or presentation of whole mycobacteria delaying secretion of key cytokines involved in TB immunity.

Association between tuberculosis, diabetes and 25 hydroxyvitamin D in Tanzania: a longitudinal case control study

Background

Vitamin D level is inversely associated with tuberculosis (TB) and diabetes (DM). Vitamin D could be a mediator in the association between TB and DM. We examined the associations between vitamin D, TB and DM.

Methods

Consecutive adults with TB and sex- and age-matched volunteers were included in a case-control study in Dar es Salaam, Tanzania. Glycemia and total vitamin D (25(OH)D) were measured at enrolment and after TB treatment in cases. The association between low 25(OH)D (<75 nmol/l) and TB was evaluated by logistic regression adjusted for age, sex, body mass index, socioeconomic status, sunshine hours, HIV and an interaction between low 25(OH)D and hyperglycemia.

Results

The prevalence of low 25(OH)D was similar in TB patients and controls (25.8 % versus 31.0 %; p = 0.22). In the subgroup of patients with persistent hyperglycemia (i.e. likely true diabetic patients), the proportion of patients with low 25(OH)D tended to be greater in TB patients (50 % versus 29.7 %; p = 0.20). The effect modification by persistent hyperglycemia persisted in the multivariate analysis (p_interaction = 0.01).

Conclusions

Low 25(OH)D may increase TB risk in patients with underlying DM. Trials should examine if this association is causal and whether adjunct vitamin D therapy is beneficial in this population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1960-x) contains supplementary material, which is available to authorized users.

Transient Hyperglycemia in Patients With Tuberculosis in Tanzania: Implications for Diabetes Screening Algorithms

BACKGROUND

Diabetes mellitus (DM) increases tuberculosis risk while tuberculosis, as an infectious disease, leads to hyperglycemia. We compared hyperglycemia screening strategies in controls and patients with tuberculosis in Dar es Salaam, Tanzania.

METHODS

Consecutive adults with tuberculosis and sex- and age-matched volunteers were included in a case-control study between July 2012 and June 2014. All underwent DM screening tests (fasting capillary glucose [FCG] level, 2-hour CG [2-hCG] level, and glycated hemoglobin A1c [HbA1c] level) at enrollment, and cases were tested again after receipt of tuberculosis treatment. Association of tuberculosis and its outcome with hyperglycemia was assessed using logistic regression analysis adjusted for sex, age, body mass index, human immunodeficiency virus infection status, and socioeconomic status. Patients with tuberculosis and newly diagnosed DM were not treated for hyperglycemia.

RESULTS

At enrollment, DM prevalence was significantly higher among patients with tuberculosis (n = 539; FCG level > 7 mmol/L, 4.5% of patients, 2-hCG level > 11 mmol/L, 6.8%; and HbA1c level > 6.5%, 9.3%), compared with controls (n = 496; 1.2%, 3.1%, and 2.2%, respectively). The association between hyperglycemia and tuberculosis disappeared after tuberculosis treatment (adjusted odds ratio [aOR] for the FCG level: 9.6 [95% confidence interval {CI}, 3.7-24.7] at enrollment vs 2.4 [95% CI, .7-8.7] at follow-up; aOR for the 2-hCG level: 6.6 [95% CI, 4.0-11.1] vs 1.6 [95% CI, .8-2.9]; and aOR for the HbA1c level, 4.2 [95% CI, 2.9-6.0] vs 1.4 [95% CI, .9-2.0]). Hyperglycemia, based on the FCG level, at enrollment was associated with tuberculosis treatment failure or death (aOR, 3.3; 95% CI, 1.2-9.3).

CONCLUSIONS

Transient hyperglycemia is frequent during tuberculosis, and DM needs confirmation after tuberculosis treatment. Performance of DM screening at tuberculosis diagnosis gives the opportunity to detect patients at risk of adverse outcome.

Type 2 diabetes control and complications in specialised diabetes care centres of six sub-Saharan African countries: the Diabcare Africa study

AIM

The Diabcare Africa project was carried out across six sub-Saharan African countries to collect standardised and comparable information for the evaluation of diabetes control, management and late complications in diabetic populations at specialist clinics.

METHODS

A cross-sectional, descriptive study of 2352 type-2 diabetes patients who were treated at specialist clinics for at least 12 months prior to the study.

RESULTS

The mean age of patients was 53.0±16.0 years and had 8.0±6.0 years known duration of diabetes. 47% had their HbA1c assessed in the past year (mean 8.2±2.4%) with 29% achieving a level <6.5%. 21% had BP within 130/80 mmHg and 65% were treated for hypertension. Fasting lipids were assessed in 45% of the patients with mean cholesterol level of 4.9±1.2 mmol/L, HDL-cholesterol of 1.3±0.7 mmol/L and triglycerides of 1.2±0.7 mmol/L. 13% of the patients were treated for hyperlipidaemia, mostly with statins. Background retinopathy (18%) and cataract (14%) were the most common eye complications. Macrovascular disease was rare, and 48% had neuropathy.

CONCLUSIONS

Half of the patients benefitted from standard care, and a third had appropriate glycaemic control - attributed to access to, rather than quality of care. This study provided evidence to support appropriate interventions to diabetic populations of sub-Saharan origin.

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.