Application of the new ADA criteria for the diagnosis of diabetes to population studies in sub-Saharan Africa. American diabetes association

The influence of fasting and post-load glucose levels on maternal and neonatal outcomes in women with hyperglycaemia in pregnancy in Uganda: A prospective observational cohort study

AIMS

The study aims to evaluate the strength of fasting versus post-load glucose levels in predicting adverse outcomes in women with hyperglycaemia in pregnancy (HIP).

METHODS

Women attending antenatal clinics in urban and peri-urban Uganda had oral glucose tolerance test between 24 and 28 weeks of gestation to screen for HIP, and were followed up to collect data on maternal and neonatal outcomes. Univariable and multivariable Poisson regression models were used to estimate the relative risk adverse outcome associated with fasting hyperglycaemia alone post-load hyperglycaemia alone, or elevation of both fasting and post-load glucose levels.

RESULTS

We included 3206 participants in the final analysis. HIP was associated with increased risk of Caesarean section, large for gestaional age babies, and neonatal intensive care admission. The risk was highest (2.54-fold compared to normal glycaemic women) when both FBG and post-load glucose levels were elevated. After adjustment for potential confounders, having elevated post-load glucose alone was not associated with increased risk of any of the outcomes, but elevated FBG alone increased the risk of Caesarian section by 1.36-fold.

CONCLUSION

Fasting hyperglycemia appears to be more strongly associated with adverse pregnancy outcomes than post-load hyperglycaemia, but the risk is even higher in women with elevation of both fasting and post-load glucose levels.

The OGTT is highly reproducible in Africans for the diagnosis of diabetes: Implications for treatment and protocol design

Whether an OGTT reproducibly detects either type 2 diabetes (T2D) or prediabetes in Africans in unknown. Therefore, 131 Africans had two OGTT. Diagnostic reproducibility for T2D was excellent (κ = 0.84), but only moderate for prediabetes (κ = 0.51). A single OGTT positive for T2D may be sufficient to guide clinical care and inform epidemiologic study design. ClinicalTrials.gov Identifier: NCT00001853.

Glycated haemoglobin threshold for dysglycaemia screening, and application to metabolic syndrome diagnosis in HIV-infected Africans

BACKGROUND

Glycated haemoglobin (HbA1c) test has been increasingly promoted as an alternative to fasting plasma glucose (FPG) or oral glucose tolerance test (OGTT) to diagnose dysglycaemia but its performance in HIV-infected Africans has yet to be established. This study aimed to assess the diagnostic accuracy of HbA1c for dysglycaemia including FPG-defined and OGTT-defined dysglycaemia, and OGTT-defined diabetes in HIV-infected Africans, and the effect of HbA1c-predicted dysglycaemia on Joint Interim Statement (JIS)-based prevalent metabolic syndrome (MS).

METHODS

A cross-sectional study included HIV-positive patients recruited across public healthcare facilities in the Western Cape. The recommended HbA1c cut-points were tested alongside the optimal cut-points obtained from receiver operating characteristic curve analyses, while the agreement between the MS criteria were assessed using kappa statistic.

RESULTS

748 participants (157 men), median age 38 years, 93% on anti-retroviral drugs were included. The optimal HbA1c cut-points of 5.75% (39.3 mmol/mol) showed 54% sensitivity, 84% specificity for FPG-defined dysglycaemia, and 52% sensitivity, 85% specificity for OGTT-defined dysglycaemia. The HbA1c value of 5.85% (40.4 mmol/mol) (63% sensitivity, 99% specificity) was optimal for diabetes. The internationally advocated cut-point of 6.5% (48 mmol/mol) had 37% sensitivity and 99% specificity for diabetes, while HbA1c ≥5.7% (≥39 mmol/mol) yielded similar performance with the study-specific cut-point for any dysglycaemia. MS prevalence by the JIS criteria (28.2%) increased to 29.7% when using HbA1c ≥5.75% (≥39.3 mmol/mol) and to 32.9% with HbA1c ≥5.7% (≥39 mmol/mol); agreement between the original and modified criteria was generally good.

CONCLUSIONS

This study agrees with the internationally recommended HbA1c cut-point for detecting dysglycaemia, but not for diabetes in HIV-infected Africans. In line with previous studies in general African populations, our findings suggest that similar factors interfere with HbA1c values regardless of HIV infection status. Replacing FPG-based with HbA1c-predicted dysglycaemia in the JIS criteria to diagnose MS is feasible in HIV-infected Africans.

Global and regional estimates of the morbidity due to type I diabetes among children aged 0-4 years: a systematic review and analysis

Background

Epidemiology of type 1 diabetes mellitus (T1DM) among children aged 0-4 years globally is not well understood. We aim to assess the incidence of T1DM in low- and middle-income countries (LMIC) by conducting a systematic review of previous reports. We also aim to address possible contribution to child mortality and to identify any temporal trends.

Methods

A systematic review was performed using a carefully designed search strategy to explore MEDLINE, EMBASE and Global Health databases. Data was extracted from all studies that satisfied the inclusion criteria –a total of 83 records extracted from 26 830 sources that were analysed. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process to assess quality of evidence and applied meta-analysis approaches to assess global and regional incidence and time trends.

Results

The overall pooled incidence of T1DM in children aged 0-4 years globally is 11.2 (95% CI = 10.0-12.3) per 100 000 child years. The regional incidence were the highest for European Region A (EUR A) at 15.5 (95% CI = 13.5-17.5) per 100 000 child years. EUR C had the incidence of 10.0 (95% CI = 6.5-13.6) and EUR B 5.8 (95% CI = 4.7-7.0), Region of the Americas A (AMR A) 11.4 (95% CI = 7.8-14.9), AMR B of 2.5 (95% CI = 0.2-4.8), Eastern Mediterranean Region (EMR B) 7.1 (95% CI = 4.2-10.0) and Western Pacific Region (WPR A) 7.0 (95% CI = 2.9-11.0) per 100 000 child years, while other regions had very low rates or no data. When data points were categorised in the study periods and re-analysed, an increasing trend of the T1DM incidence was observed, with the incidence of 20.9 (95% CI = 7.8-34.1) per 100 000 child years in the years 2010-2015, preceded by 13.2 (95% CI = 11.0-15.5) in 2000-2009 study period, 10.0 (95% CI = 8.4-11.7) in 1990-1999 and 8.3 (95% CI = 5.1-11.6) in 1980-1989, respectively. Although the data are scarce, and variation and uncertainty are large, we estimated that the number of new cases of T1DM among children aged 0-4 years in the world each year is between 100 000 and 150 000.

Conclusions

The identified large variation in incidence estimates for different parts of the world, along with scarcity of information and the identified strong temporal increase in T1DM incidence suggest a clear need for further research into this subject.

Gluconeogenesis and risk for fasting hyperglycemia in Black and White women

Black women, compared with White women, have high rates of whole-body insulin resistance but a lower prevalence of fasting hyperglycemia and hepatic steatosis. This dissociation of whole-body insulin resistance from fasting hyperglycemia may be explained by racial differences in gluconeogenesis, hepatic fat, or tissue-specific insulin sensitivity. Two groups of premenopausal federally employed women, without diabetes were studied. Using stable isotope tracers, [2H2O] and [6,62-H2]glucose, basal glucose production was partitioned into its components (gluconeogenesis and glycogenolysis) and basal whole-body lipolysis ([2H5]glycerol) was measured. Indices of insulin sensitivity, whole-body (SI), hepatic (HISIGPR), and adipose tissue, were calculated. Hepatic fat was measured by proton magnetic resonance spectroscopy. Black women had less hepatic fat and lower fractional and absolute gluconeogenesis. Whole-body SI, HISIGPR, and adipose tissue sensitivity were similar by race, but at any given level of whole-body SI, Black women had higher HISIGPR. Therefore, fasting hyperglycemia may be a less common early pathological feature of prediabetes in Black women compared with White women, because gluconeogenesis remains lower despite similar whole-body SI.

Prevalence of prediabetes and diabetes mellitus among adults residing in Cameroon: A systematic review and meta-analysis

AIMS

To summarize current data on the prevalence of prediabetes and diabetes mellitus in Cameroon.

METHODS

Population-based cross-sectional studies published between January 1, 2000 and April 30, 2017 including apparently healthy adults residing in Cameroon were searched in PubMed, EMBASE, African Journals Online, and African Index Medicus. We used a random-effects model to pool data.

RESULTS

All included studies had a low risk of bias. Six studies were conducted in an urban setting only, one in a rural setting only, and five in both settings. The overall prevalence of diabetes mellitus was 5.8% (95%CI 4.1-7.9; 12 studies) in a pooled sample of 37,147 participants. The prevalence of prediabetes was 7.1% (95%CI: 3.0-21.9; 4 studies) in a pooled sample of 5,872 people. In univariable meta-regression analysis, the prevalence of diabetes mellitus increased with age, hypertension, overweight and obesity. There was no difference for sex and settings (rural versus urban).

CONCLUSIONS

This study reports a relatively high prevalence of diabetes mellitus and prediabetes in Cameroon, with no difference between urban and rural settings and between sexes. The main drivers include increasing age, overweight and obesity. Community-based educational programs are needed to tackle the burden of the disease in the country.

Reversing the tide - diagnosis and prevention of T2DM in populations of African descent

Populations of African descent are at the forefront of the worldwide epidemic of type 2 diabetes mellitus (T2DM). The burden of T2DM is amplified by diagnosis after preventable complications of the disease have occurred. Earlier detection would result in a reduction in undiagnosed T2DM, more accurate statistics, more informed resource allocation and better health. An underappreciated factor contributing to undiagnosed T2DM in populations of African descent is that screening tests for hyperglycaemia, specifically, fasting plasma glucose and HbA_1c, perform sub-optimally in these populations. To offset this problem, combining tests or adding glycated albumin (a nonfasting marker of glycaemia), might be the way forward. However, differences in diet, exercise, BMI, environment, gene-environment interactions and the prevalence of sickle cell trait mean that neither diagnostic tests nor interventions will be uniformly effective in individuals of African, Caribbean or African-American descent. Among these three populations of African descent, intensive lifestyle interventions have been reported in only the African-American population, in which they have been found to provide effective primary prevention of T2DM but not secondary prevention. Owing to a lack of health literacy and poor glycaemic control in Africa and the Caribbean, customized lifestyle interventions might achieve both secondary and primary prevention. Overall, diagnosis and prevention of T2DM requires innovative strategies that are sensitive to the diversity that exists within populations of African descent.

Obesity and type 2 diabetes in sub-Saharan Africans - Is the burden in today's Africa similar to African migrants in Europe? The RODAM study

BACKGROUND

Rising rates of obesity and type 2 diabetes (T2D) are impending major threats to the health of African populations, but the extent to which they differ between rural and urban settings in Africa and upon migration to Europe is unknown. We assessed the burden of obesity and T2D among Ghanaians living in rural and urban Ghana and Ghanaian migrants living in different European countries.

METHODS

A multi-centre cross-sectional study was conducted among Ghanaian adults (n = 5659) aged 25-70 years residing in rural and urban Ghana and three European cities (Amsterdam, London and Berlin). Comparisons between groups were made using prevalence ratios (PRs) with adjustments for age and education.

RESULTS

In rural Ghana, the prevalence of obesity was 1.3 % in men and 8.3 % in women. The prevalence was considerably higher in urban Ghana (men, 6.9 %; PR: 5.26, 95 % CI, 2.04-13.57; women, 33.9 %; PR: 4.11, 3.13-5.40) and even more so in Europe, especially in London (men, 21.4 %; PR: 15.04, 5.98-37.84; women, 54.2 %; PR: 6.63, 5.04-8.72). The prevalence of T2D was low at 3.6 % and 5.5 % in rural Ghanaian men and women, and increased in urban Ghanaians (men, 10.3 %; PR: 3.06; 1.73-5.40; women, 9.2 %; PR: 1.81, 1.25-2.64) and highest in Berlin (men, 15.3 %; PR: 4.47; 2.50-7.98; women, 10.2 %; PR: 2.21, 1.30-3.75). Impaired fasting glycaemia prevalence was comparatively higher only in Amsterdam, and in London, men compared with rural Ghana.

CONCLUSION

Our study shows high risks of obesity and T2D among sub-Saharan African populations living in Europe. In Ghana, similarly high prevalence rates were seen in an urban environment, whereas in rural areas, the prevalence of obesity among women is already remarkable. Similar processes underlying the high burden of obesity and T2D following migration may also be at play in sub-Saharan Africa as a consequence of urbanisation.

Prevalence of diabetes and associated risk factors in a Senegalese urban (Dakar) population

AIM

The aim of this study was to estimate the prevalence of diabetes in the urban population living in Dakar, Senegal, and to investigate the factors associated with diabetes.

METHODS

Data from a 2009 survey of 600 individuals, aged 20 years or above and considered representative of the population of the city of Dakar, were evaluated. Socioeconomic characteristics, hypertension, capillary whole blood glucose, and weight and height measurements of these subjects were collected during face-to-face interviews. The statistical analyses used chi-square (chi2) tests and binary logistic regressions.

RESULTS

The percentage of participants with fasting blood glucose levels greater than or equal to 1.10 g/L and/or currently being treated for diabetes was 17.9% (n=107, 95% CI: 14.7-20.8). Observed rates of diabetes were significantly higher among women (chi2 = 6.3; P < 0.05), in subjects aged > 40 years (chi2=33.6; P < 0.001), in those with low educational levels (chi2=11.9; P < 0.05) and in those with hypertension (chi2 = 13.9; P < 0.001), and in those who were overweight (BMI ≥ 25 kg/m2 and < 30 kg/m2) or obese (BMI ≥ 30 kg/m2; chi2=40.3; P < 0.001). After adjusting for gender, age, educational level, BMI and blood pressure, the results showed that gender, age and BMI were associated with diabetes: women, older people and those with a higher BMI had significantly greater chances of being diabetic than the rest of the population, whatever their blood pressure and educational level.

CONCLUSION

Diabetes is becoming a pressing public-health problem in Senegal, and the major risk factors for the increasing diabetes prevalence in the city of Dakar are gender, age and body mass index.

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.

The performance of risk scores and hemoglobin A1c to find undiagnosed diabetes with isolated postload hyperglycemia

The aim of this study is to develop strategies to screen diabetic subjects with isolated postload hyperglycemia (IPH) in Chinese population. We included 1175 adult subjects who did not report diabetes were included. Diabetes was diagnosed by oral glucose tolerance tests. IPH was defined as fasting plasma glucose (FPG)<7 mmol/l and 2-hour post-load plasma glucose (2hPG) greater than 11.1 mmol/l. Using FPG criteria, only 59.8% of diabetic subjects were not identified, showing a poor agreement between FPG and 2hPG criteria (kappa 0.294). Age, FPG, total cholesterol, triglycerides, blood pressure, body mass index, HbA1c and medication for hypertension were associated factors for IPH. Four scores were constructed using all these factors, age and blood test results, age and HbA1c, and data from non-invasive examinations, respectively. The area under the ROC curve were 0.9296(95%CI 0.8948-0.9643), 0.9111(95%CI 0.8713-0.9508), 0.8902(95%CI 0.8341-0.9646), 0.8924(95%CI 0.7835-0.8753), and 0.8654(95%CI 0.7963-0.9345) for score 1, 2, 3, 4, and HbA1c, respectively. The sensitivity of all four risk scores to detect IPH was better than that of impaired fasting glucose (IFG). The sensitivity and specificity of HbA1c at cutoff 6.2% for detecting IPH was also better than that of IFG. In conclusion, the risk scores and HbA1c are useful to identify subjects with undiagnosed IPH, with better performance than IFG.

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.

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.

Differences in height explain gender differences in the response to the oral glucose tolerance test- the AusDiab study

AIM

To determine the extent of gender-related differences in the prevalence of glucose intolerance for the Australian population and whether body size may explain such differences.

METHODS

Cross-sectional data were collected from a national cohort of 11 247 Australians aged > or = 25 years. Glucose tolerance status was assessed according to both fasting plasma glucose (FPG) and 2-h plasma glucose (2hPG) levels following a 75-g oral glucose tolerance test (OGTT). Anthropometric and glycated haemoglobin measurements were also made.

RESULTS

Undiagnosed diabetes and non-diabetic glucose abnormalities were more prevalent among men than women when based only on the FPG results (diabetes: men 2.2%, women 1.6%, P = 0.02; impaired fasting glycaemia: men 12.3%, women 6.6%, P < 0.001). In contrast 16.0% of women and 13.0% of men had a 2hPG abnormality (either diabetes or impaired glucose tolerance, P = 0.14). Women had a mean FPG 0.3 mmol/l lower than men (P < 0.001), but 2hPG 0.3 mmol/l higher (P = 0.002) and FPG-2hPG increment 0.5 mmol/l greater (P < 0.001). The gender difference in mean 2hPG and FPG-2hPG increment disappeared following adjustment for height. For both genders, those in the shortest height quartile had 2hPG levels 0.5 mmol/l higher than the tallest quartile, but height showed almost no relationship with the FPG.

CONCLUSIONS

Men and women had different glycaemic profiles; women had higher mean 2hPG levels, despite lower fasting levels. It appeared that the higher 2hPG levels for women related to lesser height and may be a consequence of using a fixed glucose load in the OGTT, irrespective of body size.

Diabetes and impaired fasting glucose in rural and urban populations in Futa Jallon (Guinea): prevalence and associated risk factors

AIM

The authors present the results of the first survey conducted among the population of the Futa Jallon province in Guinea on the prevalence of diabetes mellitus (DM) and impaired fasting glucose (IFG) and associated risk factors for diabetes.

METHOD

A random sample of the study population selected by cluster house sampling method included 1537 Guineans (807 women and 730 men) aged 35 years and above in urban (Labé) and rural (Fellö Koundoua-Tougué) areas. Participants were examined and administered a capillary whole blood glycemia test.

RESULTS

The mean age of subjects was 49.4 years. Participation rate was 77%. Overall crude diabetes and IFG prevalence were 6.1% and 13.4%, respectively. The age-adjusted prevalence of diabetes using the standardized age distribution of Segi was 6.7% (95% CI: 5.5-7.9%). Subjects in the urban area had twice as much DM as in the rural area (OR 2.0, 95% CI: 1.3-3.2). Out of the 94 subjects with DM, 66 had no prior history of disease. Urban location, age, waist to hip ratio, excess waist circumference, hypertension, raised systolic and diastolic blood pressures were significantly positively associated with DM. In multivariate analysis, only age (P=0.002) and waist circumference (P<0.05) remained independently associated with DM.

CONCLUSION

The prevalence of DM was higher than expected in urban and rural areas. The data support the conclusion that prevalence of DM is expected to increase with the aging of the population. The factors associated with diabetes are potentially modifiable. Therefore, primary prevention through lifestyle modifications may play a critical role in the control of DM.

Prevalence of cardiovascular diseases and associated risk factors in a rural black population of South Africa

BACKGROUND

To determine the prevalence and associated risk factors of cardiovascular diseases in a rural adult black population from Limpopo Province in South Africa.

DESIGN

A cross-sectional study.

METHODS

A sample of 1608 women and 498 men aged 30 years and above participated in the study. Sociodemographic data, anthropometric measures (body mass index, waist/hip ratio), blood pressure and biochemical risk factors were measured. A global cardiovascular disease (CVD) risk profile was developed.

RESULTS

There was a high prevalence of tobacco use for men (57%) and women (35.4%), with women (28.1%) predominantly using smokeless tobacco. Alcohol use was very common in men (57.2%). Women weighed a great deal more than men, and 51.7% were either overweight or obese. Diabetes was diagnosed in 8.8 and 8.5% of women and men, respectively. High-density lipoprotein-cholesterol was relatively high, whereas 42.3% of women and 28.5% of men had low-density lipoprotein-cholesterol levels of 3 mmol/l or more. Hypertension (blood pressure > or =140/90 mmHg) was found in 25.5% of women and 21.6% of men. According to the Framingham formulae, 18.9% of women and 32.1% of men had a 20% or higher chance of having a CVD event in the next 10 years.

CONCLUSIONS

There was a high prevalence of chronic disease risk factors in the rural, poor black community in Limpopo, South Africa. Consequently, the population had a higher than expected risk of developing a CVD event in the following 10 years when compared with similar studies in black Africans.

Test agreement for classifying diabetes in indigenous Australians

OBJECTIVE

To evaluate for Indigenous Australians the agreement between a fasting plasma glucose (FPG) criterion of 7.0 mmol/L and diabetes test results using a two-hour oral glucose tolerance test (OGTT), comparing relationships between test agreement and prevalence to similar studies.

METHODS

Screening was undertaken in 25 remote settlements. Agreement between FPG and OGTT results was evaluated using the kappa coefficient (chance-corrected agreement).

RESULTS

Participants (n=3,249) ranged from 15-94 years. Kappa ranged from 0.70-0.77 for diabetes prevalence of 5-30%, with overall agreement of 0.76. In comparison studies, the relationship between kappa and diabetes prevalence was similar, but with kappa 0.21-0.48.

CONCLUSIONS AND IMPLICATIONS

A FPG test with a 7.0 mmol/L cut-off is a reliable screening method, relative to the OGTT, for remote Indigenous settlements. The level of agreement between the FPG test and the OGTT for the Indigenous population surveyed is superior by far to agreement reported for non-Indigenous samples.

The use of prescribed drugs for common chronic conditions in South Africa in 1998

PURPOSE

To determine the prescribed drug-utilisation pattern for six common chronic conditions in adult South Africans in a cross-sectional survey.

METHODS

13,826 randomly selected participants, 15 years and older, were surveyed by trained fieldworkers at their homes in 1998. Questionnaires included socio-demographic, chronic-disease and drug-use data. The prescribed drugs were recorded from participants' medication containers. The Anatomical Therapeutic Classification (ATC) code of the drugs for tuberculosis (TB), diabetes, hypertension, hyperlipidaemia, other atherosclerosis-related conditions, such as heart conditions or cerebrovascular accidents (CVA), and asthma or chronic obstructive pulmonary disease (COPD), was recorded. The use of logistic regression analyses identified the determinants of those patients who used prescription medication for these six conditions.

RESULTS

18.4% of the women and 12.5% of the men used drugs for the six chronic conditions. Men used drugs most frequently for hypertension (50.9%) and asthma or chronic bronchitis (24.3%), while in women it was for hypertension (59.9%) and diabetes (17.5%). The logistic regression analyses showed that women, wealthier and older people, and those with medical insurance used these chronic-disease drugs more frequently compared to men, younger or poor people, or those without medical insurance. The African population group used these drugs less frequently than any other ethnic group. The inappropriate use of methyldopa was found for 14.8% of all antihypertensive drugs, while very few people used aspirin.

CONCLUSIONS

The methodology of this study provides a means of ascertaining the chronic-disease drug-utilisation pattern in national health surveys. The pattern described, suggests an inequitable use of chronic-disease drugs and inadequate use of some effective drugs to control the burden of chronic diseases in South Africa.

Fasting criteria for screening: test properties and agreement with glucose tolerance

The objective of this study was to characterise test properties and agreement for fasting glucose cut-offs used for screening diabetes in Indigenous Australian communities, across a range of diabetes prevalence. The oral glucose tolerance test (OGTT) was administered to adult volunteers (n=3249) for community-based diabetes screening in isolated settlements (n=25). Two-hour post-load glucose concentration was the 'gold standard' against which test properties were characterised for fasting plasma glucose cut-offs at concentrations of > or = 7.0 mmol/l (ADA criterion) and > or = 7.8 mmol/l (WHO criterion). Test sensitivity (95% CI) was greater for the ADA (72.5%, 67.4-77.1%) versus the WHO criterion (61.5%, 56.1-66.6%). Specificity was high (>98%) using either criterion. The post-test likelihood of diabetes, given a population prevalence of 14.8%, was 89.1% using the ADA criterion, and 94.9% using the WHO criterion. The ADA criterion gave better agreement than did the WHO criterion for diabetes prevalence > or = 8.6%, and the probability of false results was lower using the ADA criterion, when diabetes prevalence was > or = 12.8%. According to the ADA criterion most individuals ascribed false negative results were aged > or = 35 years, overweight/obese, or had impaired fasting glucose. The fasting glucose criterion of 7.0 mmol/l was superior to 7.8 mmol/l in screening for diabetes.

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.

Diabetes in Ghana: a community based prevalence study in Greater Accra

Data on the prevalence of diabetes in Ghana is scanty and unreliable. In the present study we have ascertained the prevalence of diabetes, impaired fasting glycaemia (IFG) and impaired glucose tolerance (IGT) in a random cluster sample of Ghanaians aged 25 years and above from the Greater Accra area of Ghana. Diabetes, IFG and IGT were defined by criteria of the American Diabetes Association and World Health Organization. The mean age of the 4733 subjects involved in the study was 44.3+/-14.7 years, and participation rate was 75%. The crude prevalence of diabetes was 6.3%. Out of 300 subjects with diabetes, 209 (69.7%) had no prior history of the disease. Diabetes, IGT and combined IFG and IGT increased with age. The oldest age group (64+ years) had the highest diabetes prevalence (13.6%). The age-adjusted prevalence of diabetes, IFG and IGT, were 6.4, 6.0 and 10.7%, respectively. Diabetes was more common in males than females (7.7 vs. 5.5%) [P<0.05]. Worsening glycaemic status tended to be associated with increase in age, body mass index, systolic and diastolic blood pressures. Ascertainment of predictors for diabetes in Ghanaians and the significance of the relatively high rates of and IFG and IGT however, remain to be determined.

WHO and ADA criteria for the diagnosis of diabetes mellitus in relation to body mass index. Insulin sensitivity and secretion in resulting subcategories of glucose tolerance

OBJECTIVE

To determine the influence of body mass index (BMI) on agreement between the American Diabetes Association (ADA) and the new World Health Organization diagnostic criteria for the diagnosis of diabetes mellitus and to investigate the metabolic profile of the resulting subcategories.

DESIGN

Cross-sectional study

SUBJECTS

A total of 3018 subjects with no previous history of diabetes and fasting glucose <7.8 mmol/l, with a wide range of BMIs.

MEASUREMENTS

(1) Prevalence of impaired glucose regulation (IGR) and diabetes (DM) according to ADA and WHO diagnostic criteria; (2) basal and post-load insulin sensitivity and secretion, calculated on the basis of data derived from an oral glucose tolerance test (OGTT).

RESULTS

The diagnosis according to the two classifications was concordant in 2490 subjects, discordant in 528 (452 were identified as impaired glucose tolerance (IGT) and 76 as DM only by means of OGTT). The disagreement increased with increasing BMI, being as high as 25.3% in subjects with BMI > or = 35 kg/m(2). Subjects with isolated fasting hyperglycaemia were mainly characterised by reduced insulin sensitivity and secretion in the basal state, but normal first-phase insulin secretion and moderately reduced insulin sensitivity after glucose challenge. Subjects with isolated 2 h hyperglycaemia were mainly characterised by normal basal insulin secretion and by a marked insulin resistance associated with a blunted first-phase insulin secretion after the glucose load.

CONCLUSIONS

The disagreement between ADA and WHO classifications is particularly relevant in obesity, making OGTT mandatory in these subjects. Different pathogenic mechanisms are involved in isolated fasting or post-load hyperglycaemia, possibly related to a different site of insulin resistance (hepatic vs peripheral), and/or to a different disregulation of insulin secretion (basal vs post-load). A correct identification of the underlying mechanism(s) is the rationale for future studies to detect the effectiveness of different pharmacological or behavioural approaches.