Prevalence of known diabetes in an urban Indian environment: the Darya Ganj diabetes survey

Epidemiology of Ischemic Heart Disease and Diabetes in South Asia: An Overview of the Twin Epidemic

BACKGROUND & OBJECTIVES

Ischemic heart disease (IHD) is one of the most important causes of death and disability in the world and diabetes is an important risk factor. This review was performed to describe the mortality and morbidity burden from this twin epidemic in South Asian countries.

METHODS

Country-level data on the epidemiology of IHD and diabetes were obtained from the Global Burden of Disease (GBD) study. Sub-national data were available only for India. We also retrieved epidemiological studies from published reviews on IHD and diabetes in India. These were supplemented with MEDLINE search.

RESULTS

GBD study and regional epidemiological studies have reported that there are significant regional variations in IHD mortality and disease burden within South Asian countries. IHD burden has increased significantly from 2000 to 2017. Prospective Urban Rural Epidemiology study has reported that diabetes is an important IHD risk factor in the South Asian region. GBD Study and International Diabetes Federation have reported increasing diabetes-related mortality and disease burden in South Asian countries, especially India. There are regional variations in diabetes-related mortality, disease burden, and prevalence in South Asia. At the macrolevel, rapid food and nutrition transition along with increasing physical inactivity is responsible for this twin epidemic.

CONCLUSION

Increasing trends in IHD and diabetes-related mortality and disease burden with regional variations are observed in South Asian countries.

High prevalence of diabetes, prediabetes and obesity among residents of East Delhi - The Delhi urban diabetes survey (DUDS)

AIM

The burden of diabetes is very high in our country particularly in the urban metros. The present survey was planned to ascertain the current prevalence of diabetes and prediabetes in Delhi since the available prevalence estimates are over a decade old.

METHODS

The present study was conducted in urban area of east Delhi and followed a multistage random sampling design. The prevalence of known diabetes was ascertained based on self reporting and prevalence of newly detected diabetes and prediabetes was based on oral glucose tolerance test (OGTT).

RESULTS

We surveyed 470 households and included 1317 individuals. Prevalence of diabetes was 18.3% (known 10.8% and newly detected 7.5%). Prevalence of prediabetes was 21% as per WHO criteria and 39.5% as per ADA criteria. The ratio of known to unknown diabetes was 1.44:1. Every third household (35.77%) had at least one known case of diabetes. High rates of obesity and central obesity were also observed in the study population.

CONCLUSION

The present study found a strikingly high prevalence of diabetes, prediabetes and obesity in Delhi. This calls for urgent and effective preventive measures to prevent diabetes.

Diabetic retinopathy screening programme utilising non-mydriatic fundus imaging in slum populations of New Delhi, India

OBJECTIVES

To develop and implement a community-based programme for screening of diabetic retinopathy (DR) in urban populations of Delhi.

METHODS

Known diabetics (KDs) aged 40 years and older were identified through house-to-house surveys, volunteers and publicity. All KDs were referred to DR screening camps organised locally where procedures included brief medical history, ocular examination and non-mydriatic fundus photography using portable handheld camera. Fundal images were graded on the spot by trained optometrists for DR. Patients with DR were referred to tertiary centre for management.

RESULTS

A total of 11 566 KDs were identified, of whom 9435 (81.6%) visited DR screening camps and 8432 (89.4%) had DR gradable images. DR was identified in 13.5% of subjects; 351 cases were mild NPDR, 567 moderate, 92 severe. Seventy-seven had PDR, and 49 had DME, and 2.7% of participants were blind (presenting visual acuity <3/60 in better eye). Non-use of lifestyle management, presence of systemic complications, BMI <18.5 kg/m² , disease duration of >5 years and uncontrolled diabetes were associated with increased odds of DR. All cases with DR were referred, and 420 (37%) successful referrals to base hospital were observed.

CONCLUSION

The programme of creating awareness about DR, identifying KDs and optometrist-led DR screening using non-mydriatic fundus camera based in slums was successful.

Review: Type 2 diabetes in India: regional disparities

Type 2 diabetes mellitus epidemic in India is a result of societal influences and changing lifestyles. Diabetes has been known in India for centuries as a disease of the affluent class. Epidemiological studies in the 1960's and 1970's using random and post-load blood glucose estimations reported diabetes prevalence varying from 1—4% in urban populations and 1—2% in rural populations. More standardised epidemiological studies since the 1990's reported prevalence rates that vary from 5—15% among urban populations, 4—6% in semi-urban populations and 2—5% in rural populations with large location-based disparities within urban and rural populations. There is a significantly increasing trend in urban populations (exponential trend R2=0.744) while among rural populations the prevalence is increasing at a slower rate (R2=0.289). At the turn of this century diabetes in adult urban Indian populations varies from a low of 5.4% in a northern state to a high of 12.3—15.5% in Chennai, South India, and 12.3—16.8% in Jaipur, Central India. This scenario is similar to other South Asian countries and evolving populations in East Asia, Middle-East, Americas, Australasia and Pacific Islands. Gene-environment interactions appear to be responsible for this rapid increase. The insulin-resistant state that was meant to be protective mechanism for regulation of calorie and fat metabolism at times of famine has turned deleterious as affluence has increased among these populations leading to diabetes epidemic. Population based measures to prevent the control of a diabetes epidemic include avoidance of adiposity by enhanced physical activity and regulated calorie intake.

Ferritin as a Risk Factor for Glucose Intolerance amongst Men and Women Originating from the Indian Subcontinent

Background. Serum ferritin predicts the onset of diabetes; however, this relationship is not clear amongst South Asians, a population susceptible to glucose intolerance and anaemia. Objective. This study tests whether ferritin levels reflect glucose tolerance in South Asians, independent of lifestyle exposures associated with Indian or British residence. Methods. We randomly sampled 227 Gujaratis in Britain (49.8 (14.4) years, 50% men) and 277 contemporaries living in Gujarati villages (47.6 (11.8) years, 41% men). Both groups underwent a 75 g oral-glucose-tolerance test. We evaluated lifestyle parameters with standardised questionnaires and conducted comprehensive clinical and lab measurements. Results. Across sites, the age-adjusted prevalence of diabetes was 9.8%. Serum ferritin was higher amongst diabetics (P = 0.005), irrespective of site, gender, and central obesity (P ≤ 0.02), and was associated with fasting and postchallenge glucose, anthropometry, blood pressure, triglycerides, and nonesterified fatty acids (P < 0.001). Diabetes was less in those with low ferritin (<20 mg/mL), P < 0.008, and risk estimate = 0.35 (95% CI 0.15-0.81), as were blood pressure and metabolic risk factors. On multivariate analysis, diabetes was independently associated with ferritin (P = 0.001) and age (P < 0.001). Conclusion. Ferritin levels are positively associated with glucose intolerance in our test groups, independent of gender and Indian or UK lifestyle factors.

Transcultural diabetes nutrition therapy algorithm: the Asian Indian application

India and other countries in Asia are experiencing rapidly escalating epidemics of type 2 diabetes (T2D) and cardiovascular disease. The dramatic rise in the prevalence of these illnesses has been attributed to rapid changes in demographic, socioeconomic, and nutritional factors. The rapid transition in dietary patterns in India-coupled with a sedentary lifestyle and specific socioeconomic pressures-has led to an increase in obesity and other diet-related noncommunicable diseases. Studies have shown that nutritional interventions significantly enhance metabolic control and weight loss. Current clinical practice guidelines (CPGs) are not portable to diverse cultures, constraining the applicability of this type of practical educational instrument. Therefore, a transcultural Diabetes Nutrition Algorithm (tDNA) was developed and then customized per regional variations in India. The resultant India-specific tDNA reflects differences in epidemiologic, physiologic, and nutritional aspects of disease, anthropometric cutoff points, and lifestyle interventions unique to this region of the world. Specific features of this transculturalization process for India include characteristics of a transitional economy with a persistently high poverty rate in a majority of people; higher percentage of body fat and lower muscle mass for a given body mass index; higher rate of sedentary lifestyle; elements of the thrifty phenotype; impact of festivals and holidays on adherence with clinic appointments; and the role of a systems or holistic approach to the problem that must involve politics, policy, and government. This Asian Indian tDNA promises to help guide physicians in the management of prediabetes and T2D in India in a more structured, systematic, and effective way compared with previous methods and currently available CPGs.

Prevalence of diagnosed diabetes in an urban area of Puducherry, India: Time for preventive action

BACKGROUND:

Epidemiological studies in India have shown that the prevalence of diabetes in the population is at least twice the number of persons diagnosed with diabetes residing in the given area. Similarly, community-based prevalence figures are unavailable in Puducherry,.

AIMS:

The aim of this study was to estimate the number of persons diagnosed with diabetes mellitus in Puducherry.

SETTING AND DESIGN:

This study was conducted in the service area of the Urban Health Centre (UHC), Pondicherry Institute of Medical Sciences (PIMS), Puducherry with retrospective data from family records.

METHODS:

The diagnosis of diabetes was retrospectively documented by reviewing all family folders of 2667 families (Population 11,835) for the period of 1/1/2003 to 31/12/2006. The data was verified by home visits from January until March, 2007. The case definition used, was a resident diagnosed with diabetes by a medical doctor and who was on antidiabetes treatment for at least the past six months.

RESULTS:

We found 643 individuals who had been diagnosed with diabetes. The prevalence of known diabetes was estimated to be 5.6% (5.31% in males and 6.1% in females). The age-sex specific prevalence was estimated using the 2001 Census data. There are about 48,876 known diabetics living in Puducherry.

CONCLUSIONS:

(1) Community-based health surveillance data comprise a useful tool to measure the prevalence of diagnosed cases of diabetes mellitus within the Indian context; 2) Diabetes mellitus is an important public health priority requiring urgent preventive action as there are about 97,752 persons in Puducherry who have either been diagnosed with diabetes or remain undiagnosed for the disease.

The need for obtaining accurate nationwide estimates of diabetes prevalence in India - rationale for a national study on diabetes

According to the World Diabetes Atlas, India is projected to have around 51 million people with diabetes. However, these data are based on small sporadic studies done in some parts of the country. Even a few multi-centre studies that have been done, have several limitations. Also, marked heterogeneity between States limits the generalizability of results. Other studies done at various time periods also lack uniform methodology, do not take into consideration ethnic differences and have inadequate coverage. Thus, till date there has been no national study on the prevalence of diabetes which are truly representative of India as a whole. Moreover, the data on diabetes complications is even more scarce. Therefore, there is an urgent need for a large well-planned national study, which could provide reliable nationwide data, not only on prevalence of diabetes, but also on pre-diabetes, and the complications of diabetes in India. A study of this nature will have enormous public health impact and help policy makers to take action against diabetes in India.

Pakistan National Diabetes Survey: prevalence of glucose intolerance and associated factors in the Punjab Province of Pakistan

AIMS

The prevalence of diabetes mellitus and impaired glucose tolerance (IGT) and their relationship to age and obesity were estimated in Punjab, Pakistan by a population-based survey done in 1998.

METHODS

Oral glucose tolerance tests were performed in a stratified random sample of 1852 adults aged >or=25 years. The diagnosis of diabetes and IGT were made on the basis of WHO criteria.

RESULTS

The prevalence of diabetes was 12.14% in males and 9.83% in females. Overall total glucose intolerance (diabetes and IGT) was present in 16.68% males and 19.37% females. Central obesity, hypertension and positive family history were strongly associated with diabetes.

CONCLUSIONS

These results indicate that the prevalence of glucose intolerance is high in the studied population and comparable with the published data from the other three provinces of Pakistan i.e. Sindh, Baluchistan and North West Frontier Province, studied by the same group.

Current scenario of diabetes in India

India, a country experiencing rapid socioeconomic progress and urbanization, carries a considerable share of the global diabetes burden. Studies in different parts of India have demonstrated an escalating prevalence of diabetes not only in urban populations, but also in rural populations as a result of the urbanization of lifestyle parameters. The prevalence of prediabetes is also high. Recent studies have shown a rapid conversion of impaired glucose tolerance to diabetes in the southern states of India, where the prevalence of diabetes among adults has reached approximately 20% in urban populations and approximately 10% in rural populations. Because of the considerable disparity in the availability and affordability of diabetes care, as well as low awareness of the disease, the glycemic outcome in treated patients is far from ideal. Lower age at onset and a lack of good glycemic control are likely to increase the occurrence of vascular complications. The economic burden of treating diabetes and its complications is considerable. It is appropriate that the Indian Government has initiated a national program for the management and prevention of diabetes and related metabolic disorders. Lifestyle modification is an effective tool for the primary prevention of diabetes in Asian Indians. The primary prevention of diabetes is urgently needed in India to curb the rising burden of diabetes.

Detection of impaired glucose tolerance and undiagnosed type 2 diabetes in UK South Asians: an effective screening strategy

AIM

We tested a stepwise, community-based screening strategy for glucose intolerance in South Asians using a health questionnaire in conjunction with body mass index (BMI). Anthropometric measurements (waist and hip circumference, sagittal diameter and percentage body fat) were then conducted in a hospital setting followed by an oral glucose tolerance test (OGTT) to identify subjects at the highest risk and analyse the factors predicting that risk.

METHODS

A health questionnaire was administered to 435 subjects in a community setting and BMI was measured. Subjects were graded by a risk score based on the health questionnaire as high, medium and low. Subjects with high and medium risk scores and a representative sample of those with low scores had anthropometric measurements in hospital followed by an OGTT. In total, 205 (47%) of the subjects had an OGTT performed.

RESULTS

In total, 48.7% of the subjects tested with an OGTT had evidence of glucose dysregulation: 20% had diabetes and 28.7% had impaired glucose tolerance (IGT). Logistic regression model explained 49.1% of the total variability. The significant predictors of diabetes and IGT were Blood Glucose Monitoring Strips (BMI), random blood glucose (BM), sibling with diabetes and presence of diagnosed hypertension or ischaemic disease. Most of these predictors along with other heredity diabetes factors create a composite score, with high predictability, as the receiver operating curve analysis shows.

CONCLUSION

We describe a simple, stepwise strategy in a community setting, based on a health questionnaire and anthropometric measurements, to explain about 50% of cases with IGT and diabetes and diagnose about 50% of cases from the population screened. We have also identified factors that predict the risk.

Zero prevalence of diabetes in camel milk consuming Raica community of north-west Rajasthan, India

OBJECTIVES

Preliminary trials reflected the low prevalence of diabetes in Raica community consuming camel milk habitually. Our objective was to describe the prevalence and clinical factors associated with impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and diabetes (DM) among adults (>or=20 years) in large population group.

DESIGN

Population based, cross sectional study

METHODS

2099 participants from different villages of north-west Rajasthan were selected using stratified sampling of a representative Raica and non-Raica Community, consuming or not consuming camel milk. Demographic, clinical, anthropometric parameters were obtained and oral glucose tolerance tests were performed in all individuals to diagnose IFG, IGT and DM. Associations were investigated using multivariate logistic regression using SPSS Version 10.0.

RESULTS

In the present study, the prevalence of diabetes in Raica community consuming camel milk (RCCM, n=501) was 0%; Raica community not consuming camel milk (RCNCM, n=554) was 0.7%; non-Raica community consuming milk (NRCCM, n=515) was 0.4% and non-Raica community not consuming camel milk (NRCNCM, n=529) was 5.5%. Stepwise logistic regression analysis showed that consumption of camel milk was statistically highly significant as protective factor for diabetes. Multiple logistic regression analysis revealed that camel milk consumption and community factor were associated with decreased prevalence of diabetes.

CONCLUSION

Camel milk consumption and lifestyle have definite influence on prevalence of diabetes. Hence, adopting such life pattern may play protective role in preventing diabetes to some extent.

Type 2 diabetes and cardiovascular risk in the UK south Asian community

A popular hypothesis for the greater prevalence of type 2 diabetes and cardiovascular disease in UK south Asians is that they have an increased susceptibility of developing insulin resistance in response to certain environmental factors, including obesity and adoption of a sedentary lifestyle. Insulin resistance is postulated as a central feature of the metabolic syndrome, culminating in type 2 diabetes, atherosclerotic vascular disease and CHD; a pathway potentially accelerated by migration/urbanisation. We describe and compare the prevalence of type 2 diabetes, cardiovascular disease and their associated risk factors in UK south Asian and white Caucasian populations to determine possible reasons for the increased preponderance of these diseases in south Asians, and highlight key evidence for optimal risk factor management. Finally, we describe a UK community-based programme that attempts to reduce the morbidity and mortality from type 2 diabetes and cardiovascular disease in south Asians through a new approach to management.

Ethnicity and diabetic heart disease

Ethnicity is a complex yet important construct and an independent risk factor for diabetic heart disease (DHD) with paramount clinical significance. Clinicians should try to better understand the role of ethnicity through more questions. The risk of DHD is modified by ethnicity through more questions. The risk of DHD is modified by ethnicity, and its management may require a culturally sensitive individualized approach. Findings from Caucasian populations cannot be fully extrapolated to other ethnic groups, thereby emphasizing the importance of future research with ethnicity-based threshold for obesity. Available limited data support the interaction between genetic predisposition, environmental risk, and lifestyle choices and disparities based on ethnicity as the likely cause for ethnic variations in DHD.

Type 2 diabetes in South Asians: a pathophysiologic focus on the Asian-Indian epidemic

There is a high prevalence of type 2 diabetes mellitus and coronary artery disease among urban and migrant Asian Indians, despite the absence of traditional risk factors. Evidence exists that Asian Indians are more insulin resistant than white persons and that insulin resistance may play an important role in the pathogenesis of these diseases. Increased visceral fat in Asian Indians is associated with increased generalized obesity, which is not apparent from their nonobese body mass index. Increased visceral fat is related to dyslipidemia and increased frequency of insulin resistance and may account for the increased prevalence of diabetes mellitus and cardiovascular disease in Asian Indians. In addition, early protein energy deprivation, as indicated by low weight at birth and at 1 year of age, may induce a state of vulnerability to the development of type 2 diabetes in later life, especially if the quantitative and qualitative aspects of nutrition and altered lifestyles during adult years pose an additional challenge.

Medicinal plants of India with anti-diabetic potential

Since ancient times, plants have been an exemplary source of medicine. Ayurveda and other Indian literature mention the use of plants in treatment of various human ailments. India has about 45000 plant species and among them, several thousands have been claimed to possess medicinal properties. Research conducted in last few decades on plants mentioned in ancient literature or used traditionally for diabetes have shown anti-diabetic property. The present paper reviews 45 such plants and their products (active, natural principles and crude extracts) that have been mentioned/used in the Indian traditional system of medicine and have shown experimental or clinical anti-diabetic activity. Indian plants which are most effective and the most commonly studied in relation to diabetes and their complications are: Allium cepa, Allium sativum, Aloe vera, Cajanus cajan, Coccinia indica, Caesalpinia bonducella, Ficus bengalenesis, Gymnema sylvestre, Momordica charantia, Ocimum sanctum, Pterocarpus marsupium, Swertia chirayita, Syzigium cumini, Tinospora cordifolia and Trigonella foenum graecum. Among these we have evaluated M. charantia, Eugenia jambolana, Mucuna pruriens, T. cordifolia, T. foenum graecum, O. sanctum, P. marsupium, Murraya koeingii and Brassica juncea. All plants have shown varying degree of hypoglycemic and anti-hyperglycemic activity.

High prevalence of diabetes, obesity and dyslipidaemia in urban slum population in northern India

BACKGROUND AND AIMS

In this study, a prevalence survey of various atherosclerosis risk factors was carried out on hitherto poorly studied rural-urban migrants settled in urban slums in a large metropolitan city in northern India, with the aim of studying anthropometric and metabolic characteristics of this population in socio-economic transition.

DESIGN

A cross-sectional epidemiological descriptive study.

SUBJECTS

A total of 532 subjects (170 males and 362 females) were included in the study (response rate approximately 40%).

METHODS AND RESULTS

In this study, diabetes mellitus was recorded in 11.2% (95% CI 6.8-16.9) of males and 9.9% (95% CI 7.0-13.5) of females, the overall prevalence being 10.3% (95% CI 7.8-13.2). Based on body mass index (BMI), obesity was more prevalent in females (15.6%; 95% CI 10.7-22.3) than in males (13.3%; 95% CI 8.5-19.5). On the other hand, classifying obesity based on percentage body fat (%BF), 10.6% (95% CI 6.4-16.2) of males and 40.2% (95% CI 34.9-45.3) of females were obese. High waist-hip ratio (WHR) was observed in 9.4% (95% CI 5.4-14.8) of males and 51.1% (95% CI 45.8-56.3) of the females. All individual skinfolds and sum of skinfolds were significantly higher in females (P<0.001). In both males and females above 30 y of age, there was a steep increase in the prevalence of high WHR, and in females, %BF was very high (particularly in %BF quartile>30%). Furthermore, total cholesterol and low-density lipoprotein cholesterol were high in both males and females. Stepwise multiple linear regression analysis showed that for both males and females BMI, WHR and %BF were positive predictors of biochemical parameters, except for HDL-c, for which these parameters were negatively associated.

CONCLUSIONS

Appreciable prevalence of obesity, dyslipidaemia, diabetes mellitus, substantial increase in body fat, generalised and regional obesity in middle age, particularly in females, need immediate attention in terms of prevention and health education in such economically deprived populations.

Intra-urban differences in the prevalence of the metabolic syndrome in southern India -- the Chennai Urban Population Study (CUPS No. 4)

AIMS

To assess the influence of socioeconomic status on the prevalence of the metabolic syndrome in an urban south Indian population in Chennai.

METHODS

The Chennai Urban Population Study is an epidemiological study involving two residential colonies in Chennai (formerly Madras) in south India representing the middle and lower income groups. All individuals > or = 20 years of age living in the colonies were invited to participate in the study. Of the total 1399 eligible subjects, 1262 individuals (479 belonging the middle income group colony and 783 from the low income group colony) participated in the study. The overall response rate was 90.2%. The main outcome measures were the prevalence rates of the various components of the metabolic syndrome.

RESULTS

There were significant differences in the socioeconomic status and lifestyle of the inhabitants of the two areas. The mean monthly income of the Tirumangalam (middle income) group (Rs8075 +/- 3859) was significantly higher than the T. Nagar (low income) group (Rs1399 +/- 916). The dietary profile of the middle income group showed higher intake of calories, fat and sugar compared to low income group (P < 0.001). The age-standardized prevalence rates of the various components of the metabolic syndrome were significantly higher in the middle compared to the low income group - diabetes (12.4 vs. 6.5%), impaired glucose tolerance (7.5 vs. 2.9%), hypertension (14.9 vs. 8.4%), obesity (males 38 vs. 13.4%, females 33.1 vs. 24.2%), hypercholesterolaemia (24.2 vs. 14.2%) and hyperinsulinaemia (16.7 vs. 6.6%) P < 0.001). Although the prevalence of coronary artery disease and hypertriglyceridaemia were higher in the middle income group, the differences did not reach statistical significance. The relative odds ratio for diabetes and impaired glucose tolerance increased significantly with increase in income while hypercholesterolaemia, hypertriglyceridaemia, hypertension and coronary artery disease showed no significant changes. Logistic regression analysis revealed that geographical area (higher social class) had a strong association with the components of the metabolic syndrome even after inclusion of other risk factors like age and body mass index in the model.

CONCLUSIONS

Significant differences exist in the prevalence of various components of the metabolic syndrome even within an urban environment and this appears to be influenced by socioeconomic status.

Prevalence of type 2 diabetes mellitus and impaired glucose tolerance in the Kashmir Valley of the Indian subcontinent

This cross-sectional population survey was undertaken to determine the prevalence of type 2 diabetes and impaired glucose tolerance in subjects aged 40 years or more in Kashmir Valley, India. The study was carried out in two phases. In phase one, 6091 randomly selected subjects, 40 years or older, from all six districts of the valley were surveyed for prevalence of known diabetes mellitus. In phase two, 5083 subjects, 40 years or older, were screened with oral glucose tolerance test for prevalence of undiagnosed (asymptomatic) diabetes mellitus and impaired glucose tolerance. Abnormalities of carbohydrate intolerance were determined as recommended by WHO. Of 6091 subjects interviewed, 115 were known cases of diabetes mellitus with an overall prevalence of 1.89% (1.98% in males and 1.77% in females). Results of glucose tolerance test revealed that mean fasting as well as mean 2 h blood glucose was significantly more in females as compared to males (4.68+/-0.91 and 6.40+/-2.12 vs. 4.49+/-0.96 and 5.94+/-2.03 mmol/l, respectively, P < 0.0001). Of 5083 subjects who were subjected to glucose tolerance test (GTT), 627 (12.34%) had an abnormal test; with 411 (8.09%) having impaired glucose tolerance (IGT) and 216 (4.25%) having diabetes mellitus. The prevalence of IGT as well as of diabetes was significantly more in females as compared to males (P < 0.001). Subjects who had family history of diabetes had a significantly higher prevalence of abnormal GTT. Prevalence of known diabetes as well as that of abnormal GTT steadily increased with age, with a highest prevalence in the age group of > or = 70 years (P < 0.001). Obese subjects had a significantly higher basal as well as 2 h blood glucose in males as well as in females. Subjects with diabetes on GTT had a higher waist/hip ratio. Overall the prevalence of diabetes as well as IGT was significantly higher in the urban population. We conclude that 1.89% of the general population have known diabetes, 4.25% have undiagnosed diabetes and 8.09% have impaired glucose tolerance test; making the total load of abnormal glucose tolerance 14.23% in Kashmir Valley. In subjects greater than 40 years of age having a family history of diabetes, obesity, higher age (50 years or above), female sex, and urban origin have more chance (odds ratio: 4.65, 2.30, 1.87, 1.49 and 1.16, respectively) of developing abnormal glucose tolerance.

Pakistan National Diabetes Survey: prevalence of glucose intolerance and associated factors in Baluchistan province

The prevalence of diabetes mellitus (DM) and impaired glucose tolerance (IGT) and their relationship to age and obesity was estimated in a population-based survey in urban and rural areas in Baluchistan province, Pakistan. Cluster sampling of 834 adults (260 men, 574 women) in the urban and 570 adults (175 men, 395 women) in the rural areas was carried out. Oral glucose tolerance tests were performed in adults aged 25 years and above. Diagnosis of diabetes and IGT was according to the World Health Organization (WHO) criteria. The overall prevalence of diabetes and IGT in both sexes was 10.8 and 11.9% (urban) versus 6.5 and 11.2% (rural), respectively. The crude prevalence of diabetes in the urban versus rural area was 11.1% in men and 10.6% in women versus 10.3% in men and 4.8% in women. As against this IGT was found in 6.5% of men and 14.3% of women in the urban area and 7.4% of men and 13.0% of women in the rural setting. The major risk factors associated with diabetes were age, positive family history (F/H) of diabetes and obesity. Central obesity was more strongly associated with diabetes in women than men.

Non-insulin-dependent diabetes in Kuwait: prevalence rates and associated risk factors

Non-insulin-dependent diabetes mellitus (NIDDM) is a major clinical and public health problem in Kuwait. The objective of the study was to determine prevalence rates of NIDDM among a representative sample of the Kuwaiti adult population aged 20 and older in two out of five governorates and identify the associated risk factors for the disease. A total of 3003 subjects (1105 men and 1898 women) were interviewed and examined by the research team during the period September 1995 to June 1996. A specially designed questionnaire was completed and the physical examination included height, weight and blood pressure measurements. Fasting blood samples were withdrawn, centrifuged immediately and refrigerated. Interpretation of oral glucose tolerance tests were based on the World Health Organisation diagnostic criteria for diabetes mellitus (1985). The denominator used for computing the prevalence was obtained from the 1995 Kuwait census. The overall prevalence of NIDDM in this study was found to be 14.8% (14.7% in men, 14.8% in women). Diabetic subjects presented at a relatively young age, prevalence rate in the age group 20-39 was 5.7% (95% confidence interval, 4.4-7.0) and in the age group 40-59 was 18.3% (95% confidence interval, 16.1-20.6). Obesity was found to be a significant risk factor, P < 0.001. The strong association of family history of NIDDM (adjusted odds ratio = 1.80, P < 0.001) suggests a genetic component. Hypertension was markedly associated with NIDDM and IGT (P < 0.001). With the demographic transition which already started among the Kuwaiti population and if the prevalence of NIDDM remains the same, aging of the population will contribute to even more upward trends in prevalence of abnormal glucose tolerance with its serious impact on morbidity and mortality among the Kuwaiti population. The strong association between hypertension and NIDDM may suggest a common approach to the prevention and control of these two conditions.

Vascular complications in long-term south Indian NIDDM of over 25 years' duration

The prevalence of vascular complications was assessed in 726 South Indian non-insulin dependent diabetes mellitus (NIDDM) patients with over 25 years' duration of diabetes. Retinopathy was detected in 52.0% of patients which included 41.7% with non-proliferative and 10.3% with proliferative diabetic retinopathy. Nephropathy was present in 12.7% and neuropathy in 69.8% of patients. While 32.8% of patients had ischaemic heart disease, the prevalence of peripheral vascular disease was only 15.4%. Multivariate logistic regression analyses showed that serum creatinine was associated with retinopathy, creatinine and post-prandial plasma glucose with nephropathy and post-prandial plasma glucose and age with neuropathy. This is one of the first reports on vascular complications in long-term diabetes from the Indian sub-continent.

Pakistan national diabetes survey: prevalence of glucose intolerance and associated factors in Shikarpur, Sindh Province

The prevalence of diabetes mellitus and impaired glucose tolerance (IGT) and their relationship to age and obesity was estimated in the rural town of Shikarpur in Sindh Province, Pakistan by a population-based survey in 1994. Oral glucose tolerance tests were performed in a stratified random sample of 967 adults (387 men, 580 women) aged 25 years and above. The diagnoses of diabetes and IGT were made on the basis of WHO criteria. The response rate was 71% for men and 80% for women. The prevalence of diabetes was 16.2% (9.0% known, 7.2% newly diagnosed) in men, and 11.7% (6.3% known, 5.3% newly diagnosed) in women. The prevalence rose with age to a peak of 30% and 21% in 65-74 year-old men and women respectively. IGT was detected in 8.2% of men and 14.3% of women. Thus, total glucose intolerance (diabetes and IGT combined) was present in 25% of subjects examined. These results indicate that glucose intolerance in South Asians can no longer be regarded as a problem confined to migrant communities. Of the 72 subjects previously known to have diabetes, none was using insulin treatment, but 57 (79%) took oral hypoglycaemic agents. Central obesity and positive family history were strongly associated with diabetes, as was prevalence of hypertension. The association with central obesity was greater for women than for men, and suggests important, modifiable risk factor(s) related to lifestyle.

Diet, central obesity and prevalence of hypertension in the urban population of south India

Central obesity is a strong predictor of higher prevalence of diabetes, hypertension and coronary artery disease among Indian immigrants to Britain. To test this hypothesis in Indians, 1569 adults, between 25 and 64 years of age, from 750 randomly selected households (representative of 0.52 million population of Trivandrum city, Kerala) were selected for this study. The response rate was roughly 95% and the sample consisted of 1497 individuals (737 males and 760 females). The survey methods included dietary diaries for 7-day food intake record, blood pressure measurements using a mercury sphygmo-manometer and anthropometric measurements. The prevalence rates of hypertension between 25 and 64 years was 189/1000 (95% confidence limits 85-360) and between 45 and 64 years was 335/1000 (95% confidence limits 210-460) which is higher than in Western populations. The prevalence was higher in males than females in the younger age groups and comparable in both sexes in the upper age groups. The prevalence of central obesity was significantly higher among male (77.2 vs. 48.9%) and female (84.0 vs. 51.4%) hypertensives compared to non-hypertensive subjects; however, mean body weight, body mass index and waist-hip ratio (WHR) were lower among Indian men compared to a British comparison group. Thus, comparison of Indian men with Britons showed that obesity, salt and alcohol intake, sedentariness, smoking and dietary fat intake do not explain the cause of higher prevalence of hypertension among South Indian men from Kerala.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in plasma insulin responses in urban and rural Indians: a study in southern-Indians

Fasting and 2 h post glucose plasma immunoreactive insulin (fasting IRI and 2 h IRI) responses were measured in urban (n = 149) and rural (n = 40) individuals with normal glucose tolerance during an epidemiological survey. In this survey, 900 urban and 1038 rural subjects were screened for glucose intolerance by capillary blood sampling. The respective response rates were 91% and 88%. We had planned to collect venous blood for IRI estimation, i.e. from 180 urban and 200 rural subjects. The compliance for the same was poor from the rural subjects and therefore the number available for IRI estimation was small. The mean +/- SD ages of the urban and rural groups were similar (35.3 +/- 9.9 and 38.6 +/- 13.1 years, respectively). The rural population had lower body mass index (BMI) and subscapular:triceps ratio compared to the urban group (p < 0.001). The total calorie consumption was lower and physical activity was higher in rural population. Fasting and 2 h insulin values in urban population were 16.6 +/- 9.4 mU l-1 and 60.6 +/- 42.5 mU l-1 and in rural 6.7 +/- 5.1 mU l-1 and 32.4 +/- 27.8 mU l-1, respectively; the values being significantly lower in the rural population (p < 0.001). Multiple regression analysis showed that in urban population the fasting insulin was correlated to the BMI and the 2h IRI to 2 h glucose, BMI and the subscapular:triceps ratio. In the rural population, similar results were obtained, except in that the 2 h IRI was influenced by the gender also.(ABSTRACT TRUNCATED AT 250 WORDS)

Impaired glucose tolerance and diabetes mellitus in a rural population in south India

In the present study the prevalence of impaired glucose tolerance and non-insulin dependent diabetes mellitus in a rural population in South India was assessed and its associations with body mass index and a family history of diabetes mellitus. Data were obtained from inhabitants of two villages located in the North Arcot District of Tamil Nadu. After an overnight fast, 467 randomly selected subjects, aged 40 years or over, were given 75 g glucose orally. After two hours the capillary glucose level was determined. The prevalence of impaired glucose tolerance (2 h value > or = 7.8 mmol/l and < 11.1 mmol/l) was 6.6% (31 subjects). Non-insulin dependent diabetes mellitus (2 h value > or = 11.1 mmol/l) was found in 23 subjects (4.9%). Of these, 53% were previously unknown. Age and sex adjusted mean body mass index was significantly higher among subjects with impaired glucose tolerance compared to subjects without glucose intolerance, with a mean difference of 1.4 kg/m2 (95% confidence interval (CI) 0.2, 2.6). A positive family history of diabetes was non-significantly higher in subjects with impaired glucose tolerance. Subjects with non-insulin-dependent diabetes mellitus had a higher mean body mass index compared to subjects with normal glucose levels with a mean difference of 1.9 kg/m2 (95% CI 0.5, 3.3). A positive family history of diabetes was more common among diabetics with a difference of 20% (95% CI 10, 30). Our findings suggest that in a considerable proportion (11.5%) of the rural South Indian population aged 40 years or over glucose intolerance is present.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic epidemiology of NIDDM among Asian Indians

Prevalence of non-insulin-dependent diabetes (NIDDM) in India was reported to be 2.3% in the urban and 1.5% in the rural areas in the early 1970s by the Indian Council of Medical Research (ICMR). Recent studies both in the migrant Indians and in the native Indians have shown the prevalence to be much higher than the above values. Similar prevalence of NIDDM in the migrant and native Indians in affluent areas suggests that Indians as an ethnic group have a high genetic risk for diabetes. Our recent study in South India showed a high prevalence of diabetes in the urban area (8.2%) versus a low prevalence of 2.4% in the rural area. Age, urban-rural factor, body mass index (BMI) and the waist:hip ratio (WHR) were positively associated with diabetes. Interestingly, the prevalence of impaired glucose tolerance (IGT) was similar in urban and rural areas (8.7% and 7.8%, respectively) despite a four-fold lower prevalence of diabetes in the latter. The ratio of new to known diabetes was 1:2 in the urban and 3:1 in the rural areas. There was a male preponderance among Indian diabetic patients. Migration from rural to urban environment with changes in dietary habits and physical inactivity may have contributed to the increased prevalence of diabetes. A high rate of familial aggregation is noted in NIDDM in India and the genetic risk of NIDDM increases with increasing family history of diabetes. In the adult offspring of diabetic parents, hyperinsulinaemia and decreased insulin sensitivity are observed before the development of glucose intolerance.

Outcome of gestational diabetes in Bengali Asians living in an east London health district

The characteristics and outcome of pregnancy complicated by gestational glucose intolerance are described in a consecutive series of 69 Bengali Asian patients and a parallel group of 22 Caucasian patients. The Bengali patients were older and of higher parity than the Caucasians and more frequently required insulin therapy. However, the outcome of pregnancy was similar in terms of antenatal clinic attendance, the number of antenatal hospital admissions, glycaemic control, birthweight and mode of delivery. Of those patients who attended for postnatal glucose tolerance test, 20% of the Bengali population demonstrated persisting abnormality of glucose tolerance, whereas no abnormalities were evident in the Caucasian group. These findings are consistent with the high prevalence and early age of onset of non-insulin-dependent diabetes in Asian populations. The World Health Organisation (WHO) criteria for the diagnosis of impaired glucose tolerance proved insufficiently sensitive for the diagnosis of gestational diabetes. This was particularly demonstrated by four patients with apparently normal glucose tolerance by WHO criteria who subsequently required insulin therapy.

The growing prevalence of non-insulin-dependent diabetes in migrant Asian populations and its implications for Asia

Many of the prevalence studies of diabetes in Asian populations are reviewed. When compared to Whites, Asians have an even greater predominance of non-insulin-dependent (NIDDM) over insulin-dependent diabetes (IDDM). Diabetes prevalence is higher among migrant Asians than in their homelands, and is often higher than in the majority population of their new homes. It is hypothesized that when a vulnerable population experiences environmental influences accompanying 'westernization', insulin resistance and eventually glucose intolerance develop. Asians are postulated to be a vulnerable ethnic group. Since many portions of Asia are also becoming westernized, it is postulated that insulin resistance and glucose intolerance will become more common in Asia. If this prediction is correct, then NIDDM will be a major health problem in Asia in the near future.

Ethnic differences in fasting plasma C-peptide and insulin in relation to glucose tolerance and blood pressure

The frequency of non-insulin-dependent diabetes mellitus (NIDDM) and of high blood pressure (or hypertension) is higher in some ethnic groups than in others for reasons that remain unclear. To investigate the mechanisms leading to these ethnic differences, plasma C-peptide and insulin concentrations were measured after overnight fast and during an oral glucose tolerance test in subjects aged 45-74 years sampled from the practice lists of two north west London health centres. Ethnic group was defined by grandparental origin as Afro-Caribbean in 106, Gujerati Indian in 107, and white European in 101. The total age-adjusted prevalence of NIDDM was 29% in the Afro-Caribbean, 30% in the Gujerati, and 3% in the white groups, respectively. Fasting C-peptide and insulin concentrations increased from the subgroup with normal glucose tolerance, through impaired glucose tolerance, to new NIDDM, and were lower again in subjects with known NIDDM. The odds ratio for new NIDDM was 1.87 (95% confidence interval 1.26-2.77) per 1 SD increase in fasting C-peptide, which was the most powerful independent indicator of new NIDDM (p = 0.0005) and accounted for the effect of ethnic group. Fasting insulin had a similarly strong effect. There was no relation between any index of insulin secretion and blood pressure or hypertension. There were differences among the ethnic groups in the C-peptide response relative to the insulin response. These results suggest that factors determining insulin secretion and its hepatic clearance, possibly including dietary fat, are the main causes of ethnic variation in rates of new NIDDM.

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.

Central rather than generalized obesity is related to hyperglycaemia in Asian Indian subjects

The relationship of body mass index and waist-hip ratio with plasma glucose concentrations during an oral glucose tolerance test (OGTT) was studied in native Indian (Asian) subjects. A total of 389 subjects (131 non-diabetic, 74 impaired glucose tolerant (IGT) and 184 Type 2 diabetic (newly diagnosed and untreated] were studied. Prevalence of obesity (BMI greater than or equal to 27.0 kg m-2 in men and greater than or equal to 25.0 kg m-2 in women, 21% and 47%, respectively) was lower in people with Type 2 diabetes than that reported in white Caucasian and migrant Asian populations. Body mass index was highest in IGT subjects (26.1 (19.7-34.3) kg m-2, median (5-95th centile] and was higher in diabetic subjects (24.2 (19.3-32.2) kg m-2) than in non-diabetic control subjects (23.5 (17.1-30.0) kg m-2). However, waist-hip ratio was higher in both IGT (0.88 (0.75-0.98)) and diabetic subjects (0.88 (0.75-1.00)) than in non-diabetic control subjects (0.83 (0.70-0.97)), with no difference between the hyperglycaemic groups. On multivariate analysis, fasting as well as 2-h plasma glucose concentrations during OGTT were found to be related to waist-hip ratio (p less than 0.01) and subscapular fat thickness (p less than 0.01) but not to body mass index (or triceps fat thickness). Thus, in native Indians central obesity seems to be a more important association of hyperglycaemia than generalized obesity.

Some recent advances in non-communicable diseases in the tropics. 2. Diabetes mellitus in the tropics

Diabetes mellitus occurs in all parts of the world, but with striking differences in prevalence and mode of presentation. This article considers the epidemiology of diabetes world-wide and specifically the pattern of diabetes in the tropics which appears to differ from that seen in Europe and the USA. Detailed epidemiological studies will help both in understanding diabetes pathogenesis and in rational management of this very important and common disease.

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.

Asian diabetics attending a British hospital clinic: a pilot study to evaluate their care

A questionnaire survey of 40 Asian and 31 British non-insulin dependent diabetics attending a hospital clinic showed that both groups remembered receiving education about diabetes (90%) but Asian diabetics knew less about glucose monitoring and diabetic complications. Asians also had a more negative attitude towards the clinic, feeling they were made to wait longer than the British. They were frustrated by a lack of communication with the staff. Forty per cent of both Asian and British diabetics felt that diabetes prevented them from leading a normal lifestyle. Twenty seven per cent of both Asian and British diabetics used herbal or alternative medicines, but Asians differed in that they used these medicines specifically for diabetes. A further sample of 50 Asians had poorer glycaemic control than a sample of British diabetics matched for age, sex and type of diabetes. It is concluded that despite receiving the same education as British diabetics, Asians did not understand it as well. The education was often not relevant to their diets or customs. This may contribute to their poorer glycaemic control. Diabetic clinic facilities need to be improved for Asian diabetics, to improve their understanding of diabetes.

The challenge of childhood diabetes mellitus in India

The prevalence of DM is about 0.4/1000 children with a lower incidence in the rural areas. Children comprise 3-5% of the total diabetics. A study of 55 pediatric cases of DM (1980-84) showed that only 22 (40%) had ketoacidosis on admission. Ten (18.2%) had onset of illness before 4 years of age. HLA antigen studies in childhood IDDM have shown a positive linkage disequilibrium with Bw21 (RR-12.7), and DR3 (RR = 16.6). Prevalence of islet cell antibodies (ICA) was 30.9% (n = 110) as compared with 0.8% in controls. Antibodies against Coxsackie B2 virus were increased (75.5% vs 46.4% in controls). The C-peptide content was substantially low. Malnutrition related DM occurs in adolescents in some parts of India. It is characterized by moderate hyperglycemia, low serum glycerol, relative insulin insensitivity, and pancreatic malformation/calcification in about 1/4 of subjects. There is no association with HLA antigens or ICA, and the precise etiology is unclear. Mortality was 3.6% in patients admitted in our hospital but is higher in other regions due to poverty and relative lack of health care facilities.

The Eluru survey: prevalence of known diabetes in a rural Indian population

Asian Indian migrants have a strikingly high diabetes prevalence but prevalence in India has been considered to be relatively low. However, there have been few recent studies, especially in rural India. A house-to-house survey was undertaken in a defined area of Eluru, a small town in South India, and in four adjoining villages. A total of 9563 subjects (4729 male, 4834 female) were surveyed, of whom 5699 lived in Eluru and 3864 in the four villages. Enquiry was made for known diabetes in each household. In all, 157 known diabetic subjects (89 male, 68 female) were ascertained. The prevalence of known diabetes was 6.1% in all subjects aged 40 or over and rose to 13.3% in the age group 50-59 years. The overall crude prevalence of known diabetes was 1.6% (1.9% male, 1.4% female). The prevalence in Eluru (1.5%) was similar to that in the four villages (1.9%). The age-adjusted rates for known diabetes in the middle-aged and elderly subjects are unexpectedly high, considering the poor socio-economic circumstances, decreased health awareness and decreased access to medical facilities, and are comparable with those of similar surveys in relatively affluent Delhi, and in Southall, London. The prevalence in rural (as well as urban) India may be much higher than previously realised. Large formal prevalence studies are urgently required.

High prevalence of diabetes in an urban population in south India

An urban population in a township in south India was screened for diabetes with an oral glucose tolerance test, every fifth person aged 20 and over registered at the local iron ore company's hospital being screened. Of 678 people (346 men and 332 women) who were tested, 34 (5%; 20 men and 14 women) had diabetes and 14 (2%; 8 men and 7 women) had impaired glucose tolerance. Thirteen subjects were already known to be diabetic. Diabetes was present in 21% (37/179) of people aged over 40. The peak prevalence (41%; 7/17) was in the group aged 55-64. A family history of diabetes was present in 16 of the 34 subjects with diabetes and nine of the 15 with impaired glucose tolerance. Diabetes was significantly related to obesity in women but not in men (57% (8/14) v 5% (1/20)). The plasma glucose concentration two hours after glucose loading was correlated to body mass index, age, and income in both sexes. The prevalence of diabetes was significantly higher in subjects whose income was above the mean. When the overall prevalence of diabetes was adjusted to the age distribution of the Indians living in Southall, London, and in Fiji it increased to 10% and 9%, respectively. The prevalence of diabetes is high among urban Indians and is comparable with the high prevalence seen in migrant Indian populations.

The HLA-D associations of type 1 (insulin-dependent) diabetes in Punjabi Asians in the United Kingdom

Type 1 (insulin-dependent) diabetes is less common in Asian Indians than in white Caucasoids. Forty-five Punjabi Asians with Type 1 diabetes and 96 racially matched control subjects were HLA-DR typed. DR3 was increased in diabetic patients vs control subjects (82% vs 38%, p less than 10(-5)) with relative risk 7.7 and etiological fraction 0.72. DR4 was increased in diabetic patients vs control subjects (31% vs 7%, p less than 0.003) with relative risk 5.7 and etiological fraction 0.26. DR2 showed a negative association (relative risk 0.19, etiological fraction -0.28), as did DR7 (relative risk 0.21, etiological fraction -0.33). HLA-DQ beta-chain gene probing using restriction enzyme BamHI in 43 diabetic patients and 90 control subjects showed that the DR1-associated 6.2 and 3.2 kb fragments were less common in diabetic patients than in the control subjects (12% vs 36%, p less than 0.02). A 12 kb fragment was associated with DR4 in both diabetic patients and control subjects. DR3 is the major susceptibility factor for Type 1 diabetes in Punjabi Asians and DR4 is a second marker. Gene probing indicates that the same DR4 subset is associated with the condition as in white Caucasoids. DR1 and its associated DQ beta restriction fragments are reduced in Asian Type 1 diabetic patients making it unlikely that DR1 haplotypes carry a predisposing factor in this racial group. We conclude that the genetic component of Type 1 diabetes in Punjabis shows differences from that of the white Caucasoid population and that the lower frequency of DR4 in this population may contribute to the lower prevalence of Type 1 diabetes.