Family histories in Asian and European non-insulin-dependent diabetic patients

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.

Diabetes in India: what is different?

PURPOSE OF REVIEW

The purpose of this study was to review the epidemiology and pathogenesis of diabetes in Asian Indians with a particular focus on 'Asian Indian type 2 diabetes phenotype'.

RECENT FINDINGS

The prevalence of diabetes is rapidly increasing among Asian Indians, particularly in the past two decades. The diabetes rates in urban India now exceed that seen in Indians migrated to developed nations. Urbanization, changes from traditional healthier diets to high-refined carbohydrate intake, and sedentary lifestyle have contributed to this steep increase in the prevalence of diabetes in India. Type 2 diabetes among Asian Indians is characterized by onset at a younger age, greater abdominal obesity despite relatively lower BMI, greater insulin resistance, and early decline in beta cell function. Asian Indians are also at a higher risk for premature coronary artery disease.

SUMMARY

The clinical profile of type 2 diabetes in Asian Indians differs from Caucasians with higher central obesity, increased inflammatory markers such as high sensitive C-reactive protein, greater insulin resistance, early loss of beta cell function, and a higher risk of coronary artery disease. Mechanistic studies are needed to characterize the pathophysiology of the Asian Indian phenotype.

Lean people with dysglycemia have a worse metabolic profile than centrally obese people without dysglycemia

AIM

This study compared metabolic profiles of Asian Indians with normal waist circumference (WC) and dysglycemia versus those with high WC without dysglycemia.

SUBJECTS AND METHODS

In 2,350 subjects ≥20 years of age from the Chennai Urban Rural Epidemiology Study with full anthropometric and biochemical characterization, high WC was defined as ≥90 cm in males and ≥80 cm in females. Dysglycemia was defined as prediabetes (fasting plasma glucose ≥100 mg/dL and/or 2-h plasma glucose ≥140 mg/dL) or diabetes (fasting plasma glucose ≥126 mg/dL, 2-h plasma glucose ≥200 mg/dL, or treatment for diagnosed diabetes). Coronary artery disease (CAD) was defined as known myocardial infarction or Q waves on electrocardiography. Multivariable logistic regression models were used to explore factors associated with CAD.

RESULTS

Of the subjects, 260 (11.1%) had dysglycemia with normal WC, and 679 (28.9%), had high WC without dysglycemia. Compared with subjects with high WC without dysglycemia, those with dysglycemia/normal WC, adjusted for age, were more likely to be males (P<0.001) and have higher systolic blood pressure (P<0.05), higher serum triglycerides (P<0.001), higher tumor necrosis factor-α (P<0.001), lower high-density lipoprotein cholesterol (P<0.05), and higher prevalence of CAD (6.3% vs. 2.0%; odds ratio 3.25 [95% confidence interval 1.52-6.94]; P=0.002).

CONCLUSIONS

Dysglycemia is associated with a worse cardiometabolic profile than central obesity alone.

Association of His1085His INSR gene polymorphism with type 2 diabetes in South Indians

BACKGROUND AND OBJECTIVE

The INSR gene, which encodes the insulin receptor, is a candidate gene for type 2 diabetes (T2D). The objective of the present study was to sequence some of the crucial exons in the INSR gene such as exon 2, which encodes the insulin-binding domain of the INSR protein, and exons 17-21, which encode the protein tyrosine kinase domain for mutations/polymorphisms, and to study their association with T2D in the South Indian population.

SUBJECTS AND METHODS

The INSR gene was sequenced in 25 normal glucose-tolerant (NGT) and 25 T2D subjects, and the variant found was genotyped by polymerase chain reaction-restriction fragment length polymorphism in 1,016 NGT and 1,010 T2D subjects, randomly selected from the Chennai Urban Rural Epidemiology Study.

RESULTS

Only one previously reported polymorphism, His1085His [rs1799817, (C→T)], in exon 17 was detected by sequencing. The frequency of the "T" allele of the His1085His polymorphism was significantly lower in the T2D subjects (31%) compared with the NGT subjects (35%) and showed significant protection against diabetes (odds ratio 0.85, 95% confidence interval 0.75-0.97, P=0.019). Regression analysis according to a recessive model taking the CC+CT genotype as the reference showed that the TT genotype was protective against diabetes (odds ratio 0.71, 95% confidence interval 0.50-0.99, P=0.048). Adjusting this P value by the number of competing models (three) using Bonferroni's correction, we found that the association finding did not remain significant.

CONCLUSIONS

The "T" allele of the His1085His polymorphism in the INSR gene shows significant protection against diabetes. This study gains importance because there are no data available to date on the role of INSR variants in T2D in the Indian population.

Prevalence and clinical profile of autosomal dominant type 2 diabetes from a diabetes centre in India

AIMS

To study the prevalence, and clinical profile of autosomal dominant (AD) inherited forms of type 2 diabetes mellitus (T2DM).

METHODS

Detailed pedigree charts were drawn on 510 consecutive T2DM subjects attending a tertiary care diabetes centre in South India. Clinical and biochemical features of T2DM subjects with and without AD inheritance were compared.

RESULTS

Overall, 36.1% of T2DM had one parent with diabetes, in 10.6%, both parents had diabetes and 10.2% had features of AD. Age at diagnosis of diabetes was the lowest among AD group compared to other groups (p for trend <0.001). Only 22.6% of T2DM with AD inheritance had age at diagnosis of diabetes below 25 years and in 26.4%, it was diagnosed above 45 years. There were no significant differences in the clinical features, including prevalence of diabetic complications, between T2DM with and without AD inheritance.

CONCLUSIONS

In this clinic-based study, 10.2% of T2DM subjects had evidence of AD inheritance. While the AD cases occurred at younger age, older age at diagnosis was not uncommon. Clinical features, including complications, did not differ between the T2DM patients with or without AD.

Peroxisome proliferator-activated receptor-gamma co-activator-1alpha (PGC-1alpha) gene polymorphisms and their relationship to Type 2 diabetes in Asian Indians

AIMS

The objective of the present investigation was to examine the relationship of three polymorphisms, Thr394Thr, Gly482Ser and +A2962G, of the peroxisome proliferator activated receptor-gamma co-activator-1 alpha (PGC-1alpha) gene with Type 2 diabetes in Asian Indians.

METHODS

The study group comprised 515 Type 2 diabetic and 882 normal glucose tolerant subjects chosen from the Chennai Urban Rural Epidemiology Study, an ongoing population-based study in southern India. The three polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Haplotype frequencies were estimated using an expectation-maximization (EM) algorithm. Linkage disequilibrium was estimated from the estimates of haplotypic frequencies.

RESULTS

The three polymorphisms studied were not in linkage disequilibrium. With respect to the Thr394Thr polymorphism, 20% of the Type 2 diabetic patients (103/515) had the GA genotype compared with 12% of the normal glucose tolerance (NGT) subjects (108/882) (P = 0.0004). The frequency of the A allele was also higher in Type 2 diabetic subjects (0.11) compared with NGT subjects (0.07) (P = 0.002). Regression analysis revealed the odds ratio for Type 2 diabetes for the susceptible genotype (XA) to be 1.683 (95% confidence intervals: 1.264-2.241, P = 0.0004). Age adjusted glycated haemoglobin (P = 0.003), serum cholesterol (P = 0.001) and low-density lipoprotein (LDL) cholesterol (P = 0.001) levels and systolic blood pressure (P = 0.001) were higher in the NGT subjects with the XA genotype compared with GG genotype. There were no differences in genotype or allelic distribution between the Type 2 diabetic and NGT subjects with respect to the Gly482Ser and +A2962G polymorphisms.

CONCLUSIONS

The A allele of Thr394Thr (G --> A) polymorphism of the PGC-1 gene is associated with Type 2 diabetes in Asian Indian subjects and the XA genotype confers 1.6 times higher risk for Type 2 diabetes compared with the GG genotype in this population.

Association of physical inactivity with components of metabolic syndrome and coronary artery disease--the Chennai Urban Population Study (CUPS no. 15)

AIM

The aim of the study was to assess the influence of physical activity on the components of metabolic syndrome (MS) in an urban south Indian population in Chennai.

METHODS

The Chennai Urban Population Study (CUPS) is an epidemiological study involving two residential areas in Chennai in South India. Of the total of 1399 eligible subjects (age > or = 20 years), 1262 individuals participated in the study. MS was diagnosed based on modified Adult Treatment Panel (ATP) III guidelines. Details about the physical activity were collected using questionnaire, which included job-related and leisure-time activities, and specific questions on exercise. Study individuals were then graded as light, moderate and heavy using a scoring system. We assessed the relationship between the grades of physical activity and the components of MS and coronary artery disease (CAD). Insulin resistance was calculated using the homeostasis assessment model (HOMA-IR).

RESULTS

Prevalence of most of the components of MS (diabetes P < 0.001, obesity P = 0.003, abdominal obesity P < 0.001 and hypertension P < 0.001) and MS per se (P < 0.001) increased significantly with decrease in physical activity. Among non-diabetic subjects, HOMA-IR was significantly higher in subjects who did light-grade activity compared with heavy-grade activity (P = 0.041). Logistic regression analysis revealed physical activity to be significantly associated with MS [heavy activity: reference, moderate activity, odds ratio (OR) 1.639, (P = 0.017); light activity: OR 2.289, (P < 0.001)]. Subjects in the light-grade activity group also had higher odds of CAD (OR 2.42, 95% confidence interval 1.40, 4.24, P = 0.011), compared with the heavy-grade activity group.

CONCLUSION

Physical inactivity is associated with the components of MS and CAD in this urban south-Indian population. Lifestyle changes focusing on increasing physical activity could help to prevent the exploding epidemic of MS and CAD in India.

Lack of excess maternal transmission of type 2 diabetes in a Korean population

The purpose of this study was to assess the familial clustering of type 2 diabetes and to investigate the presence of excess maternal transmission of type 2 diabetes in Korea. The medical records of 56,492 subjects (31,680 men and 24,812 women), who attended the Health Promotion Center were examined. The subjects were questioned about their parents' diabetes status. All study subjects were classified into the three groups (normal fasting glucose (NFG), impaired fasting glucose (IFG), and diabetes). Offspring with paternal diabetes (odds ratio 2.54, 95% CI 2.22-2.91, P < 0.001) and those with maternal diabetes (odds ratio 3.10, 95% CI 2.76-3.49, P < 0.001) were at increased risk for diabetes when compared to subjects without parental diabetes and adjusted for other clinical and biochemical variables. Offspring with bilineal parental diabetes were at a greater risk for diabetes (odds ratio 6.09, 95% CI 4.55-8.16, P < 0.001) when compared to subjects without parental diabetes. In both genders, offspring with maternal diabetes showed no increased risk for diabetes (odds ratio 1.22, 95% CI 0.92-1.37, P + 0.266 in men; odds ratio 1.31, 95% CI 0.95-1.81, P = 0.104 in women) when compared with those with paternal diabetes. The data suggested that parental type 2 diabetes was an independent risk factor for offspring type 2 diabetes in this Korean population. Excess maternal transmission of type 2 diabetes was not observed.

Effects of genetic predisposition on proinsulin responses in Asian Indians

This study was done in adult offspring of two diabetic (NIDDM) parents (ODP) to look for changes in specific insulin (insulin) and proinsulin responses due to strong familial background and also in different states of glucose intolerance. Equal numbers (20 in each group) of ODP with normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and diabetes (DM) were chosen. Twenty, age and BMI matched healthy controls, without family history of diabetes, were also studied for comparison. Plasma specific insulin and proinsulin were measured by radioimmunoassays in fasting and 120' plasma samples collected during the GTT. Proinsulin to insulin ratio were calculated. Insulin resistance (IR-HOMA) was calculated. In NGT, fasting proinsulin-insulin ratio was significantly higher than the control value (P = 0.023). Insulin values at 120' was higher than control values, though it did not reach statistical significance. Proinsulin at 120' was higher than controls (P = 0.016). In IGT, the fasting proinsulin to insulin ratio, the 120' proinsulin and insulin values were higher than controls (P = 0.048, 0.0013 and 0.0001, respectively). Fasting proinsulin-insulin ratio in IGT was similar to the value in NGT. In diabetic subjects proinsulin concentrations were significantly higher than controls at fasting (P = 0.0004), and 120' (P = 0.0007). The fasting values were higher compared to NGT also (P = 0.037). Proinsulin-insulin ratios were higher than the values in controls (P = 0.0008), IGT (P = 0.047) and NGT (P = 0.05). Diabetic subjects had higher fasting insulin values compared to the control values although between the groups no statistical significance was found (P = 0.22 by Kruscall Wallis test). At 120' both insulin and proinsulin values increased from NGT to IGT, but with development of diabetes a reduction was seen in the responses. Insulin resistance (IR-HOMA) increased steadily from NGT to diabetes. The difference between NGT and controls in IR was not statistically significant. This study of Asian Indian offspring of diabetic parents has shown that genetic predisposition to diabetes resulted in increased proinsulin to insulin ratio at the fasting state. Absolute hyperproinsulinaemia occurred only with development of diabetes.

Prevalence of retinopathy in non insulin dependent diabetes mellitus at a diabetes centre in southern India

A cohort of 6792 NIDDM patients attending a diabetes centre at Madras in South India was screened using a combination of retinal photography and clinical examination by retinal specialists. A total of 2319 patients (34.1%) had evidence of retinopathy. This included 2090 patients (30.8%) with non-proliferative diabetic retinopathy including 435 patients (6.4%) with maculopathy and 229 patients (3.4%) with proliferative diabetic retinopathy. Multiple logistic regression analyses showed that duration of diabetes, glycosylated haemoglobin, type of treatment (insulin treatment versus non-insulin treatment), systolic and diastolic blood pressures and serum creatinine, showed a positive association with retinopathy while body mass index (BMI) showed an inverse association. The prevalence rates of retinopathy in Southern Indians are comparable to those seen in Europeans. However in view of the high prevalence of diabetes in the Indian sub-continent, diabetic retinopathy could become a formidable challenge in the future.

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.

Maternally inherited diabetes mellitus: the role of mitochondrial DNA defects

Several studies have shown a consistent maternal effect in the transmission of Type 2 diabetes (NIDDM). The mitochondrial encephalomyopathies are a group of diseases characterized by maternal inheritance and a variety of mitochondrial DNA defects. Diabetes is a feature of some of these disorders and therefore the hypothesis arose that mitochondrial DNA mutations might play a role in patients with diabetes but no other features of neurological disease. Recent studies have confirmed that a specific point mutation in the gene encoding the mitochondrial tRNA for leucine segregates with diabetes and nerve deafness in families from the UK, Holland, France and Japan. Mitochondrial gene deletions have also been reported. Affected subjects present with progressive insulin deficiency and may fall into the broad classifications of either Type 1 (IDDM) or Type 2 diabetes (NIDDM). Future studies are aimed at searching for other mitochondrial gene defects in diabetes and attempting to explain the mechanism of hyperglycaemia by the development of phenotypic expression systems. Although an exciting development in the genetics of diabetes, currently described mitochondrial mutations do not fully explain the maternal effect in the transmission of Type 2 diabetes.

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)

Mitochondrial gene defects in patients with NIDDM

Non-insulin-dependent diabetes mellitus (NIDDM) has a strong genetic component and maternal factors have recently been implicated in disease inheritance. The mitochondrial myopathies are a group of diseases which often show maternal inheritance as a result of mtDNA defects; some patients have impaired glucose tolerance. Occasional families with maternally inherited diabetes and deafness associated with a deletion or point mutation of mtDNA have been reported. To assess the importance of mitochondrial gene defects in NIDDM, 150 unrelated diabetic subjects from Wales, UK and 68 unrelated patients with diabetes and at least one affected sibling from England, UK were studied. Southern blot analysis did not show any large mtDNA deletions or duplications. One patient had a mutation in the mitochondrial tRNAleu(UUR) gene at bp 3243. This mutation is commonly associated with the syndrome of mitochondrial encephalomyopathy, lactic acidosis and stroke like episodes (MELAS). Study of this patient and his siblings showed a distinct form of late-onset diabetes associated with nerve deafness but no clinical features of the MELAS syndrome. No diabetic subject was shown to have the mtDNA mutation at position 8344 (tRNA(lys)) which has previously been described in the syndrome of mitochondrial encephalomyopathy and red-ragged fibres (MERRF). The role of other mitochondrial gene defects in diabetes and the pathophysiological basis of glucose intolerance in patients with the MELAS mutation requires further elucidation.

Suspected synergism between consanguinity and familial aggregation in type 2 diabetes mellitus in Saudi Arabia

A retrospective study of 210 cases of diabetes was carried out at King Khalid University Hospital diabetes clinic to delineate etiologic factors in non-insulin dependent diabetes mellitus (NIDDM). Standardised detailed questionnaires were administered to both cases and controls and the information sought included general demographics, dietary patterns, anthropometric values, family history, consanguinity and familial aggregation of Diabetes Mellitus (DM). Familial aggregation yielded an odds ratio of 6:2 which suggests a causal association with DM. A synergistic effect of familial aggregation was observed which needs to be further explored in future studies.

Prevalence of diabetes in different regional and religious south Asian communities in Coventry

The prevalence of Type 2 (non-insulin-dependent) diabetes in different South Asian (Asian) communities was compared during the Coventry Diabetes Study, a cross-sectional house to house screening programme for diabetes. Screening was by capillary whole blood glucose measurement with oral glucose tolerance tests when concentrations were greater than or equal to 6.0 mmol l-1 within 2 h of a meal or greater than or equal to 5.0 mmol l-1 2 h or more after a meal and a random 10% of others. Of the 4395 resident Asians, 94% were represented by five communities: Punjabi Sikhs, Punjabi Hindus, Gujerati Moslems, Gujerati Hindus, and Pakistani Moslems. Response to screening was 77-89% and to glucose tolerance test was 59-79%. Differences in anthropometry, socioeconomic circumstances, and migratory patterns were found, but all groups had a higher prevalence of Type 2 diabetes than Europeans. Gujerati Moslems had the highest age-adjusted prevalence (per 1000) of Type 2 diabetes (males: 160 (95% CI 107-228), females: 204 (95% CI 144-283)) when compared with the other Asian groups (males: Punjabi Sikhs 89(72-110), Pakistani Moslems 91(67-120), Gujerati Hindus 84(57-120), Punjabi Hindu 113(74-171); females: Punjabi Sikhs 75(60-94), Pakistani Moslems 103(78-133), Gujerati Hindus 88(62-122), Punjabi Hindu 116(77-174)). That all the Asian groups had a high prevalence of diabetes, in spite of their known dietary, cultural, and socioeconomic differences, suggests that the Asian predisposition to Type 2 diabetes is inherited although environmental factors may be necessary for this to be expressed.

A comparison of the clinical features and vascular complications of diabetes between migrant Asians and Caucasians in Leicester, U.K

907 consecutive patients, (456 Asian and 451 Caucasian) were assessed, employing a similar methodology to the multi-centre WHO study. The Asians were older at diagnosis (46.5 years compared with 40.6 years, P less than 0.01); they had a shorter duration of diabetes (6.3 years versus 11.4 years, P less than 0.1), a higher rate of diabetes in the first degree relatives (29.5% compared with 16%, P less than 0.1), less ketonuria at presentation (85.3% compared with 47.8%, P less than 0.1), and fewer were treated with insulin (31.4% compared with 68.7%). Comparing the prevalence of complications between Asians and Caucasians, the ischaemic heart disease rate was similar; peripheral vascular disease was less (3.7% Asian, 9.3% Caucasian, P less than 0.05); retinopathy was less (11.6% Asian, 32.3% Caucasian, P less than 0.01) but renal disease was more (22.3% Asian, 12.6% Caucasian, P less than 0.01). After adjusting for age, sex, duration of diabetes, age at diagnosis, hypertension, smoking and treatment with or without insulin, these differences remained significant. Multivariate logistic regression failed to reveal a significant contribution due to any of the above variables, or due to body mass index (BMI), haemoglobin A (HbA1), or physical activity in the prevalence of complications in Asians compared with Caucasians. Marked heterogeneity in the complications of diabetes in the two ethnic groups studied was found, but must be confirmed from population-based studies.

Glycosuria and diabetes mellitus in children and adolescents in south India

In Madras city (India) 10,513 school students between 3 and 20 yr of age were investigated for glycosuria and its causes. While no previously known cases of diabetes mellitus of any type were encountered, four students (0.038%) in the survey population were found to have glycosuria. One (0.009%) had renal glycosuria, two (0.019%) were possibly NIDDY (MODY) and one (0.009%) had transient glycosuria while receiving anti-tuberculous chemotherapy. It is therefore concluded that neither diabetes mellitus nor glycosuria of non-diabetic causes is a crucial health problem in Indian children and adolescents. While the reasons for this are not known, further research in this field could be of global interest.

Importance of maternal history of non-insulin dependent diabetic patients

OBJECTIVE

To assess the family history of diabetes in non-insulin dependent diabetes mellitus with particular emphasis on parental phenotype.

DESIGN

Family histories were obtained from an existing computerised database and supplemented by postal questionnaires.

SETTING

Diabetic service of a provincial teaching hospital.

SUBJECTS

A total of 1326 patients with non-insulin dependent diabetes who had been referred to diabetic clinics over the past 10 years and from whom data had been collected for inclusion in the database, of whom 347 had affected first degree relatives. Nineteen non-white patients were excluded because of the differential hereditability of the disease, and 230 (70%) patients with an affected first degree relative responded to the postal questionnaire.

RESULTS

Mothers were implicated in significantly more cases than fathers in patients with a single affected parent: 125 mothers and 48 fathers from database; 82 mothers and 34 fathers from postal questionnaire; p less than 0.001 in both cases.

CONCLUSIONS

Maternal influences seem to have an important role in the inheritance of non-insulin dependent 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.

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.