Do known risk factors explain the higher coronary heart disease mortality in South Asian compared with European men? Prospective follow-up of the Southall and Brent studies, UK

Aims/hypothesis We examined prospectively whether measured risk factors can explain the higher CHD mortality in South Asians compared with Europeans.Materials and methods Conventional CHD risk factors and those associated with insulin resistance were measured in 1,787 European and 1,420 South Asian men aged 40 to 69 years at baseline in the population-based Southall and Brent studies (London) between 1988 and 1990. Participants were followed up for mortality.Results By February 2006, there were 202 CHD deaths (108 Asian, 94 European). South Asian men had double the CHD mortality of European men in Cox regression analyses adjusted for age, smoking, and cholesterol (hazard ratio [HR] 2.14, 95% CI 1.56–2.94, p<0.001). Nearly half of all South Asian CHD deaths versus 13% of deaths among Europeans were among persons with diabetes. Asian men had greater CHD mortality than Europeans, both in the with- and the without-diabetes categories at baseline. CHD mortality remained significantly higher in South Asian men in multivariable models that adjusted for conventional risk factors and diabetes and/or impaired glucose regulation, features of insulin resistance, or the metabolic syndrome (HR 1.6–1.9). Accounting for co-morbidity and socio-economic status did not materially alter the findings.Conclusions/interpretation These data confirm that South Asian men have significantly higher CHD mortality than their European counterparts, while indicating that neither conventional risk factors, nor insulin resistance parameters or metabolic syndrome criteria as currently defined can account for this excess risk. The contribution of unmeasured factors to the elevated vascular risk in South Asians should be addressed in future studies.     

Diabetes in the Elderly: An Under-diagnosed Condition

The proportion of the population aged 65 years and over is increasing. The Coventry Diabetes Study was able to investigate the prevalence of diagnosed and undiagnosed diabetes among elderly (aged ≥ 65 years) Europeans (n = 1600) and South Asians (n = 288) in Foleshill, Coventry. The total prevalence of diabetes was higher in South Asians than Europeans among males (30.7 (95% CI 24.0–37.9)% vs 7.7 (95% CI 5.8–10.0)%, respectively) and females (24.0 (95% CI 17.5–32.4)% vs 12.5 (95% CI 10.6–14.8)%, respectively). The proportion with diagnosed diabetes was higher among South Asians than Europeans (55% vs 33%, p < 0.001), possibly because of their earlier onset. These findings suggest that detection of diabetes in elderly Europeans in urban areas may be inadequate.     

Parity, ethnic group and the prevalence of type 2 diabetes: the Coventry Diabetes Study.

The prevalence of Type 2 (non-insulin-dependent diabetes) in relation to parity was compared among South Asian (Asian) and European women during a cross-sectional house-to-house screening programme for diabetes in Foleshill, Coventry, UK. The parity of female residents was ascertained in 8 of the 12 areas visited. These areas contained 2096 European (68 with diabetes diagnosed) and 1148 Asian women (95 with diabetes diagnosed). Crude prevalence of Type 2 diabetes was 3.2% and 14.7% in Europeans aged 30-64 years and > or = 65 years, respectively, and 10.9% and 36.5% in similarly aged Asians, respectively. In those aged 30-64 years, the age and body mass index adjusted prevalence of Type 2 diabetes was highest among nulliparous (Europeans 4.4%, Asians 16.3%) and grand multiparous (parity > or = 5: Europeans 6.3%, Asians 16.5%) women when compared with women who had had 1 or 2 deliveries (Europeans 0.9%, Asians 3.3%, p < 0.001, both ethnic groups). However, parity had no effect among women aged > or = 65 years.     

Comparison of prevalence and risk factors for microalbuminuria in South Asians and Europeans with Type 2 diabetes mellitus

Although Type 2 (non-insulin-dependent) diabetes mellitus (Type 2 DM) is more common in South Asians than in Europeans in the UK, very little is known about complications and their risk factors in South Asians. We sought microalbuminuria in a cross-sectional study of 583 European and 889 South Asian Type 2 DM clinic attenders to Ealing Hospital, London, over 1 year. Albumin/creatinine ratios were measured in early morning urines. Prevalence of microalbuminuria was greater in South Asians compared to Europeans (40 % versus 33 % in men, p = 0.003, and 33 % versus 19 % in women, p < 0.0001). Glycaemic control was worse and prevalence of hypertension, retinopathy and heart disease was higher in South Asians. Key risk factors for microalbuminuria in both ethnic groups were glycaemic control, diabetes duration, blood pressure, triglyceride and retinopathy, but none accounted for the higher microalbuminuria prevalence in South Asians. Age and sex adjusted odds ratio for microalbuminuria was 1.78 (95 % CI 1.02, 2.82, p = 0.02) in South Asians versus Europeans. After adjustment for confounders, this became 2.07, 95 % CI 1.13, 3.79, p = 0.02. We conclude that microalbuminuria is more common in South Asians with Type 2 DM than in Europeans and, although risk factor relationships appeared similar in both groups, and some risk factors were more prominent in South Asians, this cannot account for the high prevalence of microalbuminuria observed in South Asians. © 1998 John Wiley & Sons, Ltd.     

Diabetes Care in South Asian and White European Patients with Type 2 Diabetes

Aspects of diabetes care in South Asian and white European patients with Type 2 diabetes attending a hospital review clinic were explored. Among the clinic population of 1710 patients, 25B (15%) were of South Asian origin. A significantly greater proportion (95% CI for difference in proportions 8–22%) of these patients was treated with oral hypoglycaemic drugs than in white Europeans, in whom there was a correspondingly greater proportion receiving insulin treatment. In a case-control study, where 154 patients in each racial group were stratified according to treatment regimen, significantly more South Asian patients (13/30 vs 6/30, p < 0.05) on insulin were treated with a once-daily regimen. Despite these observed differences in treatment of diabetes, glycaemic control was no worse in South Asian patients when compared to their white European counterparts. South Asian diabetic patients attending hospital diabetes clinics in the UK can experience similar levels of glycaemic control to white Europeans.     

Higher Levels of Microproteinuria in Asian Compared with European Patients with Diabetes Mellitus and Their Relationship to Dietary Protein Intake and Diabetic Complications

Asian patients with diabetes have a higher prevalence of renal disease than their European counterparts. The aim of the study was to investigate the pattern of the renal excretion of proteins in 70 Asian and 70 European patients with diabetes and to relate it to dietary intake of protein and prevalence of diabetic complications. Compared with matched Europeans, Asian patients had an increased urinary excretion of albumin and transferrin (p < 0.02) with 14 Asians and 6 Europeans having significant microalbuminuria (> 30 μg min^?1). In 12 Asians and all 6 Europeans this was associated with complications from diabetes, particularly vascular. Asian patients had significantly more ischaemic heart disease (p < 0.001) but less neuropathy (p < 0.001) and retinopathy (p < 0.05) than their matched European counterparts. Asian diets were lower in protein (median (range) Asian vs European: 12.5% (6–29%) vs 19% (11–27%); p <0.01) and carbohydrate but higher in fat than European diets. There was no correlation between dietary protein intake and excretion of any of the urinary proteins measured. However, a significant correlation was found in Asians between protein intake and length of residence in the UK (p < 0.005). Unless ways to reduce complications can be found then future allocation of resources will need to take this into consideration in areas with large Asian communities.     

Metabolic syndrome and coronary heart disease in South Asians, African-Caribbeans and white Europeans: a UK population-based cross-sectional study

Aims/hypothesis The aim of this study was to study differences in the prevalence of the metabolic syndrome and its associations with prevalent CHD according to ethnicity and sex.Methods We performed a combined analysis of two population-based cross-sectional studies conducted between 1988 and 1991 that followed identical protocols. Participants (aged 40–69 years) comprised 2,346 Europeans (76% male), 1,711 South Asians (83% male) and 803 African-Caribbeans (57% male) resident in west London. Fasting blood, overnight urine collection, clinical and anthropometric measurements were performed. Clinical history or major ECG changes defined prevalent CHD. The metabolic syndrome was defined according to the criteria recommended by the World Health Organization (WHO) and the National Cholesterol Education Programme (NCEP).Results The prevalence of the metabolic syndrome was highest in South Asians (WHO, men 46%, women 31%; NCEP, men 29%, women 32%) and lowest in European women (WHO, 9%; NCEP, 14%). The prevalence of CHD was 10% in South Asian men, 9% in European men, 5–6% in African-Caribbeans and European women, and 2% in South Asian women. The metabolic syndrome was associated with prevalent CHD in European men [NCEP, odds ratio (OR)=1.6, 95% CI 1.2–2.4; WHO, OR=1.7, 95% CI 1.2–2.5] and South Asian men (NCEP, OR=2.1, 95% CI 1.5–3.1; WHO, OR=1.6, 95% CI 1.1–2.3). Associations with CHD were weaker in African-Caribbeans and were inconsistent among European women.Conclusions/interpretation The current definitions of the metabolic syndrome give an inconsistent picture of cardiovascular disease risk when applied to different ethnic groups within the UK. Prospective studies are needed to validate workable ethnic-specific definitions.Electronic Supplementary Material Supplementary material is available in the online version of this article at     

Random Blood Glucose as a Screening Test for Diabetes in a Biethnic Population

Screening asymptomatic subjects for diabetes is often undertaken using a random capillary whole blood sample for glucose estimation. The test characteristics of this method for screening were assessed using a glucose oxidase method among 3425 Europeans and 3469 South Asians who gave such a sample during the Coventry Diabetes Study, a house-to-house diabetes prevalence study. Glucose tolerance tests were performed on those with a high blood glucose and 10% of others. Previously undiagnosed diabetes was found in 73 Europeans and 110 South Asians. If the random glucose was ≥ 7.0 mmol l^?1, 8.0% of Europeans and 6.7% of South Asians would need a further diagnostic test and the sensitivity of this cut-off was 51.7 (95.0% CI: 43.5–59.9)% in Europeans and 68.4 (60.6–76.2)% in South Asians. Sensitivity was increased in South Asians but not Europeans by defining the time since last meal (South Asians < 2 h: 83.9 (72.3–92.0)%; ≥ 2 h: 54.9 (42.7–66.8)%). Sensitivity was poorest among Europeans aged ≥ 65 years (40–64 years 69.0 (49.2–84.7)%, ≥ 65 years 49.4 (38.2–60.6)%). Screening asymptomatic individuals using an isolated capillary random whole blood glucose measure is a poor test for diabetes, although slight improvement can be obtained among South Asians by testing within 2 h of a meal.     

Mortality of South Asian patients with insulin-treated diabetes mellitus in the United Kingdom: a cohort study.

AIMS: To investigate mortality in South Asian patients with insulin-treated diabetes and compare it with mortality in non South Asian patients and in the general population. METHODS: A prospective cohort study was conducted of 828 South Asian and 27 962 non South Asian patients in the UK with insulin-treated diabetes diagnosed at ages under 50 years. The patients were followed for up to 28 years. Ethnicity was determined by analysis of names. Standardized mortality ratios (SMRs) were calculated, comparing mortality in the cohort with expectations from the mortality experience of the general population. RESULTS: SMRs were significantly raised in both groups of patients, particularly the South Asians, and especially in women and subjects with diabetes onset at a young age. The SMRs for South Asian patients diagnosed under age 30 years were 3.9 (95% CI 2.0-6.9) in men and 10.1 (5.6-16.6) in women, and in the corresponding non South Asians were 2.7 (2.6-2.9) and 4.0 (3.6-4.3), respectively. The SMR in women was highly significantly greater in South Asians than non South Asians. The mortality in the young-onset patients was due to several causes, while that in the patients diagnosed at ages 30-49 was largely due to cardiovascular disease, which accounted for 70% of deaths in South Asian males and 73% in females. CONCLUSIONS: South Asian patients with insulin-treated diabetes suffer an exceptionally high mortality. Clarification of the full reasons for this mortality are needed, as are measures to reduce levels of known cardiovascular disease risk factors in these patients.     

Risk of diabetes-related amputation in South Asians vs. Europeans in the UK.

AIMS: To compare the risk of and risk factors for diabetes-related amputation in South Asians and Europeans. METHODS: This was a population-based case control study based in the health districts of Bolton, Oldham and Central Manchester in the UK. Cases with diabetes-related amputation performed between 1992 and 1997 (n = 172) and controls with diabetes and no amputation (n = 376) were selected from the primary care-based North-west Diabetes Foot Study database. Risk factor data were also collected. RESULTS: Age at diagnosis adjusted odds ratio (OR) of amputation in South Asians compared with Europeans was 0.26, 95% confidence interval (CI) 0.11-0.65, P = 0.004. In the control population, South Asians were less likely than Europeans to have peripheral vascular disease (PVD) (9% vs. 24%, P = 0.02), neuropathy (30% vs. 54%, P = 0.003), and less likely to have ever been smokers (31% vs. 57%, P = 0.03). When these factors were added to the model, the OR was attenuated to 0.84, 95% CI 0.23-3.08, P = 0.8. CONCLUSIONS: South Asians with diabetes have about a quarter of the risk of amputation of Europeans. This is mostly explained by low rates of PVD and neuropathy in South Asians, in part associated with low rates of smoking. The reasons for the South Asian protection from both PVD and neuropathy deserve further exploration.     

Childhood-onset Diabetes in the White and South Asian Population in Leicestershire,UK

The prevalence of childhood-onset Type 1 diabetes mellitus is important for determining health care provisions. In Leicestershire 13.5% of the childhood population (0–14 years) is of South Asian origin (census 1991). This study determined the prevalence of Type 1 diabetes in Whites and South Asians in Leicestershire, using a capture/recapture method to coincide with the 1991 Census day. Children (0–14 years) with Type 1 diabetes were captured from the central diabetic register. The health visitor and consultant records were used to recapture the cases. Total ascertainment of cases was 95–100%. The prevalence of Type 1 diabetes in White children (107 cases) was 0.75/1000 children (95% CI 0.61–0.89) compared with the South Asian prevalence (18 cases) of 0.77/1000 (95% CI 0.41–1.13). The overall prevalence in White males was 0.82/1000 (0.61–1.03) compared with 0.68/1000 (0.48–0.87) in females. In South Asian males it was 0.59/1000 (0.15–1.03) compared with 0.96/1000 (0.39–1.53) in females. The prevalence of Type 1 diabetes in children of South Asian migrants to the United Kingdom cannot be said to be different from White children.     

Microalbuminuria is more frequent in South Asian than in European origin populations: a comparative study in Newcastle, UK.

AIMS: We aimed to compare levels of urinary albumin excretion and the prevalence of microalbuminuria in UK South Asians and Europeans. Microalbuminuria predicts cardiovascular disease in European origin populations, but evidence from the general population of South Asians is lacking. Coronary heart disease (CHD) mortality is 40-50% higher in UK South Asians compared with the whole population, for reasons that are incompletely understood. METHODS: Microalbuminuria was measured using the albumin-creatinine ratio in an age- and sex-stratified random sample of 1509 adults from European (n = 825), Indian (n = 259), Pakistani (n = 305) and Bangladeshi (n = 120) ethnic groups. RESULTS: Levels of urinary albumin excretion were substantially higher in South Asians (geometric mean albumin creatinine ratio (95% confidence interval) 0.83 (0.75, 0.91)) than in Europeans (0.55 (0.51, 0.60)). Microalbuminuria was associated with older age, hypertension and diabetes, but independently of these risk factors urinary albumin excretion was higher in South Asians than Europeans. CONCLUSIONS: Urinary albumin excretion is higher and microalbuminuria more frequent in UK South Asians compared with the majority ethnic population. Microalbuminuria may be relevant to the causal pathways leading to the excess of cardiovascular mortality and possibly renal failure in UK South Asians.     

The association between triglyceride to high-density-lipoprotein cholesterol ratio and insulin resistance in a multiethnic primary prevention cohort

The objective was to explore the clinical utility of triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) ratio in predicting insulin resistance (IR) in 4 ethnic groups and the relationship between IR and TG/HDL-C in comparison to that with other lipid measures. Apparently healthy Aboriginals, Chinese, Europeans, and South Asians (N = 784) were assessed for sociodemographics, lifestyle, anthropometry, lipids, glucose, and insulin. The homeostasis model assessment of IR was used as a measure of IR. Compared with other lipid parameters, TG/HDL-C was the highest correlate of the homeostasis model assessment of IR (age and sex adjusted) in Aboriginals (r = 0.499, P < .001), Chinese (r = 0.432, P < .001), Europeans (r = 0.597, P < .001), and South Asians (0.372, P < .001). For a 1-unit increase in TG/HDL-C, the odds of being insulin resistant increased about 4 times (odds ratio [OR], 3.95; 95% confidence interval [CI], 1.86-8.42; P < .001) in Aboriginals, 3.4 times in Chinese (OR, 3.44; 95% CI, 1.79-6.62; P < .001), 1.9 times in Europeans (OR, 1.94; 95% CI, 1.00-3.75; P = .049), and 1.8 times in South Asians (OR, 1.77; 95% CI, 0.91-3.45; P = .094) (age, sex, smoking, physical activity, body mass index, and waist circumference adjusted). Receiver operating characteristic curve analyses revealed areas under the curve (95% CI) of 0.777 (0.707-0.847) in Aboriginals, 0.723 (0.647-0.798) in Chinese, 0.752 (0.675-0.828) in Europeans, and 0.676 (0.590-0.762) in South Asians. Optimal cutoffs (sensitivity, specificity) of TG/HDL-C for identifying individuals with IR were 0.9 (93.0%, 51.9%), 1.1 (71.7%, 61.5%), 1.1 (73.5%, 70.9%), and 1.8 (52.0%, 77.9%) in Aboriginal, Chinese, European, and South Asian individuals, respectively. The TG/HDL-C ratio may be a good marker to identify insulin-resistant individuals of Aboriginal, Chinese, and European, but not South Asian, origin.     

Factors associated with obesity in South Asian, Afro-Caribbean and European women

OBJECTIVE: To investigate correlates of body mass index (BMI) and other anthropometric measurements in South Asian, Afro-Caribbean and European women in the UK. SUBJECTS: 291 South Asian, 303 Afro-Caribbean, and 559 European women aged 40-69y in West London, UK. DESIGN: Cross-sectional survey. MAIN OUTCOME MEASURES: BMI, waist-to-height ratio (WHt), and skinfold thicknesses. RESULTS: Compared with European women, South Asian and Afro-Caribbean women were more like to be obese (odds ratios (OR) 1.83 and 3.01, respectively), but less likely to rate themselves as overweight (BMI-adjusted OR 0.19 and 0.34, respectively). The proportion of women who walked at least 2.5 km/d, excluding activity at work, was lower in South Asians (22%) than in Europeans (44%) or Afro-Caribbeans (40%). Among employed women, the proportion who were active at work was higher in South Asians (63%) and Afro-Caribbeans (70%) than in Europeans (49%). In Europeans, obesity was inversely associated with social class, education, smoking, alcohol intake, and distance walked, and positively associated with time spent watching television. Adjustment for alcohol intake, smoking, education and transport, physical activity explained over 80% of the difference in BMI between South Asians and Europeans, but not the difference between Afro-Caribbeans and Europeans. CONCLUSION: The factor that may be most amenable to intervention in South Asian women is low physical activity outside the workplace. The high prevalence of obesity in Afro-Caribbean women, however, is not accounted for by any behavioural factors measured in this study, and the reasons for high rates of obesity in this group remain to be established.     

Serological evidence of Helicobacter pylori infection in UK South Asian and European populations: implications for gastric cancer and coronary heart disease

OBJECTIVES: To describe the prevalence of serological evidence of infection with Helicobacter pylori among people of South Asian and European ethnic origins and to assess its association with prevalent coronary heart disease (CHD). METHODS: We used a quantitative method to compare IgG antibodies to H. pylori in a population sample of 300 South Asians and 302 Europeans in Newcastle upon Tyne, UK. RESULTS: For men and women, respectively, H. pylori IgG (95% confidence interval) was 16.7 microg/ml (13.9, 20.2) and 11.3 (9.4, 13.5) among Europeans and 11.6 (9.8, 13.7) and 14.3 (12.1, 16.9) among South Asians. Levels were higher in older participants and in those of lower socioeconomic status. The ratio of geometric mean IgG, (95% confidence interval) adjusted for age, sex and socioeconomic status, in those with and without CHD was 1.02 (0.49, 2.11) among Europeans and 1.79 (1.01, 3.17) among South Asians. Antibodies against staphylococcal enterotoxins A and B were higher among South Asians than Europeans. CONCLUSIONS: The prevalence of H. pylori infection among UK South Asians does not reflect that of their countries of origin, nor their lower prevalence of gastric cancer. The association with CHD in South Asians requires corroboration in other studies.     

Acculturation and the prevalence of pain amongst South Asian minority ethnic groups in the UK

BACKGROUND: Musculoskeletal pain is reported more commonly by South Asians in the UK than by white Europeans. This may result from a variety of factors, including cultural differences, and thus we investigated the extent to which differences in the prevalence of pain within the South Asian population could be explained by differences in acculturation (the extent to which immigrants take on the culture of their host population). METHODS: Nine hundred and thirty-three Europeans and 1914 South Asian (1165 Indian, 401 Pakistani and 348 Bangladeshi) subjects were recruited from the age-sex registers of 13 general practices in areas with high densities of South Asian populations (Bolton, Oldham, Ashton-under-Lyne and Birmingham). A 28-item acculturation scale was developed, based, on aspects including use of language, clothing style, and use of own-culture media. Principle component analysis generated a score (range 0-100), which was validated against constructs expected to relate to acculturation, such as years of full time education and time spent in the UK. The presence of widespread pain was assessed by the answer to the question 'Have you suffered from pain all over the body in the past month?' RESULTS: Widespread pain was more common in all three South Asian ethnic groups than in the white Europeans [odds ratio (OR) = 3.7, 95% confidence interval (CI) 2.9-4.9], with this increase ranging from 2.7 to 5.8 in the different South Asian subgroups. There was a similar increase in consultation rates for pain. Within the South Asians, pooling all three groups, there was a strong negative association between acculturation score and widespread pain, which remained after adjusting for age and sex: [OR (95% CI) per standard deviation decrease in acculturation score -1.2 (1.0-1.3)]. Adjusting for acculturation accounted for some, but not all, of the differences between the ethnic groups in the prevalence of widespread pain: OR 2.0 (95% CI 1.4-3.0). CONCLUSIONS: Widespread pain is more commonly reported in South Asians though there are interesting differences within the South Asian community. Lower acculturation has a strong influence on the reporting of pain, but cannot explain all of the difference between South Asian and European populations.     

FTO gene variants are strongly associated with type 2 diabetes in South Asian Indians

Aims and hypothesis  Variants of the FTO (fat mass and obesity associated) gene are associated with obesity and type 2 diabetes in white Europeans, but these associations are not consistent in Asians. A recent study in Asian Indian Sikhs showed an association with type 2 diabetes that did not seem to be mediated through BMI. We studied the association of FTO variants with type 2 diabetes and measures of obesity in South Asian Indians in Pune. Methods  We genotyped, by sequencing, two single nucleotide polymorphisms, rs9939609 and rs7191344, in the FTO gene in 1,453 type 2 diabetes patients and 1,361 controls from Pune, Western India and a further 961 population-based individuals from Mysore, South India. Results  We observed a strong association of the minor allele A at rs9939609 with type 2 diabetes (OR per allele 1.26; 95% CI 1.13–1.40; p = 3 × 10⁻⁵). The variant was also associated with BMI but this association appeared to be weaker (0.06 SDs; 95% CI 0.01–0.10) than the previously reported effect in Europeans (0.10 SDs; 95% CI 0.09–0.12; heterogeneity p = 0.06). Unlike in the Europeans, the association with type 2 diabetes remained significant after adjusting for BMI (OR per allele for type 2 diabetes 1.21; 95% CI 1.06–1.37; p = 4.0 × 10⁻³), and also for waist circumference and other anthropometric variables. Conclusions  Our study replicates the strong association of FTO variants with type 2 diabetes and similar to the study in North Indians Sikhs, shows that this association may not be entirely mediated through BMI. This could imply underlying differences between Indians and Europeans in the mechanisms linking body size with type 2 diabetes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorised users. C. S. Janipalli, S. Bhaskar, S. R. Kulkarni and R. M. Freathy contributed equally to this study.     

Trends in the prevalence of type 2 diabetes and its association with mortality rates in Asians vs. Whites: Results from the United States National Health Interview Survey from 2000 to 2014

Aims

To identify the prevalence and mortality of type 2 diabetes in Asian Americans (Asians) vs. non-Hispanic whites (Whites).

British South Asians aged 13-16 years have higher fasting glucose and insulin levels than Europeans.

AIM: To examine whether plasma glucose, insulin resistance and markers of adiposity differed between British adolescents of South Asian and European origin. METHODS: School-based cross-sectional study (1998-2000), in which detailed measurements of adiposity, fasting plasma glucose and serum insulin were made in 90 South Asian and 1248 European pupils (overall 69% response rate). RESULTS: Compared with Europeans, South Asian subjects had higher mean fasting insulin levels (percentage mean difference 17.2%, 95% confidence interval 7.2-26.1%, P = 0.001), a higher mean fasting glucose (mean difference 0.19 mmol/l, 95% confidence interval 0.08-0.29 mmol/l, P = 0.0005) and a higher prevalence of impaired fasting glucose (> or = 6.1 mmol/l) (5.6% vs. 1.5%, odds ratio 3.9, 95% confidence interval 1.4-10.9, P = 0.004). Although South Asian children tended to have slightly higher indices of adiposity than Europeans (other than body mass index), the differences in glucose and insulin levels persisted after adjustment for adiposity and for pubertal status. CONCLUSIONS: The predisposition to Type 2 diabetes observed in South Asian adults is apparent before adult life. Establishing the contributions of the childhood and fetal environments and of genetic factors to the development of these ethnic differences is an important priority. Prevention of Type 2 diabetes in British South Asians needs to begin before adult life.