The Southall Diabetes Survey: prevalence of known diabetes in Asians and Europeans

Impact of age and duration on sight–threatening retinopathy in South Asians and Caucasians attending a diabetic clinic

AIMS

To examine diabetic retinopathy in Asians and Caucasians attending a hospital diabetic clinic and to evaluate the impact of the significant risk factors on the probability of sight-threatening retinopathy.

METHODS

A total of 500 diabetic patients (268 Asians, 232 Caucasians) who attended a diabetic clinic within a defined time period were examined for severity of diabetic retinopathy. The existence of sight-threatening retinopathy (STR) was compared in the two groups. Significant risk factors such as age, duration and hypertension were analysed against the probability of STR in each of the two races.

RESULTS

Asians demonstrated significantly higher rates of STR. Univariate analysis showed age, duration, race, gender, and insulin-requiring status to be significantly associated with STR. Multivariate logistic regression showed a significant association of STR with race, age and duration of diabetes, with no significant interaction effects between variables. The logistic regression model predicted STR in Asians to be matched to that in Caucasians by a 12.5-year difference factor; that is, Caucasians were older by 12.5 years or had a 12.5-year longer duration than Asians for the same level of STR.

CONCLUSIONS

After adjusting for age and duration of diabetes, the probability of STR in Asian diabetic patients attending the diabetic clinics in Bradford is significantly higher than that in Caucasians (odds ratio=3.184, P<0.05). The impact of age and duration was significantly higher in patients of South Asian origin compared to Caucasians.

A pilot randomized trial in primary care to investigate and improve knowledge, awareness and self-management among South Asians with diabetes in Manchester

AIMS

To investigate whether a secondary-primary care partnership education package could improve understanding of diabetes care among South Asians.

METHODS

In a pilot randomized controlled trial, in the setting of eight general practices randomized to intervention or control, patients were invited to four or more rotating visits per year by one of a diabetes specialist nurse, dietician or chiropodist working with general practice staff. Participants were from lists of South Asian patients with known Type 2 diabetes in each (general) practice.

RESULTS

Patients and practice scores at baseline and 1-year follow-up, from an interview using a questionnaire on knowledge, awareness and self-management of diabetes. Responses were developed into educational packages used during intervention. Of the 411 patients listed at baseline only 211 were traced for interview (refusal only 4%). Mean age was 55.4 years, age of diabetes onset 47.1 years. Fourteen percent were employed and 35% were able to communicate in English fluently. Only 118 could be traced and interviewed at 1 year, although there was no significant difference in demography between those who completed the study and those who did not. Despite a mean of four visits/patient, intervention had no impact on scores for diabetes knowledge, or awareness [score change 0.14, 95% confidence interval (CI) -0.20, 0.49] or self-management (-0.05, 95% CI -0.48, 0.39) between baseline and 1 year.

CONCLUSIONS

This form of secondary/primary care support did not transfer information effectively, and we suspect similar problems would arise in other similar communities. Different methods of clinician/patient information exchange need to be developed for diabetes in this South Asian group.

Genetic polymorphism PC-1 K121Q and ethnic susceptibility to insulin resistance

Genetic susceptibility may be responsible for high prevalence of insulin resistance in Asian Indians. This study was carried out in samples of local Asian Indians and Caucasians to determine whether plasma cell membrane glycoprotein (PC)-1 K121Q and insulin receptor substrate-1 (IRS-1) G972A polymorphisms contribute significantly to susceptibility to insulin resistance in Asian Indians. The frequency of carrying at least one copy of the PC-1 121Q variant in Asian Indians was significantly higher than that in Caucasians (P = 0.01), but the frequency was similar for IRS-1 972A (6% and 7%). A significantly higher insulin area under the curve during oral glucose tolerance testing (P < 0.0001) and lower insulin sensitivity during hyperinsulinemic-euglycemic clamps (P = 0.04) were found in Asian Indians with PC-1 121Q variant compared with Asian Indians with wild-type PC-1 and with Caucasians with or without the polymorphism. IRS-1 972A was not associated with any change in insulin sensitivity. We conclude that the PC-1 K121Q polymorphism associates with primary insulin resistance in migrant Asian Indians. A relatively high frequency of this polymorphism thus may be one factor contributing to insulin resistance susceptibility in Asian Indians. This finding indicates the need for expanded studies on the association between PC-1 K121Q and insulin resistance in a representative sample of the Asian Indian population.

Dietary, evolutionary, and modernizing influences on the prevalence of type 2 diabetes

An evolutionary perspective is used to elucidate the etiology of the current epidemic of type 2 diabetes estimated at 151 million people. Our primate legacy, fossil hominid, and hunting-gathering lifestyles selected for adaptive metabolically thrifty genotypes and phenotypes are rendered deleterious through modern lifestyles that increase energy input and reduce output. The processes of modernization or globalization include the availability and abundance of calorically dense/low-fiber/high-glycemic foods and the adoption of sedentary Western lifestyles, leading to obesity among both children and adults in developed and developing countries. These trends are projected to continue for a number of decades.

Explaining variations in reported diabetes prevalence in general practice: how much variation is explained by differences between practice populations?

There are large variations in reported diabetes prevalence within United Kingdom (UK) populations. Linear regression was used to investigate whether population characteristics could explain the variation in prevalence between 19 practices with relatively complete diagnostic recording. Population obesity and South Asian ethnicity largely explained observed variation in prevalence (adjusted R2 = 0.80). When adjusted for obesity and ethnicity, the deprivation score was no longer a predictor of diabetes prevalence. If true variation in prevalence between practices is largely predicted by population ethnicity and obesity, these population characteristics could be used to predict expected prevalence and to assess the completeness of practice registers.

Type 2 and other forms of diabetes in 0-30 year olds: a hospital based study in Leeds, UK

BACKGROUND AND AIMS

Following recent reports of increased numbers of adolescents being diagnosed with the adult or type 2 form of diabetes we aimed to describe the prevalence of both type 2 and other forms of diabetes in an urban population of children and young people in northern England.

METHODS

A hospital based cross sectional study was performed in patients aged < or =30 years attending diabetic clinics in Leeds during the year 2000.

RESULTS

A total of 677 subjects were identified, of whom 621 (92%) and 37 (5%) had type 1 and type 2 diabetes respectively. Four patients had confirmed maturity onset diabetes of the young, while the cause was uncertain for four. Median age of all patients was 22 years, with 396 (58%) aged 20-30; 32/37 patients with type 2 diabetes were aged 20-30. The prevalence of type 2 diabetes was 0.13 per 1000 overall, compared to 2.2 per 1000 for patients with type 1 diabetes. Of all type 2 diabetes patients, 24% were south Asian compared to 5% of the background population; 87% were categorised into the two least affluent tertiles of the Townsend score. This link with deprivation was not explained by the proportion of Asian patients across tertiles (approximately 25%).

CONCLUSIONS

This study shows extremely low prevalence of type 2 diabetes in 10-19 year olds, but will provide a baseline for future comparisons. Overall, type 2 diabetes is seen more commonly in south Asians, and an association with deprivation is suggested.

Hidden diabetes in the UK: use of capture-recapture methods to estimate total prevalence of diabetes mellitus in an urban population

An early requirement of the UK's Diabetes National Service Framework is enumeration of the total affected population. Existing estimates tend to be based on incomplete lists. In a study conducted over one year in North Liverpool, we compared crude prevalence rates for type 1 and type 2 diabetes with estimates obtained by capture-recapture (CR) analysis of multiple incomplete patient lists, to assess the extent of unascertained but diagnosed cases. Patient databases were constructed from six sources-a hospital diabetes centre; general practitioner registers; hospital admissions with a diagnosis of diabetes; a hospital diabetic retinal clinic; a research list of patients with diabetes admitted with stroke; and a local children's hospital. Log linear modelling was used to estimate missing cases, hence total prevalence. The crude prevalence of diabetes was 1.5% (95% confidence interval [CI] 1.41, 1.52), compared with a CR-adjusted rate of 3.1% (CI 3.03, 3.19). Age-banded CR-adjusted prevalence was always higher in males than in females and the difference became more pronounced with increasing age. Among males, CR-adjusted prevalence rose from 0.4% at age 10-19 years to 18.3% at 80+ years; in females the corresponding figures were 0.4% and 9.3%. The gap between crude and CR-estimated prevalence points to a rate of 'hidden diabetes' that has substantial implications for future diabetes care.

Hidden diabetes in the UK: use of capture-recapture methods to estimate total prevalence of diabetes mellitus in an urban population

An early requirement of the UK's Diabetes National Service Framework is enumeration of the total affected population. Existing estimates tend to be based on incomplete lists. In a study conducted over one year in North Liverpool, we compared crude prevalence rates for type 1 and type 2 diabetes with estimates obtained by capture-recapture (CR) analysis of multiple incomplete patient lists, to assess the extent of unascertained but diagnosed cases. Patient databases were constructed from six sources-a hospital diabetes centre; general practitioner registers; hospital admissions with a diagnosis of diabetes; a hospital diabetic retinal clinic; a research list of patients with diabetes admitted with stroke; and a local children's hospital. Log linear modelling was used to estimate missing cases, hence total prevalence. The crude prevalence of diabetes was 1.5% (95% confidence interval [CI] 1.41, 1.52), compared with a CR-adjusted rate of 3.1% (CI 3.03, 3.19). Age-banded CR-adjusted prevalence was always higher in males than in females and the difference became more pronounced with increasing age. Among males, CR-adjusted prevalence rose from 0.4% at age 10-19 years to 18.3% at 80+ years; in females the corresponding figures were 0.4% and 9.3%. The gap between crude and CR-estimated prevalence points to a rate of 'hidden diabetes' that has substantial implications for future diabetes care.

The role of culture and religion in the management of diabetes: a study of Kashmiri men in Leeds

This research attempted to explore the current experience and attitude towards control of diabetes among Kashmiri men with diabetes in Leeds. The data was collected by the author by conducting interviews among a total of 106 men. The results of this survey indicate that a large number of men with diabetes were failing to control and manage their condition. The overall attitude was to enjoy life and "leave the rest to Allah". Data indicated the large influence of cultural values dominating the behaviour of the sample population. The data showed that although a large majority of the men had been told by health professionals that they were overweight, a majority of them did not believe themselves to be so. This belief seems to have been influenced by cultural norms in which the overweight figures tend to project prosperity and well-being in the community. Similarly, first cousin marriages are common in this community. Such cultural practices may lay foundations for future hereditary complications. The study concluded that there is a need to change attitudes towards food and exercise, and controlling sugar level and blood pressure to avoid diabetic complications. For this, both the men as well as the women must be targeted separately in the form of open days, meetings and discussions to promote healthy food consumption, physical activity and healthy living.

The impact of atherosclerotic renovascular disease on diabetic renal failure

Atherosclerotic renovascular disease (ARVD) is common in the general population, and its prevalence increases with age. Parallel studies show it is also common in patients with diabetes. The widespread use of angiotensin converting enzyme inhibitors and angiotensin receptor antagonists for heart and kidney disease might therefore expose arteriopathic diabetic patients to potential harm if they had critical renal artery stenosis. This review looks at the natural history of ARVD in the diabetic and non-diabetic populations: while it is common, it only rarely leads to renal failure. Hence intervention to revascularize ischaemic kidney son the basis of radiological appearances alone may subject some patients to unnecessary therapy. Although untested by randomized trial, a policy of watchful waiting may be the simplest strategy for most diabetic patients with suspected ARVD, reserving angiography and angioplasty (usually backed up by a stent) for those with an abrupt decline in renal function and no other cause for renal deterioration. Future clinical trials may better define subgroups of patients who will truly benefit from renal revascularization.

Nutrition intervention in ethnic minority groups

Development of effective intervention strategies to meet the needs of people with ethnic minority origins is dependent on two factors: an understanding of the modifiable risk factors which can form the basis of intervention; an understanding of the relevant health behaviours so that appropriate strategies can be designed. The present paper briefly reviews the evidence concerning the part that nutritional and dietary factors play in the aetiology of the observed patterns of disease in these groups and the limitations of the data as a basis for intervention. Consideration is also given to the available information concerning factors influencing health behaviour (particularly eating behaviour) and the applicability of commonly-used models of behaviour change to people of ethnic minority origin. Finally, the results of nutrition intervention programmes will be examined with a view to identifying lessons for the future.

The lifecycle effects of nutrition and body size on adult adiposity, diabetes and cardiovascular disease

This study was undertaken to review the links between maternal nutrition, offspring's birth weight and the propensity to early insulin resistance and high diabetes rates in Indian adults. Studies included a comparison of maternal size and nutrition with birth weights in Pune, India, and Southampton, UK. In Pune, the growth, insulin resistance and blood pressure of four-year-old children were assessed. Adults >40 years of age, who were resident in rural areas, were compared with adults living in urban areas for size, glucose handling, lipid status and blood pressure. Newly diagnosed diabetic adults living in urban areas were also monitored. Height, weight, head, waist and hip circumferences, skin-fold measurements and blood pressure were routinely measured. Fasting glucose, insulin, total and high-density lipoprotein cholesterol and triglycerides were linked to the glucose and insulin responses during glucose tolerance tests. Cytokine levels were measured in plasma samples of urban and rural adults. Indian babies were lighter, thinner, shorter and had a relatively lower lean tissue mass than the Caucasian babies. However, the subcutaneous fat measurements of these babies were comparable to those of the white Caucasian babies. The Indian mothers were small, but relatively fat mothers produced larger babies. Maternal intake of green vegetables, fruit and milk, and their circulating folate and vitamin C levels, predicted larger fetal size. Rapid childhood growth promoted insulin resistance and higher blood pressure. Rural adults were thin, with a 4% prevalence of diabetes and a 14% prevalence of hypertension, but the risks increased within the normal body mass index (BMI) range. Type 2 diabetes was common in urban adults younger than 35 years of age. Although the average BMI was 23.9 kg m(-2), central obesity and thin limbs were noteworthy. Levels of interleukin-6 and tumour necrosis factor-a were markedly increased in urban dwellers. Hence, there is evidence of a remarkably powerful, intergenerational effect on body size and total and central adiposity. Indians are highly susceptible to insulin resistance and cardiovascular risks, with babies being born small but relatively fat. Insulin resistance is amplified by rapid childhood growth. Dietary factors seem to have profound long-term metabolic influences in pregnancy. Overcrowding with infections and central obesity may amplify cytokine-induced insulin resistance and early diabetes in Indian adults with a low BMI.

Estimation of the prevalence of diagnosed diabetes from primary care and secondary care source data: comparison of record linkage with capture-recapture analysis

STUDY OBJECTIVE

To compare multiple source linkage and capture-recapture analysis in determining the current age and gender specific prevalence of type 1 and type 2 diabetes in a UK white population. To assess whole population trends in diabetes prevalence and treatment by comparison with previous studies.

DESIGN

Data were obtained from hospital sources and all 74 general practices in the study population. Analyses were carried out both by record linkage and by use of a two source capture-recapture model to correct for incomplete ascertainment.

SETTING

County of Clwyd, North Wales: total population 418,200.

MAIN RESULTS

By record linkage the age adjusted prevalence of all diabetes was 2.04 (95% confidence intervals 2.00 to 2.09)%. Using the capture-recapture method it was 2.29 (2.24 to 2.33)%. From capture-recapture data the age adjusted prevalence of type 1 diabetes was 0.40 (0.37 to 0.43)% in men and 0.28 (0.25 to 0.30)% in women; the prevalence of type 2 was 2.03 (1.97 to 2.09)% in men and 1.67 (1.62 to 1.72)% in women. These figures represent an increase compared with previous surveys. The age specific prevalence of type 2 diabetes was greater in men in a ratio of approximately 1.5:1 and there were more patients treated by diet alone.

CONCLUSIONS

Record linkage using multiple sources underestimates the prevalence of diabetes compared with capture-recapture estimates. The results suggest the prevalence of known diabetes in the UK has approximately doubled in less than 20 years. There is an increasing preponderance of male patients and of patients treated currently with diet alone.

The genetics of type 2 diabetes

Type 2 diabetes mellitus is not a single disease but a genetically heterogeneous group of metabolic disorders sharing glucose intolerance. The precise underlying biochemical defects are unknown and almost certainly include impairments of both insulin secretion and action. The rapidly increasing prevalence of T2D world wide makes it a major cause of morbidity and mortality. Understanding the genetic aetiology of T2D will facilitate its diagnosis, treatment and prevention. The results of linkage and association studies to date demonstrate that, as with other common diseases, multiple genes are involved in the susceptibility to T2D, each making a modest contribution to the overall risk. The completion of the draft human genome sequence and a brace of novel tools for genomic analysis promise to accelerate progress towards a more complete molecular description of T2D.

The Poole Diabetes Study: how many cases of Type 2 diabetes are diagnosed each year during normal health care in a defined community?

We have investigated the incidence of newly diagnosed Type 2 diabetes in the Poole area and extrapolated it to the rest of the UK.

METHODS

this prospective observational study used a surveillance programme in primary and secondary care. We identified all cases of newly diagnosed Type 2 diabetes mellitus occurring from 1st May 1996 to 30th June 1998 through the normal health care process without any active screening in 186889 people registered with 24 primary care practices in the Poole area.

RESULTS

the 1996 prevalence of diagnosed Type 2 diabetes in this population was 1.59 (95% CI 1.53-1.65%)%. During the first 24 months of the study, 706 new cases of Type 2 diabetes mellitus, 382 men and 324 women, were identified. The crude annual incidence of newly diagnosed Type 2 diabetes, thus was 1.93/1000 (95% CI 1.73-2.13%) and age/sex adjusted incidence was 1.67/1000 (95% CI 1.49-1.84%). The age-adjusted incidence was higher in men, 1.86/1000 (95% CI 1.60-2.13), than in women, 1.48/1000 (95% CI 1.25-1.71%), relative risk 1.26 (95% CI 0.997-1.527%), but this difference did not reach statistical significance. Mean HbA1c at diagnosis was 10.8 (S.D. 2.9%)%. Men were younger at diagnosis than women (mean age, 62.9 vs. 65.9%, P<0.01).

CONCLUSION

in UK, prior to the change in the WHO diagnostic criteria for diabetes, we estimate that over 98000 new cases of Type 2 diabetes were diagnosed each year.

C-reactive protein, insulin resistance, central obesity, and coronary heart disease risk in Indian Asians from the United Kingdom compared with European whites

BACKGROUND

Indian Asians in the United Kingdom have increased coronary heart disease (CHD) mortality compared with European whites, but the causes are not well understood. Increased circulating concentrations of C-reactive protein (CRP) are an independent risk factor for CHD. Therefore, we investigated this marker of inflammation in healthy UK Indian Asian and European white men. Methods and Results-- We measured serum CRP concentrations and conventional CHD risk factors in 1025 healthy male subjects (518 Indian Asians and 507 European whites) aged 35 to 60 years who were recruited at random from general practitioner lists. The geometric mean CRP concentration was 17% higher (95% confidence interval, 3% to 33%) in Indian Asians compared with European whites. CRP values were strongly associated with conventional CHD risk factors, measures of obesity, and metabolic disturbances associated with insulin resistance in both racial groups. The difference in CRP concentrations between Indian Asians and European whites remained after adjustment for conventional CHD risk factors but was eliminated by an adjustment for central obesity and insulin resistance score in Asians. On the basis of these results, we estimate that the processes underlying elevated CRP and/or increased CRP production itself are associated with an approximately 14% increase in population CHD risk among Indian Asians compared with European whites.

CONCLUSIONS

CRP concentrations are higher in healthy Indian Asians than in European whites and are accounted for by greater central obesity and insulin resistance in Indian Asians. Our results suggest that inflammation or other mechanisms underlying elevated CRP values may contribute to the increased CHD risk among Indian Asians.

Understanding of heart disease and diabetes in a South Asian community: cross-sectional study testing the 'snowball' sample method

South Asian people living in the UK have a higher rate of heart disease and non-insulin-dependent diabetes. Research into health knowledge and beliefs around these diseases is lacking. Accessing South Asian communities is difficult and is a barrier to research. We have undertaken a cross-sectional survey of South Asian people living in South Tyneside (UK) in 1996 based on a snowball sample to assess understanding of heart disease and diabetes. 334 South Asian men and women aged 16-74 y were interviewed. For heart disease, 115 (35%) people said they did not understand the meaning of the term, 62 (19%) were unable to provide any description, 48 (14%) could not give a single cause, and 54 (17%) could not suggest a preventive measure. For diabetes, 92 (28%) people did not understand the term, 43 (13%) could not provide any description, 75 (22%) were unable to suggest any risk factor and 64 (20%) could not give a preventive measure. For both heart disease and diabetes, two-thirds of respondents said they did not understand enough about the conditions to prevent them. There were important differences by sex and country of origin on the level of understanding with women and Bangladeshi people having lower levels of knowledge. Three of 20 people diagnosed with heart disease knew no preventive measure, and of 16 people with diabetes, six could not name any risk factors for diabetes. There is a major, urgent need for education within the South Asian communities on the causes and prevention of heart disease and diabetes.

Relationship between ethnicity and glycemic control, lipid profiles, and blood pressure during the first 9 years of type 2 diabetes: U.K. Prospective Diabetes Study (UKPDS 55)

OBJECTIVE

To assess the relationship among self-reported ethnicity, metabolic control, and blood pressure during treatment of type 2 diabetes.

RESEARCH DESIGN AND METHODS

We studied 2,999 newly diagnosed type 2 diabetic patients recruited to the U.K. Prospective Diabetes Study who were randomized to conventional or intensive glucose control policies if their fasting plasma glucose levels remained >6 mmol/l after a dietary run-in. A total of 2,484 patients (83%) were white Caucasian (WC), 265 patients (9%) were Afro-Caribbean (AC), and 250 patients (8%) were Asian of Indian origin (IA). Variables were assessed at 3, 6, and 9 years.

RESULTS

During the 9-year study period, body weight increased more in WC patients (mean 5.0 kg) than in AC (3.0 kg) and IA (2.5 kg) patients (P < 0.001). After adjusting for age, sex, baseline value, treatment allocation, and change in weight, there were no consistent ethnic differences in mean change in fasting plasma glucose or HbA(1c). After adjustment for antihypertensive therapy, increase in systolic blood pressure at 9 years was greatest in AC patients (7 mmHg; P < 0.01 vs. WC patients). Mean diastolic blood pressure, total cholesterol, and LDL cholesterol decreased progressively during the 9 years in each group. In AC patients, the mean increase in HDL cholesterol (0.16 mmol/l) at 3 years, maintained to 9 years, and the mean decrease in plasma triglyceride level (0.4 mmol/l) at 9 years were greater than in WC and IA patients (P < 0.001).

CONCLUSIONS

This study shows important ethnic differences in body weight, lipid profiles, and blood pressure, but not glycemic control, during 9 years after diagnosis of type 2 diabetes. AC patients maintained the most favorable lipid profiles, but hypertension developed in more AC patients than WC or IA patients. Ethnicity-specific glycemic control of type 2 diabetes seems unnecessary, but other risk factors need to be addressed independently.

Short-term mortality among middle-aged cataract surgery patients

PURPOSE

To investigate the short-term mortality of middle-aged patients undergoing cataract surgery in the United Kingdom (UK), to compare this with the expected mortality for the UK population of similar age and to try to identify at-risk groups.

METHODS

In a retrospective study, the 5-10 year mortality of all middle-aged patients undergoing cataract surgery between 1989 and 1993 was determined. Expected mortality was calculated from UK Interim Life Tables for 1991. Cox's regression analysis was performed using age, sex and self-assigned ethnic group as variables.

RESULTS

From the 709 patients in the study group, there were 86 deaths. This is significantly greater than expected (p < 0.01). Ethnic minority status (hazard ratio = 1.72, confidence interval = 1.12-2.64) and male sex (HR = 1.68, CI = 1.08-2.63) were found to be significantly associated with early mortality (p < 0.05).

CONCLUSIONS

This study suggests that, for some middle-aged patients, cataract is associated with a reduced life expectancy and may be a feature of premature ageing, reflecting systemic ill-health. Screening these and younger patients for systemic disease when they present with cataract provides the best opportunity to affect this increased mortality. The findings of this study are particularly relevant for patients from ethnic minority groups.

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.

Fetal, infant, and childhood growth are predictors of coronary heart disease, diabetes, and hypertension in adult men and women

Many human fetuses have to adapt to a limited supply of nutrients. In doing so they permanently change their structure and metabolism. These programmed changes may be the origins of a number of diseases in later life, including coronary heart disease, hypertension, and noninsulin- dependent diabetes. We review epidemiologic studies in which the incidence of these diseases has been related to the recorded, early growth of individuals, while considering factors in the adult lifestyle, such as obesity and socioeconomic status. We discuss possible mechanisms. For hypertension these mechanisms include placentation, maternal blood pressure, fetal undernutrition; childhood growth, activation of the renin-angiotensin system, renal structure, programming of the hypothalamic-pituitary-adrenal axis, vascular structure, and sympathetic nervous activity. For noninsulin-dependent diabetes we discuss mechanisms concerning both insulin resistance and insulin deficiency. We include a review of evidence for the programming of serum cholesterol and clotting factor concentrations. We address the timing of critical windows for coronary heart disease, reviewing studies that allow assessment of the relative importance of fetal, infant, and childhood growth. We argue for a research strategy that combines clinical, animal, and epidemiological studies.

Frequency of consumption and nutrient composition of composite dishes commonly consumed in the UK by South Asian Muslims originating from Bangladesh, Pakistan and East Africa (Ismailis)

INTRODUCTION: This paper presents information on the nutrient composition of commonly consumed traditional dishes eaten by the three major South Asian Muslim groups residing in Britain, namely Bangladeshi, Pakistani and East African Ismaili Muslims. METHODS: Information regarding the most common dishes consumed by South Asian Muslims originating from Bangladesh, Pakistan and East Africa (Ismailis) and living in London was obtained from 7-day menu records over two seasons. For each common dish, weighed recipes were collected in triplicate and the composition (energy and selected nutrients) was calculated from the ingredients and cooked weight of the dish. RESULTS: The three Muslim groups showed considerable variation in traditional foods commonly consumed as well as variation in fat and energy contents of similar recipes both within and between groups. Nutrient composition of commonly consumed dishes is presented calculated from the recipe nearest the average in terms of fat and energy for a particular dish. DISCUSSION AND CONCLUSIONS: The potential uses of the data, one of which would be to improve dietary compliance (especially to lower fat intakes) amongst the three diverse South Asian Muslim groups, are discussed.

Correlation between fasting plasma glucose and two-hour plasma glucose during oral glucose tolerance test in South Indians

The diagnostic criteria for diabetes have been recently revised and the fasting plasma glucose (FPG) level reduced to 126 mg/dL, since the earlier cutoff of 140 mg/dL was considered to correspond to a much higher level than the 2-hour postglucose (2 h PG) value of 200 mg/dL. However, there are few data directly correlating FPG and 2 h PG during an oral glucose tolerance test (OGTT). This study reports on a retrospective analysis of 5,936 OGTTs performed at a diabetes center in South India and attempts to correlate the FPG and 2 h PG values. Using a 2 h PG of 200 mg/dL or higher as the diagnostic criterion, 46.7% of the cohort had diabetes. The corresponding values using the old FPG of 140 mg/dL or higher and the new FPG of 126 mg/dL or higher were 31.7% and 39.8%, respectively. If the FPG was further reduced to 118 mg/dL, the "diabetic yield" increased to 45.8%, ie, it approached the figures based on a 2 h PG of > or =200 mg/dL. Various regression equations were used to correlate FPG and 2 h PG values. When FPG was used as the dependent variable, the semilogarithmic regression equation provided the best fit, and using this model, the 2 h PG of 200 mg/dL corresponds to a FPG of 118 mg/dL. When the 2 h PG was used as the dependent variable, the log-log model provided the best fit, and using this model, a 2 h PG of 200 mg/dL corresponds to a FPG of 118 mg/dL. Thus, a FPG of 118 mg/dL seems to correlate with a 2 h PG of 200 mg/dL in South Indians.

Increased waist size and weight in relation to consumption of Areca catechu (betel-nut); a risk factor for increased glycaemia in Asians in east London

Type 2 diabetes is commoner in Asians than Caucasians. Many nitrosamines are diabetogenic, causing both type 2 and type 1 diabetes. Of CD1 mice fed with betel-nut or associated nitrosamines 8.5% develop glucose intolerance with marked obesity. Glycaemia and anthropometric risk markers for type 2 diabetes were therefore examined in relation to betel usage in 993 'healthy' Bangladeshis by one bilingual research-worker (N.M.). Of these, 12% had known diabetes. A further 145 of 187 subjects 'at-risk' of diabetes (spot glucose > 6.5 mmol/l < 2 h after food, or > 4.5 mmol/l > 2 h after food) had a second blood glucose sample taken; sixty-one were confirmed as 'at-risk', and had an oral glucose tolerance test; nine new diabetics were identified. Multiple regression analysis showed that spot blood glucose values decreased with time after eating (P = 0.0005) and increased independently with waist size (P = 0.0005) and age (P = 0.0005) without relationships to other aspects of the diet, season or smoking. Waist size was strongly related to betel usage independent of other factors such as age. Betel use interacted with sex, relating to increasing glycaemia only in females. Since waist and age were the major markers of increasing glycaemia we suggest that betel chewing, a habit common to about 10% of the world population (more than 200 million people) may contribute to the risk of developing type 2 diabetes mellitus.

Racial variation in cardiovascular morbidity and mortality in essential hypertension

OBJECTIVES

To perform a longitudinal comparison of morbidity and mortality among white, south Asian and Afro-Caribbean hypertensive patients in relation to baseline demographic characteristics and clinic and ambulatory blood pressure variables.

DESIGN

Observational follow up study.

SETTING

District general hospital and community setting in Harrow, England.

PATIENTS

528 white, 106 south Asian, and 54 Afro-Caribbean subjects with essential hypertension who had undergone 24 hour ambulatory intra-arterial blood pressure monitoring.

INTERVENTIONS

Follow up for assessment of all cause morbidity and mortality over a mean (SD) of 9.2 (4.1) years.

MAIN OUTCOME MEASURES

Non-cardiovascular death, coronary death, cerebrovascular death, peripheral vascular death, non-fatal myocardial infarction, non-fatal stroke, coronary revascularisation.

RESULTS

South Asians had the highest all cause event rate of 3.46, compared with 2.50 (NS) and 0.90 (p = 0.002) events/100 patient-years for whites and Afro-Caribbeans, respectively. This was because of an excess of coronary events (2.86 v 1.32 events/100 patient-years in south Asians v whites, respectively; p = 0.002). Age (p < 0.001), sex (p < 0.001), race (south Asians : whites, hazard ratio 1.79; p = 0.008), diabetes (p = 0.05), previous history of cardiovascular disease (p < 0.001), and 24 hour ambulatory systolic blood pressure (p = 0.006) were independent predictors of time to a first event. Clinic blood pressure did not provide additional prognostic information.

CONCLUSIONS

South Asian origin was an independent predictor of all cause events, mainly because of an excess of coronary events in this group. Ambulatory but not clinic blood pressure was of additional value in predicting subsequent morbidity and mortality.

Plasma homocysteine concentrations and risk of coronary heart disease in UK Indian Asian and European men

BACKGROUND

Reasons for the increase in mortality due to coronary heart disease (CHD) in UK Indian Asians are not well understood. In this study, we tested the hypotheses that elevated plasma homocysteine concentrations are a risk factor for CHD in Indian Asians, and explain part of their increased CHD risk, compared with Europeans.

METHODS

We undertook two parallel case-control studies, one in Europeans and one in Indian Asians. We recruited 551 male cases (294 European, 257 Indian Asian) and 1025 healthy male controls (507 European, 518 Indian Asian). Fasting and post-methionine load homocysteine, vitamin B12 and folate concentrations, and conventional CHD risk factors were measured.

FINDINGS

Fasting homocysteine concentrations were 8% higher (95% CI 3-14) in cases compared with controls, in both ethnic groups. The odds ratio of CHD for a 5 micromol/L increment in fasting plasma homocysteine was 1.3 (1.1-1.6) in Europeans and 1.2 (1.0-1.4) in Indian Asians. The association between fasting plasma homocysteine and CHD was independent of conventional CHD risk factors in both ethnic groups. Post-load homocysteine concentrations were not significantly different in cases compared with controls. Among the controls, fasting homocysteine concentrations were 6% (2-10) higher in Indian Asians than in Europeans. From the results we estimate that elevated homocysteine may contribute to twice as many CHD deaths in Indian Asians, compared with Europeans. The differences in homocysteine concentrations between the two ethnic groups were explained by lower vitamin B12 and folate levels in Asians.

INTERPRETATION

Plasma homocysteine is a novel and independent risk factor for CHD in Indian Asians, and may contribute to their increased CHD risk. Raised homocysteine concentrations in Indian Asians may be related to their reduced vitamin B12 and folate levels, implying that the increased CHD risk in this group may be reduced by dietary vitamin supplementation.

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.

In utero programming of cardiovascular disease

Low birth weight, thinness and short body length at birth are now known to be associated with increased rates of cardiovascular disease and non-insulin dependent diabetes in adult life. The fetal origins hypothesis proposes that these diseases originate through adaptations which the fetus makes when it is undernourished. These adaptations may be cardiovascular, metabolic or endocrine. They permanently change the structure and function of the body. Prevention of the diseases may depend on prevention of imbalances in fetal growth or imbalances between pre- and post-natal growth, or imbalances in nutrient supply to the fetus.

Attitudes to organ donation among South Asians in an English high street

In the UK, people of South Asian origin are at more than twice the risk of end-stage renal failure encountered in the Caucasian population but are under-represented among organ donors. Difficulties with matching mean that few donated kidneys are suitable for transplantation to South Asian recipients. A survey of attitudes in 100 South Asian adults was conducted in the main street of Southall, Middlesex. 90 of those questioned were aware of organ transplantation and 69 had heard about donor cards. However, the 16% who carried a donor card was lower than the 28% reported in the general population. The main reason for the low organ donation rate by South Asians seemed to be lack of knowledge, and this could be remedied by more targeting of information in the Asian media.

Cardiovascular and cancer mortality among Canadians of European, south Asian and Chinese origin from 1979 to 1993: an analysis of 1.2 million deaths

BACKGROUND

Cardiovascular disease and cancer are important health problems worldwide, yet our knowledge of these conditions is derived principally from populations of European descent. To investigate ethnic variations in major causes of death in Canada, the authors examined total and cause-specific mortality among European, south Asian, and Chinese Canadians.

METHODS

Canadians of European, south Asian and Chinese origin were identified in the Canadian Mortality Database by last name and country of birth and in the population census by self-reported ethnicity. Age-standardized death rates by cause, per 100,000 population, were calculated for ages 35 to 74 years from 1979 to 1993 and in 5-year intervals grouped around census years (1979/83, 1984/88 and 1989/93).

RESULTS

Rates of death from ischemic heart disease were highest among Canadians of south Asian origin (men 320.2, women 144.5) and European origin (men 319.6, women 109.9) and were markedly lower among Canadians of Chinese origin (men 107.0, women 40.0); the rates declined significantly in all 3 groups over the study period. Rates of death from cerebrovascular disease were relatively low and showed less ethnic variation (Canadian men of European, south Asian and Chinese origin 49.5, 47.0 and 45.8 respectively; Canadian women of European, south Asian and Chinese origin 34.8, 39.0 and 42.2 respectively) and declined similarly in all groups over time. Rates of death from cancer were highest among Canadians of European origin (men 343.6, women 236.2), intermediate among those of Chinese origin (men 258.1, women 161.6) and lowest among those of south Asian origin (men 122.3, women 131.3). Over time, cancer mortality increased in Canadians of European origin but remained constant or declined in those of south Asian and Chinese origin.

INTERPRETATION

Substantial differences exist in rates of death from ischemic heart disease and cancer among European, south Asian and Chinese Canadians.

Familial clustering of type II diabetes mellitus (DM) diagnosed under the age of 40 years in Yemen: Is it early-onset type II DM or maturity-onset diabetes of the young?

BACKGROUND

Clinical presentation of type II diabetes mellitus (DM) has frequently been observed at an early age in developing countries, probably as a result of genetic, epidemiological and demographic factors. This study aimed to investigate the pattern of familial clustering of type II DM in patients who developed clinical diabetes before the age of 40 years.

PATIENTS AND METHOD

The study involved family pedigrees, clinical assessments and laboratory investigations of 191 patients with type II DM, and 260 age-matched randomly selected non-diabetic controls.

RESULTS

The prevalence of type II DM was found to be statistically higher among parents (P<0.0001), fullsiblings (P<0.0001), half-siblings (P<0.001), uncles (P<0.01) and aunts (P<0.001) of the index patients, as compared to the corresponding relatives of nondiabetic controls. The odds ratio of the family history index (FHI), in association with type II DM in probands who had no family history of diabetes (FHI=0.0), was significantly negative (OR=0.34; 95% CI 0.23, 0.52; P<0.0001). At an FHI level of 0.5-1.0, there was a slight nonsignificant increase in odds ratio for diabetes (OR=1.53; 95% CI 0.95, 2.45; P=0.08). A higher level of FHI (A(3)1.5) was associated with a significant increase in odds ratio for diabetes (OR=3.75; 95% CI 2.13, 6.64; P<0.0001). The age-corrected relative risk of type II DM for the offspring of diabetic parents was found to be progressively increasing from a nonconsanguineous diabetic father (22%) or mother (26.5%), to nonconsanguineous conjugal diabetic parents (27%) and to the offspring of consanguineous single or conjugal diabetic parents (37.5%). On the contrary, the age-corrected relative risk for the offspring of nonconsanguineous and consanguineous nondiabetic parents was characteristically lower (14% for each). Maturityonset diabetes of the young (MODY) was suspected in 10 probands (5%), and early-onset type II DM in the offspring of conjugal diabetic parents in 16 probands (9%). The remaining 165 probands (86%) were unclassified due to lack of specific classification criteria.

CONCLUSION

The considerable familial clustering of type II DM diagnosed under the age of 40 years in this study population reflects the presence of a strong genetic component in its etiology. In addition, the development of early-onset type II DM was more likely associated with a consanguineous and/or conjugal diabetic parents and probably MODY subtype among a substantial number of patients. Epidemiological and demographic factors might have been implicated, especially in those with negative parental diabetic history.

Pakistani moslems with Type 2 diabetes mellitus: effect of sex, literacy skills, known diabetic complications and place of care on diabetic knowledge, reported self-monitoring management and glycaemic control

AIMS

To study factors such as sex, educational status and place of care, which might influence knowledge and self-management of diabetes, and glycaemic control in a Pakistani moslem diabetic population attending primary care general practices (GP) and secondary care clinics at the Manchester Diabetes Centre (MDC).

METHODS

Patients with Type 2 diabetes mellitus took part in a one-to-one semi-structured interview and gave blood for haemoglobin A1c levels.

RESULTS

Two hundred and one patients entered the study. Knowledge about diabetic diets was good (average scores 72%), and patients claimed to perform regular glucose measurements (66%), but they were not good at applying their knowledge to problems in daily life. Only 24% knew how to manage persistent hyperglycaemia. Women were worse than men at this (19 vs. 31% (chi2 = 3.8, P = 0.05)), were less likely to understand why glucose levels should be monitored, and had poorer glycaemic control overall (HbA1c 8.8 vs. 8.1%, P = 0.04). Fifty-four patients were completely illiterate. They had similar knowledge scores to readers but were less able to handle problem scenarios. Forty-five of these patients were women, and multiple regression analysis showed they were more likely to have the poorest glycaemic control. No major differences were found between general practitioner and hospital attenders, or between patients with and without known complications, except that hospital attenders were more likely to have complications and poorer control.

CONCLUSIONS

Women who cannot read in this population are likely to have poorer glycaemic control and may be finding it more difficult to learn how to apply their knowledge to daily life. This subgroup may need more intensive, culturally appropriate, health education and support.

The epidemiology of Type 2 diabetes and its current measurement

Type 2 diabetes is globally increasing in prevalence and is widely recognized as a major cause of morbidity and mortality, as well as being a burden to the health-care services. Planning for current and future diabetes services requires up-to-date prevalence information. The enumeration of Type 2 diabetes is, however, surprisingly difficult. Large numbers of people are undiagnosed, and those known cases have variable loci of care. Traditional techniques include cross-sectional diagnostic surveys, postal or house-to-house surveys and cohort surveys. All are time-consuming and expensive, and may potentially undercount. The use of multiple patient lists (e.g. hospital clinic data, general practitioner (GP) lists, prescribing information, etc.) can, however, increase accuracy and, if the data are computerized, may be rapid and inexpensive. A new and potentially exciting tool to utilize multiple lists in Type 2 diabetes prevalence assessment is known as 'capture-recapture'. In this, statistical models are used to estimate prevalence from the degree of overlap between lists. Capture-recapture is emerging as a valuable tool in the epidemiological assessment of Type 2 diabetes.

Collation and comparison of multi-practice audit data: prevalence and treatment of known diabetes mellitus

BACKGROUND

Different methods have been used to determine the prevalence and treatment of diabetes. Despite the large number of studies, previous estimations of prevalence and treatment have been carried out on relatively small numbers of patients, and then in only a few practices in single geographical regions.

AIM

To investigate the feasibility of collating data from multi-practice audits organized by primary care audit groups in order to estimate the prevalence and treatment of patients with known diabetes, and to discuss the methodological issues and reasons for variation.

METHOD

A postal questionnaire survey of all primary care audit groups in England and Wales that had conducted a multi-practice audit of diabetes between 1993-1995. Prevalence rates and patterns of diabetic care were compared with other community-based surveys of known diabetes from 1986-1996 identified on MEDLINE.

RESULTS

Twenty-five (43%) audit groups supplied data from multi-practice audits of diabetes. Seven (28%) multi-practice audits involving 259 practices fulfilled the inclusion criteria for prevalence estimation. The overall prevalence of diabetes based on a population of 1,475,512 patients was 1.46% (range between audit groups = 1.18% to 1.66%; chi 2 = 308; df = 6; P < 0.0001). Male to female ratio was 1.15:1. Treatment of diabetes could be ascertained for 10 (40%) audit groups comprising 319 practices. Of these, 23.4% (range = 16.5%-27.4%) were controlled by diet, 48.5% (range = 43.6%-55.8%) were prescribed oral hypoglycaemic drugs, and 28.2% (range = 25.0%-32.4%) were treated with insulin. There were significant variations between audit groups in treatment pattern (chi 2 = 250; df = 18; P < 0.0001).

CONCLUSION

Prevalence and treatment rates of diabetes and other chronic diseases can be assessed and compared using data from multi-practice audits. Collation of audit data could improve the precision of quantitative estimates of health status in populations. A standard method of data recording and collection may provide a new approach that could considerably improve our ability to monitor disease and its management.

Abnormalities of vascular endothelial function may contribute to increased coronary heart disease risk in UK Indian Asians

OBJECTIVE

To test the hypothesis that abnormalities of endothelial function are present in Indian Asians and may contribute to their increased coronary heart disease risk.

SETTING

Single centre in west London.

PATIENTS

26 Indian Asian and 18 European white healthy male subjects, aged 35 to 61 years recruited from general practice lists.

DESIGN

Brachial artery diameter responses to reactive hyperaemia and sublingual glyceryl trinitrate were compared using high resolution ultrasound.

RESULTS

Mean (SEM) flow mediated, endothelium dependent dilatation was reduced in Indian Asians compared with European whites, at 3.2 (0.8)% v 5.9 (1.0)%, p = 0.03. In contrast, there were no significant differences in baseline brachial arterial diameter (4.6 (0.1) v 4.6 (0.1) mm, p = 0.65) or glyceryl trinitrate induced dilatation (18.8 (1.5)% v 18.5 (1.7)%, p = 0.90) between Indian Asians and European whites, respectively. Univariate analysis showed that Indian Asian race was significantly associated with impaired flow mediated dilatation (regression coefficient = -2.8 (1.3)%, p = 0.03), and in multivariate analysis, this relation was independent of both conventional coronary heart disease risk factors and markers of insulin resistance.

CONCLUSIONS

Endothelial function is impaired in healthy UK Indian Asians compared with European whites, and the defect is not accounted for by major coronary heart disease risk factors. Endothelial function may be modulated by novel risk factors in Indian Asians.

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.

Relationship of glucose and insulin levels to the risk of myocardial infarction: a case-control study

OBJECTIVE

To assess the relationship between dysglycemia and myocardial infarction in nondiabetic individuals.

BACKGROUND

Nondiabetic hyperglycemia may be an important cardiac risk factor. The relationship between myocardial infarction and glucose, insulin, abdominal obesity, lipids and hypertension was therefore studied in South Asians-a group at high risk for coronary heart disease and diabetes.

METHODS

Demographics, waist/hip ratio, fasting blood glucose (FBG), insulin, lipids and glucose tolerance were measured in 300 consecutive patients with a first myocardial infarction and 300 matched controls.

RESULTS

Cases were more likely to have diabetes (OR 5.49; 95% CI 3.34, 9.01), impaired glucose tolerance (OR 4.08; 95% CI 2.31, 7.20) or impaired fasting glucose (OR 3.22; 95% CI 1.51, 6.85) than controls. Cases were 3.4 (95% CI 1.9, 5.8) and 6.0 (95% CI 3.3, 10.9) times more likely to have an FBG in the third and fourth quartile (5.2-6.3 and >6.3 mmol/1); after removing subjects with diabetes, impaired glucose tolerance and impaired fasting glucose, cases were 2.7 times (95% CI 1.5-4.8) more likely to have an FBG >5.2 mmol/l. A fasting glucose of 4.9 mmol/l best distinguished cases from controls (OR 3.42; 95% CI 2.42, 4.83). Glucose, abdominal obesity, lipids, hypertension and smoking were independent multivariate risk factors for myocardial infarction. In subjects without glucose intolerance, a 1.2 mmol/l (21 mg/dl) increase in postprandial glucose was independently associated with an increase in the odds of a myocardial infarction of 1.58 (95% CI 1.18, 2.12).

CONCLUSIONS

A moderately elevated glucose level is a continuous risk factor for MI in nondiabetic South Asians with either normal or impaired glucose tolerance.

Dietary intake of Indians living in the metropolitan area of Durban

OBJECTIVE

To report on energy and nutrient intakes, as a risk factor for coronary heart disease in Indian South Africans.

DESIGN

Cross-sectional dietary study as part of a coronary heart disease survey.

SETTING

Metropolitan area of Durban, South Africa.

SUBJECTS

Free-living Indian men (n = 406) and women (n = 370) 15-69 years of age.

METHODOLOGY

Dietary data were collected by three interviewers using a 24-h dietary recall and expressed as median intakes of macronutrients.

RESULTS

Results reported a low energy intake and the percentage of energy derived from total fat varied between 32.3 and 34.9% in men and between 33.1 and 36.1% in women. The energy intake to basal metabolic rate (EI:BMR) ratios were low for all age groups suggesting potential under-reporting. Intake of polyunsaturated fatty acids was high, more than 10% of energy, with a median polyunsaturated to saturated fatty acid ratio (P:S ratio) that varied between 1.38 and 1.96 for the various age and sex groups. Dietary cholesterol varied between 66 and 117 mg per 4.2 MJ in men and between 76 and 109 mg per 4.2 MJ in women. Dietary fibre intakes were low and varied between 8.0 and 11.0 g per 4.2 MJ in men and between 7.6 and 9.6 g per 4.2 MJ in women.

CONCLUSIONS

The dietary P: S ratios were high and the effect of such a high P:S ratio on the oxidation of low density lipoprotein in this population, with a high prevalence of coronary heart disease (CHD), should be investigated as a possible risk factor for CHD.

Screening for Type 2 diabetes mellitus in the UK Indo-Asian population

AIMS

Type 2 diabetes mellitus (DM) has a high prevalence in Asian subjects. A simple method of screening using self-testing for postprandial glycosuria achieved a good response rate and a sensitivity which compared favourably to more expensive and invasive methods in a semirural Caucasian population. We examined its effectiveness in Asian subjects.

METHODS

Caucasian and Indo-Asian subjects aged 35-70 years in two general practices in Leicester (n=9896 (6198=Asian subjects, 3698=Caucasian)) were screened. Those known to have diabetes were excluded. Subjects were asked to self-test for glycosuria 1 h after their main meal. Instruction and response cards were translated in Punjabi and Gujarati and sent to the Asian subjects, depending on age and surname.

RESULTS

Response rate was 34.4% in Asian subjects compared to 54.0% in Caucasian subjects. Prevalence of glycosuria was 8.2% in Asian subjects and 3.2% in Caucasian subjects. Two hundred and thirty-nine subjects recorded glycosuria and 202 (84.5% of the total, 86.9% of Asian subjects, 78.1% of Caucasian) attended for oral glucose tolerance test (OGTT). Sixty-three (31.2%) were found to have diabetes (46, 73% Asian), 29 (14.4%) impaired glucose tolerance (24, 82.8% Asian) and 110 (54.4%) normal glucose tolerance (82, 74.6% Asian). Thus 30% of Asian subjects and 34% of Caucasian subjects had diabetes on OGTT. The prevalence of diabetes in 35-70 years in the total population after screening was 5.6% (6.8% in Asian subjects, 3.6% in Caucasian) and in the screened population was 12.7% (17.9% in Asian subjects, 6.3% in Caucasian).

CONCLUSIONS

Screening for diabetes using this method, in terms of response rate, is not as effective in a large city setting, particularly in the Asian population. However, the yield of diabetes in the age group 35-64 years compares well to much more expensive and labour intensive approaches and its use in this population in a primary care setting is justified.

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.

The prevalence of type 2 diabetes and gestational diabetes mellitus in an inner city multi-ethnic population

Zeeburg', a multiethnic town borough in the Amsterdam-East region, has one of the city's highest rates of immigrants. In the total population of 19,825 Surinam (mainly Creole), Turkish, Moroccan, and Dutch adults the prevalence of known type 2 diabetes in 1994 and of gestational diabetes mellitus (GDM) between January 1992 and January 1997 was investigated. Based on World Health Organization (WHO) criteria of 1985, the age-standardized prevalence of type 2 diabetes was similar in men (6.4%; 95% confidence interval [CI]: 5.6-7.2) and women (6.4%: 95% CI: 5.8-7.0) for all ethnic groups combined. However, the age- and sex-standardized prevalence of type 2 diabetes was significantly greater in the non-Dutch inhabitants than in the Dutch inhabitants (17.3% [95% CI: 12.9-21.6] in Surinam inhabitants, 10.9% [95% CI: 9.7-12.2] in Turkish inhabitants, 12.4% [95% CI: 9.7-15.0] in Moroccan inhabitants, and 3.6% [95% CI: 3.2-3.9] in Dutch inhabitants). The odds ratios for type 2 diabetes for the separate immigrant groups relative to the Dutch group were 5.88 (95% CI: 4.54-7.69) for Surinam inhabitants, 4.00 (95% CI: 2.86-5.55) for Turkish inhabitants, and 4.17 (95% CI: 3.03-5.55) for Moroccan inhabitants. GDM was present in 2.59% of women of non-Dutch origin compared with 0.62% of women of Dutch origin. A significant positive association was found between the non-Dutch origin and the occurrence of GDM (chi2 = 6.7; p < 0.01). The study highlights a high prevalence of known type 2 diabetes and GDM in the immigrant inhabitants and emphasizes that appropriate interventions are necessarily with implications for health targets and capitation based budgets.

The impending kidney transplant crisis for the Asian population in the UK

Kidney transplantation offers the opportunity of an improved quality of life for those patients suffering from renal failure. Unfortunately, this treatment is not available to all people as this is influenced by the increasing demand for a limited supply of suitable organs. This situation is particularly alarming for the UK's Asian population with their higher susceptibility to end-stage renal failure which has resulted in a greater demand for transplants. Consequently, the proportion of Asians on transplant waiting lists is growing rapidly. Coupled with this are problems of cross-racial tissue type matching which has led to longer waiting times for a transplant. The situation is clear, there is an urgent need to address the number of Asians requiring a kidney transplant otherwise the human and economic costs will be very severe. In the short term there needs to be a greater number of donors coming forward from the Asian communities to increase the pool of suitable organs. In the long term, there needs to be greater attention on preventive strategies to reduce the number of Asians requiring renal replacement therapy.

Abdominal obesity, impaired nonesterified fatty acid suppression, and insulin-mediated glucose disposal are early metabolic abnormalities in families with premature myocardial infarction

British Indian Asian men aged <40 years have a twofold to threefold increased risk of death from coronary heart disease (CHD) compared with British whites. Epidemiological studies have suggested an association between glucose intolerance and hyperinsulinemia with premature CHD in Indian Asians. We tested the association of insulin action with myocardial infarction (MI) by using the hyperinsulinemic-euglycemic clamp in 17 MI patients: 8 Punjabi Sikhs (PSMIs), 9 British whites (BWMIs), and 17 control subjects (9 PSCs and 8 BWCs). Metabolic factors associated with insulin resistance were investigated in 51 MI patients (24 PSMIs and 27 BWMIs) and 53 control subjects (28 PSCs and 25 BWCs). Familial aggregation of defective insulin action was examined by studying five pedigrees of Sikh survivors of MI. Sikh survivors of premature MI demonstrated impaired insulin-mediated glucose uptake (P<.001) by use of the clamp technique and nonesterified fatty acid (NEFA) suppression (P<.05) by using both clamp techniques and the oral glucose tolerance test, as compared with Sikh control subjects. White patients had impaired insulin-mediated glucose uptake but normal NEFA suppression. Metabolic factors usually associated with insulin resistance, including increased 2-hour post-oral glucose tolerance test triglycerides, smaller low density lipoprotein particle size, and increased plasminogen activator inhibitor-1, were present in white (all P<.05) but surprisingly absent in Sikh (all P>.05) MI patients compared with respective ethnic control subjects. Fasting glucose and total cholesterol levels did not differ between patients and control subjects. Abdominal obesity, impaired NEFA suppression after oral glucose, and fasting hyperinsulinemia were present in Sikh MI patients and their nondiabetic first-degree relatives compared with Sikh control subjects. PS survivors of premature MI demonstrated impaired insulin-mediated glucose disposal and NEFA suppression compared with ethnic control subjects. BWMI patients showed abnormalities of carbohydrate, but not of NEFA, metabolism compared with white control subjects. Defects of insulin action manifested as abdominal obesity, impaired NEFA suppression, and fasting hyperinsulinemia are present in Sikh MI patients and their asymptomatic, nondiabetic, first-degree relatives. We suggest that these defects may be early metabolic markers that predict risk of premature MI among PSs.

Classifying ethnicity utilizing the Canadian Mortality Data Base

The study of ethnic differences in disease is a methodological challenge as ethnicity is often not identified in existing datasets and surrogate measures need to be used. We have developed a novel methodology combining last name and country of birth to study mortality patterns of Canadians of South Asian (SA) and Chinese (CH) ethnic origin and have compared death rates among SA, CH, and White (WH) Canadians.

METHODS

SA and CH were identified in the Canadian Mortality Data Base (CMDB) using the last name and country of birth of the deceased. Records of people who had been born in countries with large South Asian and Chinese populations (e.g. India, Pakistan, China, Hong Kong) were selected and manually screened by last name. A name directory was then created of distinct South Asian and Chinese names and this directory was used to search all other records in the CMDB for SA and CH deaths. Where necessary, other identifying characteristics such as first name and parents' last name were also used. Population counts were obtained from the Census self-reported question on ethnicity for SA and CH. WH were identified as non-immigrant Canadians who were neither SA nor CH. The method of assigning ethnicity in the CMDB and Census were assessed for comparability and issues of validity and reliability were addressed.

RESULTS

Using this method, 10,989 SA and 21,548 CH deaths were identified. There was marked heterogeneity in birthplace, with only 56% of SA born in South Asia and only 74% of CH born in Greater China. Last names had high validity for self-reported ethnicity in a population sample of SA and were highly reproducible. Mortality rates varied dramatically between groups studied. SA and WH had high rates of ischemic heart disease while stroke mortality was similar among all three groups. Cancer death rates were high in CH and WH and much lower in SA.

CONCLUSION

Last names and country of birth can be used to determined ethnicity of SA and CH with validity and reliability, and leads to a more accurate classification than country of birth alone. The contrasting patterns observed in mortality from major causes of death suggest many interesting hypotheses for further study.

Appreciating background and culture: the South Asian elderly and mental health

In the next decade there will be an increase in the number of elderly people from a South Asian background. All too often minority groups are treated as homogeneous, leading to inappropriate generalisations, unmet need, and unsuitable treatment and management. In order to understand and manage a person's illness it is necessary to appreciate the effects of their culture, experiences and environment. The South Asian community is well established in the UK and the attitudes of the growing elderly population towards mental illness, their expressions of distress, and views on management and treatment are only now being canvassed. Awareness of these issues is essential before epidemiological studies of depression and dementia and use of health services by this group will provide beneficial results.

The epidemiology of tuberculosis by ethnic group in Birmingham and its implications for future trends in tuberculosis in the UK

OBJECTIVES

To describe the epidemiology of tuberculosis (TB) in Birmingham, UK, by ethnic group and to assess the implications of the findings for future trends in TB in the UK.

METHODS

Retrospective review of records of all patients notified with TB in Birmingham during 1989-1994.

RESULTS

The decline in TB notifications in Birmingham halted and then reversed in 1987-1992. Trends in overall notifications were mainly influenced by trends in cases of Asian origin. Crude notification rates in 1989-1994 are 17 times higher in Asian than Caucasian residents (p < 0.01). Rates in African Caribbean residents are also statistically significantly higher than in Caucasians (p < 0.01) but significantly lower than in Asians. Crude rates for Asian people born abroad are 4.1 times higher than for Asians born in the UK (p < 0.01) but only 3.8% of Asian patients had been resident in the UK for less than 1 year. The group accounting for the highest number of cases were female Asians aged 20-29, followed by male Asians of the same age. Age-specific rates show that incidence increases with age in both Asian and white groups, with a small peak in 20-29-year-old Asians. TB is uncommon in all Caucasian age-groups under 50 years of age (less than 1 per 10,000) but is relatively common in all Asian age-groups over 15 years of age (over 10 per 10,000).

CONCLUSIONS

The different epidemiology of TB in the Caucasian and Asian populations in the UK suggests that from about the second decade of the next century, TB in the UK will almost be entirely a problem of ethnic minorities and that even if new infection was eliminated now in Asian people, cases due to reactivation would continue to occur until the third quarter of the next century.

Demographic and clinical features of diabetes mellitus in 1095 Yemeni patients

The ever-increasing incidence of diabetes mellitus is a cause for growing public health concern in both developed and developing countries. In this study, we aim to explore the special demographic and clinical features of diabetes, as seen in a large sample of Yemeni patients, and to compare these features with those reported in other countries. All patients referred to our diabetic clinic over a five-year period were investigated according to a standardized protocol. Data was collected and fed into a personal computer with a software statistical package for analysis. The relative frequencies of clinical classes of diabetes were 10.5% for IDD, 58.6% for non-obese NIDDM; 26.2% for obese NIDDM, and 4.7% for IGT. In the IDDM class, the age-specific relative frequency rate showed a higher and earlier onset peak frequency in females than in males. Among NIDDM class, about 31% of patients were diagnosed under the age of 45 years, and only 12% were first diagnosed after the age of 65 years. Most NIDDM patients came from social classes I and II (professionals and intermediate professionals) and most IDDM patients came from social class IIIM (skilled manual). A positive family history of diabetes among first-degree relatives of index patients was observed in 33.7% of IDDM patients, in 30% of non-obese NIDDM patients, in 39.2% of obese NIDDM patients and 32% of IGT patients. Female NIDDM patients had a significantly higher mean body mass index (BMI) than males (P<0.0001). Hypertension was recognized in 24.2% of the diabetic population aged 20 to A(3) 65 years. Large vessel disease (LVD) was observed in 28% of patients, small vessel disease (SVD) in 45%, and peripheral neuropathy in 40.7%. Inadequate glycemic control was noticed during follow-up in the majority of patients. Diabetes mellitus in Yemen, especially NIDDM, is characterized by an earlier age at onset, and predominance of males and non-obese NIDM subclass. Other characteristics include moderate genetic susceptibility, inadequate glycemic control and high prevalence of chronic complications.