D.R.R. Williams

Prevalence of diabetes in a predominantly Asian community: preliminary findings of the Coventry diabetes study.

To assess the prevalence of both diagnosed and undiagnosed diabetes mellitus in an area of predominantly Asian population the Coventry diabetes study is carrying out house to house screening for diabetes in people aged 20 and over in Foleshill, Coventry. In the first five of 12 areas to be studied 2130 of 2283 Asian (93.3%) and 1242 of 1710 white subjects (72.6%) aged 20-79 agreed to be screened. The prevalence of diabetes adjusted to 1987 demographic estimates was 11.2% in Asian men and 8.9% in Asian women whereas it was 2.8% in white men and 4.3% in white women. The excess of diabetes in Asian subjects was predominantly of non-insulin-dependent diabetes, and no significant differences in body mass were found to account for the higher prevalence. Diabetes had not been diagnosed previously in at least 26% of the white and 30% of the Asian diabetics screened, and it is estimated that in this community the condition remains undiagnosed in 42% of white and 40% of Asian diabetics.

Undiagnosed glucose intolerance in the community : the isle of Ely diabetes project

The Isle of Ely Diabetes Project is a prospective population‐based study of the aetiology and pathogenesis of Type 2 diabetes mellitus. Between 1990 and 1992, 1156 subjects aged between 40 and 65 years underwent a standard 75 g oral glucose tolerance test (OGTT). A total of 1122 individuals who were not known to have diabetes completed the test and were classified according to WHO criteria; 51 subjects (4.5%) had previously undiagnosed diabetes and 188 (16.7%) had impaired glucose tolerance. The subjects with newly diagnosed glucose intolerance were significantly older, more obese, and shorter than those with normal glucose tolerance. Blood pressure, cholesterol, triglyceride, and LDL‐cholesterol concentrations were elevated and HDL‐cholesterol levels were lower among those with abnormal rather than normal glucose tolerance. In multiple regression analyses stratified by gender and including age, body mass index, and the waist‐hip ratio as covariates, there were significant differences between those with normal and abnormal glucose intolerance in blood pressure, triglyceride, and HDL‐cholesterol, but not total or LDL‐cholesterol. In both male and female subjects, height had a significant independent negative association with the plasma glucose at 120 min after administration of oral glucose (standardized β coefficient = ‐0.12, p<0.01).

Height and glucose tolerance in adult subjects

SummaryIn a prospective study concerning the pathogenesis of impaired glucose tolerance and Type 2 (non-insulindependent) diabetes mellitus, 346 subjects with no clinical history of diabetes were given a standard 75 g oral glucose tolerance test. The expected positive associations between 120-min plasma glucose concentration and age and body mass index were observed in both sexes and between 120-min plasma glucose and waist/hip ratio in male subjects. An unexpected negative correlation was found between 120-min plasma glucose and height in both sexes (r = − 0.23, (95% confidence interval, − 0.38− − 0.07) p<0.007 for male subjects and r = − 0.24, (− 0.37− − 0.11) p<0.006 for female subjects). These negative associations with height remained significant after controlling for age and body mass index in male subjects but not in female subjects. In the latter a highly significant negative relationship of height with age was recorded (r = − 0.33, (− 0.45− − 0.20) p<0.0001). Comparison between individuals with impaired glucose tolerance and control subjects matched for sex, age and body mass index showed that subjects with impaired glucose tolerance are significantly shorter. Mean (± SEM) height in the male subjects with impaired glucose tolerance (n = 29) was 173.4 ± 1.1 cm vs 176.9 ± 1.3 cm in control subjects, p = 0.02. In the female subjects(n = 39)mean(±SEM)height was 159.4±1.0 cm vs 162.4±1.0 cm in control subjects, p = 0.02. The negative relationship between height and glucose tolerance is a new epidemiological observation which has not been previously reported. One possible reason for this is that the most commonly used anthropometric index, body mass index, eliminates height as an independent analytical variable.

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

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

Knowledge of diabetes in Asians and Europeans with and without diabetes: the Coventry Diabetes Study.

Knowledge about the nature, symptoms, complications, and treatment of diabetes was assessed among United Kingdom Europeans and Asians with and without diabetes during the Coventry Diabetes Study. An open questionnaire was validated for use among Asians and Europeans and a ‘Knowledge Index’ constructed. The questions were answered by 3814 (87%) of 4395 Asians and 3783 (69%) of 5508 Europeans. Among those with known diabetes, 216 (96%) of 223 Asians and 98 (94%) of 104 Europeans answered the questions. The nature of diabetes was unknown in 30% of Europeans and 44% of Asians with diabetes, and 42% and 67%, respectively, could not name a single complication. Most of those without diabetes were unable to name either a complication (Europeans 66%, Asians 89%) or a single symptom (66% and 83%, respectively). The Knowledge Index was highest in Europeans, increased with increasing educational achievement, and was lowest in non‐diabetic subjects without a family history of diabetes. Even those with diabetes had a low Knowledge Index.

Decreased non-esterified fatty acid suppression and features of the insulin resistance syndrome occur in a sub-group of individuals with normal glucose tolerance

SummaryTo investigate causes of increased triglyceride concentrations in subjects with normal glucose tolerance (determined by oral glucose tolerance testing using World Health Organization criteria) 883 healthy subjects (389 men and 494 women) between 40 and 65 years of age were studied. Subjects were divided by gender into four groups according to 120-min glucose concentrations. Individuals in the highest quartile of glucose concentration had the highest mean triglyceride concentrations (p<0.0001) and highest mean non-esterified fatty acid (NEFA) concentrations (p<0.0001). There was also a clustering of cardiovascular risk factors normally associated with the insulin resistance syndrome in subjects in this group. Regression analysis showed that the most important determinants of triglyceride levels were smoking (men p=0.001, women p=0.005), waist:hip ratio (men p=0.01, women p<0.001) and NEFA suppression (men p=0.02, women p=0.005). NEFAs suppressed 16.7% in women compared to 2.4% in men during the first 30 min of the oral glucose tolerance test (p<0.001). These results show that a clustering of cardiovascular risk factors associated with decreased NEFA suppression occurs in a sub-group of subjects with normal glucose tolerance and that the pattern of NEFA suppression differs between men and women.

Interpreting hospital admissions data across the Körner divide: the example of diabetes in the north western region.

Hospital admission rates and hospital bed utilization rates are presented for all admissions assigned to diabetes mellitus as principal cause in the North Western Region from 1980/81 to 1990/91. Data are derived from Hospital Activity Analysis (1980/81–1986/87) and from the Regional Information System (1988/89–1990/91). Admission rates for all categories of diabetes combined showed little change until 1986/87 after which they rose progressively each year. Hospital bed utilization rates fell progressively from 1986/87 onwards, the number of bed days attributed to diabetes falling from 1.9 % to 0.8 % of the total for all causes. Most of the rise in admission rates from 1988/89 onwards was attributable to diabetes with ophthalmic complications (ICD 250.4). This was heavily influenced by the enumeration of day cases in the Regional Information System. When these are discounted, admission rates for the more recent years are stable. Diabetes without mention of complications (ICD 250.0) showed the most dramatic decline in its contribution to hospital bed utilization. This may be the result of increasing outpatient support from diabetes specialist nurses whose numbers increased in inverse proportion to the fall in bed utilization attributed to ICD 250.0.

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.