Abdominal obesity and physical inactivity as risk factors for NIDDM and impaired glucose tolerance in Indian, Creole, and Chinese Mauritians

A comparative study of generalised obesity and anatomical distribution of subcutaneous fat in adult white and Pakistani migrant males in Peterborough

Obesity can be defined in two main ways--generalised obesity (measured as Body Mass Index (BMI)) and anatomical distribution of adiposity. A comparative study of generalised obesity (body mass index) and the anatomical distribution of subcutaneous fat in adult White and Pakistani migrant males was carried out in Peterborough. No significant difference in the prevalence of obesity as measured by the BMI was observed between Whites and Pakistani migrants. The mean BMI values were similar in both ethnic groups. However, Pakistanis had significantly more truncal fat compared with Whites whereas the latter group had more upper extremity fat compared with the former. No significant difference was observed in the amount of fat deposited on the lower extremities between the two ethnic groups. The Pakistanis also had significantly more total (sum of all skinfolds) subcutaneous fat compared with Whites. These preliminary results clearly indicate that there is a tendency for accumulation of truncal adiposity in Asians of Pakistani origin compared with Whites irrespective of the level of generalised (BMI) obesity. The health implications of body fat patterning on non-insulin-dependent diabetes mellitus (NIDDM) and coronary heart disease (CHD) are well known. It is possible that the pattern of fat distribution observed in migrant Pakistani males in this study exists in other migrant groups originating from the Indian subcontinent. This pronounced truncal distribution of body fat could be one of the risk factors predisposing migrant Asians in the UK to develop NIDDM and CHD irrespective of their BMI. Future epidemiological studies should lay more emphasis on morphological fat patterning rather than BMI in Asian migrants in the UK.

Using central cancer-registry data to monitor progress in early detection of breast and cervical cancer (Illinois, United States)

Cases of breast and cervical cancer account for almost 40 percent of all cancers diagnosed in Illinois (United States) women. Information on screening rates, however, is not collected routinely for the populations at risk. This paper reports on surveillance indicators designed to identify target populations and evaluate programs. All cases of cancers of the breast (n = 38,824, including in situ) and invasive cervix (n = 2,763) with a known stage, among women aged 40 to 74, were identified through the population-based Illinois State Cancer Registry for 1986 to 1992. The proportion of breast cancer cases with in situ disease-stage and cervical cancer cases with a late invasive stage were selected as surveillance indicators. Differences by age and race were evaluated, as were age- and race-specific trends. The data suggest that Black women, aged 40 to 74 years, and White women, aged 65 to 74 years, should be targeted for breast-cancer-screening interventions. All women, aged 40 to 74, should be targeted for enhanced cervical-cancer-screening interventions. Significant trends in in situ breast cancer diagnoses were apparent in all age-race groups, however no significant decline in invasive cervical cancer was found for any age-race group. The indicators identified the age- and race-specific disparities among potential target populations for breast and cervical cancer screening.

Insulin and colon cancer

Some factors related to Westernization or industrialization increase risk of colon cancer. It is believed widely that this increase in risk is related to the direct effects of dietary fat and fiber in the colonic lumen. However, the fat and fiber hypotheses, at least as originally formulated, do not explain adequately many emerging findings from recent epidemiologic studies. An alternative hypothesis, that hyperinsulinemia promotes colon carcinogenesis, is presented here. Insulin is an important growth factor of colonic epithelial cells and is a mitogen of tumor cell growth in vitro. Epidemiologic evidence supporting the insulin/colon-cancer hypothesis is largely indirect and based on the similarity of factors which produce elevated insulin levels with those related to colon cancer risk. Specifically, obesity--particularly central obesity, physical inactivity, and possibly a low dietary polyunsaturated fat to saturated fat ratio--are major determinants of insulin resistance and hyperinsulinemia, and appear related to colon cancer risk. Moreover, a diet high in refined carbohydrates and low in water-soluble fiber, which is associated with an increased risk of colon cancer, causes rapid intestinal absorption of glucose into the blood leading to postprandial hyperinsulinemia. The combination of insulin resistance and high glycemic load produces particularly high insulin levels. Thus, hyperinsulinemia may explain why obesity, physical inactivity, and a diet low in fruits and vegetables and high in red meat and extensively processed foods, all common in the West, increase colon cancer risk.

Incidence and predictors of diabetes in Japanese-American men. The Honolulu Heart Program

Reports on the incidence and predictors of diabetes in minority populations are infrequent. The 6-year cumulative incidence of diabetes between 1965 and 1974 was estimated among 7210 Japanese-American men aged 45 to 68 years who were enrolled in the Honolulu Heart Program and were free of clinically recognized diabetes at baseline. The incidence of "possible" diabetes (based on history, medication, or hospital diagnosis) was 12.8% and the incidence of "probable" diabetes (based on diabetic medication) was 5.7%. Estimates of incidence in subjects with a nonfasting glucose concentration less than 225 mg/dL 1 hour after a 50-g load were 9.7 and 4.0%, respectively. Multivariate adjusted odds ratios (ORs) for probable diabetes in all subjects comparing the upper quintile with the lower four quintiles combined for continuous variables indicated statistically significant direct associations with body mass index (OR, 1.69; 95% confidence interval (CI), 1.31 to 2.18), 1-hour postchallenge glucose level (OR, 5.79; 95% CI, 4.58 to 7.33), triglyceride levels (OR, 1.47; 95% CI, 1.14 to 1.91), systolic blood pressure (OR, 1.36; 95% CI, 1.05 to 1.76), and parental history of diabetes (OR, 1.73; 95% CI, 1.29 to 2.33), and an inverse association with physical activity (OR, 0.49; 95% CI, 0.34 to 0.72), using logistic regression models including these variables as well as age, subscapular/triceps skinfold ratio, and hematocrit simultaneously. Associations were similar but slightly weaker in men with glucose levels less than 225 mg/dL and in those who remained free of cardiovascular disease. When older men (55 to 68 years old) were compared with younger (45 to 54 years old) men, associations among the older group were stronger for body mass index, physical activity, and systolic blood pressure and they were weaker for glucose levels, triglyceride values, and parental diabetes. Results suggest that body mass index, physical inactivity, glucose level, and parental diabetes appear to be independent risk factors for diabetes, while triglyceride and systolic blood pressure levels may be markers for an adverse cardiovascular risk factor profile associated with diabetes and may reflect an insulin resistance syndrome.

Associated risk factors of diabetes in Kin-Hu, Kinmen

This is a community-based survey carried out by the Yang-Ming Crusade to investigate potential risk factors of non-insulin-dependent diabetes in Kin-Hu, Kinmen. A total of 3236 people completed both questionnaire and venipuncture (1536 men and 1700 women). Sex, age, education level, family history, obesity, hypertension, triglyceride, cholesterol levels and usage of diuretics were found significantly correlated with diabetes in univariate analyses. The stepwise logistic regression was used in multivariate analysis. Important correlates were age (OR = 1.03; 95% CI, 1.02-1.05), body mass index (OR = 1.96; 95% CI, 1.31-2.94), waist/hip ratio (OR = 2.08; 95% CI, 1.38-3.13), triglyceride (OR = 1.47; 95% CI, 1.19-1.81), cholesterol (OR = 1.47; 95% CI, 1.23-1.77), HDL-cholesterol (OR = 0.50; 95% CI, 0.25-0.99) and previous hypertension (OR = 1.66; 95% CI, 1.05-2.61). In addition to body mass index, waist/hip ratio was an independent risk factor. Besides the risk factor of total cholesterol, HDL-cholesterol was an independent protective factor. Previous history of hypertension was a stronger predictor on diabetes than current hypertension.

Effect on central obesity and associated disturbances of low-energy, fruit- and vegetable-enriched prudent diet in north Indians

The effects of fruit and vegetables in conjunction with low-energy diet as adjuncts to a prudent diet were compared for 6 months in a randomized, single blind trial in the management of 202 group A and 204 group B patients with acute myocardial infarction. Dietary intakes were obtained based on weighing of fruit, vegetable and legume intake and weekly diet diaries. After 6 months of follow-up, mean body weight, waist/hip ratio and glucose intolerance fell significantly in patients in group A compared with those in group B. Body weight declined by 5.3 kg in group A versus 2.2 kg in group B (95% confidence interval of difference (CI) 1.28-4.92), waist/hip ratio decreased by 0.05 in group A and 0.02 in group B (95% CI 0.01-0.10), and glucose intolerance decreased by 0.85 mmol/l in group A versus 0.19 mmol/l in group B (95% CI 0.19-1.21). There was a significant net decrease in serum triglycerides (0.18 mmol/l), systolic and diastolic blood pressures (7.9/4.7 mmHg), and a net increase in high-density lipoprotein cholesterol (0.10 mmol/l). Underlying these changes, group A patients had 393 g/day net increase in the consumption of fruit and vegetables and 1,160 kJ/day net decrease in energy intake compared to these changes in groups. Those who made greater changes in diet also had greater improvements in central obesity, glucose intolerance and in other associated disturbances.

The epidemiology of obesity

Obesity and pattern of fat distribution are both important factors related to poor health outcomes. Many measures of obesity and fat distribution pattern have been employed by different authors and to facilitate interpopulation comparisons and interpretation of secular trends it is necessary that standardized methods for measurement and classification are set in place. The use of BMI as a measure of fatness for epidemiological studies is widely accepted, easily measured and BMI predicts morbidity and mortality in many populations. The most appropriate level at which to define obesity is a matter of debate but systems which use BMI > or = 25 and < or = 30 kg/m2 as overweight, and BMI > 30 kg/m2 as obese for all adults are simple, easily remembered, already widely used and BMIs above 30 kg/m2 are clearly associated with increased risk of morbidity and mortality. In some populations there may be a case for using a lower cut-off but not unless there is specific evidence to support this. For the present WHR is probably the best method for assessing fat distribution, although waist circumference on its own may be more useful in determining risk levels. Standard sites for measurement of both waist and hip girths have been described. There is a large variation in the prevalence of obesity across the populations for which data is available, with high prevalences of obesity and dramatic secular trends especially apparent in modernizing Pacific Island populations. The 'thrifty genotype' hypothesis has been invoked to try and explain this situation. The clustering of obesity, NIDDM and CVD risk factors has been recognized and various 'syndromes' have been described which group different factors together, with hyperinsulinaemia and insulin resistance proposed as the underlying problem.

Is hyperinsulinaemia a central characteristic of a chronic cardiovascular risk factor clustering syndrome? Mixed findings in Asian Indian, Creole and Chinese Mauritians. Mauritius Noncommunicable Disease Study Group

The aim of the study was to investigate whether the constellation of cardiovascular disease risk factors, described as Insulin Resistance Syndrome, exists in the multi-ethnic population of Mauritius, and to assess whether hyperinsulinaemia is the key feature of this syndrome. A sample of 5080 Mauritian subjects (aged 25-74 years) was examined in a noncommunicable diseases survey in 1987. Survey procedure included an oral glucose tolerance test, and anthropometric, blood pressure, plasma lipids and serum insulin measurements. Abnormal glucose tolerance (diabetes and impaired glucose tolerance), general obesity, upper-body obesity, hypertension, low HDL-cholesterol, and hypertriglyceridaemia were defined as risk factor conditions. Mean values for a series of risk factor variables were compared between reference subjects (no risk factors) and those with a risk factor condition (either one condition only, or in combination with one or more others). Prevalence estimates for each risk factor condition in combination with three or more other conditions were three to four times greater than expected by chance, and levels of risk factors for subjects with more than one risk factor condition were further away from the reference levels than for those with just one condition. Fasting and 2-h serum insulin levels were elevated for each condition when in combination with others, or to a lesser extent when isolated. However, this was not the case for isolated hypertension where insulin levels were not elevated. When adjusted for age, sex, and body mass index, insulin levels were only significantly elevated in subjects with upper-body obesity if in association with general obesity.(ABSTRACT TRUNCATED AT 250 WORDS)

Body mass, fat distribution and cardiovascular risk factors in a lean population of south China

The associations of body mass index and abdominal adiposity, represented by an elevated waist/hip circumference ratio, with cardiovascular risk factors were examined in men and women, aged 28-69 years, from urban and rural areas of Guangzhou, China. Mean body mass index ranged from 20.1 to 21.9 kg/m2 across the four sex- and area-groups. Mean waist/hip ratio was 0.84 in men and 0.80 in women. After accounting for age and body mass index, waist/hip ratio was associated negatively (p < 0.05) with fasting serum HDL cholesterol (both sexes), and positively with serum triglycerides (both sexes), total and LDL cholesterol (men only), uric acid (both sexes), glucose (women only), and mean systolic blood pressure (women only). Body mass index was associated in a similar direction with most of these risk factors. These data confirm that abdominal adiposity is independently associated with cardiovascular disease risk factors, even in a lean Asian population.

Serum insulin and ECG abnormalities suggesting coronary heart disease in the populations of Mauritius and Nauru: cross-sectional and longitudinal associations

Cross-sectional associations between insulin and ECG abnormalities suggestive of 'possible' and 'probable' coronary heart disease (CHD) in the populations of Nauru (n = 568) and Mauritius (n = 3280) have been examined in both non-diabetic and diabetic subjects. Additionally, the longitudinal relationship between baseline insulin and incident ECG abnormalities has been explored in non-diabetic Nauruans (n = 177) over 5 years. Age-adjusted mean 2-hour serum insulin was generally higher in subjects with ECG abnormalities than those with a normal ECG, but the difference was significant only for non-diabetic Mauritian men (p < 0.01). There was no clear association between prevalence of ECG abnormalities and quintiles of fasting or 2-hr insulin in Mauritians, and in non-diabetic Nauruans there was a non-significant positive association between prevalence of ECG abnormalities and tertiles of 2-hr insulin. Logistic regression analyses showed a slight positive association between 2-hr insulin and ECG abnormalities in non-diabetic Mauritians (p = 0.06 in males, p = 0.09 in females), and non-diabetic male Nauruans (p = 0.054) independent of possible confounders. Fasting insulin was not associated in any group. In longitudinal analyses in Nauruans there were no significant differences in mean baseline fasting or 2-hr serum insulin between subjects who maintained a normal ECG and those who developed abnormalities consistent with 'possible CHD' (there were no changes suggestive of 'probable CHD'). The incidence of ECG changes suggesting 'possible CHD' was slightly higher in the upper tertile of baseline fasting insulin in both sexes and 2-hr insulin in females, but when other factors were accounted for, multiple logistic regression analyses did not support this finding. Data from the populations of Mauritius and Nauru do not support a major role for serum insulin in ECG abnormalities suggestive of CHD.

Pressão arterial, glicemia capilar e medidas antropométricas em uma população Yanomámi

Com o objetivo de avaliar o comportamento da glicemia capilar e das pressões arteriais sistólica (PAS) e diastólica (PAD) em função de medidas antropométricas, foram examinados 72 Yanomámi adultos na Área de Relações Intercomunitárias de Surucucus, Estado de Roraima. A pressão arterial foi mais elevada nos homens do que nas mulheres (PAS = 109,8 mm Hg e 100,2 mm Hg; PAD = 71,2 mm Hg e 63,5 mm Hg, respectivamente). Não houve valores compatíveis com a hipertensão arterial. A PAS correlacionou-se negativamente com a idade e positivamente com altura, peso, índice de massa corporal (IMC) e circunferências abdominal e do quadril. O controle pelo IMC não alterou a correlação inversa entre PAS e idade. A correlação da PAS com a altura inverteu-se quando controlada pelo peso, enquanto o controle pela altura não alterou a correlação positiva entre peso e PAS. A PAD correlacionou-se positivamente com o peso e a altura. A glicemia foi significativamente mais elevada nas mulheres do que nos homens (114,1 mg/dl e 98,4 mg/dl, respectivamente). Controlando-se pelo peso, a circunferência abdominal correlacionou-se positivamente com a glicemia. Ao se controlar pela circunferência abdominal, o peso e o IMC correlacionaram-se inversamente com a glicemia. Os achados sugerem que, enquanto a PAS correlaciona-se principalmente com a massa corporal, a glicemia capilar está mais correlacionada com a concentração abdominal de gordura.

Serum insulin distributions and reproducibility of the relationship between 2-hour insulin and plasma glucose levels in Asian Indian, Creole, and Chinese Mauritians. Mauritius NCD Study Group

The relationship of 2-hour (post-75 g oral glucose) serum insulin levels with plasma glucose levels was studied in a population-based random sample comprising 2,627 Hindu Indians, 685 Muslim Indians, 1,351 Creoles (African, European, and Indian admixture), and 415 Chinese from the Indian Ocean island of Mauritius. Known diabetic subjects taking oral hypoglycemic drugs or insulin were excluded from these analyses; 64% of all diabetic subjects had usable glucose and insulin data. Both fasting and 2-hour postload insulin levels were significantly higher in women than in men, and levels in both sexes were significantly greater in Hindu and Muslim Indian subjects than in Creoles or Chinese even after controlling for differences in age, body mass index (BMI), waist to hip ratio (WHR), and plasma glucose level. Levels in Muslims were higher than those in Hindus; it was unclear whether these ethnic differences represented hereditary or unmeasured environmental factors closely associated with ethnicity. All four ethnic groups demonstrated similar inverted U- or V-shaped curves when 2-hour insulin was plotted against either basal or 2-hour glucose. Both quadratic (U) and two-piece (V) regression models improved over linear models for 2-hour insulin versus either fasting or 2-hour glucose in all ethnic groups, although in statistical terms they were good models only for the 2-hour glucose comparison. The two-piece models were associated with modest increases in R2 compared with the quadratic models, but it was not possible to precisely determine optimal turning points with either model. However, in all ethnic groups, 2-hour insulin levels decreased above glucose levels of 7.1 to 7.8 (fasting) and 11.3 to 13.5 mmol/L (2-hour) in quadratic models, and 7.5 to 9.5 (fasting) and 8.5 to 10.5 mmol/L (2-hour) in two-piece models. The shape and point of inflection of the quadratic and two-piece curves were influenced little by gender, obesity, fat distribution, and physical activity. These results are in accord with those observed in cross-sectional and longitudinal studies in other ethnic groups, and support the generality of the plasma glucose levels currently used to define diabetes mellitus, which physiologically correspond with a decrease in beta-cell responsiveness to glucose. Asian Indians appear to have an ethnic propensity to hyperinsulinemia that is not explained by obesity or adverse fat distribution.

The association of physical activity with obesity, fat distribution and glucose intolerance in Pima Indians

The relationships between physical activity, obesity, fat distribution and glucose tolerance were examined in the Pima Indians who have the highest documented incidence of non-insulin-dependent diabetes. Fasting and 2-h post-load plasma glucose concentrations, body mass index, and waist-to-thigh circumference ratios were determined in 1054 subjects aged 15-59 years. Current (during the most recent calendar year) and historical (over a lifetime) leisure and occupational physical activity were determined by questionnaire. Current physical activity was inversely correlated with fasting and 2-h plasma glucose concentrations, body mass index and waist-to-thigh ratios for most sex-age groups even when diabetic subjects were excluded. Controlled for age, obesity and fat distribution, activity remained significantly associated with 2-h plasma glucose concentrations in males. In subjects aged 37-59 years, individuals with diabetes compared to those without reported significantly less leisure physical activity during the teenage years (median hours per week of activity, 9.1 vs 13.2 for men; 1.0 vs 2.2 for women). Controlled for body mass index, sex, age and waist-to-thigh ratio, subjects who reported low levels of historical leisure physical activity had a higher rate of diabetes than those who were more active. In conclusion, current physical activity was inversely related to glucose intolerance, obesity and central distribution of fat, particularly in males. Subjects with diabetes were currently less active and reported less historical physical activity than non-diabetic subjects. These findings suggest that activity may protect against the development of non-insulin-dependent diabetes both directly and through an influence on obesity and fat distribution.

The prevalence of diabetes mellitus and impaired glucose tolerance among Hong Kong Chinese adults of working age

We studied 1513 employees (910 men and 603 women) from a public utility company and a regional hospital to document the prevalence of diabetes mellitus (DM) and impaired glucose tolerance (IGT) in the Chinese working population of Hong Kong using a 75-g oral glucose tolerance test and World Health Organisation (1985) criteria. The overall prevalence of DM was 4.5 (95% confidence interval: 3.5-5.7%) and that of IGT 7.3 (6.0-8.6%). The prevalence of DM was 5.1 (3.7-6.5%) in men and 3.6 (2.1-5.1%) in women, while that of IGT was 7.4 (5.7-6.5%) in men and 7.1 (5.1-9.1%) in women. The truncated age-adjusted rate of DM for age 30-64 is 7.7% which is comparable to the age-adjusted prevalence rates among Chinese living in Singapore and Mauritius but in marked contrast to the low prevalence rate in Chinese living in Mainland China. Among the diabetic subjects, 38.2% had been previously diagnosed and 32% gave a family history affecting at least one first degree relative. Using polychotomous logistic regression analysis, the independent predictive factors for the development of DM include age (t = 7.31, P < 0.001), family history (t = 5.1, P < 0.001), waist hip ratio (t = 4.05, P < 0.001) and body mass index (t = 4.62, P < 0.001). Our data further confirm that Hong Kong Chinese have a moderate to high susceptibility to non-insulin-dependent diabetes (NIDDM) when exposed to sufficient environmental and lifestyle factors. The high prevalence of IGT indicates a potential for the prevalence of DM to continue to rise unless effective preventive measures are implemented.

The prevalence of coronary heart disease in the multi-ethnic and high diabetes prevalence population of Mauritius

The prevalence of coronary heart disease (CHD) was determined in a population survey in Mauritius where the prevalence of non-insulin dependent diabetes and mortality from CHD are amongst the highest in the world. Men and women aged 35-74 years of all major ethnic groups were included: Asian Indians (Hindus and Muslims), Creoles and Chinese. ECG abnormalities suggesting either 'probable CHD' or 'possible CHD' were defined using standard criteria. The overall prevalence of probable CHD was 2.7% in men and 0.9% in women, and that of probable or possible CHD together 17.8% in men and 33.3% in women. The prevalence of CHD did not vary significantly between the four ethnic groups. In the multivariate analyses, age and high blood pressure were the most important independent predictors of ECG abnormalities. Neither diabetes nor serum insulin seemed to contribute independently to the prevalence of CHD. This survey confirmed the high ranking of Mauritius in international mortality statistics. The high rates of CHD seen in Asian Indians, African-origin Creoles and Chinese in the rapidly developing country of Mauritius may be a pointer to future problems in their regions of origin.

A study of response pattern of non-insulin dependent diabetics to yoga therapy

Changes in blood glucose and glucose tolerance by oral glucose tolerance test (OGTT) after 40 days of yoga therapy in 149 non-insulin-dependent diabetics (NIDDM) were investigated. The response to yoga in these subjects was categorized according to a severity scale index (SSI) based on area index total (AIT) under OGTT curve. One hundred and four patients showed a fair to good response to the yoga therapy. There was a significant reduction in hyperglycemia and AIT with decrease in oral hypoglycemia and AIT with decrease in oral hypoglycemic drugs required for maintenance of normoglycemia. It is concluded that yoga, a simple and economical therapy, may be considered a beneficial adjuvant for NIDDM patients.

Is serum anhydroglucitol an alternative to the oral glucose tolerance test for diabetes screening? The Mauritius Noncommunicable Diseases Study Group

The oral glucose tolerance test is inconvenient for diabetes screening. In clinical studies a reduced serum anhydroglucitol level has proved to be a sensitive and specific test for diabetes. A new minicolumn enzymatic method which is simple and robust makes use in population screening feasible. The aim of our study was to assess the usefulness of a single measurement of anhydroglucitol to screen for diabetes and impaired glucose tolerance. Assays were performed on samples taken from 227 Mauritian Chinese subjects at the time of glucose tolerance testing. Subjects had normal glucose tolerance (n = 82), impaired glucose tolerance (n = 76), newly diagnosed diabetes (n = 38), and known diabetes (n = 31). Anhydroglucitol concentrations (mean +/- SD) were similar for normal and impaired glucose tolerance subjects (23.7 +/- 8.2 vs 23.4 +/- 8.6 mg l-1). Although the differences between normal and newly diagnosed diabetes (15.0 +/- 11.0 mg l-1) and known diabetic subjects (11.8 +/- 10.6 mg l-1) were significant (p < 0.001), diagnostic sensitivity and specificity were poor. We conclude that measurement of serum anhydroglucitol is not suitable for screening for the diagnoses of impaired glucose tolerance and diabetes.

Relationship of glucose intolerance and hyperinsulinaemia to body fat pattern in south Asians and Europeans

Type 2 (non-insulin-dependent) diabetes mellitus and insulin resistance are associated with centrally-distributed obesity. These disturbances are especially prevalent in people of South Asian (Indian, Pakistani and Bangladeshi) descent. We examined the relationship of glucose intolerance to body fat pattern in a population survey of 2936 men and 537 women of South Asian and European origin living in London, UK. In both groups glucose intolerance (defined as diabetes or impaired glucose tolerance) was more strongly associated with waist-hip girth ratio than with skinfolds or body mass index. The associations between body mass index and glucose intolerance were fully accounted for by waist-hip ratio. In European men with normal glucose tolerance fasting insulin levels were more strongly correlated with body mass index than with waist-hip ratio. Physical activity scores were lower in South Asians than in Europeans but no statistically significant associations between glucose intolerance and low physical activity were detectable. Leisure-time physical activity scores were inversely correlated with 2 h insulin levels in both groups. In contrast with other studies these results suggest that a specific effect of intra-abdominal fat deposition underlies the association between glucose intolerance and obesity. The association between hyperinsulinaemia and obesity is less specific for centrally-distributed fat. When measured appropriately waist-hip ratio is the most valid anthropometric index for identifying individuals whose obesity predisposes them to glucose intolerance.

Electrocardiographic abnormalities and associated factors in Chinese living in Beijing and in Mauritius. The Mauritius Non-Communicable Disease Study Group

OBJECTIVE

To compare the prevalence of electrocardiographic abnormalities and to evaluate the association between these abnormalities and the levels of coronary heart disease among Chinese living in different environments.

DESIGN

Cross sectional surveys.

SETTING

Beijing, China, and the island of Mauritius.

SUBJECTS

Random samples of people aged 35-64 years in Beijing (621 men, 642 women) in 1984 and in Mauritius among Chinese (137 men, 130 women) and non-Chinese (1265 men, 1432 women) in 1987.

MAIN OUTCOME MEASURES

Prevalence of electrocardiographic abnormalities suggesting coronary heart disease and of associated risk factors.

RESULTS

Prevalence of electrocardiographic abnormalities suggesting coronary heart disease was significantly lower in Beijing (4.0%) than in Mauritian Chinese (24.3%) and Mauritian non-Chinese (24.5%). Mean serum concentrations of total and non-high density lipoprotein cholesterol were lower in Beijing Chinese than in Mauritian Chinese, but smoking and hypertension were slightly more prevalent. Overall, men with electrocardiographic abnormalities had higher risk factor levels than those with a normal electrocardiogram regardless of ethnic origin.

CONCLUSIONS

The prevalence of coronary heart disease and associated risk factors was different among Chinese living in two different environments: in Beijing in the People's Republic of China and in Mauritius. Chinese, who traditionally have a very low frequency of coronary heart disease, are by no means protected against coronary heart disease and other non-communicable diseases. Therefore, primary prevention of coronary heart disease is a major challenge for preventive medicine in China, as well as in many other developing countries.

Role of diabetes

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Physical activity and incidence of non-insulin-dependent diabetes mellitus in women

The potential role of physical activity in the primary prevention of non-insulin-dependent diabetes mellitus (NIDDM) is largely unknown. We examined the association between regular vigorous exercise and the subsequent incidence of NIDDM in a prospective cohort of 87,253 US women aged 34-59 years and free of diagnosed diabetes, cardiovascular disease, and cancer in 1980. During 8 years of follow-up, we confirmed 1303 cases of NIDDM. Women who engaged in vigorous exercise at least once per week had an age-adjusted relative risk (RR) of NIDDM of 0.67 (p less than 0.0001) compared with women who did not exercise weekly. After adjustment for body-mass index, the reduction in risk was attenuated but remained statistically significant (RR = 0.84, p = 0.005). When analysis was restricted to the first 2 years after ascertainment of physical activity level and to symptomatic NIDDM as the outcome, age-adjusted RR of those who exercised was 0.5, and age and body-mass index adjusted RR was 0.69. Among women who exercised at least once per week, there was no clear dose-response gradient according to frequency of exercise. Family history of diabetes did not modify the effect of exercise, and risk reduction with exercise was evident among both obese and nonobese women. Multivariate adjustments for age, body-mass index, family history of diabetes, and other variables did not alter the reduced risk found with exercise. Our results indicate that physical activity may be a promising approach to the primary prevention of NIDDM.