Prevalence of type 2 (non-insulin-dependent) diabetes mellitus and impaired glucose tolerance in the Japanese general population: the Hisayama Study

Alveolar bone loss associated with glucose tolerance in Japanese men

AIMS

Type 2 diabetes is known to affect alveolar bone loss (ABL). The purpose of this study was to examine whether impaired glucose tolerance (IGT) is associated with ABL, as is diabetes.

METHODS

A case-control study was performed with 664 Japanese men aged 46-57 years. Panoramic radiographs revealed 513 severe ABL cases, 22 moderate ABL cases, and 129 controls with good alveolar bone. Diabetes status was classified into normal glucose tolerance (NGT), impaired fasting glucose (IFG), IGT, and newly diagnosed diabetes according to the fasting plasma glucose and 75-g oral glucose tolerance test (OGTT). Diabetes under treatment was excluded. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from ordinal logistic regression analysis. Statistical adjustment was made for total cholesterol, HDL-cholesterol, triglyceride, rank in the Self Defence Forces (SDF), cigarette-years, alcohol use, body mass index, previous 10 years' brushing habits and instrument use other than toothbrush, and history of periodontal treatment.

RESULTS

A significant, approximately three-fold increase in the crude OR (crude OR=3.28; 95% CI=1.16-9.27) and non-significant 2.6-fold increase in the adjusted OR (adjusted OR=2.55; 95% CI=0.86, 7.54) of ABL was observed among men with newly diagnosed Type 2 diabetes compared with the reference group (NGT combined with IFG). However, there was no association between IGT and ABL (adjusted OR=0.99; 95% CI=0.59,1.64).

CONCLUSIONS

Type 2 diabetes, but not IGT, was positively associated with ABL. Preventive maintenance against periodontitis is important in middle-aged men with diabetes.

Prevalence and risk factors for epiretinal membranes in a Japanese population: the Hisayama study

PURPOSE

To examine the prevalence and risk factors for epiretinal membranes (ERMs) in a sample Japanese population.

METHODS

In 1998 a cross-sectional community survey was conducted among residents of Hisayama. A total of 688 men and 1087 women living in Hisayama, Japan, aged 40 years or older consented to participate in the study. Each participant underwent a comprehensive physical examination that included an ophthalmic examination. The presence of ERMs was judged from grading based on fundus examination using indirect ophthalmoscopy, slit lamp examination, and color fundus photographs. This study used non-stereoscopic 45 degrees fundus photographs to grade ERMs, whereas the other population-based studies used 30 degrees stereoscopic fundus photographs, which might explain some differences in prevalence of ERMs. Multiple logistic regression analysis was performed on the cross-sectional data to determine the risk factors for ERMs. The following ten possible risk factors were used: age; gender; hypertension; diabetes; serum cholesterol; serum HDL cholesterol; serum triglycerides; smoking habits; alcohol intake; and body mass index.

RESULTS

The prevalence of ERMs was 4.0%, and increased with age. The ERMs were more prevalent in women (4.3%) than in men (3.5%). Multiple logistic regression analysis showed that age and serum cholesterol significantly associated with ERMs.

CONCLUSIONS

This study suggests that ERMs are less common in the Japanese population than in similar populations in Western countries, and that hypercholesterolemia is a relevant risk factor for ERMs.

Age, body mass index and Type 2 diabetes-associations modified by ethnicity

AIMS/HYPOTHESIS

The aim of this study was to assess the effect of ethnicity on the association between age and body mass index as well as the prevalence of diabetes.

METHODS

We selected population-based studies carried out after 1980 in the DECODE/A studies representing different ethnic groups: 11 European, 1 Maltese, 3 Indian, 2 Chinese and 3 Japanese surveys. The total numbers of subjects were 14,240 men and 15,129 women who were 30 to 89 years of age. Diabetes was diagnosed according to the 1999 World Health Organization criteria based on a standard 75 g OGTT. Sex-specific prevalence of diabetes by age and BMI was stratified by ethnic group, in particular the interaction of ethnicity on the associations between age/BMI and the prevalence of diabetes.

RESULTS

The prevalence of diabetes was higher in studies from India and Malta compared to Japan, China, and the rest of Europe. The association between BMI and diabetes, adjusted for age, showed noticeable differences between the ethnic groups with an increase in prevalence starting at a BMI between 15 and 20 kg/m(2) in the Maltese and Indian populations compared to 25 kg/m(2 )in Europeans.

CONCLUSION/INTERPRETATION

The effect of BMI on the age-adjusted prevalence of Type 2 diabetes was modified by ethnicity with considerably lower thresholds in Indian and Maltese subjects compared to those from the rest of Europe. This difference should be reflected in national and international recommendations regarding "optimal" BMI.

Age- and sex-specific prevalence of diabetes and impaired glucose regulation in 11 Asian cohorts

OBJECTIVE

To report the age- and sex-specific prevalence of diabetes and impaired glucose regulation (IGR) according to revised World Health Organization criteria for diabetes in Asian populations.

RESEARCH DESIGN AND METHODS

We performed 11 studies of 4 countries, comprising 24,335 subjects (10,851 men and 13,484 women) aged 30-89 years who attended the 2-h oral glucose tolerance test and met the inclusion criteria for data analysis.

RESULTS

The prevalence of diabetes increased with age and reached the peak at 70-89 years of age in Chinese and Japanese subjects but peaked at 60-69 years of age followed by a decline at the 70 years of age in Indian subjects. At 30-79 years of age, the 10-year age-specific prevalence of diabetes was higher in Indian than in Chinese and Japanese subjects. Indian subjects also had a higher prevalence of IGR in the younger age-groups (30-49 years) compared with that for Chinese and Japanese subjects. Impaired glucose tolerance was more prevalent than impaired fasting glycemia in all Asian populations studied for all age-groups.

CONCLUSIONS

Indians had the highest prevalence of diabetes among Asian countries. The age at which the peak prevalence of diabetes was reached was approximately 10 years younger in Indian compared with Chinese and Japanese subjects. Diabetes and IGR will be underestimated in Asians based on the fasting glucose testing alone.

Risk factors for age related maculopathy in a Japanese population: the Hisayama study

AIMS

To examine the risk factors for age related maculopathy (ARM) in a sample Japanese population.

METHODS

In 1998, a cross sectional community survey was conducted among residents of Hisayama. A total of 596 men and 886 women living in Hisayama, Japan, aged 50 years or older consented to participate in the study. Each participant underwent a comprehensive examination that included an ophthalmic examination. The presence of ARM was determined by grading from fundus examination by indirect ophthalmoscopy, slit lamp examination, and colour fundus photographs. Using these cross sectional data, logistic regression analyses were performed to determine the risk factors for ARM. The following 10 possible risk factors were used: age, cataract, hypertension (history), hypertension (history or examination), diabetes, hyperlipidaemia, current smoker, alcohol intake, BMI, and WBC.

RESULTS

ARM was detected in 19.5% of men and 14.9% of women. Men were found to have a significantly higher prevalence of ARM than women. Multiple logistic regression analysis showed that age and hypertension (history or examination) were significantly associated with ARM in men, whereas only age was a significant risk factor for ARM in women.

CONCLUSIONS

This study suggests that higher age and male sex are relevant risk factors for ARM in Japan. In addition, hypertension is a relevant risk factor in men.

Impaired chronotropic response to exercise in acute myocardial infarction patients with type 2 diabetes mellitus

This study was undertaken in acute myocardial infarction (AMI) patients with non-insulin-dependent diabetes mellitus (type 2 DM) to investigate their impaired chronotropic response to exercise. Seventy-one AMI subjects entered the study, 30 with type 2 DM and 41 age- and body mass index-matched non-DM (control) patients. One month after the onset of AMI, these patients underwent cardiopulmonary exercise testing on a treadmill under a ramp protocol. Anaerobic threshold (AT) and peak oxygen uptake (peak VO2) were determined as indicators of exercise capacity. Plasma norepinephrine (NE) concentration was measured in blood samples obtained at 2 time points: during pre-exercise rest and immediately after peak exercise. The change in NE concentration during exercise, as an index of sympathetic nervous activity, was calculated as a percentage: deltaNE = [(NE during exercise) - (resting value)]/(resting value) x 100. The change in heart rate (HR) during exercise was calculated as a simple difference: deltaHR = [(peak HR) - (rest HR)]. Index of chronotropic response to exercise was then quantified as the deltaHR/deltaNE during exercise. No significant intergroup differences in ejection fraction at rest or HR at peak exercise were observed. However, VO2 at AT, peak VO2, deltaHR, and deltaHR/deltaNE were significantly lower in the type 2 DM group than in the non-DM group. DeltaHR correlated with VO2 at AT (r = 0.49, P<0.001) and with peak VO2 (r = 0.53, P<0.001) in all subjects. Also, deltaHR/deltaNE correlated with VO2 at AT (r = 0.42, P<0.001) and with peak VO2 (r = 0.44, P<0.001) in all subjects. AMI patients with type 2 DM had impaired cardiopulmonary responses to maximal and submaximal exercise testing and impaired chronotropic response to exercise, even though their cardiac function at rest was similar to that of non-DM AMI patients. The data suggest that one mechanism of impaired cardiopulmonary response to exercise in AMI patients with type 2 DM groups is an impaired chronotropic response.

The prevention of type 2 diabetes--lifestyle change or pharmacotherapy? A challenge for the 21st century

Diabetes mellitus is occurring in epidemic proportions in many countries. In Australia 7.4% of people over 25 years of age have diabetes (mostly type 2) and comparable or higher prevalences have been reported in the United States and a number of Asian countries. The enormous economic and social cost of this disease makes a compelling case for prevention. Epidemiological studies have shown clearly that type 2 diabetes results from an interaction between a genetic predisposition and lifestyle factors including obesity, sedentary behaviour and both calorie excess and various dietary constituents. The natural history of type 2 diabetes includes a preceding period of impaired glucose tolerance (IGT)/impaired fasting glucose (IFG) which provides an opportunity for targeted intervention within large communities. Lifestyle intervention studies have consistently shown that quite modest changes can reduce the progression from IGT to diabetes by 50-60%. It may, however, not be possible to translate these successful findings to larger cohorts or maintain the lifestyle changes longer term. This has lead to consideration of pharmacotherapy. While small studies with sulphonylureas are inconclusive, benefits have been found for metformin, acarbose and troglitazone. Big intervention studies with ramipril, rosiglitazone, valsartan and nateglinide are underway. Pharmacological intervention raises a whole range of ethical, economic and practical issues not the least of which is the problem of long term therapy of the 'otherwise well'.

Detection of cardiovascular risk factors by indices of obesity obtained from anthropometry and dual-energy X-ray absorptiometry in Japanese individuals

OBJECTIVE

To determine the cut-off points of indices of obesity for detecting hypertension, dyslipidemia and diabetes mellitus in Japanese individuals.

DESIGN

Cross-sectional study.

SUBJECTS

A total of 2728 Japanese individuals (768 males and 1960 females, aged 20-79 y) who attended the Fukuoka Health Promotion Center, Japan for health check-up.

MEASUREMENTS

Body mass index (BMI), waist circumference (WC) and waist-hip ratio (WHR) were measured. Percentage fat mass (%FM), trunk fat mass (FM(trunk)) and trunk fat mass-leg fat mass ratio (FM(trunk)/FM(legs)) were obtained by dual-energy X-ray absorptiometry (DXA). Cardiovascular risk factors were determined by blood pressure, serum lipids, fasting blood glucose and hemoglobin A(1C).

RESULTS

The cut-off points of BMI, WC and WHR were around 23.5 kg/m(2), 84 cm and 0.9 for males, and 22.5 kg/m(2), 72 cm and 0.8 for females. The cut-off points of %FM, FM(trunk) and FM(trunk)/FM(legs) were around 24%, 8 kg and 1.6 for males, and 35%, 9 kg and 1.4 for females. WHR and FM(trunk)/FM(legs) most accurately detected the risk factors.

CONCLUSIONS

For Japanese individuals, the cut-off points for detecting cardiovascular risk factors are lower than the criteria by the World Health Organization. Indices of fat distribution detected the cardiovascular risk factors more accurately than those of overall adiposity. The accuracy of detecting the risk factors was comparable between the anthropometric indices and indices obtained by DXA.

Glucose intolerance and serum aminotransferase activities in Japanese men

BACKGROUND/AIMS

Elevated activities of serum aminotransferase are commonly observed in patients with diabetes mellitus. Few studies have addressed the relation between glucose intolerance and serum activities of aminotransferase in free-living populations.

METHODS

Using a 75 g oral glucose tolerance test, we examined the association of impaired fasting glycemia (IFG), impaired glucose tolerance (IGT), and type 2 diabetes mellitus with serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT) among 4621 men aged 49-59 years of the Japan Self-Defense Forces. Statistical adjustment was made for body mass index, waist-hip ratio, and other possible confounding factors.

RESULTS

Proportions of an elevated ALT (>50 IU/l) in men with normal glucose tolerance, IFG, IGT, and newly diagnosed diabetes mellitus were 3.5%, 9.5%, 7.7%, and 18.0%, respectively. Adjusted odds ratios of an elevated ALT for IFG, IGT, and newly diagnosed diabetes mellitus were 2.2 (95% confidence interval 1.1-4.3), 1.7 (1.2-2.4), and 4.4 (3.0-6.6), respectively. IGT and diabetes mellitus were also significantly positively associated with elevated AST (>40 IU/l) and GGT (>50 IU/l).

CONCLUSIONS

Glucose intolerance is associated with elevated serum aminotransferase independent of obesity, but even a mildly elevated ALT is relatively uncommon in free-living men with glucose intolerance.

Alcohol reduces insulin-hypertension relationship in a general population: the Hisayama study

Insulin resistance may be a factor in the etiology of hypertension, and habitual alcohol intake may modify this relationship. We prospectively examined this hypothesis in 1,133 nonhypertensive, nondiabetic Japanese subjects, aged 40-79 years. Alcohol drinkers were more frequent among men than women at baseline (57.7 vs. 8.2%). The age-adjusted incidence of hypertension significantly increased with the elevating baseline insulin levels in women (P =.003 for trend), but not in men. The age- and sex-adjusted insulin levels and insulin resistance index decreased with elevating alcohol intake, while fasting glucose levels remained unchanged, suggesting that alcohol improves insulin sensitivity. Among nondrinkers, the age-adjusted incidence of hypertension significantly increased with elevating insulin tertiles in both sexes (P =.048 and.002 for trend in men and women, respectively), but not among drinkers. Our findings suggest a close association between insulin resistance and the incidence of hypertension in Japanese. However, alcohol modified and reduced this relationship.

Glucose intolerance and associated factors in Mongolia: results of a national survey

AIMS

Prevalence of glucose intolerance-diabetes and impaired glucose tolerance (IGT)-and of related conditions such as obesity and hypertension, was studied in six population samples in Mongolia in 1999.

METHODS

Diagnosis of glucose intolerance was made on the basis of 2-h blood glucose concentration, according to criteria recommended by the latest report of a WHO Expert Group.

RESULTS

Crude prevalence of diabetes was 2.9% (2.6% in men and 3.2% in women). Prevalence of IGT was 10.2% (9.3% in men and 10.8% in women). Age standardization to the standard world population of Segi resulted in a total sample prevalence of 3.1% for diabetes and 9.2% for IGT. Prevalence of abnormal glucose tolerance differed according to district of residence. Approximately one-third of the subjects with diabetes were diagnosed prior to the survey. Of those who were diagnosed previously, approximately one-half were not under any form of treatment. Subjects with abnormal glucose tolerance were older, more obese and had higher blood pressure and prevalence of hypertension than those with normoglycaemia. One-half of men and almost one-half of women were hypertensive. Three-quarters of the diabetic subjects were hypertensive. One-third of all subjects were centrally obese. Considering the conditions of principal interest-glucose intolerance, hypertension and obesity-one-half of all subjects demonstrated one or more of these conditions. Central obesity was the most common condition, followed by hypertension and then glucose intolerance. Central obesity and hypertension was the most common combination (17% of all subjects) and 4% exhibited all three conditions.

CONCLUSIONS

Non-communicable diseases are already a threat to public health in Mongolia. Although the prevalence of diabetes is not high by international standards, the relatively high prevalence of IGT suggests that the situation may deteriorate in the future in the absence of concerted action to prevent and control diabetes and related conditions.

The fasting plasma glucose cut-point predicting a diabetic 2-h OGTT glucose level depends on the phenotype

To assess the use of fasting plasma glucose (FPG) alone for the screening of diabetes as defined by a 2-h plasma glucose (2-h PG) > or =11.1 mmol/l following a 75-g oral glucose tolerance test, we collated the results from 17512 subjects aged 30-89 years without a previous history of diabetes from 12 general population-based Asian studies. The performance of FPG corresponding to the 2-h PG > or =11.1 mmol/l was characterized. The prevalence of diabetes was 4.0% by the FPG criteria only and 6.0% by the 2-h PG criteria only. The FPG value of 7.0 mmol/l gave a sensitivity for diabetes as defined by a 2-h PG > or =11.1 mmol/l of 46% and specificity of 99%. The FPG associated with a 2-h PG > or =11.1 mmol/l with optimal sensitivity and specificity was 5.8 mmol/l (sensitivity 79%, specificity 85%). The optimal FPG cut-point was affected by gender, age, body mass index and the presence of hypertension, and the resulting sensitivity and specificity corresponding to each optimal cut-point changed. The FPG was a specific but insensitive screening test for diabetes defined by 2-h PG > or =11.1 mmol/l. There seems to be ethnic differences with respect to optimal FPG cut-point, and different screening strategies may be necessary in different parts of the world.

Global burden of cardiovascular diseases: Part II: variations in cardiovascular disease by specific ethnic groups and geographic regions and prevention strategies

This two-part article provides an overview of the global burden of atherothrombotic cardiovascular disease. Part I initially discusses the epidemiological transition which has resulted in a decrease in deaths in childhood due to infections, with a concomitant increase in cardiovascular and other chronic diseases; and then provides estimates of the burden of cardiovascular (CV) diseases with specific focus on the developing countries. Next, we summarize key information on risk factors for cardiovascular disease (CVD) and indicate that their importance may have been underestimated. Then, we describe overarching factors influencing variations in CVD by ethnicity and region and the influence of urbanization. Part II of this article describes the burden of CV disease by specific region or ethnic group, the risk factors of importance, and possible strategies for prevention.

Prevalence of age related maculopathy in a representative Japanese population: the Hisayama study

AIM

To determine the prevalence of age related maculopathy (ARM) in a representative older Japanese population.

METHODS

1486 residents of Hisayama town, Fukuoka, Japan, aged 50 years or older were examined and the presence of ARM was determined by grading from fundus examination by indirect ophthalmoscope, slit lamp, and colour fundus photographs.

RESULTS

The prevalence rate of drusen, which occurred with comparable frequency in men and women, was 9.6%. The frequency of drusen increased with age (p <0.01). Hyperpigmentation and/or hypopigmentation of the retina was present in 3.2%, geographic atrophy in 0.2%, and neovascular age related macular degeneration in 0.67%. The frequency of neovascular age related macular degeneration was significantly higher in the men (1.2% v. 0.34%, p <0.01).

CONCLUSIONS

Early and late stage ARM is less common among Japanese people than among white people in Western countries, while late stage ARM is more common among Japanese than among black people.

Role of hypertension, dyslipidemia and diabetes mellitus in the development of coronary atherosclerosis in Japan

The present study evaluated the effect of hypertension (HT), dyslipidemia and diabetes mellitus (DM) on the development of coronary atherosclerosis in the Japanese population, using a cross-sectional study of 433 patients (254 men and 179 women) aged 30 years or older who underwent coronary angiography for suspected or known coronary heart disease angina at 5 cardiology departments in the Fukuoka area between September 1996 and August 1997. Patients with a disease duration of 6 months or more were excluded. The main outcome measure was angiographically defined coronary artery stenosis and was found to a significant degree in 146 patients (33.7%). HT, DM, low levels of high-density lipoprotein cholesterol (HDL-C) and hypertriglyceridemia remained as significant coronary artery disease (CAD) risk factors even after controlling for age, sex, hospital, smoking, alcohol use, body mass index and leisure time physical activity. However, hypercholesterolemia was not a significant risk factor after adjusting for these variables. After controlling for these variables, DM, low HDL-C and hypertriglyceridemia were significant CAD risk factors for men, but only DM was a significant CAD risk factor in women. These results indicate that in Japan DM, low HDL-C and hypertriglyceridemia may be more important CAD risk factors than hypercholesterolemia.

Body fatness and fat distribution as predictors of metabolic abnormalities and early carotid atherosclerosis

OBJECTIVE

To test the hypothesis that intra-abdominal fat plays a primary role over general adiposity for metabolic abnormalities and atherosclerosis.

RESEARCH DESIGN AND METHODS

We cross-sectionally studied 849 Japanese men aged 50.3 +/- 8.5 years (range 20-78) with BMI 23.5 +/- 2.9 kg/m(2). Intimal-medial thickness (IMT) of the carotid artery was measured by ultrasound. General adiposity was assessed by BMI. Waist circumference and waist-to-hip ratio (WHR) were used as a surrogate measure for abdominal fat. Abdominal subcutaneous fat area (ASF) and intra-abdominal fat area (IAF) were measured by computed tomography. Correlations between these measures and carotid IMT were analyzed. The interaction of generalized adiposity (BMI) and IAF in relation to metabolic variables, such as glucose tolerance, insulin resistance, and serum lipids, was also evaluated.

RESULTS

BMI, waist circumference, WHR, ASF, and IAF were all correlated with carotid IMT. Adjustment for BMI eliminated the associations between IMT and waist circumference, ASF, and IAF. In contrast, WHR retained a significant correlation with IMT. BMI and IAF were associated with insulin resistance, glucose tolerance, HDL cholesterol, and blood pressure independently of each other. IAF was an independent correlate for serum triglyceride, but BMI was not.

CONCLUSIONS

The primary importance of IAF over general adiposity for carotid atherosclerosis was not confirmed. Caution is recommended when using WHR as a measure of abdominal fat. The roles of IAF for metabolic abnormalities may be more limited than conventionally thought. BMI and WHR are simple and better clinical predictors for carotid atherosclerosis versus IAF.

Prevalence of type 2 diabetes mellitus and impaired glucose tolerance in a rural area of Japan. The Funagata diabetes study

PURPOSE

To determine the prevalence of type 2 diabetes and impaired sucrose tolerance (IGT) among people aged 40 and over in a rural area, Funagata, Japan, by using a 75-g oral glucose tolerance test (OGTT), and to compare the prevalence to that obtained from a more urban area, Hisayama, Japan.

METHODS AND RESULTS

Total eligible subjects for the Funagata study were 3526. Among them, 140 were confirmed to have diabetes judged by the 1985 WHO criteria. A 75-g OGTT was conducted, excluding the 140 known cases of diabetes. The 1985 WHO criteria were used to classify the current diabetes status of participants. The overall participation rate was 74.4%. The prevalence of diabetes (known and newly diagnosed cases combined) was 9.1% for men and 10.8% for women. The prevalence of IGT was 12. 0% for men and 16.5% for women. Age-adjusted prevalence (using 1990 Japanese census) of diabetes and IGT in men in Hisayama is two times higher than in Funagata (12.8% vs. 6.8% for diabetes, 19.5% vs. 10. 3% for IGT). Age-adjusted prevalence of IGT in women in Hisayama is significantly higher than in Funagata.

CONCLUSIONS

The prevalence of type 2 diabetes among people aged 40 and over is approximately 10% even in a rural area of Japan. Prevalence of diabetes and IGT is much higher in an urban area than in a rural area in Japan.

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.

Impaired glucose tolerance, diabetes mellitus, and gallstone disease: an extended study of male self-defense officials in Japan

Few studies have investigated the relation between glucose tolerance status and ultrasonographically determined gallstone disease. Using a 75-g oral glucose tolerance test, we examined the association of impaired glucose tolerance (IGT) and non-insulin-dependent diabetes mellitus (NIDDM) with gallstone disease in Japanese men. Subjects were men aged 48 to 59 of the Japan Self-Defense Forces who received a preretirement health examination between October 1986 to December 1994. After exclusion of 12 men under insulin treatment in the consecutive series of 7637 men, 174 were found to have gallstones; 103 were at the state of postcholecystectomy, and 6899 had normal gallbladder. IGT and NIDDM were associated with a modestly increased risk of gallstone disease; adjusted odds ratios were 1.3 (95% confidence interval [CI]: 0.9-1.8) for IGT and 1.3 (95% CI: 0.8-2.0) for NIDDM after adjustment for hospital, rank, smoking, alcohol use, and body mass index. Adjusted odds ratio for IGT and NIDDM combined was 1.3 (95% CI: 1.0-1.7, p=0.08). When prevalent gallstones and postcholecystectomy were considered separately, NIDDM showed a significant, positive association with postcholecystectomy, but not with prevalent gallstones. The findings add to evidence that glucose intolerance is associated with a modest increase in the risk of gallstone disease.

Waist to hip ratio, body mass index, and glucose intolerance from Funagata population-based diabetes survey in Japan

To examine the association of body mass index (BMI) and waist-to-hip ratio (WHR) with glucose intolerance among adults age 45 and over, we conducted a population-based study using an oral glucose tolerance test as a primary examination in two areas of Funagata, Japan, in 1990 and 1992. The number of eligible subjects was 1673. The participation rate was 84% (1408/1673). Glucose tolerance was assessed by the 1985 World Health Organization criteria as having diabetes (DM), impaired glucose tolerance (IGT), or normal glucose tolerance (NGT). Analyses by the generalized linear model revealed that both BMI and WHR were higher in the subjects with DM and IGT than those with NGT in both men and women after controlling for age. Analyses employing multiple logistic regression indicated that BMI and WHR were independently associated with IGT and DM in both men and women, except for BMI with IGT for men. The odds ratios for IGT associated with BMI were 1.06 (p=0.19) for men and 1.11 (p<0.01) for women. Those associated with WHR were 2.14 (p<0.01) for men and 1.35 (p<0.01) for women. These results imply that WHR plays an important role for developing DM independent of BMI.

Association of a T-cell receptor constant alpha chain gene polymorphism with progression of IgA nephropathy in Japanese patients

Immunogenetic studies have suggested the role of the T-cell receptor (TCR) in the development of immune-mediated diseases. We investigated whether a genetic polymorphism in the TCR constant alpha (Calpha) chain region might modify the susceptibility or progression of immunoglobulin A (IgA) nephropathy. The TCR Calpha chain genotype was studied in 213 Japanese patients with IgA nephropathy and 73 individuals from the general population. A polymerase chain reaction-based TaqI restriction fragment length polymorphism assay (TaqI RFLP) was applied on the 5' flanking region of the TCR Calpha first exon. The TaqI-undigested (t) and TaqI-digested (T) alleles showed similar genotype distributions between the patients with IgA nephropathy and controls (tt:Tt:TT = 16.9%:46.5%:36.6% in IgA nephropathy v 9.6%:58.9%:31.5% in controls; chi(2) = 1.9; P = not significant). To further investigate the role of TCR Calpha chain gene polymorphism in renal prognosis, we analyzed those patients with IgA nephropathy in whom renal status had been monitored for a period of more than 3 years (n = 182). According to outcome, two groups were formed. The stable (S) group included 98 patients with renal function that remained unchanged during an average follow-up of 10.7 +/- 0.4 (SE) years. The progressive (P) group (n = 84) included patients with progressively declining renal function, with an average follow-up of 11.9 +/- 0.5 years. The genotype distributions of the TCR Calpha chain gene polymorphisms between these two groups differed significantly (tt:Tt:TT = 25.5%:40.8%:33.7% in S v 10.7%:44.1%:45.2% in P; chi(2) = 7.0; P < 0.05). The frequency of the T allele was greater in the P group (67.3% in P v 54.1% in S; chi(2) = 6.6; P = 0.01). The TT or Tt genotypes were more commonly observed in patients from the P group (89.3% of T allele carriers in P v 74.5% in S; chi(2) = 6.5; P = 0.01). It appeared the T allele might foreshadow a poor renal prognosis, conferring a potential risk for developing renal failure with time (odds ratio, 2.7; confidence interval, 1.2 to 6.0; P < 0.05). In summary, TCR Calpha chain genetic variability was associated with loss of renal function over time in patients with IgA nephropathy. In conclusion, the TCR Calpha chain polymorphism might prove helpful to predict progression to chronic renal failure in Japanese patients with IgA nephropathy.

Prevalence of intracranial saccular aneurysms in a Japanese community based on a consecutive autopsy series during a 30-year observation period. The Hisayama study

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage is a life-threatening disease that occurs mostly because of the rupture of intracranial saccular aneurysms. However, little is known about the prevalence of ruptured and unruptured aneurysms in the general population. The aim of the present study was to examine the prevalence of intracranial aneurysms on the basis of a consecutive autopsy series over a 30-year observation period in a general Japanese population in Hisayama.

METHODS

We evaluated 1230 consecutive autopsy cases with craniotomy among the total deaths of Hisayama residents during 1962 through 1991 (overall autopsy rate, 80.1%).

RESULTS

A total of 73 intracranial saccular aneurysms were found in 57 cases (4.6%). The prevalence of aneurysms for women was 2.4 times higher than that for men (7.1% versus 2.9%). Among men, the prevalence of aneurysms remained unchanged across the range of age groups. In contrast, there were 2 peaks in the prevalence of aneurysms for women falling in the 40- to 49-year (14.3%) and 60- to 69-year age groups (14.5%). The most common site of the aneurysms was the middle cerebral artery (31.5%), followed by the anterior communicating artery (30.1%), anterior cerebral artery (15.1%), vertebrobasilar artery (12.3%), and internal carotid artery (11.0%). Among these 73 aneurysms, 29 (39.7%) were ruptured. Ruptured aneurysms were common in subjects <80 years of age, whereas unruptured aneurysms were prevalent in those >/=80 years of age. The frequency of ruptured aneurysms was highest in the vertebrobasilar system (66.7%) and lowest in the middle cerebral artery (13.0%).

CONCLUSIONS

Our data suggest that intracranial aneurysms are more frequent in women in the general Japanese population. Aneurysms are more prevalent in the middle cerebral artery, but the risk of rupture is highest in the vertebrobasilar system.

Effect of hyperinsulinemia on renal function in a general Japanese population: the Hisayama study

BACKGROUND

Insulin resistance and hyperinsulinemia induce glomerular hypertension and hyperfiltration, which may result in glomerulosclerosis. However, the relationship between hyperinsulinemia and renal function is uncertain.

METHODS

To elucidate whether hyperinsulinemia plays a significant part in the initiation and development of renal dysfunction, we examined in 1988 the relationship between serum insulin and renal function on data from a cross-sectional community survey conducted among residents from Hisayama Town, Japan, who were aged 40 to 79 years old. A total of 1065 men (72.0% of the total population in the same age range) and 1381 women (79.0%) without renal failure (creatinine clearance of more than 30 ml/min) underwent a comprehensive examination, including a 75 g oral glucose tolerance test.

RESULTS

The correlation analysis showed that serum insulin, blood pressure, total cholesterol, low-density lipoprotein cholesterol, triglycerides, and body mass index were all negatively correlated with the reciprocal of serum creatinine level (P < 0.01), and alcohol intake was positively correlated (P < 0.05) in both sexes. High-density lipoprotein cholesterol and smoking habits were positively correlated (P < 0.05) in men. When the subjects were divided into quartiles based on the sum of fasting and two-hour postloading insulin levels, the averages of the reciprocal of serum creatinine were significantly lower in the fourth quartile (0.90 +/- 0.10 for men and 1.10 +/- 0.14 for women) compared with the lowest quartile (0.95 +/- 0.12 and 1.13 +/- 0.13, respectively) in both sexes (P < 0.05). In multiple regression analysis, the correlation between the sum of insulin levels and the reciprocal of serum creatinine remained significant even after controlling for age, sex, body mass index, blood pressure, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, alcohol intake, and smoking habits. We could not find appropriate correlations of creatinine clearance calculated by the Cockcroft-Gault formula with the covariates including serum insulin.

CONCLUSIONS

The findings of this study suggest that hyperinsulinemia is a significant relevant factor of renal function in the general population.

Impaired glucose tolerance, diabetes mellitus, and gallstone disease: an extended study of male self-defense officials in Japan

Few studies have investigated the relation between glucose tolerance status and ultrasonographically determined gallstone disease. Using a 75-g oral glucose tolerance test, we examined the association of impaired glucose tolerance (IGT) and non-insulin-dependent diabetes mellitus (NIDDM) with gallstone disease in Japanese men. Subjects were men aged 48 to 59 of the Japan Self-Defense Forces who received a preretirement health examination between October 1986 to December 1994. After exclusion of 12 men under insulin treatment in the consecutive series of 7637 men, 174 were found to have gallstones; 103 were at the state of postcholecystectomy, and 6899 had normal gallbladder. IGT and NIDDM were associated with a modestly increased risk of gallstone disease; adjusted odds ratios were 1.3 (95% confidence interval [CI]: 0.9-1.8) for IGT and 1.3 (95% CI: 0.8-2.0) for NIDDM after adjustment for hospital, rank, smoking, alcohol use, and body mass index. Adjusted odds ratio for IGT and NIDDM combined was 1.3 (95% CI: 1.0-1.7, p=0.08). When prevalent gallstones and postcholecystectomy were considered separately, NIDDM showed a significant, positive association with postcholecystectomy, but not with prevalent gallstones. The findings add to evidence that glucose intolerance is associated with a modest increase in the risk of gallstone disease.

Ionizing radiation and genetic risks. VI. Chronic multifactorial diseases: a review of epidemiological and genetical aspects of coronary heart disease, essential hypertension and diabetes mellitus

This paper provides a broad overview of the epidemiological and genetical aspects of common multifactorial diseases in man with focus on three well-studied ones, namely, coronary heart disease (CHD), essential hypertension (EHYT) and diabetes mellitus (DM). In contrast to mendelian diseases, for which a mutant gene either in the heterozygous or homozygous condition is generally sufficient to cause disease, for most multifactorial diseases, the concepts of genetic susceptibility' and risk factors' are more appropriate. For these diseases, genetic susceptibility is heterogeneous. The well-studied diseases such as CHD permit one to conceptualize the complex relationships between genotype and phenotype for chronic multifactorial diseases in general, namely that allelic variations in genes, through their products interacting with environmental factors, contribute to the quantitative variability of biological risk factor traits and thus ultimately to disease outcome. Two types of such allelic variations can be distinguished, namely those in genes whose mutant alleles have (i) small to moderate effects on the risk factor trait, are common in the population (polymorphic alleles) and therefore contribute substantially to the variability of biological risk factor traits and (ii) profound effects, are rare in the population and therefore contribute far less to the variability of biological risk factor traits. For all the three diseases considered in this review, a positive family history is a strong risk factor. CHD is one of the major contributors to mortality in most industrialized countries. Evidence from epidemiological studies, clinical correlations, genetic hyperlipidaemias etc., indicate that lipids play a key role in the pathogenesis of CHD. The known lipid-related risk factors include: high levels of low density lipoprotein cholesterol, low levels of high density lipoprotein cholesterol, high apoB levels (the major protein fraction of the low density lipoprotein particles) and elevated levels of Lp(a) lipoprotein. Among the risk factors which are not related to lipids are: high levels of homocysteine, low activity of paraoxonase and possibly also elevated plasma fibrinogen levels. In addition to the above, hypertension, diabetes and obesity (which themselves have genetic determinants) are important risk factors for CHD. Among the environmental risk factors are: high dietary fat intake, smoking, stress, lack of exercise etc. About 60% of the variability of the plasma cholesterol is genetic in origin. While a few genes have been identified whose mutant alleles have large effects on this trait (e.g., LDLR, familial defective apoB-100), variability in cholesterol levels among individuals in most families is influenced by allelic variation in many genes (polymorphisms) as well as environmental exposures. A proportion of this variation can be accounted for by two alleles of the apoE locus that increase (&epsi;4) and decrease (&epsi;2) cholesterol levels, respectively. A polymorphism at the apoB gene (XbaI) also has similar effects, but is probably not mediated through lipids. High density lipoprotein cholesterol levels are genetically influenced and are related to apoA1 and hepatic lipase (LIPC) gene functions. Mutations in the apoA1 gene are rare and there are data which suggest a role of allelic variation at or linked LIPC gene in high density lipoprotein cholesterol levels. Polymorphism at the apoA1--C3 loci is often associated with hypertriglyceridemia. The apo(a) gene which codes for Lp(a) is highly polymorphic, each allele determining a specific number of multiple tandem repeats of a unique coding sequence known as Kringle 4. The size of the gene correlates with the size of the Lp(a) protein. The smaller the size of the Lp(a) protein, the higher are the Lp(a) levels. (ABSTRACT TRUNCATED)

Potential errors resulting from sex and age difference in assessing family history of diabetes

BACKGROUND

Diabetes mellitus occurs nearly exponentially with aging and its occurrence differs between men and women in adulthood. Therefore, the sex and age of family members should be considered in assessing the family history. In this report the effects of sex and age on the positivity of family history were estimated numerically.

METHODS

Sex- and age-specific proportion of a positive history of diabetes mellitus among 24,273 family members was obtained from a questionnaire survey of 2,316 high school students in Japan. By analyzing the sex- and age-specific proportion with the logistic regression model, odds ratios were estimated which indicated potential bias or misclassification resulting from sex and age differences.

RESULTS

The odds ratios were 1.97 (95% confidence interval, 1.74-2.23) for the sex difference and 1.05 (95% confidence interval, 1.04-1.05) for an age difference of 1 year. This indicated that a male family member had a 1.97 times higher chance of having a positive history than a female member and that a positive history increased by (1.05)y, where y was age difference in years.

CONCLUSION

A control for sex and age of family members will be required in assessing the family history of diabetes mellitus as a risk factor.

Development of ischemic stroke in normotensive and hypertensive diabetic patients with or without antihypertensive treatment: an 8-year followup study

Although the impact of hypertension as a risk factor for brain infarction in diabetes mellitus is evident, the beneficial effect of antihypertensive therapy has not been demonstrated. Therefore, we designed a prospective cohort study to elucidate the effects of antihypertensive therapy on the development of ischemic stroke in diabetic outpatients. Two hundred forty patients, 219 non-insulin-dependent diabetes mellitus (NIDDM) and 21 insulin-dependent diabetes mellitus (IDDM), without history of cerebrovascular accident were followed for 8 years, from January 1981 until December 1988, in our diabetic clinic. Forty-eight of 88 hypertensive patients had received antihypertensive drugs. Among 40 untreated hypertensive and 152 initially normotensive diabetics, 14 hypertensives and 11 normotensives required antihypertensive therapy during followup period. Twenty-three patients were dropped out because of the unidentified reasons. Cerebrovascular accident occurred in 24 patients (10%): 18 brain infarctions, 4 transient ischemic attack (TIA), 1 subarachnoidal hemorrhage, and 1 brain hemorrhage. The percent incidence of ischemic strokes in the hypertension-treated patients was 8.9% which was similar to the 8.1% of the normotensives. In contrast, ischemic strokes developed in 29% of the untreated hypertensives, being significantly more frequent than in the former two groups. Multivariate analysis showed that serum total cholesterol and male gender were independent significant precursors of brain infarction in diabetic patients. In conclusion, antihypertensive treatment decreased the incidence of ischemic stroke in diabetics. Serum total cholesterol turned to independent risk factors for ischemic stroke in diabetic patients.

Identification and treatment of women with hyperglycaemia diagnosed during pregnancy can significantly reduce perinatal mortality rates

We wished to determine whether gestational diabetes was associated with an increased perinatal mortality rate, and to investigate the cause for the observed increase in the incidence of gestational diabetes. We therefore reviewed the results of glucose tolerance tests and pregnancy outcome in 116,303 pregnancies, 1971-1994, at the Mercy Hospital for Women. The main outcome measurements were the presence or absence of gestational diabetes, and perinatal mortality. Over the entire period of the study, gestational diabetes was associated with an increased risk of perinatal mortality (Mantel-Haenszel adjusted odds ratio 1.53, 95% CI 1.13-2.06, p = 0.0069). Women with gestational diabetes that was only diagnosed retrospectively had a higher perinatal mortality rate than their contemporaries with normal glucose tolerance (OR 2.31, 95% CI 1.37-3.91, p = 0.0025). Women in whom a glucose tolerance test was not performed continued to have a higher perinatal mortality rate than women who were tested (adjusted OR 2.21, 95% CI 1.56-3.12, p < 0.00001). There has been an increase in the prevalence of gestational diabetes from 2.9% to 8.8%. Some of this is due to changes in population characteristics (increases in maternal age, obesity and proportion from South-East Asia), but there was still an independent increase over time. We conclude that identification and treatment of women with gestational diabetes can reduce perinatal mortality rates. Similarly to diabetes mellitus in the total population, the prevalence of gestational diabetes has increased over time.

The association of the insulin resistance syndrome with impaired glucose tolerance and NIDDM in the Japanese general population: the Hisayama study

To elucidate the risk factors for initiating glucose intolerance, the relevant factors were explored in a cross-sectional survey conducted in a sample population aged 40-79 years old selected from a Japanese community, Hisayama, Japan in 1988. A 75-g oral glucose tolerance test was used to classify 1,073 men (72.5% of the entire population in the same age range) and 1,407 women (80.5%) into normal, impaired glucose tolerance and diabetes mellitus groups. In all age and sex groups with normal glucose tolerance, the sum of fasting and 2-h post-load insulin values varied widely and demonstrated significant positive correlations with triglycerides, body mass index, waist-hip ratio, systolic and diastolic blood pressure, while it negatively correlated to HDL cholesterol (p < 0.05). Insulin resistance was presumed to develop in normal glucose tolerance subjects with hyperinsulinaemia. The sum of the insulin concentrations, triglycerides, body mass index, waist-hip ratio and blood pressure levels was significantly associated with impaired glucose tolerance in all age and sex groups after adjustment for age (p < 0.05) and was also related to diabetes in either all or some age and sex groups, respectively (p < 0.05). It was shown that glucose intolerance in the general population was associated with the factors related to insulin resistance. These cross-sectional data, therefore, support the hypothesis that insulin resistance is the primary defect in the development of glucose intolerance in the Japanese general population. However, a further prospective study is still needed in order to confirm this hypothesis.

Increase in extracranial atherosclerotic carotid lesions in patients with brain ischemia in Japan. An angiographic study

BACKGROUND AND PURPOSE

Atherosclerotic lesions in the cerebral arteries are distributed heterogeneously among different races. Intracranial carotid lesions are reported to be more common than extracranial carotid lesions among Japanese people, which is in sharp contrast to the pattern of cerebral atherosclerosis in whites. However, several Japanese clinicians have the impression, which has yet to be clinically proven, that extracranial carotid diseases are recently increasing in number.

METHODS

One hundred twenty-one patients who developed ischemic stroke and underwent angiography were examined in the study. Seventy were admitted to our clinic from 1963 to 1965 (early group); the remaining 51 patients were seen from 1989 to 1993 (recent group). Angiographic findings and vascular risk factors were compared between the two groups.

RESULTS

Severe atherosclerotic lesions of the extracranial internal carotid arteries increased significantly during the ensuing 24 years between the end of the first period until the beginning of the second period (from 1965 to 1989), whereas lesions in the intracranial carotid system were similar between the two groups. Severe atherosclerosis in the extracranial internal carotid artery was more frequent in patients with diabetes mellitus, which proved to be the only risk factor that showed a temporal increase.

CONCLUSIONS

The proportion of severe atherosclerosis in Japanese patients with brain ischemia has been increasing in the extracranial internal carotid artery, while that in the intracranial carotid system remains unchanged. Such a temporal change may be the result, at least in part, of an increase in the prevalence of diabetes mellitus.