Descriptive epidemiology of body mass index in Japanese adults in a representative sample from the National Nutrition Survey 1990-1994

New Body Mass Index Criteria of Central Obesity for Male Japanese

In recent years, intra-abdominal visceral fat leads to obesity-related complications. A simple indicator that reflects the mass of visceral fat is also needed to enable practical screening of patients. The present study was designed to establish new body mass index (BMI) criteria of central obesity for male Japanese. The subjects were 516 men aged from 19 to 80 years old who were examined at the physical examination center in the regular health check conducted by their company. Correlations between visceral fat area (VFA) or subcutaneous fat area (SFA) and BMI in the subjects were investigated. Receiver Operating Characteristics (ROC) curve was used to find out the optimal cut-off values of BMI to predict central obesity. We compared the percentile ranks corresponding to VFA of 100 cm2, BMI of 25 kg/m2 and new BMI criteria to check to see whether the present BMI criteria classify correctly Japanese men as central obesity. Further evidence for the effectiveness of BMI for VFA is needed. The correlation coefficient between VFA or SFA and BMI was 0.59 or 0.67, respectively. At the cut-off for BMI that maximized sensitivity and specificity for predicting central obesity was 24 kg/m2. Moreover, the percentile value corresponding to VFA of 100 cm2, BMI of 24 kg/m2, and BMI of 25 kg/m2 was the 53, 50 and 61 percentile, respectively. It is necessary to lower a cut-off point for central obesity from BMI of 25 kg/m2 to 24 kg/m2.

Alanine aminotransferase elevation not associated with fatty liver is frequently seen in obese Japanese women

OBJECTIVE

To determine the prevalence of fatty liver and alanine aminotransferase (ALT) elevation in obese Japanese women and to clarify the factors contributing to fatty change and ALT elevation in the cohort.

DESIGN

Cross-sectional and population-based study.

SUBJECTS

From 4366 women who received their annual health check-up, 4211 women were selected for analysis. All 4211 women were negative for hepatitis virus markers.

MEASUREMENTS

Peripheral blood cell counts, liver biochemical tests, fasting glucose, cholesterol and triglyceride levels, uric acids, glycosylate hemoglobin A1c, and ultrasound examination.

RESULTS

Ultrasonographic evidence of fatty liver and ALT elevation was seen in 391 (9.3%) and 238 (5.7%), respectively, of the 4211 women. Frequencies of both fatty liver and ALT elevation increased with increase in the degree of obesity. The frequency of ALT elevation was higher in women with fatty liver than in women without fatty liver among the nonobese or mildly obese group. However, the frequency of ALT elevation was not significantly different between women with fatty liver and women without fatty liver among the severely obese group. Multivariate analysis showed that obesity, hemoglobin (> or = 14 g/dl), triglyceride (> or = 150 mg/dl), diabetes mellitus, and fatty liver were significant predictors of ALT elevation. However, only two variables, hemoglobin (> or = 14 g/dl) and presence of diabetes, were significant in the severely obese group.

CONCLUSIONS

ALT elevation not associated with fatty liver was frequently seen in obese women, suggesting that obesity is directly associated with the elevated ALT level in Japanese obese women. In addition, hemoglobin (> or = 14 g/dl) was a strong predictor of ALT elevation in the severely obese group.

Long-period accelerometer monitoring shows the role of physical activity in overweight and obesity

CONTEXT

Physical activity (PA) plays an important role in obesity. A new accelerometer has been developed to assess total energy expenditure as well as PA.

OBJECTIVE

To investigate the association of PA with overweight and obesity in Japanese men and women, a large cross-sectional study was performed using a single-axis accelerometer.

DESIGN, SETTING AND PARTICIPANTS

Population-based cross-sectional study of Japanese 18-84 y of age. Height, body weight and PA were measured in 400 male and 388 female Japanese volunteers from 1999 to 2000. The outcome measurements were overweight and obesity, which are defined as a body mass index >/=25 kg/m(2). PA was measured for 1 to 4 weeks and was then categorized into three activity levels, which were defined as light, moderate and vigorous PA.

RESULTS

Prevalence of overweight and obesity was 22.3%. Number of steps and time spent in moderate and vigorous PA per day were lower in overweight and obese individuals. No difference was found in time spent in light PA. Individuals who are in the 4th and 5th quintile of moderate and vigorous PA showed a significantly lower body mass index. When odd ratios (ORs) of overweight and obesity estimated by logistic regression were used as effect measures, overweight and obesity were negatively associated with vigorous PA (ORs=0.91).

CONCLUSION

These results indicate that overweight and obese individuals have a lower step rate and are spending less time for moderate to vigorous PA. Participation in vigorous PA is an important predictor of overweight and obesity.

Circulating insulin-like growth factor-1 and insulin-like growth factor binding protein-3 are associated with early carotid atherosclerosis

OBJECTIVE

Growth hormone (GH)-insulin-like growth factor (IGF)-1 axis regulates growth and survival of vascular cells and cardiomyocytes. The role of GH-IGF-1 axis in cardiovascular disease is controversial.

METHODS AND RESULTS

We assessed the association of circulating levels of IGF-1 and IGF binding protein-3 (IGFBP-3) with early carotid atherosclerosis and atherosclerotic risk factors in 330 Japanese men (age 51.6+/-8.6 years, range 29 to 77, body mass index [BMI] 23.6+/-2.9 kg/m2). Intima-media thickness (IMT) of the common carotid artery was measured by ultrasound. Abdominal visceral adipose and subcutaneous adipose tissue area by computer-assisted tomographic scan were determined. Correlation coefficients were calculated by partial correlation analysis. BMI and plasma insulin showed positive associations with circulating IGF-1 and IGFBP-3. Subcutaneous adipose tissue was correlated with IGF-1. High-density lipoprotein cholesterol was inversely associated with IGF-1. Blood pressure, total cholesterol, triglyceride, and visceral adipose tissue were positively associated with IGFBP-3. IGF-1 and IGFBP-3 were associated with carotid IMT independent of age, BMI, blood pressure, and insulin. Insulin was associated with carotid IMT in univariate analysis. However, it was not correlated with carotid IMT in the multivariate analyses which included IGF-1 or IGFBP-3 as a covariate.

CONCLUSIONS

Increased circulating IGF-1 and IGFBP-3 may be stimulators of atherosclerosis.

Obesity and risk of cancer in Japan

We conducted a population-based prospective cohort study in Japan to examine the relationship between body mass index (BMI) and the risk of incidence of any cancer and of cancer at individual sites. Body mass index was calculated from self-administered body weight and height at baseline. Relative risks (RR) and 95% confidence intervals (CI) were calculated in multivariate proportional-hazards models. Among 27,539 persons (15,054 women and 12,485 men) aged 40 years or older who were free of cancer at enrollment in 1984, 1,672 (668 women and 1,004 men) developed cancer during 9 years of follow-up. In women, after adjustment for potential confounders, the RR of all cancers associated with different BMI, relative to a BMI of 18.5-24.9, were 1.04 (95% CI = 0.85-1.27) for BMI = 25.0-27.4, 1.29 (1.00-1.68) for BMI = 27.5-29.9 and 1.47 (1.06-2.05) for BMI >/=30.0 (p for trend = 0.007). Higher BMI was also significantly associated with higher risk of cancers of the colorectum, breast (postmenopausal), endometrium and gallbladder in women. In men, we observed significantly increased all-cancer risk among only never-smokers. Overweight and obesity could account for 4.5% (all subjects) or 6.2% (never-smokers) of the risk of any cancer in women and -0.2% (all subjects) or 3.7% (never-smokers) in men. The value for women was within the range among women reported from Western populations (3.2%-8.8%). Our data demonstrate that excess weight is a major cancer risk among Japanese women.

Trends in childhood obesity in Japan over the last 25 years from the national nutrition survey

OBJECTIVE

To describe the 25-year changes in BMI (measured in kilograms per meters squared) and the prevalence of obesity in Japanese children with special reference to urban-rural differences.

RESEARCH METHODS AND PROCEDURES

We used the data sets from the cross-sectional annual nationwide surveys (National Nutrition Survey, Japan) conducted from 1976 to 2000 and comprising 29,052 boys and 27,552 girls between 6 and 14 years of age. We carried out the trend analyses with the data on sex and age groups and on residential areas according to the size of the municipality (metropolitan areas, cities, and small towns).

RESULTS

The mean (age-adjusted) BMI increased by +0.32 kg/m(2) per 10 years in boys and by +0.24 kg/m(2) per 10 years in girls, increases that were remarkable in small towns. The prevalence of obese boys and girls increased from 6.1% and 7.1%, respectively, in the time-period 1976 to 1980, to 11.1% and 10.2% in 1996 to 2000. The increasing trend was most evident in 9- to 11-year-old children of both sexes living in small towns, whereas no changes were observed in girls in metropolitan areas.

DISCUSSION

Our data clearly show increasing trends in obesity prevalence in Japanese school children. Degrees of the increasing trends, however, differed across sex and age groups and residential areas, demonstrating a particular phenomenon that girls in metropolitan areas were unlikely to become obese. These epidemiological aspects indicate the priorities for intervention in population strategies to control obesity in children.

Lispro is superior to regular insulin in transient intensive insulin therapy in type 2 diabetes

OBJECTIVE

The optimal approach to relatively recent onset type 2 diabetes patients is still unknown. We speculated that the use of short-acting insulin analogs might be of particular benefit in this context.

PATIENTS AND METHODS

To explore this possibility, we compared the effect on beta- and alpha-cell function of transient intensive insulin therapy using lispro versus human regular insulin in a total of 21 type 2 diabetic patients who were randomly assigned to 14-days intensive insulin therapy consisting of bedtime NPH insulin plus three injections of mealtime lispro (n=11) or regular insulin (n=10). The dosages of both types of insulin were adjusted to attain preprandial glucose levels of <6.1 mmol/l within 1 week with similar rates of glucose decline. An oral glucose tolerance test (OGTT) was performed at day 0 (baseline), 7, and 14; plasma glucose, serum insulin, and plasma glucagon responses over 0-120 minutes were measured, and calculated as the area under the curve (AUC).

RESULTS

Lispro led to a significant reduction in glucose-AUC and also an increase in insulin-AUC versus regular insulin on day 7. Glucagon secretion following OGTT was well suppressed with lispro on day 14 compared to regular insulin.

CONCLUSION

Two-week intensive insulin therapy with lispro appeared to be more effective than that with regular insulin in type 2 diabetes in attaining both more rapid beta-cell rest and greater suppression of glucagon. These changes may provide significant long-term benefits.

Target value of intraabdominal fat area for improving coronary heart disease risk factors

OBJECTIVE

The goal of this study was to determine an intraabdominal fat (IF) area target value for improving coronary heart disease (CHD) risk factors in response to weight reduction.

RESEARCH METHODS AND PROCEDURES

Subjects were 279 obese Japanese women, 21 to 66 years old, who were divided into diet-alone and diet-plus-exercise groups and participated in a 14-week weight reduction program. The IF area was measured by computerized tomography scans. Systolic blood pressure > or = 140 mm Hg, diastolic blood pressure > or = 90 mm Hg, total cholesterol > or = 5.70 mM, triglycerides > or = 1.70 mM, and fasting plasma glucose > or = 6.99 mM were defined as CHD risk factors.

RESULTS

The best trade-off between sensitivity (probability of correctly detecting true positive) and specificity (probability of correctly detecting true negative) was found at 100 cm2 pretreatment in combined data of the two groups. At posttreatment, although a slight difference was found in the target value between the treatment groups (60 cm2 for diet alone and 50 cm2 for diet plus exercise), the combined data showed that the best trade-off occurred at 60 cm2 (sensitivity and specificity were 0.55 and 0.63, respectively). The percentage of subjects having no CHD risk factors was significantly lower in the group that had large IF areas (> or = 60 cm2) (46%) compared with the group that had normal IF areas (<60 cm2) (65%). However, the percentage of subjects having multiple CHD risk factors was significantly greater in the group that had large IF areas (16%) compared with the group with normal IF areas (7%) at posttreatment.

DISCUSSION

Our longitudinal data suggest that obese Japanese women should reduce their IF areas to < 60 cm2 through weight reduction to improve CHD risk factors independent of treatment.

Primacy of beta-cell dysfunction in the development of hyperglycemia: a study in the Japanese general population

To elucidate the hierarchy in the evolution of glucose intolerance in the general population, the relationship between plasma glucose (PG), beta-cell function (insulinogenic index [II] = DeltaIRI(0-30)/DeltaPG(0-30) on 75 g oral glucose tolerance test [OGTT], where IRI is immunoreactive insulin), insulin sensitivity (Si; determined by quantitative insulin sensitivity check index [QUICKI]), age, and body mass index (BMI) were analyzed in 504 Japanese health examinees (men/women: 347/157). The mean (+/-SD) age was 53 (+/-11) years, BMI 23.6 (+/-3.2) kg/m2, fasting PG (FPG) 5.61 (+/-0.97) mmol/L, 2-hour PG 7.42 (+/-3.1) mmol/L, II 74.2 (+/-169.3) [pmol/L]. [mmol/l](-1), and QUICKI 0.385 (+/-0.057) [log (microU/mL) + log (mg/100 mL)](-1). Higher FPG and 2-hour PG, respectively, were independently correlated with lower II, lower QUICKI, higher age, and higher BMI; the standardized correlation coefficient was largest for the correlation between PG and II. Based on the multiple linear regression, FPG = 8.565 - 1.201. log [II] - 5.374. QUICKI + 0.007. age + 0.030. BMI (r2 = 0.442), and 2-hour PG = 14.239 - 4.206. log [II] - 0.141. QUICKI + 0.034 - age + 0.141. BMI (r2 = 0.493). Thus, elevation of PG correlated most prominently with beta-cell dysfunction and less prominently with decreased Si, higher age, and BMI (especially so in the case of 2-hour PG). In conclusion, the primacy of beta-cell dysfunction in the process of developing glucose intolerance was strongly suggested in the Japanese general population.

Health attitudes and behaviors: comparison of Japanese and Americans of Japanese and European Ancestry

Adults living in Japan (N = 357) and the US (N = 223) completed semi-structured interviews assessing health-related attitudes and practices. The US respondents were of Japanese (N = 106) and European (N = 117) ancestry. Results indicated considerable similarity between the two US groups and significant differences between the Japanese and American respondents. The Japanese respondents placed less priority on health, had less belief in the efficacy of health screening tests, lower levels of internal health locus of control (HLOC), and higher levels of chance and powerful-others HLOC. While Japanese and Americans had similar overall levels of healthy behaviors, the Japanese were less likely to have obtained health screening tests (especially gynecologic exams). The findings have implications for adapting health promotion programs in the context of Japanese and American cultures.

Mitochondrial genome single nucleotide polymorphisms and their phenotypes in the Japanese

Polymorphisms in the human mitochondrial genome have been used for the elucidation of phylogenetic relationships among various ethnic groups. Because analysis by mitochondrial genetics has detected pathogenic mutations causing mitochondrial encephalomyopathy or cardiomyopathy, most of the mitochondrial single nucleotide polymorphisms (mtSNPs) found in control subjects have been regarded as merely normal variants. However, we cannot exclude the possibility that the mitochondrial functional differences among individuals are ascribable at least in part to the mtSNPs of each individual. Human lifespan in ancient history was much shorter than that at the present time. Therefore, it is reasonable to speculate that certain mtSNPs that predispose one toward susceptibility to adult- or elderly-onset diseases, such as Parkinson's disease and Alzheimer's disease, have never been a target for natural selection in the past. Similarly, thrifty mtSNPs that had been advantageous for survival under severe famine or cold climate conditions might turn out to be related to satiation-related diseases, such as diabetes mellitus and obesity. To examine these hypotheses, we have constructed a mtSNP database by sequencing the entire mitochondrial genomes of 672 subjects: 96 in each of seven groups (i.e., centenarians, young obese or non-obese subjects, diabetic patients with or without major vascular involvement, patients with Parkinson's disease, and those with Alzheimer's disease).

Metabolic syndrome is directly associated with gamma glutamyl transpeptidase elevation in Japanese women

AIM: This study aimed to determine whether metabolic syndrome is directly or indirectly, through fatty liver, associated with elevated gamma-glutamyl transpeptidase (GGT) levels in Japanese women.

METHODS: From 4366 women who received their annual health check-up, 4211 women were selected for analysis. All 4211 women were negative for both hepatitis B surface antigen and antibody to hepatitis C virus. Clinical and biochemical variables were examined by using univariate and multivariate analysis.

RESULTS: A raised GGT level ( > 68 IU/L) was seen in 258 (6.1%) of the 4211 women. In univariate analysis, all variables examined (age, body mass index, blood pressure, hemoglobin concentration, fasting blood glucose, glycosylated hemoglobin A1c, cholesterol, triglyceride, and uric acid) were associated with the elevated GGT level, whereas in multivariate analysis, four variables (age ≧ 50 yr, hemoglobin ≧ 14 g/dL, triglyceride ≧ 150 mg/dL, and presence of diabetes) were significantly and independently associated with raised GGT level. Clinical variables predicting the presence of ultrasonographic evidence of fatty liver were also examined by multivariate analysis; four variables were associated with the presence of fatty liver: BMI ≧ 25 kg/m², hemoglobin ≧ 14 g/dL, triglyceride ≧ 150 mg/dL, and uric acid ≧ 7 mg/dL. There was no significant association between the raised GGT level and the presence of fatty liver. Hypertriglyceridemia was significantly and independently associated with both the raised GGT level and the presence of fatty liver.

CONCLUSION: Metabolic syndrome seemed to be directly, not indirectly through fatty liver, associated with the raised GGT level in Japanese women.

Correlation study on oral health and electrocardiogram abnormalities

The purpose of this study was to investigate the association between periodontal conditions and electrocardiogram test results that were obtained to screen for coronary heart disease risk factors. The present study included a total of 578 subjects who underwent annual medical check-ups at the Total Health Care Center in Otsu, Shiga Prefecture, Japan. To calculate the odds ratios for the electromyography abnormalities, we performed a logistic regression analysis for the oral examination, electrocardiogram, and blood analysis data. The crude odds ratio was obtained by a logistic regression analysis of age, sex, number of missing teeth, number of filled teeth, simplified oral hygiene index, community periodontal index, and blood analysis factors and results indicated there was a statistically significant correlation with the prevalence of electrocardiogram abnormalities. However, electrocardiogram abnormalities have a strong correlation with demographic factors such as sex and age. Therefore the experimental factors representing oral status were reexamined after the odds ratios were adjusted for age and sex. As a result of this adjustment, the new odds ratios that were determined indicated that there were no correlations between the oral factors and the prevalence of electrocardiogram abnormalities.

The effect of polymorphism in the intestinal fatty acid-binding protein 2 gene on fat metabolism is associated with gender and obesity amongst non-diabetic Japanese-Americans

AIM

The role of the codon 54 polymorphism of the fatty acid-binding protein 2 (FABP2) gene on fat metabolism has been controversial. Assuming that the effects of the polymorphism were modulated by gender and obesity which were related to lipid and glucose metabolism, we investigated this polymorphism and its effect on fat metabolism according to such factors.

METHODS

Subjects were Japanese-Americans (123 men and 126 women) who were diagnosed as non-diabetic by a 75 g oral glucose tolerance test at the baseline.

RESULTS

During approximately 7.8 years, 49 (24 men and 25 women) were diagnosed with type 2 diabetes. In a Cox proportional hazards model, this polymorphism was not a significant variable in the incidence of diabetes in either gender. Amongst non-obese men with the Thr54 allele, there was a significant elevation of triglycerides (TGs) (p=0.033) compared with alanine (Ala) homozygotes. Women with the Thr54 allele had significantly elevated total cholesterol (p=0.033) and low-density lipoprotein-cholesterol (LDL-C) (p=0.023) compared with Ala54 homozygotes.

CONCLUSIONS

These results therefore suggested that the effects of the FABP2 polymorphism on TG, LDL-C and body mass index were associated with gender difference and obesity amongst non-diabetic Japanese-American subjects.

A common polymorphism of uncoupling protein 2 gene is associated with hypertension

OBJECTIVES

The genes responsible for obesity are also candidate genes for obesity-related conditions, such as hypertension and type 2 diabetes. A functional polymorphism in the uncoupling protein 2 (UCP2) promoter has been reported to be associated with obesity in Caucasians. To clarify the contribution of this polymorphism to obesity and related conditions, we studied the association of the -866 G/A polymorphism of the UCP2 gene with obesity, hypertension and type 2 diabetes mellitus.

METHODS

A total of 632 unrelated Japanese subjects were studied: 342 type 2 diabetic patients (among them, 158 patients complicated with hypertension), 156 hypertensive patients without diabetes mellitus and 134 control subjects. The -866 G/A polymorphism of UCP2 was determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP).

RESULTS

The frequency of the minor A allele was significantly higher in Japanese than in Caucasians (48.9 versus 37.2%, P=0.01). In contrast to the significant association with obesity in Caucasians, the polymorphism was not associated with obesity in Japanese. The polymorphism, however, was significantly associated with hypertension in Japanese (frequency of A allele: 51.8% in hypertensives versus 46.6% in normotensives, P<0.05). No significant difference was observed in body mass index (BMI), fasting insulin level or HOMA-R between patients with different genotypes.

CONCLUSION

These data indicate that the polymorphism of the UCP2 gene is associated with hypertension, and suggest the possibility of UCP2 as a target molecule for studies on the etiology and treatment of hypertension.

Long-term body weight variability is associated with elevated C-reactive protein independent of current body mass index among Japanese men

OBJECTIVE

To elucidate the effect of long-term weight variability on C-reactive protein (CRP) levels.

DESIGN

Cross-sectional study of the circulating CRP.

SUBJECTS

A total of 637 Japanese men aged 40-49 y in1997.

MEASUREMENTS

Serum CRP levels, body mass index in 1997 (current BMI), the slope of weight on age (weight-slope) representing an individual's weight trend of direction and magnitude, and the root mean square error around the slope of weight on age (weight-RMSE) representing the weight fluctuation magnitude, as calculated by a simple linear regression model in which each value of the subject's five actual weights (aged 20, 25, 30 y, five years ago, and current) was a dependent variable and the subject's ages independent variables.

RESULTS

After adjustment for age and confounders, including smoking and health status, the odds ratios of elevated CRP (> or =0.06 mg/dl) were 1.83 (95% CI: 1.25-2.69), 2.63 (1.69-4.11), and 10.31 (2.17-48.98) for upper normal-weight (BMI: 22-<25 kg/m(2)), overweight (25-<30), and obese (> or =30) persons, respectively, compared with lower normal-weight persons (18.5-<22). Adjusting for age, confounders, and current BMI, weight-slope was positively associated with CRP level especially among subjects with BMI> or =25 kg/m(2) (trend P<0.01), and weight-RMSE was positively associated with CRP level particularly among subjects with BMI <25 kg/m(2) (trend P<0.05).

CONCLUSION

Our results suggest a state of low-grade systemic inflammation not only in overweight and obese persons, but also in normal-weight persons with large weight fluctuation, possibly explaining in part the positive association between weight fluctuation and CVD.

Prevalence of overweight and obesity and its associated factors: findings from National Nutrition and Health Survey in Taiwan, 1993-1996

BACKGROUND

To report the overall and regional prevalence of obesity/overweight in Taiwan and to study its associated risk factors.

METHODS

A total of 3046 adults > or = 20 years of age collected in National Nutrition and Health Survey in Taiwan, 1993-1996.

RESULTS

Prevalence rates of overweight and obesity were 21.1 and 4.0% under the current WHO definition. The prevalence rates of overweight and obesity, using the Taiwanese definition (BMI = 24-26.99 kg/m(2) and > or = 27 kg/m(2), respectively), were 22.9 and 10.5% for males and 20.3 and 13.2% for females, respectively. The highest prevalence rates of obesity were found in the mountainous areas. In addition to age and residing location, education level in women and metabolic equivalent (MET) score and alcohol consumption in men were correlates of obesity. Effects of nutrition/health-related behaviors might be in part explained by education level and residing location of the subjects.

CONCLUSION

The prevalence of obesity defined by WHO criteria among people in Taiwan was moderate, with considerable regional variation. The regional differences in obesity prevalence could not be completely accounted for by the sociodemographic and lifestyle factors studied.

A cross-cultural analysis of 'motivation for eating' as a potential factor in the emergence of global obesity: Japan and the United States

This exploratory study compared motivation for eating between individuals from two different cultures that have moved through the nutrition transition at different rates and to different degrees. The analysis was based on a convenience sample of 1218 participants aged >or=18 years attending colleges in the US and Japan. The Motivation for Eating Scale (MFES) was used to evaluate different motivations for eating by nation and gender. The MFES consists of 12 items classified into three subscales: emotional, physical and environmental eating. The questionnaire used in the study also included responses about participants' motivation to lose weight, frequency of dieting, presence of previous or existing eating disorders, and frequency of exercise. Results showed no significant differences in the three MFES subscales for men in the US and Japan. For women, however, significant differences were seen for all three subscales. Women in the US were more likely to initiate eating for emotional reasons, while women in Japan were more likely to eat for physical or environmental reasons. Women and men in the US were more likely than the Japanese respondents to eat in response to watching TV or movies. These results suggest that there are national differences in the cultural environment that may impact individual motivations for eating. As such, various cultural perceptions of food should be considered in attempts to understand more fully the mechanics of the nutrition transition as it operates within a given country. By extension, public health policies and health promotion initiatives that are designed to limit the negative impacts of the nutrition transition may benefit from a greater understanding of the larger role that cultural perceptions of food may play in influencing individual motivations for eating.

[Prevalence of obesity in Spain: results of the SEEDO 2000 study]

BACKGROUND AND OBJECTIVE

Obesity is a major public health problem in developed countries. It is of key importance to ascertain its magnitude and to identify main groups at risk. In this paper the prevalence of obesity in Spanish adult population aged 25-60 is estimated, based on measured height and weight.

SUBJECTS AND METHOD

Pooled-analysis of regional cross-sectional nutrition surveys performed on representative random population samples. Randomly selected 9,885 free living subjects aged 25-60 years respondents of population nutritional surveys carried out in eight Spanish regions (Andalucía, Balearic Islands, Basque Country, Canary Islands, Catalunya, Galicia, Madrid and Valencia) between 1990 to 2000. Weight and height were measured on each individual by trained observers following standardised procedures and measuring instruments. The samples were pooled together and weighted according to the distribution of Spanish adult population aged 25-60 years. Obesity was defined as body mass index (BMI) >= 30 kg/m2. The protocol used in each survey was in accordance to the recommendations of the Spanish Society for the study of Obesity (SEEDO) to estimate the prevalence of obesity in population studies.

RESULTS

The prevalence of obesity in Spanish adult population was 14.5% (95% CI, 13.93-15.07%), significantly higher among women 15.75% (95% CI, 14.89-16.61%), than men 13,39% (95% CI, 11.84-14.94%) (*2 = 12.470; p = 0.000). Prevalence of obesity significantly increased with age in men and women. The highest rates were estimated for the age group older than 55 years, both among males and females, 21.58% (95% CI, 18.68-24.48%) and 33.9% (95% CI, 32.73-35.07%), respectively.

CONCLUSION

Obesity is a health problem which affects an important proportion of the Spanish adult population. Considering its potential impact on Public Health, it would be required to design and implement effective strategies aimed at the early detection of subjects at risk and the provision of adequate treatment, as well as to establish suitable preventive programmes.

Waist-to-height ratio, a simple and practical index for assessing central fat distribution and metabolic risk in Japanese men and women

OBJECTIVE

The normal body mass index (BMI) range, as defined by the World Health Organization (WHO), is quite wide, and some people within this range may have excessive central fat accumulation and elevated metabolic risks. We hypothesize that the waist-to-height ratio (W/Ht), an effective index for assessing central fat distribution among Japanese people, can be used to identify subjects who are at higher metabolic risk within the normal as well as the overweight range.

METHODS

We investigated: (1). the values of BMI, waist circumference, and W/Ht in 6141 men and 2137 women at various age intervals and calculated gender (female to male) ratios for all these anthropometric indices; (2). the relation between age and each anthropometric index, between age and morbidity index for coronary risk factors (sum of the scores for hyperglycemia, hypertension, hypertriglyceridemia, hypercholesterolemia, and low HDL cholesterol; one point for each condition if present), and between morbidity index for coronary risk factors and each anthropometric index; (3). the distributions of the subjects, using various proposed indices of waist circumference (those suggested by WHO, the Japan Society for the Study of Obesity, and the Asia-Pacific perspective), and our proposed boundary value, W/Ht 0.5, among the WHO categories based on BMI; (4). the metabolic risks (coronary risk factors, hyperuricemia, high gamma-glutamyltransferase, and fatty liver diagnosed by ultrasonography), and exercise habits among normal-weight subjects with W/Ht<0.5 or >or=0.5.

RESULTS

(1). For the various anthropometric indices in all age groups, the gender ratio for W/Ht was closest to 1, indicating that a single set of values for W/Ht can be used for men and women. (2). Height correlated negatively with age. Among the anthropometric indices, only W/Ht correlated positively with age for both men and women, while age and all anthropometric indices, except height, correlated positively with the morbidity index for coronary risk factors. For both men and women, the highest correlation coefficient was between W/Ht and the morbidity index for coronary risk factors. (3). Nearly all overweight men and women (BMI>or=25) had W/Ht>or=0.5 (98.5% of men and 97.5% of women). None of the underweight subjects had W/Ht>or=0.5. However, 45.5% of men and 28.3% of women of normal weight (BMI 18.5-<25) had W/Ht>or=0.5. W/Ht, of all the indices investigated, was the best index for signaling metabolic risk in the normal-weight subjects as well as the overweight subjects. (4). Age- and BMI-adjusted odds ratios for multiple metabolic risks, and history of no habitual exercise were significantly higher in normal-weight men and women with W/Ht>or=0.5 than in others of normal weight.

CONCLUSIONS

Waist circumference is improved by relating it to height to categorized fat distribution of different genders and ages. W/Ht is a simple and practical anthropometric index to identify higher metabolic risks in normal and overweight Japanese men and women.

Event rates of acute myocardial infarction and coronary deaths in Niigata and Nagaoka cities in Japan

Mortality from coronary heart disease in Japan is the among lowest recorded in the industrialized nations; however, little is known about the rate of events including nonfatal cases. A survey of event registration and a review of death certificates was carried out to estimate event rates of acute myocardial infarction (AMI) and coronary deaths in the largest 2 cities of the Niigata prefecture where there are 480,720 residents aged between 15 and 65 years. The definitions for these cardiac events used for the WHO-MONICA project were: (1)'definite AMI', (2) 'possible AMI or coronary death' (not including unclassifiable fatal events), and (3) 'unclassifiable fatal events'. Age-adjusted rates for AMI and coronary deaths (per 100,000/year) according to the registration survey were 54.6 for men and 7.2 for women according to definition 1 and 41.9 for men, and 5.3 for women according to definition 2. When data from the death certificate review were taken into account for the estimation, these rates increased to 80.6 for men and 14.2 for women according to definition 1, and 50.0 for men and 9.0 for women according to definition 2. These estimated rates are considerably lower than those in other industrialized nations surveyed in the WHO-MONICA project, and these findings are consistent with those from other studies conducted in Japan.

New criteria for 'obesity disease' in Japan

The present study was designed to establish adequate criteria for categorizing 'obesity disease' in Japan in relation to obesity-related complications. The subjects were 1,193 Japanese subjects (775 men, 418 women; age: 20-84 years old, body mass index (BMI): 14.9-56.4 kg/m(2)) including subjects undergoing a health examination and obese subjects visiting an obesity clinic. Visceral fat area (VFA) and subcutaneous fat area (SFA) were determined by computed tomography (CT) at the umbilical level. Anthropometric parameters, including BMI, waist circumference (W), waist/hip circumference (W/H), ratio and waist circumference/body height (W/BH) ratio, were measured. Hyperglycemia, dyslipidemia, and hypertension were evaluated as obesity-related complications. The relationship between each parameter and the prevalence of the complications was investigated. The number of complications increased in accordance with BMI and the average value was greater than 1.0 at a BMI of 25. The best combination of the sensitivity and specificity for detecting subjects with multiple risk factors was a BMI of 25. BMI showed a close positive correlation with SFA (r=0.82), even for BMI > or =25 (r=0.77), but had a weaker correlation with VFA (r=0.54). The obese subjects with a BMI > or =25 had no correlation between BMI and VFA because of the wide individual variation of VFA. The number of disorders was greater than 1.0 at 100 cm(2) of VFA and the best combination of the sensitivity and specificity for determining subjects with multiple risk factors was 100 cm(2) of VFA. Between the simple anthropometric values and measurement of VFA, it was proven that W had the closest relationship with VFA in both men (r=0.68) and women (r=0.65). The regression line obtained from simple correlation analyses indicated that the W corresponding to 100 cm(2) of VFA was 84.4 cm in men and 92.5 cm in women. These data suggest that obesity is adequately specified as a BMI > or =25 in Japan where the prevalence and degree of obesity remains mild. It is reasonable to establish the cut-off point of VFA at 100 cm(2) as indicative of the risk of obesity-related disorders and a waist circumference of 85 cm in men and 90 cm in women approximates to this visceral fat mass.

Who is becoming overweight during the elementary school years?

OBJECTIVE

To determine the risk of becoming overweight for every first grader during the elementary school years and to determine whether the overall risk of becoming overweight for first graders is increasing.

STUDY DESIGN

A descriptive study using school-based surveys of 12,588 boys and 12,264 girls who entered elementary school between 1989 and 1994. Six years later, the follow-up survey was conducted. Overweight was defined using the BMI percentile cut-off points.

MEASUREMENTS

For every 5th percentile rank of first graders, the odds ratio for becoming overweight at seventh grade was calculated. A hockey stick regression analysis and the yearly trend of the risk for becoming overweight at 7th grade were also investigated.

RESULTS

For overweight children in first grade, the odds ratio for staying at the same level was extremely high in both boys (35.0) and girls (63.9). The threshold effects of the BMI percentile value at first grade for becoming overweight were the 81st and 87th percentiles for boys and girls, respectively, according to the hockey stick model. The overall risk for becoming overweight significantly increased in boys during the study period (P=0.009).

CONCLUSION

The present study determined the exact level of the risk for becoming overweight for every first grader at a different BMI percentile rank. The risk of overweight children in first grade who stayed at the same level at seventh grade was higher in girls than in boys. On the other hand, the trend of the entire population for becoming overweight presents only in boys. The different pattern of the trend of population for becoming overweight by sex during elementary school period may provide evidence to understand and predict overweight in adolescents and adults.

Obesity and cardiovascular risk factors in Hong Kong Chinese

The purpose of this cross-sectional study was to examine the risk associations between obesity indexes [body mass index (BMI) and waist circumference (WC)], cardiovascular risk factors [plasma glucose and lipids, blood pressure and urinary albumin excretion (UAE)] and morbidity conditions (Type 2 diabetes mellitus, hypertension, dyslipidaemia and/or albuminuria) in Hong Kong Chinese. Seven-hundred and two Hong Kong Chinese subjects (18-65 years of age, 59.4% of whom had at least one morbidity condition) were recruited from the Prince of Wales Hospital, Hong Kong SAR. The measurements taken of the subjects included: height; weight; waist and hip circumferences; blood pressure; fasting plasma glucose and lipids; and 24-h UAE. The mean BMI was 22.4 and 25.7 kg m(-2) in healthy subjects and patients, respectively. The mean WC measurements of healthy subjects and patients were 77.1 and 86.4 cm in males and 71.0 and 81.8 cm in females, respectively. There were increasing trends between obesity indexes and the severity of cardiovascular risk factors and the prevalence of morbidity conditions (all P-values for trend <0.05). Using 19.0-20.9 kg m(-2) and <70 cm as a referent, subjects with a BMI of > or =25.0 kg m(-2) (in both sexes) and/or a WC of > or =85 cm in males and > or =75 cm in females had an age-adjusted odds ratio between 3.2 and 4.4 for the occurrence of at least one morbidity condition. Patients with a greater number of comorbidities also had higher BMI and WC measurements (all P-values for the trend were <0.05 with adjustment for age and gender). Hence, despite Hong Kong Chinese being less obese than Caucasians, the intimate relationships among obesity, cardiovascular risk factors and morbidity conditions remain. Our data support using lower BMI and WC levels to define obesity and its associated health risks rather than using the criteria established from Caucasians who generally have larger body frames.

Medical care expenditure associated with body mass index in Japan: the Ohsaki Study

OBJECTIVE

To examine the impact of body mass index (BMI) upon medical care use and its costs in Japan.

DESIGN

A population-based prospective cohort study from 1995 to 1998.

SUBJECTS

A cohort of 41 967 Japanese adults aged 40-79 y. Subjects who died during the first year of follow-up, or who at baseline reported having had cancer, myocardial infarction, stroke or kidney disease were excluded.

MEASUREMENTS

Medical care use and its costs, actual charges, by linkage with the National Health Insurance claim history files after adjustment of smoking, drinking and physical functioning status.

RESULTS

There was a U-shaped association between BMI and total medical costs. The nadir of the curve was found at a BMI of 21.0-22.9 kg/m(2). Relative to the nadir, total costs were 9.8% greater among those with BMIs of 25.0-29.9 (rate ratio, 1.10; 95% confidence interval (CI), 1.03-1.17), and 22.3% greater among those with BMIs of 30.0 or higher (rate ratio, 1.22; 95% CI, 1.08-1.37). Estimated excess direct costs attributable to overweight (BMI of 25.0-29.9 kg/m(2)) and obesity (BMI of 30.0 kg/m(2) or higher) represent 3.2% of total health expenditure in the present study, which is within the range reported in Western countries (0.7-6.8%).

CONCLUSION

Our prospective data demonstrate that the impact of overweight and obesity upon medical care costs in Japan is as large as in Western countries, despite the much lower mean BMI in Japanese populations.

Twenty-year changes in the prevalence of overweight in Japanese adults: the National Nutrition Survey 1976-95

The aim of this study was to describe the 20-year changes in body mass index (BMI; kgm(-2)) and the prevalence of overweight in Japanese adults. Cross-sectional annual nationwide surveys (National Nutrition Survey, Japan) were carried out with a large probability sample of the Japanese population. Data sets of the 1976-95 surveys, comprising 91983 men and 120822 women (> or =20 years of age), were used. The analyses were carried out in age and gender groups, and by residential area according to the size of the municipality (metropolitan areas, cities and small towns). The mean BMI increaseed in men with an increment of +0.44 kg m(-2) 10 years(-1) and slightly decreased in women, by -0.09 kg m(-2) 10 years(-1), after adjustment for age. A decreasing trend of mean BMI was most significant in the female 20-29 years age-group (-0.38 kg m(-2) 10 years(-1)), in contrast to an increasing trend observed in elderly women (60-69 and 70+ years age-groups). The prevalence of preobese (BMI: 25-29.9kg m(-2)) and obese (BMI > or = 30 kg m(-2)) men increased from 14.5% and 0.8%, respectively, in the time-period 1976-80 to 20.5% and 2.01% during 1991-95. The increasing trend was most evident in the youngest age-group (20-29 years) and in those from small towns. The overall prevalence of preobese and obese women did not change during the 20-year study period. The prevalence in younger women decreased, this trend being more prominent in metropolitan areas. Although the prevalence of overweight (BMI > or =25 kg m(-2)) in Japanese men and elderly women has increased in the last 20 years, the mean BMI in younger women, especially those in metropolitan areas, has decreased. A population approach to control obesity and prevent obesity-associated diseases should be mainly focused on men and women older than 40 years of age.

Single nucleotide polymorphisms of thrifty genes for energy metabolism: evolutionary origins and prospects for intervention to prevent obesity-related diseases

The "thrifty" genotype and phenotype that save energy are detrimental to the health of people living in affluent societies. Individual differences in energy metabolism are caused primarily by single nucleotide polymorphisms (SNPs), some of which promote the development of obesity/type 2 diabetes mellitus. In this review, four major questions are addressed: (1) Why did regional differences in energy metabolism develop during evolution? (2) How do genes respond to starvation and affluence? (3) Which SNPs correspond to the hypothetical "thrifty genes"? (4) How can we cope with disease susceptibility caused by the "thrifty" SNPs? We examined mtDNA and genes for energy metabolism in people who live in several parts of Asia and the Pacific islands. We included 14 genes, and the SNP frequencies of PPAR gamma 2, LEPR, and UCP3-p and some other genes differ significantly between Mongoloids and Caucasoids. These differences in SNPs may have been caused by natural selection depending on the types of agriculture practiced in different regions. Interventions to counteract the adverse effects of "thrifty" SNPs have been partially effective.

Diminution of early insulin response to glucose in subjects with normal but minimally elevated fasting plasma glucose. Evidence for early beta-cell dysfunction

AIM

Systematic analysis of beta-cell function in Japanese health examinees.

METHODS

In 938 Japanese health examinees (627 men and 311 women, mean age and body mass index, 54.0 years and 23.6 kg/m2, respectively), plasma specific insulin was measured at fasting and during a 75-g oral glucose tolerance test. The subjects were stratified into six groups based on fasting plasma glucose < or = 5.1 mmol/l, 5.2-6.0 mmol/l, 6.1-6.9 mmol/l, 7.0-7.8 mmol/l, 7.9-8.7 mmol/l, and > or = 8.8 mmol/l as the 1st, 2nd, 3rd, 4th, 5th and 6th groups, respectively.

RESULTS

Distribution of fasting insulin showed a very modest 'inverted U' shape, with the peak in the 5th group. Progressive increase from the 1st toward the 5th group was significant. In contrast, the ratio of change in insulin to change in glucose from 0 to 30 min during the glucose tolerance test was greatest in the 1st group and progressively declined in the groups with higher fasting glycaemia. Difference in the ratio was most striking and highly significant between the 1st and 2nd groups. Distribution of the insulin to glucose ratio of subjects with normal glucose tolerance significantly overlapped with that of untreated patients with diabetes.

CONCLUSIONS

In a Japanese population, (i) beta-cell starts to deteriorate during normoglycaemia with a minimal elevation of fasting plasma glucose, and (ii) there are glucose-tolerant subjects with beta-cell dysfunction.

Under- and overweight impact on mortality among middle-aged Japanese men and women: a 10-y follow-up of JPHC study cohort I

OBJECTIVE

Although obesity is a major health problem in Western countries, its impact may differ in another culture. This paper examines the association between body mass index (BMI; kg/m2) and mortality in Japan, where the mortality profile and BMI distribution differ substantially from Western countries.

DESIGN

The JPHC Study cohort I, a population-based prospective study in four public health center areas, started in 1990 and was followed-up to the end of 1999.

SUBJECTS

A total of 19,500 men and 21,315 women aged 40-59 y who submitted their body weight and height and did not report any serious disease at baseline.

MEASUREMENT

Risk of death by category of BMI.

RESULTS

During 10 y of follow-up, 943 and 483 deaths were documented in the men and women, respectively. The association between BMI and all-cause mortality was U-shaped: compared with a category of 23.0-24.9, the statistically significant elevations in relative risk were observed in both under- and overweight categories (2.26 in 14.0-18.9, 1.57 in 19.0-20.9, 1.33 in 21.0-22.9 and 1.38 in 27.0-29.9, 1.97 in 30.0-39.9 in men, 1.94 in 14.0-18.9 and 1.91 in 30.0-39.9 in women) after adjustment for possible confounders and weight change. The U-shaped association did not change after excluding deaths occurring in the first 5 y of follow-up or even after excluding subjects who reported a weight loss of 5 kg or more since 20-y-old, or after stratifying subjects by smoking status.

CONCLUSION

Both under- and overweight are important determinants of premature death among the Japanese population.

[Weight excess and abdominal fat in the metabolic syndrome among Japanese-Brazilians]

OBJECTIVE

Obesity, especially abdominal, has been associated with cardiovascular risk factors such as dyslipidemia, hypertension and diabetes mellitus (DM). The importance of these risk factors among Japanese-Brazilians was previously shown, although obesity is not a typical characteristic of Japanese migrants. In this study the prevalence of weight excess and central adiposity (CA) among Japanese-Brazilians and their association with metabolic disorders was evaluated.

METHODS

A sample of 530 1st and 2nd generation Japanese-Brazilians (aged 40 - 79 years) went through anthropometric and blood pressure measurements, lipid profile and oral glucose tolerance tests. The prevalence rate (point and confidence interval) of overweight was calculated using a cut-off value of >26.4 kg/m2. CA diagnosis was based on waist-to-hip circumference ratio (WHR): greater-than-or-equal 0.85 and 0.95 in women and men, respectively.

RESULTS

The prevalence of weight excess was 22.4% (CI 95% 20.6 - 28.1), and CA was 67.0% (95% CI 63.1 - 70.9). In addition to higher prevalence of DM, hypertension and dyslipidemia, stratifying by BMI and WHR, people with weight excess and CA revealed a poorer metabolic profile: blood pressure levels were significantly higher among those with weight excess with or without CA; CA individuals had higher glucose, triglycerides, total and LDL cholesterol, and lower HDL than those without weight excess or CA; fasting insulinemia was significantly higher among subjects with weight excess (with or without CA) than among those without weight excess or CA.

CONCLUSION

Comparing subgroups with and without CA supports the hypothesis that abdominal fat accumulation represents a risk factor for insulin resistance-related diseases, even among Japanese descendants. The increased prevalence of metabolic syndrome among Japanese migrants could be attributed to visceral fat deposition, which has been implicated in the genesis of insulin resistance.

Increasing obesity among male workers in Japan: 1992-1997

OBJECTIVE

To examine changes in the Body Mass Index (BMI) and in the prevalence of obesity among male Japanese workers after five years.

DESIGN

Follow-up study, based on data from annual health checkups performed at workplaces.

SUBJECTS AND METHODS

We had access to the data for a total of 63,951 male workers aged 20 through 54 years in 1992 who were examined in both 1992 and 1997. In quinquennial cohorts, we compared the findings for mean BMI and the prevalence of obesity in 1992 with the findings in 1997.

RESULTS

Between 1992 and 1997, in all cohorts the mean BMI increased significantly. For each adjacent cohort pair the mean BMI value in 1997 was significantly higher than in 1992. In 1992, 21.3% of all subjects were obese, increasing by 3.4% after five years to 24.7% in 1997. In the younger 1968-1972 and 1963-1967 cohorts the prevalence of obesity increased by 6.3% during five years. The significant increase in the obesity prevalence was observed from 1992 to 1997 for each age-adjusted cohort.

CONCLUSIONS

These results suggest a substantial increase in obesity among male Japanese workers. The notable increase in the prevalence of obesity among young male adults and the general trend toward widespread obesity during five years signal an increasing risk of lifestyle-related diseases.

Comparison of the effects of amlodipine and losartan on 24-hour ambulatory blood pressure in hypertensive patients

Effects of amlodipine (AML), a long-acting calcium antagonist, and losartan (LOS), an angiotensin II receptor antagonist, on 24-hr blood pressure profile were compared in 15 patients with essential hypertension. After 4 weeks of placebo period, the patients were treated with AML or LOS in a random crossover design for 12-16 weeks each. Either drug was given once daily at 0800 and the doses were titrated so that the office blood pressure was reduced lower than 140/90mmHg. At the end of each period, 24-hr blood pressure was monitored. Average office blood pressure was lowered from 158 +/- 2/ 98 +/- 2 mmHg to 134 +/- 1/87 +/- 1 mmHg by AML and 134 +/- 2/88 +/- 1 mmHg by LOS. Average 24-hr blood pressure was also reduced from 144 +/- 3/ 92 +/- 2 mmHg to 131 +/- 2/84 +/- 2 mmHg by AML and 135 +/- 3/85 +/- 2 mmHg by LOS. The averaged 24-hr systolic blood pressure was significantly lower in AML than in LOS (p < 0.05). Then, the 24-hr blood pressure was analyzed for four segments; morning (0530-0900 h), daytime (0930-1800 h), evening (1830-2300 h) and night (2330-0500 h). Although the daytime blood pressure was comparable between AML and LOS, systolic blood pressure in the evening and morning hours were lower in AML than in LOS (133 +/- 2 vs. 138 +/- 3mmHg,p<0.01; 129 +/- 3 vs. 134 +/- 4,p<0.05). Troughtopeakratio of antihypertensive effect on systolic blood pressure was significantly greater in AML than in LOS (62 +/- 5% vs. 55 +/- 4%, p < 0.05). Either drug did not cause reflective increase in pulse rate over 24 hours. These results suggest that both AML and LOS are equally effective in lowering daytime blood pressure without eliciting reflex tachycardia, however, the antihypertensive effect of AML lasts longer than that of LOS. Such information seems important to achieve 24-hr blood pressure control using these drugs.

Visceral fat is a major contributor for multiple risk factor clustering in Japanese men with impaired glucose tolerance

OBJECTIVE

The significance of abdominal visceral fat accumulation was evaluated in Japanese men with impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS

The IGT subjects (n = 123) were aged 55 +/- 9 years with a BMI of 24 +/- 3 kg/m(2). The 148 control subjects with normal glucose tolerance (NGT) were matched for age and BMI. IGT and NGT were classified according to the 1985 World Health Organization criteria. Abdominal fat distribution was analyzed by computed tomography at umbilical level. Plasma lipid, glucose, and insulin concentrations and blood pressure (BP) were measured.

RESULTS

In subjects with IGT, the average visceral fat area (VFA) was significantly greater than in subjects with NGT. Fasting insulin, the sum of insulin concentrations during an oral glucose tolerance test, insulin resistance according to a homeostasis model assessment for insulin resistance (HOMA-IR), systolic BP, and serum triglyceride were significantly higher, whereas the DeltaI(30-0)/DeltaG(30-0) was significantly lower, in subjects with IGT. Subjects with IGT and NGT were then divided into three subgroups according to the number of risk factors they possessed (dyslipidemia, hypertension, neither, or both). In both IGT and NGT subjects, BMI, VFA, subcutaneous fat area, fasting insulin, HOMA-IR, and insulin secretion of the homeostasis model assessment were significantly higher in the double-risk factor subgroup than in the no-risk factor subgroup, and VFA was a potent and independent variable in association with the presence of a double risk factor.

CONCLUSIONS

Visceral fat accumulation is a major contributor for multiple risk factor clustering in Japanese men with IGT and NGT.

Association between simple anthropometric indices and cardiovascular risk factors

OBJECTIVE

To identify which of the three simple anthropometric indices, body mass index (BMI), waist-to-hip ratio (WHR) and waist circumference (WC), best predicts cardiovascular risk factors, and to determine if the association between the anthropometric indices and cardiovascular risk factors varies with gender.

DESIGN AND METHODOLOGY

A cross-sectional population-based survey was carried out during 1995-1996. One thousand and ten Chinese people (500 men and 510 women) aged 25-74 y were recruited as subjects for the study. Metabolic profiles and anthropometric indices were measured.

RESULTS

Partial correlation and co-variance analyses showed that WC exhibited the highest degree of association with almost all of the studied metabolic profiles for both men and women. We observed significant gender differences in the association between central or general obesity with cardiovascular risk factors. BMI had an independent and significant association with metabolic risks in men, but not in women, whereas WHR was more strongly correlated with metabolic risks for women than for men. Logistic regression analysis further confirmed the magnitude of the association between the obesity indices and metabolic risks. Among the studied metabolic variables, serum insulin showed the highest degree of association with the obesity indices, followed by plasma glucose, triglyceride, HDL and blood pressure. Total cholesterol and LDL-cholesterol had a small but significant correlation with obesity. No threshold values in the relation between either the anthropometric indices and metabolic values, or with hypertension, diabetes and dislipidemia were observed.

CONCLUSION

The association of central or general obesity and metabolic syndrome varied with gender. In addition, the useful anthropometric predictors for cardiovascular risk factors were BMI and WC for men, and WC and WHR for women.

Effects of increased physical activity and mild calorie restriction on heart rate variability in obese women

The effects of exercise and mild calorie restriction on heart rate variability (HRV) were investigated in 12 mildly obese, normotensive Japanese women aged 45.8+/-4.2 (SEM) years with a body mass index (BMI) of 27.3+/-0.4 kg/m2. The subjects participated in a 3-month program aimed at increasing physical activity and modifying eating behavior (intervention group). The control group consisted of 12 women (age 50.1+/-4.8 years, BMI 27.2+/-0.6 kg/m2) who did not attend the program. The frequency domain of HRV was calculated from 5-min Holter recordings while the subjects rested in a supine position. After 3 months, BMI decreased to 25.0+/-0.5 kg/m2 (p<0.001 vs baseline) in the intervention group, which was accompanied by decreases in body fat mass, waist circumference, serum total cholesterol and triglycerides, and improvement in insulin sensitivity. The mean and SD of the RR intervals, total power, and low and high frequency power of HRV significantly increased after the intervention, whereas no significant changes were seen for the controls. The changes in these HRV variables (calculated by subtracting the baseline values from the follow-up values) negatively correlated with the change in waist circumference, with the Pearson correlation coefficients being between -0.50 and -0.62 (p<0.05). A negative correlation was also seen between the changes in high frequency power and insulin resistance estimated by homeostasis model assessment (r=-0.49, p<0.05). The combination of exercise and mild calorie restriction led to changes in HRV indicative of an improvement in parasympathetic modulation.

Relation between body composition and age in healthy Japanese subjects

OBJECTIVE

To describe the relation between body composition and age measured by dual-energy X-ray absorptiometry (DXA) in healthy Japanese adults.

DESIGN

Cross-sectional study.

SUBJECTS AND MEASUREMENTS

The subjects were 2411 healthy Japanese adults (males 625, females 1786, age 20--79 y) who attended the Fukuoka Health Promotion Center, Fukuoka, Japan for health check-up. Body composition was determined by DXA (QDR-2000, Hologic) for the whole body and three anatomical regions of arms, legs and trunk.

RESULTS

The mean values of body mass index (BMI) and percentage fat mass (%FM) were 23.2+/-3.1 (s.d.) kg/m(2) and 21.8+/-6.8% for males and 22.1+/-3.3 kg/m(2) and 32.0+/-7.5% for females, respectively. For males, curvilinear relations with the peaks in their forties or fifties were seen for the variables associated adiposity, ie BMI, waist and hip circumference, waist-hip ratio, total or regional fat mass (FM), %FM and ratio of trunk FM to leg FM. For females, most of these variables increased linearly in older subjects. Lean mass (LM), bone mineral content (BMC) and bone mineral density (BMD) of the whole body and appendicular LM were relatively constant until the forties and then decreased in both sexes. The rates of decrease in the total or appendicular LM were larger for males than for females, whereas those in BMC or BMD were larger for females than for males.

CONCLUSIONS

This study presents the first detailed data on body composition in Japanese, which may be useful when comparing with populations of different racial and ethnic backgrounds and studying ill subjects.

Mutations in the small heterodimer partner gene are associated with mild obesity in Japanese subjects

Mutations in several genes encoding transcription factors of the hepatocyte nuclear factor (HNF) cascade are associated with maturity-onset diabetes of the young (MODY), a monogenic form of early-onset diabetes mellitus. The ability of the orphan nuclear receptor small heterodimer partner (SHP, NR0B2) to modulate the transcriptional activity of MODY1 protein, the nuclear receptor HNF-4alpha, suggested SHP as a candidate MODY gene. We screened 173 unrelated Japanese subjects with early-onset diabetes for mutations in this gene and found five different mutations (H53fsdel10, L98fsdel9insAC, R34X, A195S, and R213C) in 6 subjects as well as one apparent polymorphism (R216H), all present in the heterozygous state. Interestingly, all of the subjects with the mutations were mildly or moderately obese at onset of diabetes, and analysis of the lineages of these individuals indicated that the SHP mutations were associated with obesity rather than with diabetes. Therefore, an additional group of 101 unrelated nondiabetic subjects with early-onset obesity was screened for mutations in the SHP gene. Two of the previously observed mutations (R34X and A195S) and two additional mutations (R57W and G189E) were identified in 6 subjects, whereas no mutations were identified in 116 young nondiabetic lean controls (P = 0.0094). Functional studies of the mutant proteins show that the mutations result in the loss of SHP activity. These results suggest that genetic variation in the SHP gene contributes to increased body weight and reveal a pathway leading to this common metabolic disorder in Japanese.

Mutations in the small heterodimer partner gene are associated with mild obesity in Japanese subjects

Mutations in several genes encoding transcription factors of the hepatocyte nuclear factor (HNF) cascade are associated with maturity-onset diabetes of the young (MODY), a monogenic form of early-onset diabetes mellitus. The ability of the orphan nuclear receptor small heterodimer partner (SHP, NR0B2) to modulate the transcriptional activity of MODY1 protein, the nuclear receptor HNF-4alpha, suggested SHP as a candidate MODY gene. We screened 173 unrelated Japanese subjects with early-onset diabetes for mutations in this gene and found five different mutations (H53fsdel10, L98fsdel9insAC, R34X, A195S, and R213C) in 6 subjects as well as one apparent polymorphism (R216H), all present in the heterozygous state. Interestingly, all of the subjects with the mutations were mildly or moderately obese at onset of diabetes, and analysis of the lineages of these individuals indicated that the SHP mutations were associated with obesity rather than with diabetes. Therefore, an additional group of 101 unrelated nondiabetic subjects with early-onset obesity was screened for mutations in the SHP gene. Two of the previously observed mutations (R34X and A195S) and two additional mutations (R57W and G189E) were identified in 6 subjects, whereas no mutations were identified in 116 young nondiabetic lean controls (P = 0.0094). Functional studies of the mutant proteins show that the mutations result in the loss of SHP activity. These results suggest that genetic variation in the SHP gene contributes to increased body weight and reveal a pathway leading to this common metabolic disorder in Japanese.

Relationship between intraocular pressure and obesity in Japan

BACKGROUND

Some cross-sectional studies have suggested that age, systolic blood pressure and obesity are positively related to intraocular pressure (IOP), but few longitudinal studies have examined this relationship. This study was carried out to evaluate the association between intraocular pressure and obesity by cross-sectional and longitudinal analyses in a large Japanese population.

METHODS

Data were collected from annual health examinations between 1989 and 1997 and reviewed retrospectively. Subjects of the cross-sectional analysis were 70 139 males and females aged 14-94 years. Among these subjects, 25 216 males and females who had undergone IOP measurements more than three times were analysed longitudinally. The association between IOP and obesity was examined cross-sectionally and longitudinally.

RESULTS

Cross-sectional analysis: The mean IOP at the last visit was 11.6 mmHg. The IOP decreased gradually with age and was significantly higher in males than in females in almost all age groups. Body mass index (BMI) significantly correlated with IOP after controlling for age, gender and blood pressure. Longitudinal analysis: There was a significant association between longitudinal change in IOP and change in weight. This relationship remained significant after controlling for initial BMI, initial blood pressure, change in blood pressure, gender and age.

CONCLUSION

This study showed a significant association between IOP and obesity in both cross-sectional and longitudinal analysis. These findings suggest that obesity is an independent risk factor for increase in IOP.

Relationship of intra-abdominal adiposity and peripheral fat distribution to lipid metabolism in an island population in western Japan: gender differences and effect of menopause

Intra-abdominal adiposity is associated with unfavorable serum lipid profiles (high total cholesterol or triacylglycerol, and low high-density lipoprotein cholesterol) in obese people. However, the relation in mainly nonobese Japanese population is not well known. We examined the relationship between intra-abdominal adiposity measured by ultrasonography and body fat distribution with serum lipids in Japanese people living in an island in western Japan. Mainly nonobese healthy individuals (98 men, 72 premenopausal and 182 postmenopausal women) aged between 33 and 69 years were examined. Accumulation of intra-abdominal fat (Pmax) and abdominal subcutaneous fat (Smin) was measured by ultrasonography. We also measured triceps and subscapular skinfold thicknesses, and the concentrations of total cholesterol, triacylglycerol and high-density lipoprotein (HDL) cholesterol. In men and postmenopausal women, Pmax correlated significantly with the majority of serum lipids after adjusting for age, body mass index and smoking habit. In premenopausal women, Pmax correlated significantly with only total cholesterol, but marginally with triacylglycerol and HDL/total cholesterol ratio after adjustment. Our findings suggest that intra-abdominal adiposity is related to unfavorable lipid profile in both genders among mainly nonobese Japanese population.