The role of obesity in the association of cardiovascular risk factors and glucose intolerance in small Japanese and North American communities

Modulation of Small Artery Function by Insulin in Young Women: Role of Adiposity

OBJECTIVES

Vascular dysfunction is common in obesity. Insulin can directly modulate arterial function, but its role is unclear in obesity. We examined the influence of adiposity on direct effects of insulin on human artery responses.

METHODS

22 healthy women were stratified by median BMI into lower (LA) (n=11) and higher adiposity (HA) (n=11). Small arteries from gluteal biopsies were tested for contractile responses to Noradrenaline (NA), the endothelium-dependent dilator Carbachol and the endothelium-independent dilator sodium nitroprusside were examined before and after incubation with 100 mU/ml human insulin.

RESULTS

Contractile responses were similar in the two groups. Insulin reduced NA-induced contraction in HA [3.5 (2.4-4.6) vs. 2.4 (1.4-3.4) mN/mm: p=0.004] but not those from LA [4.1 (2.8-5.3) vs. 3.7 (2.5-5.0) mN/mm: p=0.33]. Endothelium-dependent dilation (EDD) was significantly reduced in arteries from women in the HA (34.7 (18.8-50.6%)) compared to those from women in the LA (62.3 (46.2- 78.4); p=0.013). Insulin improved EDD (change in maximal dilation before/after insulin (%)) in arteries from the HA (37.7 (18.0 to 57.3) but not the LA (6.3 (-6.5 to 19.1), p=0.007.

CONCLUSION

Reduced EDD evident in arteries from HA subjects improve by incubating in insulin. Hyperinsulinaemia may be necessary in maintaining endothelial function in obesity.

Chronic HCV infection was associated with severe insulin resistance and mild atherosclerosis: a population-based study in an HCV hyperendemic area

BACKGROUND

Hepatitis C virus (HCV) affects glucose and lipid metabolism in vitro; however, it is unclear whether HCV infection is associated with insulin resistance and atherosclerosis at the population level. We aimed to investigate this association in a Japanese cohort of the Seven Countries Study, and our investigation was conducted in Tanushimaru, an HCV hyperendemic area.

METHODS

A total of 1908 inhabitants of Tanushimaru were classified into 3 groups according to HCV infection status: those who were uninfected (n = 1780), those with transient infection (n = 88), and those with chronic infection (n = 40). Insulin resistance and atherosclerosis were evaluated by homeostasis model assessment for insulin resistance (HOMA-IR) and carotid intima-media thickness (IMT), respectively. Intergroup differences in variables were evaluated by age- and sex-matched multivariate regression analysis.

RESULTS

Significant intergroup differences were seen in fasting glucose and insulin levels. The HOMA-IR value was significantly higher in the group with chronic infection than the values in the uninfected and transiently infected groups (3.0 ± 0.39 vs. 1.3 ± 0.03 vs. 1.5 ± 0.14; P < 0.001). In contrast, low-density lipoprotein (LDL)-cholesterol and triglyceride levels were significantly lower in the group with chronic infection than the levels in the other groups. IMT was reduced in the group with chronic infection, with a significant intergroup difference (0.67 ± 0.02 vs. 0.71 ± 0.003 vs. 0.72 ± 0.01 mm; P = 0.003).

CONCLUSIONS

This population-based study in an HCV hyperendemic area revealed that chronic HCV infection was associated with severe insulin resistance and with mild atherosclerosis, suggesting a unique characteristic of HCV-related metabolic abnormality.

Habitual coffee but not green tea consumption is inversely associated with metabolic syndrome: an epidemiological study in a general Japanese population

In Japan, metabolic syndrome used to be rare, and the level of coffee consumption was low. However, the Japanese life style has been changing rapidly, and these changes have been associated with a steady increase in the frequency of metabolic syndrome and with greater consumption of coffee. We examined the relationship between metabolic syndrome and the consumption of coffee or green tea. A total of 1902 Japanese aged over 40 years (785 men and 1117 women) received population-based health check-up in 1999. We measured components of metabolic syndrome (blood pressure, waist circumference, fasting plasma glucose, and lipid profiles). Eating and drinking patterns were evaluated by a food frequency questionnaire. Multivariate analyses were performed to clarify the association between coffee or green tea consumption and the components of metabolic syndrome. All components of metabolic syndrome except for HDL-cholesterol were significantly (p<0.01) and inversely related to coffee but not green tea consumption by multivariate analysis after adjusting for confounding factors. The larger was the number of components of metabolic syndrome, the lower was the level of coffee consumption (p<0.0001). In addition, there was a high frequency of metabolic syndrome in small coffee drinkers. Thus, coffee but not green tea consumption was inversely associated with metabolic syndrome.

Radiology of the Laparoscopic Roux-en-Y Gastric Bypass Procedure: Conceptualization and Precise Interpretation of Results

Obesity is an epidemic in the United States. The laparoscopic Roux-en-Y gastric bypass procedure is an effective surgical intervention that can produce dramatic weight loss in morbidly obese patients. Despite the inherent risks, the surgery is increasing in popularity. Radiology plays a crucial role in postoperative evaluation. Upper gastrointestinal (UGI) series and abdominal computed tomography (CT) are the primary radiologic tools used in assessment of possible complications. With knowledge of the normal postoperative appearance, performance of UGI studies and interpretation of the results should be easy. The 24-hour postoperative examination allows reliable detection of anastomotic leaks. Although strictures of the gastrojejunal anastomosis are a common complication, they are often diagnosed and treated with endoscopy. In a thorough examination, one also evaluates for degraded pouch restriction, including a patulous gastrojejunal anastomosis or gastrogastric fistula, as a late cause of weight gain. Knowledge of the postoperative anatomy also assists in detection of internal hernias. CT is invaluable in detection and characterization of small bowel obstructions and internal hernias. CT may allow diagnosis of anastomotic leaks, abscesses, gastrogastric fistulas, and intra-abdominal hematomas. CT-guided percutaneous procedures, such as placement of gastrostomy tubes or drainage of fluid collections, can obviate emergency exploration and may be the only procedural intervention necessary for a cure.

Prevalence of obesity in Kuwait and its relation to sociocultural variables

This study ascertains the prevalence of obesity and its relationship with some sociocultural characteristics in Kuwaiti society. The sample involved 212 men and 212 women, most of whom are overweight and obese. Grades 1 (body mass index [BMI] > 25-30 kg m(-2)), 2 (BMI > 30-40) and 3 (BMI > 40) of obesity characterize 71.2% of the sample. Most individuals are in grade 2 obesity, 37.2%. Grade 1 obesity is seen in 31.4% of the sample. Obesity increases with age, especially in women. The heaviest women are aged 60 years or older (mean BMI of 33.8), about the same mean as in the 50-59-year-old age group. The highest frequency of grades 1 and 2 obesity occur in women 30-39 years old. Fifty per cent of the underweight women are 20-29 years old or are over 60 years old. Most women of normal weight are 20-29 years old. For the men, 60% of the underweight sample are 50-60 years old. Male respondents between 30 and 39 years old are the heaviest; 42.7% of the sample are within grade 1 obesity and 40.7% of the sample within grade 2 obesity. The smallest percentage of men in grades 1 and 2 obesity are those 50-59 years old. An association was found between some sociocultural variables and obesity. Data show an increasing prevalence of obesity in Kuwait compared with some previous studies.

Trends in nutritional intake and serum cholesterol levels over 40 years in Tanushimaru, Japanese men

BACKGROUND: Rapid socioeconomic development in Japan since the beginning of the Seven Countries Study in 1958 has brought remarkable changes in lifestyle and dietary patterns. We investigated the relationship between time trends in nutrient intake and serum cholesterol levels in a Japanese cohort of the Seven Countries Study, in Tanushimaru, a typical farming town on Kyushu Island.

METHODS: Subjects totaled 628 in 1958, 539 in 1977, 602 in 1982, 752 in 1989, and 402 in 1999, and all of the subjects were men aged 40-64 years. Eating patterns were evaluated by 24-hour dietary recall from 1958 through 1989, and by a food frequency questionnaire in 1999. We also measured serum cholesterol levels in each health examination.

RESULTS: The total daily energy intake decreased from 2837 kcal in 1958 to 2202 kcal in 1999. The carbohydrate intake in percentage of total daily energy intake decreased markedly, from 84% in 1958 to 62% in 1999, in contrast to large increases during this period in protein intake (from 11% to 18%) and fat intake (from 5% to 20%). In proportion to the dramatic change in protein and fat intake, serum cholesterol levels showed large increases (from 152.5mg/dl to 194.2 mg/ dL).

CONCLUSIONS: In spite of such big dietary changes toward a westernized diet, the incidence of coronary artery disease in a rural Japanese area remains low. However, careful surveillance is needed in the future because of the remarkably increasing intake of fats, especially saturated fatty acids.

The new BMI criteria for asians by the regional office for the western pacific region of WHO are suitable for screening of overweight to prevent metabolic syndrome in elder Japanese workers

Obesity occurs less frequently in Japanese than in various other ethnic populations. A person with abnormal glucose tolerance is often found to have one or more of the other cardiovascular disease risk factors, such as obesity, hypertension and hyperlipidemia. This clustering has been labeled as metabolic syndrome (WHO, 1998). It was suggested that Japanese, categorized as having normal weight (BMI of less than 25.0), as defined by the WHO (2000), have an increasing tendency toward metabolic syndrome. Our objective was to analyze metabolic syndrome in "Overweight" with BMI of 23.0-24.9 in Japanese workers, and to assess the suitability for Asians of the Regional Office for the Western Pacific Region of WHO criteria pertaining to obesity (WPRO criteria, 2000). We conducted a cross-sectional study in the workplace setting and investigated the relationship between BMI classification based on WPRO criteria and metabolic syndrome by gender and age group (18-44 yr vs. 45-60 yr). Three hundred seventy-nine men and 432 women Japanese workers participated in this study. BMI were categorized as 20% "Overweight" (23.0-24.9 BMI), 20% "Obese I" (25.0-29.9 BMI) and 2% "Obese II" (over 30.0 BMI), based on WPRO criteria. Graded increases in BMI were positively associated with body fat percentage, waist circumference, hip circumference and waist/hip ratio in both genders and age groups. A progressively increasing BMI category in the elder group aged 45-60 yr in both genders was positively related with parameters constituting metabolic syndrome. Graded increases in BMI classes in elder workers based on WPRO criteria were positively associated with prevalence of metabolic syndrome, and "Overweight" elder women had significantly higher prevalence of metabolic syndrome. The present investigation, based on the increasing risks of "Overweight" with a BMI of 23.0-24.9, suggests that WPRO criteria are suitable for Japanese workers aged over 45 yr.

Overweight Japanese with body mass indexes of 23.0-24.9 have higher risks for obesity-associated disorders: a comparison of Japanese and Mongolians

OBJECTIVE

The degree of obesity of Asians is less than that of Caucasians. It has been suggested that Japanese, categorized as having normal weight (BMI<25.0), as defined by WHO (2000), have a tendency toward increased incidences of dyslipidemia and diabetes. Our objective was to analyze parameters constituting obesity-associated disorders in overweight Japanese and Mongolians with a body mass index (BMI) of 23.0-24.9, and to assess the suitability for Asians of the Regional Office for Western Pacific Region of WHO criteria pertaining to obesity (WPRO criteria, 2000).

DESIGN

Cross-sectional study in a workplace setting.

SUBJECTS

A total of 386 Japanese men and 363 Japanese women, and 102 Mongolian men and 155 Mongolian women.

MEASUREMENTS

Anthropometric measurements (weight, height, waist circumference, hip circumference and blood pressure) and metabolic measurements (plasma levels of total cholesterol, HDL cholesterol, triglyceride, glucose and insulin).

RESULTS

Graded increases in BMI of Japanese and Mongolians were positively associated with body fat percent, waist circumference, hip circumference and waist/hip ratio. The Japanese were categorized as 22% overweight, 22% obese I, 3% obese II; the Mongolians rated as 18% overweight, 34% obese I, 19% obese II, based on the WPRO BMI criteria. The Mongolians had a higher prevalence of obesity and a higher body fat percent, but a lesser gradation of dyslipidemia, than did the BMI-matched Japanese groups. Overweight Japanese (BMI 23.0-24.9), in comparison to normal Japanese (BMI 18.5-22.9), had significant differences in systolic blood pressure, HDL-cholesterol and triglyceride in men, and in systolic and diastolic blood pressure, HDL-cholesterol, triglyceride, insulin and Homoeostasis model assessment-insulin resistance in women. In contrast, the Mongolians showed no significant differences in metabolic parameters between overweight and normal subjects, except for diastolic blood pressure.

CONCLUSION

Since the relationship between abdominal fat mass and BMI is ethnic-specific, a universal BMI cutoff point is inappropriate for Asian populations such as the Japanese and Mongolians. The present investigation suggests that, while the WPRO criteria are suitable for Japanese, the WHO criteria are more appropriate for Mongolians.

Exercise, body mass index, caloric intake, and cardiovascular mortality

BACKGROUND

The association of physical inactivity and elevated body mass index (BMI) with cardiovascular disease (CVD) risk is well established. The relationship of dietary caloric intake and CVD risk is less certain.

METHODS

The epidemiologic follow-up of the First National Health and Nutrition Examination Survey (1971-1992) was examined to determine the relationship of caloric intake, BMI, and physical activity to CVD mortality. Of 14,407 participants, 9790 subjects aged 25 to 74 years met inclusion criteria. The CVD mortality rate was the outcome.

RESULTS

During the 17 years of follow-up, there were 3183 deaths, 1531 of which were due to CVD (9.11/1000 person-years). People with relatively less physical activity, lower caloric intake, and who were overweight (BMI 25 to 29.9 kg/m(2)) and obese (BMI > or =30 kg/m(2)) had a less favorable baseline CVD risk profile than did those who were more active and of normal weight and had greater caloric intake. Age- and race/ethnicity-adjusted CVD mortality rates were highest among those with the least physical activity and lowest caloric intake, and who were overweight or obese. Moreover, subjects of normal weight who exercised most were more likely to have high caloric intake and lower CVD mortality (5.9 vs 14.7 per 1000 person-years, p =0.01) than subjects who were obese and exercised least. In Cox regression analysis, controlling for relevant CVD risk factors, least physical activity was independently associated with increased CVD mortality (hazard ratio=1.32, 95% confidence interval [CI]=1.13-1.53); and obesity was associated with increased CVD mortality (hazard ratio=1.24, 95% CI=1.06-1.44). Although highest dietary caloric intake was associated with reduced CVD mortality (hazard ratio=0.83, 95% CI=0.74-0.93), after adjusting for physical activity and BMI, there was no significant association of highest caloric intake with CVD mortality (hazard ratio=0.91, 95% CI=0.81-1.01).

CONCLUSIONS

In this large general population sample, lower levels of physical activity and obesity were independently associated with decreased CVD survival. Moreover, when BMI, physical activity, and other relevant characteristics were taken into account, caloric intake was not related to CVD mortality.