Diet of second-generation Japanese-American men with and without non-insulin-dependent diabetes

Higher High Density Lipoprotein 2 (HDL2) to Total HDL Cholesterol Ratio Is Associated with a Lower Risk for Incident Hypertension

BACKGROUND

Recent studies have suggested that high density lipoprotein (HDL) cholesterol is inversely associated with the development of hypertension. We aimed to determine the association between different HDL cholesterol subclasses and risk of future hypertension.

METHODS

A total of 270 Japanese Americans (130 men, 140 women) without hypertension between the ages of 34 to 75 years were enrolled. Blood pressure was measured with a mercury sphygmomanometer, and average blood pressure was calculated. Incident hypertension was determined 5 to 6 and 10 to 11 years after enrollment. HDL2, HDL3, and total HDL cholesterol were measured at baseline.

RESULTS

During 10 years of follow-up, the cumulative incidence of hypertension was 28.1% (76/270). In univariate analysis, age, diabetes, waist circumference, systolic and diastolic blood pressure, fasting glucose, insulin resistance index, total and low density lipoprotein cholesterol, and visceral adipose tissue were significant predictors for incident hypertension. Among the HDL cholesterol subclass, HDL2 cholesterol was inversely associated with hypertension incidence, but both total and HDL3 cholesterol were not. In addition, HDL2/HDL cholesterol was inversely associated with future hypertension risk. In multivariate analysis, age (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.26 to 2.31; P=0.001), systolic blood pressure (OR, 1.83; 95% CI, 1.31 to 2.56; P<0.001), and HDL2/HDL cholesterol (OR, 0.71; 95% CI, 0.52 to 0.98; P=0.035), were associated with future development of hypertension.

CONCLUSION

A higher proportion of HDL2 cholesterol among total HDL cholesterol predicted a lower risk for incident hypertension. However, concentrations of total HDL, HDL2, and HDL3 cholesterol were not independent predictors of incident hypertension.

Effects of Diets with Different Proportions of Protein/Carbohydrate on Retinal Manifestations in db Mice

BACKGROUND/AIM

Diabetic nephropathy is aggravated by a higher intake of total protein. The effects of diets with different proportions of protein and carbohydrate on diabetic retinopathy in db mice, a type-2 diabetes animal model, were examined, as well as diabetic nephropathy.

MATERIALS AND METHODS

Control and db mice at 5 weeks of age were fed the diets (% energy of protein/carbohydrate/fat; L-diet: 12/71/17; H-diet: 24/59/17) under ad libitum conditions and pair-feeding conditions for 6 weeks, respectively.

RESULTS

Mice fed the H-diet showed significantly greater retinal thickness by optical coherence tomography, and lower mRNA levels of angiotensinogen. Comparing combinations of diets and genotypes, db-H mice showed significantly higher mRNA levels of angiotensin-converting enzyme, advanced glycosylation end product-specific receptor, and cluster of differentiation molecule 11b (a microglial marker) than db-L mice.

CONCLUSION

Dietary protein and carbohydrate proportions influenced retinal manifestations, including retinal thickness and gene expression in control and diabetic mice.

Vegetarian Diet and Cardiometabolic Risk among Asian Indians in the United States

Research studies have shown that plant-based diets confer cardiovascular and metabolic health benefits. Asian Indians (AIs) in the US (who have often followed plant-based diets) have elevated risk for chronic diseases such as diabetes, metabolic syndrome, and obesity suggesting ethnic vulnerability that imply genetic and/or lifestyle causative links. This study explored the association between this ethnic group and diabetes, obesity, and metabolic syndrome after controlling for demographics, acculturation, family history of diabetes, and lifestyle and clinical risk factors. The sample comprised of 1038 randomly selected adult AIs in seven US sites. Prevalence and metabolic syndrome was estimated, and obesity was calculated using the WHO Asian criteria. Multivariate analysis included multinomial logistic regression. The mean age and length of residency in the US were 47 and 18.5 years, respectively. The majority of respondents were vegetarians (62%) and educated. A vegetarian lifestyle was associated with females, food label users, respondents with poor/fair current health status, less acculturated, and those who reported their diet had not changed after coming to the US. Vegetarian status was a protective factor and lowered the risk for diabetes but not for metabolic syndrome and obesity in the regression model. Results provide a firm basis for educational programs.

Sex Effects at the Ramparts: Nutrient- and Microbe-Mediated Regulation of the Immune-Metabolic Interface

The relationships between dietary compounds, derivative metabolites, and host metabolism and immunity are controlled by diverse molecular mechanisms. Essential contributions to these dynamics come from the community of microbes (the microbiome) inhabiting the human digestive tract. The composition and function of the microbiome are shaped by available nutrients, and reciprocally, these organisms produce an as yet poorly defined repertoire of molecules that communicate with the epithelial barrier and the mucosal immune system. We present evidence that diet-derived vitamins and lipids regulate immunity and metabolic function and highlight the diverse mechanisms through which these effects are impacted by sex. We discuss exciting new data emerging from studies using high-throughput sequencing technology, specialized mouse models, and bio-specimens, and clinical data from human subjects that have begun to reveal the complexity of these interactions. Also profiled in this chapter are the striking sex differences in pathways by which dietary nutrients and gut microbes modify metabolism, immunity, and immune- and inflammation-mediated diseases. Although the incidence, severity, and therapeutic responses of many autoimmune diseases differ by sex, the molecular mechanisms of these effects remain poorly understood.

Red Meat and Health

Despite its nutritional benefits, there is an increasing body of evidence to suggest that regular consumption of red meat may negatively impact health and disease risk, including the risk of most common chronic diseases. This chapter reviews the current evidence linking red and processed meat intakes with chronic disease, obesity and mortality risks and discusses possible mechanisms to explain these associations. Research on the health benefits of diets low in red meat, including vegetarian, vegan, Mediterranean and other plant-based diets, is also reviewed.

New Insight into the Dietary Cause of Atherosclerosis: Implications for Pharmacology

At present, the guideline approach to the medical treatment and prevention of atherosclerotic cardiovascular disease (ASCVD) is to classify patients by risk and treat the known risk factors (contributory causes), e.g., hypertension, diabetes, obesity, smoking, and poor diet, as appropriate. All high-risk patients should receive statins. This approach has had substantial success but ASCVD still remains the number one cause of death in the United States. Until recently, the underlying cause of ASCVD remained unknown, although a potential dietary cause was suggested by the fact that vegetarians, especially vegans, have a much lower incidence of ASCVD than animal flesh eaters. Recently, consistent with the vegetarian data, substantial evidence for a cause of ASCVD in animals and humans has been discovered. Trimethylamine (TMA)-containing dietary compounds in meat, milk, and other animal foods (e.g., lecithin, choline, and carnitine) are converted by closely related gut bacterial TMA lyases to TMA, which is absorbed and converted predominantly by flavin mono-oxygenase 3 to the toxic trimethylamine N-oxide (TMAO). TMAO causes atherosclerosis in animals and is elevated in patients with coronary heart disease. Inhibition of bacterial lyases in mice prevents TMA and secondarily TMAO formation and atherosclerosis, strong evidence for the TMAO hypothesis. At present, the challenge for the pharmaceutical industry is to discover and develop a potent "broad spectrum" bacterial lyase inhibitor that, along with diet and exercise, could, if the TMAO hypothesis is correct, revolutionize the preventive treatment of ASCVD.

Red Meat and Health

Despite its nutritional benefits, there is an increasing body of evidence to suggest that regular consumption of red meat may negatively impact health and disease risk, including the risk of most common chronic diseases. This chapter reviews the current evidence linking red and processed meat intakes with chronic disease, obesity and mortality risks and discusses possible mechanisms to explain these associations. Research on the health benefits of diets low in red meat, including vegetarian, vegan, Mediterranean and other plant-based diets, is also reviewed.

Deteriorated glucose metabolism with a high-protein, low-carbohydrate diet in db mice, an animal model of type 2 diabetes, might be caused by insufficient insulin secretion

PURPOSE

We previously showed the deleterious effects of increased dietary protein on renal manifestations and glucose metabolism in leptin receptor-deficient (db) mice. Here, we further examined its effects on glucose metabolism, including urinary C-peptide. We also orally administered mixtures corresponding to low- or high-protein diets to diabetic mice.

METHODS

In diet experiments, under pair-feeding (equivalent energy and fat) conditions using a metabolic cage, mice were fed diets with different protein content (L diet: 12 % protein, 71 % carbohydrate, 17 % fat; H diet: 24 % protein, 59 % carbohydrate, 17 % fat) for 15 days. In oral administration experiments, the respective mixtures (L mixture: 12 % proline, 71 % maltose or starch, 17 % linoleic acid; H mixture: 24 % proline, 59 % maltose or starch, 17 % linoleic acid) were supplied to mice. Biochemical parameters related to glucose metabolism were measured.

RESULTS

The db-H diet mice showed significantly higher water intake, urinary volume, and glucose levels than db-L diet mice but similar levels of excreted urinary C-peptide. In contrast, control-H diet mice showed significantly higher C-peptide excretion than control-L diet mice. Both types of mice fed H diet excreted high levels of urinary albumin. When maltose mixtures were administered, db-L mixture mice showed significantly higher blood glucose after 30 min than db-H mixture mice. However, db mice administered starch-H mixture showed significantly higher blood glucose 120-300 min post-administration than db-L mixture mice, although both groups exhibited similar insulin levels.

CONCLUSIONS

High-protein, low-carbohydrate diets deteriorated diabetic conditions and were associated with insufficient insulin secretion in db mice. Our findings may have implications for dietary management of diabetic symptoms in human patients.

Change in Intra-Abdominal Fat Predicts the Risk of Hypertension in Japanese Americans

In Japanese Americans, intra-abdominal fat area measured by computed tomography is positively associated with the prevalence and incidence of hypertension. Evidence in other populations suggests that other fat areas may be protective. We sought to determine whether a change in specific fat depots predicts the development of hypertension. We prospectively followed up 286 subjects (mean age, 49.5 years; 50.4% men) from the Japanese American Community Diabetes Study for 10 years. At baseline, subjects did not have hypertension (defined as blood pressure ≥140/90 mm Hg) and were not taking blood pressure or glucose-lowering medications. Mid-thigh subcutaneous fat area, abdominal subcutaneous fat area, and intra-abdominal fat area were directly measured by computed tomography at baseline and 5 years. Logistic regression was used to estimate odds of incident hypertension over 10 years in relation to a 5-year change in fat area. The relative odds of developing hypertension for a 5-year increase in intra-abdominal fat was 1.74 (95% confidence interval, 1.28-2.37), after adjusting for age, sex, body mass index, baseline intra-abdominal fat, alcohol use, smoking status, and weekly exercise energy expenditure. This relationship remained significant when adjusted for baseline fasting insulin and 2-hour glucose levels or for diabetes mellitus and pre-diabetes mellitus classification. There were no significant associations between baseline and change in thigh or abdominal subcutaneous fat areas and incident hypertension. In conclusion, in this cohort of Japanese Americans, the risk of developing hypertension is related to the accumulation of intra-abdominal fat rather than the accrual of subcutaneous fat in either the thigh or the abdominal areas.

Visceral abdominal fat accumulation predicts the conversion of metabolically healthy obese subjects to an unhealthy phenotype

Background

A proportion of obese subjects appear metabolically healthy (MHO) but little is known about the natural history of MHO and factors predicting its future conversion to metabolically unhealthy obese (MUO).

Objectives

The aim was to determine prospectively the frequency of conversion of MHO to MUO and the clinical variables that independently predicted this conversion, with a particular focus on the role of body composition.

Methods

We identified 85 Japanese Americans with MHO (56 men, 29 women), aged 34–73 years (mean age 49.8 years) who were followed at 2.5, 5, and 10 years after enrollment with measurements of metabolic characteristics, lifestyle, and abdominal and thigh fat areas measured by computed tomography. Obesity was defined using the Asian body mass index criterion of ≥ 25 kg/m². Metabolically healthy was defined as the presence of ≤ 2 of 5 metabolic syndrome components proposed by the National Cholesterol Education Program Adult Treatment Panel III, while metabolically unhealthy was defined as ≥ 3 components.

Results

Over 10 years of follow-up, 55 MHO individuals (64.7%) converted to MUO. Statistically significant univariate predictors of conversion included dyslipidemia, greater insulin resistance, and greater visceral abdominal (VAT) and subcutaneous abdominal fat area (SAT). In multivariate analysis, VAT (odds ratio per 1 SD increment (95% confidence interval) 2.04 (1.11 – 3.72), P=0.021), high density lipoprotein (HDL) cholesterol (0.24 (0.11 – 0.53), P<0.001), fasting plasma insulin (2.45 (1.07 – 5.62), P=0.034), and female sex (5.37 (1.14 – 25.27), P=0.033) were significantly associated with future conversion to MUO. However, SAT was not an independent predictor for future conversion to MUO.

Conclusions

In this population, MHO was a transient state, with nearly two-thirds developing MUO over 10 years, with higher conversion to MUO independently associated with VAT, female sex, higher fasting insulin level, and lower baseline HDL cholesterol level.

Fat intake and the development of type 2 diabetes

The increase in the number of patients with diabetes has become a worldwide healthcare issue, with numbers predicted to reach approximately 600 million by 2035. In Asia-Pacific region, the prevalence of type 2 diabetes has increased dramatically in recent decades, of which the major causes are believed to be modern lifestyle changes, e.g., Western dietary pattern and reduced physical activity, on their genetic basis of lower insulin secretory capacity. Particularly, in East Asian countries, the amount of fat intake has increased nearly three-fold over this half of century; dietary fat appears to be the major culprit of type 2 diabetes pandemic in East Asia. However, convincing evidence has not yet been provided as to whether high-fat diet causes type 2 diabetes in epidemiological cohort studies. Here, we summarize clinical studies regarding fat intake and type 2 diabetes, and animal studies on high-fat diet-induced diabetes including our recent works on the novel mouse lines (selectively bred diet-induced glucose intolerance-prone [SDG-P] and -resistant [SDG-R]) to address the etiology of high-fat diet-induced diabetes. These epidemiological and experimental findings would provide further insight into the etiology of type 2 diabetes under the modern nutritional environment, namely in the context of increased fat intake.

Low-protein diet improves blood and urinary glucose levels and renal manifestations of diabetes in C57BLKS-db/db mice

PURPOSE

Dietary protein content is related clinically to the development of diabetic nephropathy. Here, we investigated how dietary protein content (12-24 % energy) within the range used by humans affected renal manifestations including the expressions of genes involved in the renin-angiotensin (RA) system in control and diabetic mice. Moreover, we examined the effects of dietary protein content on HbA1c and urinary glucose.

METHODS

Control (CT) and leptin receptor-deficient obese (db) mice, 5 weeks old, were fed the diets below. Under ad libitum conditions, mice were fed 12, 18, and 24 % energy from protein (L-, M-, and H-diets) for 8 weeks. Under pair-feeding conditions, db mice were supplied H-diet (db-Hp) to the equivalent energy to that consumed by db-L mice. Renal manifestations and values related to glucose and insulin were examined biochemically and pathologically.

RESULTS

Under ad libitum conditions, db mice consumed food and water dose dependently of the dietary protein content, although they were consumed similarly by CT mice. CT-L mice showed lower urinary albumin and kidney weight, in association with lower mRNA levels of angiotensinogen and renin, than CT-H mice. Under pair-feeding conditions, db-L mice showed a lower ratio of kidney/body weight, HbA1(C), and urinary glucose, and a higher β-cell distribution rate in the pancreas than db-Hp mice.

CONCLUSIONS

Low-protein intake in the range used by humans may relieve renal manifestations through the suppressed expression of genes in the renal RA system of CT mice. On the other hand, in db mice, low-protein intake improved hyperglycemia and the renal manifestations of diabetes.

Risk Factors for Type 2 Diabetes: Lessons Learned from Japanese Americans in Seattle

Migrant Japanese populations in both the United States and Brazil have for a long time shown a higher prevalence of type 2 diabetes than in native Japanese, suggesting an interaction of lifestyle and genetic predisposition in the etiology of type 2 diabetes. The overall objective of the Seattle Japanese American Community Diabetes Study was to learn more about the etiology and pathogenesis of type 2 diabetes in Japanese Americans. This metabolically based epidemiologic study included extensive assessments of insulin sensitivity, insulin response, and adiposity with the latter including measurements of body fat distribution by both anthropometry and computed tomography. Because of this, the importance of visceral adiposity as a risk factor for abnormal glucose tolerance, hypertension, coronary heart disease, and the metabolic syndrome was demonstrated. In conjunction with an examination of diet and physical activity patterns, the result was a clearer understanding of the etiology and pathogenesis of type 2 diabetes in Japanese Americans. Wepropose that a lifestyle that fosters increased weight gain, especially in the visceral adipose depot, promotes the development of insulin resistance which in turn exposes an underlying reduced beta-cell reserve in susceptible individuals, resulting in glucose intolerance and eventually in many the development of diabetes. We have shown that it may be possible to delay or prevent the development of diabetes through dietary and exercise interventions in individuals identified as having impaired glucose tolerance. The lessons learned from studying migrant Japanese in Seattle may in many ways be applicable to other populations of Asian origin.

Short-term effects of liraglutide on visceral fat adiposity, appetite, and food preference: a pilot study of obese Japanese patients with type 2 diabetes

Background

To examine the effects of liraglutide, a glucagon-like peptide-1 (GLP-1) analogue, on visceral fat adiposity, appetite, food preference, and biomarkers of cardiovascular system in Japanese patients with type 2 diabetes.

Methods

The study subjects were 20 inpatients with type 2 diabetes treated with liraglutide [age; 61.2 ± 14.0 years, duration of diabetes; 16.9 ± 6.6 years, glycated hemoglobin (HbA1c); 9.1 ± 1.2%, body mass index (BMI); 28.3 ± 5.2 kg/m², mean ± SD]. After improvement in glycemic control by insulin or oral glucose-lowering agents, patients were switched to liraglutide. We assessed the estimated visceral fat area (eVFA) by abdominal bioelectrical impedance analysis, glycemic control by the 75-g oral glucose tolerance test (OGTT) and eating behavior by the Japan Society for the Study of Obesity questionnaire.

Results

Treatment with liraglutide (dose range: 0.3 to 0.9 mg/day) for 20.0 ± 6.4 days significantly reduced waist circumference, waist/hip ratio, eVFA. It also significantly improved the scores of eating behavior, food preference and the urge for fat intake and tended to reduce scores for sense of hunger. Liraglutide increased serum C-peptide immunoreactivity and disposition index.

Conclusions

Short-term treatment with liraglutide improved visceral fat adiposity, appetite, food preference and the urge for fat intake in obese Japanese patients with type 2 diabetes.

Vegetarian Diets and Diabetes

A large body of evidence suggests that vegetarian and plant-based diets provide exceptional health benefits, including a reduced risk of obesity, diabetes, heart disease and some types of cancer, and increased longevity. Vegetarian diets are typically lower in fat, particularly saturated fat, and higher in dietary fiber. They are also likely to include more whole grains, legumes, nuts, and soy protein, which together provide micro-nutrients and protective factors at higher levels than most Western diets. In observational studies, a vegetarian or vegan diet is associated with reduced risk of development of type 2 diabetes and lower risk of complications in those with existing diabetes. Although it is often difficult to separate vegetarianism from other healthy lifestyle behaviors, this eating pattern and the absence of red meat and processed meat products may provide particular benefits in the management of diabetes and prediabetes. This article critically reviews the scientific evidence for the role of vegetarian diets in the prevention and management of diabetes.

Intra-abdominal fat accumulation is greatest at younger ages in Japanese-American adults

AIMS

We evaluated whether changes over 10-11 years in weight, subcutaneous abdominal fat (SQAF), and intra-abdominal fat (IAF) differ by age and contrasted age-related adiposity changes by gender.

METHODS

This is a prospective cohort study of non-diabetic, Japanese-American men and women aged 34-74 years. IAF and SQAF were measured by CT scan at baseline and 10-11-year follow-up visits.

RESULTS

The youngest participants gained the most weight, SQAF and IAF over 10-11 years. Older age at baseline was associated with significantly less change in weight (beta-coefficient: -0.19, 95% CI -0.22, -0.15), SQAF (beta-coefficient: -0.07, 95% CI -0.11, -0.02) and IAF (beta-coefficient: -0.74, 95% CI -1.03, -0.45) that persisted even after adjustments for sex, smoking, caloric intake, adiposity at baseline, and change in physical activity. Age was positively correlated with change in SQAF (beta-coefficient: 0.14, 95% CI 0.10, 0.18) and IAF (beta-coefficient: 0.51, 95% CI 0.21, 0.81) in separate models after further adjustment for weight change. Gender did not alter the associations between adiposity change and age.

CONCLUSIONS

Men and women gained the greatest absolute amount of weight, SQAF, and IAF at younger ages; however, older adults with comparable weight changes had relatively greater fat accumulation within IAF and SQAF depots.

Report of a National Heart, Lung, And Blood Institute Workshop: heterogeneity in cardiometabolic risk in Asian Americans In the U.S. Opportunities for research

The Asian and Pacific Islander population (Asian Americans) in the U.S. has increased dramatically in the last few decades. Yet, data on cardiovascular disease (CVD) in this population are scarce. The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health conducted an Expert Workshop to: 1) assess the importance of studying CVD in Asian Americans in the U.S.; and 2) consider strategic options for further investigations of CVD in this population. There is considerable geographical, ethnic, cultural, and genetic diversity within this population. Limited data also suggest striking differences in the risk of CVD, obesity, type 2 diabetes mellitus, and other CVD risk factors across the Asian-American population. The Asian-American population is a new diverse pool with less contemporary genetic and cultural admixture relative to groups that have lived in the U.S. for generations, plus it is diverse in lifestyle including culture, diet, and family structure. This diversity provides a window of opportunity for research on genes and gene-environment interactions and also to investigate how acculturation/assimilation to U.S. lifestyles affects health and CVD risk among relatively homogenous groups of recent immigrants. Given the heterogeneity in body weight, body size, and CVD risk, the Asian-American population in the U.S. offers a unique model to study the interaction and relationships between visceral adiposity and adipose tissue distribution and beta cell function, insulin resistance, and atherosclerosis.

Serum phospholipid and cholesteryl ester fatty acids and estimated desaturase activities are related to overweight and cardiovascular risk factors in adolescents

AIM/HYPOTHESIS

The objective of this study was to describe the relation of serum fatty acids and desaturase activity (DA) to overweight, insulin sensitivity and cardiovascular disease (CVD) risk factors in adolescents.

METHODS

The relations of % serum phospholipid (PL) and cholesteryl ester (CE) fatty acids and estimated DA with CVD risk factors were examined in 264 adolescents (average age 15 years). Fatty acids were determined by gas liquid chromotography. Surrogate measures of DA were expressed as ratios of serum fatty acids: Delta9 DA=16:0/16:1; Delta6 DA=20:3,n6/18:2,n6 (PL) or 18:3,n6/18:2,n6 (CE); and Delta5 DA=20:4,n6/20:3,n6. Spearman partial correlations of fatty acids (%) and DA ratios with CVD risk factors were reported, adjusting for age, sex, race, Tanner stage, energy intake and physical activity.

RESULTS

Overweight adolescents compared to normal weight had more adverse levels of CVD risk factors, composition of PL and CE fatty acids in serum, and Delta6 DA and Delta5 DA ratios. Linoleic acid was inversely related to body mass index (BMI), waist circumference and triglycerides (P

CONCLUSION

These findings support those observed in adults, that factors, such as type of dietary fat, physical activity, and obesity, may influence fatty acid metabolism and are important in the development of adverse CVD risk factors as early as adolescence.

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Key Words Collapse

MESH Headings

• Adolescent
• Body Mass Index
• Cardiovascular Diseases/etiology
• Cholesterol Esters/blood
• Fatty Acid Desaturases/blood
• Fatty Acids/blood
• Female
• Humans
• Insulin Resistance
• Male
• Overweight/blood
• Overweight/physiopathology
• Phospholipids/blood
• Risk Factors
• Waist Circumference

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Grants

• M01 RR000400 NCRR NIH HHS
• R01 HL052851-13 NHLBI NIH HHS
• MO1RR00400 NCRR NIH HHS
• HL52851 NHLBI NIH HHS
• R01 HL052851 NHLBI NIH HHS

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Affiliation(s)

L M Steffen Division of Epidemiology and Community Health, University of Minnesota School of Public Health, Minneapolis, MN 55454, USA.
B Vessby
D R Jacobs
J Steinberger
A Moran
C-P Hong
A R Sinaiko

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All-cause mortality among Japanese-Brazilians according to nutritional characteristics

The aim of this study was to verify the association between nutritional variables and mortality in a Japanese-Brazilian cohort. In 1993, 647 subjects were interviewed with food frequency questionnaires and scheduled for physical procedures (weight, height, blood pressure) and biochemical tests (oral glucose tolerance test). Student's t test was used to compare the mean values of target variables between living and deceased subjects. Mortality rate and hazard ratios were obtained (crude and adjusted) according to the nutritional variables. Overall mortality rates were 21.4 and 11.7/1,000 person-years for males and females, respectively. Smoking, diabetes, sedentary lifestyle, hypertension, higher mean age, high blood pressure, high blood glucose, and higher percent weight gain and rate of weight gain were observed in the history of deceased subjects. After adjusting for control variables, an increase was observed in mortality among individuals with lower carbohydrate and cholesterol intake. The results suggest that mortality risk factors like age, chronic diseases, sedentary lifestyle, smoking, and inadequate diet must also be acting in the Japanese-Brazilian population.

Effect of dietary protein level and origin on the redox status in the digestive tract of mice

The present study was undertaken to evaluate the effects of high protein (soybean protein or casein) on the balance between production of free radicals and antioxidant level in digestive organs of mice. For this purpose, male (C57BL/6J) mice were adapted to experimental diets containing soybean protein or casein with 20% (normal protein diets, NPDs) or 60% (high protein diets, HPDs), and HPDs supplemented with 0.06g/kg cysteamine. After two weeks of feeding, oxidative and antioxidative parameters in duodenum, liver and pancreas were measured. The results show that ingestion of high protein markedly increased contents of superoxide anion and malondialdehyde (MDA), decreased activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and Na⁺ K⁺-ATPase, and content of reduced glutathione (GSH) in digestive organs of mice (P<0.05). Levels of oxidative parameters were lower and antioxidant capacity of both enzyme and non-enzyme was higher in mice fed with soybean protein than those fed with casein. In groups fed HPDs supplemented with cysteamine, oxidative stress was mitigated. However, oxidative parameter levels were still higher than those of NPD-fed groups. The present study indicates that ingestion of high protein diets could result in an imbalance between oxidant and antioxidant, and thus induce oxidative stress in digestive organs of mice. The oxidative damage was smaller in mice fed with high level of soy protein in comparison with casein.

Determining the relationship between dietary carbohydrate intake and insulin resistance

Insulin resistance underlies type 2 diabetes, CVD and the metabolic syndrome, driven by changes in diet, lifestyle, energy over–consumption and obesity. Nutritional recommendations for insulin resistance remain an area of controversy, particularly the quantity and types of dietary carbohydrate. The present review gives an overview of insulin resistance, its relationship to impaired insulin secretion and the metabolic syndrome, research methodologies used to measure insulin action and the epidemiological and intervention studies on the relationship between dietary carbohydrate and insulin resistance. Epidemiological studies provide little evidence to suggest that total dietary carbohydrate predicts risk of type 2 diabetes, and high–carbohydrate, high–fibre diets with low–glycaemic index (GI) may even contribute to diabetes prevention. Despite inherent limitations associated with techniques used to measure insulin resistance and dietary assessment, most intervention studies reveal an increase in glucose tolerance or insulin sensitivity with high–carbohydrate, low–fat diets in non–diabetic and diabetic individuals. When energy is restricted the source or reduced content of carbohydrate does not appear to be as important as fat for body weight. Thus, low energy intake is key to weight loss and augmentation of insulin sensitivity. Given this, widespread adoption of popular low–carbohydrate high–fat diets highlights the necessity to evaluate dietary interventions regarding safety and metabolic effects. While current evidence supports FAO/WHO recommendations to maintain a high–carbohydrate diet with low–GI foods, the relationships between carbohydrate and insulin sensitivity remains an important research area. Emerging technologies should further enhance understanding of gene–diet interactions in insulin resistance, providing useful information for future nutrition policy decisions.

Measuring dietary acculturation in Japanese Americans with the use of confirmatory factor analysis of food-frequency data

BACKGROUND

Epidemiologic evidence suggests that dietary changes associated with acculturation to a Western diet may increase the risk of type 2 diabetes in Japanese Americans.

OBJECTIVE

We hypothesized that dietary acculturation patterns could be measured by confirmatory factor analysis (CFA) by using a culturally sensitive food-frequency questionnaire (FFQ). We examined the utility of the estimated factor scores by testing for associations with diabetes and 2 risk factors for diabetes-body mass index (BMI; in kg/m(2)) and C-reactive protein (CRP).

DESIGN

By using cross-sectional data from a sample of 219 Nisei (second-generation Japanese American; mean age 70 y) and 277 Sansei (third-generation Japanese American; mean age 42 y) participants in the Japanese American Family Study, we conducted CFA on 5 items characteristic of a Japanese diet and 4 items characteristic of a Western diet. The resulting factor scores were examined for associations with diabetes by using logistic regression and for associations with BMI and CRP by using linear regression.

RESULTS

CFA confirmed the presence of Japanese and Western food factors. The Nisei had a significantly higher average factor score for the Japanese food factor and significantly lower average factor score for the Western food factor than did the Sansei. In Sansei persons, but not in Nisei persons, the Western food factor score was significantly associated with plasma CRP concentration (P = 0.02), BMI (P = 0.02), and diabetes (P = 0.001).

CONCLUSIONS

In this Japanese American sample, dietary acculturation can be estimated by using CFA on FFQ data. Future studies should investigate the effects of dietary acculturation on disease risk independent of other lifestyle factors.

Chronic Diseases and Dietary Changes in Relation to Korean Americans’ Length of Residence in the United States

BACKGROUND

National health in the United States is influenced by the dietary norms brought into the country by an increasing number of immigrants.

OBJECTIVES

This cross-sectional study aimed to document dietary changes and disease prevalence in relation to the length of residence in the United States for Korean Americans in Michigan.

DESIGN

Of 1,860 questionnaires mailed out, 637 (34.3%) were returned with respondent-reported information, including demographics, weight and height, chronic diseases, and dietary patterns.

SUBJECTS/SETTING

Included in the final analyses were 497 first-generation Korean-American immigrants (263 men, 234 women, aged 30 to 87 years).

STATISTICAL ANALYSES PERFORMED

Analysis of covariance with the Tukey test and logistic regression models provided sex-specific analysis of dietary changes and disease patterns. All statistical analyses were adjusted for age.

RESULTS

Chronic diseases reported most frequently by men and women, respectively, were hypertension, digestive diseases, arthritis, and diabetes. Length of residence in the United States (<or=15 years, 16 to 25 years, or >or=26 years) was inversely associated with the prevalence of digestive diseases in men (P=0.017) and women (P=0.001), and positively with respiratory diseases in men and thyroid disease in women (P<0.05). Length of residence in the United States was inversely associated with intake of rice/rice dishes in both men (servings per week, P<0.001) and women (P=0.012). The prevalence of digestive diseases associated inversely with length of residence and positively with servings of rice/rice dishes consumed for Korean-American men. The age-adjusted odds ratio for digestive diseases was highest among men who had the shortest length of residence in the United States (<or=15 years) and greater consumption of rice/rice dishes (>2 servings per day) (odds ratio 12.10; P=0.03).

CONCLUSIONS

Dietary changes of Korean-American immigrants in the United States over time were associated with changes in their chronic disease patterns. These findings may help food and nutrition professionals who work with minority immigrants because they identify factors that affect changes in dietary patterns and work toward preventing diet-related diseases. Prospective studies could address underlying mechanisms of the observed diet-disease relationship with subsequent generations of Korean Americans, as well as various ethnic minority immigrants in the United States.

Long-term sucrose-drinking causes increased body weight and glucose intolerance in normal male rats

The current epidemic of diabetes likely reflects marked changes in environmental factors, although genetic susceptibility plays a powerful role in the occurrence of diabetes in certain populations. We investigated whether long-term sucrose-drinking causes hyperglycaemia in male Wistar-Imamichi littermates (n 32), which are not genetically susceptible to diabetes or obesity. Each litter was divided equivalently into two groups, the sucrose group and the control group. The sucrose group received 300 g/l sucrose water and the control group received regular water until 42 weeks of age. Rats were weighed every 1 or 2 weeks. Oral glucose tolerance tests were performed at 28 and 36 weeks of age. Plasma glucose and insulin concentrations were measured. Body weights were significantly greater in the sucrose group than in the control group in 18-week-old rats (P<0·05), and the difference between the two groups reached 163 g by the end of the study (P<0·01). The 120 min post-load plasma glucose concentration in the sucrose group was 11·4 (sd 2·8) mmol/l in 28-week-old rats and 12·7 (sd 2·2) mmol/l in 36-week-old rats, while that of the control group remained approximately 7·3–7·7 mmol/l. In the sucrose group, the plasma insulin peak occurred 30 min post-load at 28 weeks of age; but the peak disappeared and hyperinsulinaemia was prolonged at 36 weeks of age. In conclusion, long-term sucrose-drinking causes increased body weight and glucose intolerance in normal male rats.

Diet, nutrition and the prevention of type 2 diabetes

Objectives:

The overall objective of this study was to evaluate and provide evidence and recommendations on current published literature about diet and lifestyle in the prevention of type 2 diabetes.

Design:

Epidemiological and experimental studies, focusing on nutritional intervention in the prevention of type 2 diabetes are used to make disease-specific recommendations. Long-term cohort studies are given the most weight as to strength of evidence available.

Setting and subjects:

Numerous clinical trials and cohort studies in low, middle and high income countries are evaluated regarding recommendations for dietary prevention of type 2 diabetes. These include, among others, the Finnish Diabetes Prevention Study, US Diabetes Prevention Program, Da Qing Study; Pima Indian Study; Iowa Women's Health Study; and the study of the US Male Physicians.

Results:

There is convincing evidence for a decreased risk of diabetes in adults who are physically active and maintain a normal body mass index (BMI) throughout adulthood, and in overweight adults with impaired glucose tolerance who lose weight voluntarily. An increased risk for developing type 2 diabetes is associated with overweight and obesity; abdominal obesity; physical inactivity; and maternal diabetes. It is probable that a high intake of saturated fats and intrauterine growth retardation also contribute to an increased risk, while non-starch polysaccharides are likely to be associated with a decreased risk. From existing evidence it is also possible that omega-3 fatty acids, low glycaemic index foods and exclusive breastfeeding may play a protective role, and that total fat intake andtransfatty acids may contribute to the risk. However, insufficient evidence is currently available to provide convincing proof.

Conclusions:

Based on the strength of available evidence regarding diet and lifestyle in the prevention of type 2 diabetes, it is recommended that a normal weight status in the lower BMI range (BMI 21–23) and regular physical activity be maintained throughout adulthood; abdominal obesity be prevented; and saturated fat intake be less than 7% of the total energy intake.

[Changes in dietary intake among Japanese-Brazilians in Bauru, São Paulo, Brazil, 1993-2000]

Cross-sectional surveys were performed in 1993 and 2000 on Japanese-Brazilians (n = 328) of both sexes, aged 40 to 79 years in 1993, living in Bauru, São Paulo State. Both surveys examined food intake using food frequency questionnaires. Dietary intake in both surveys was compared to Wilcoxon tests according to gender (p < 0.05). Calories from dietary fat increased by 16% in both genders (mean values in 2000: 31.5% for women and 30.8% for men). When the surveys were compared, the main dietary changes were: (a) a 40% increase in oleic and linoleic acids and calories from fat and (b) a 20% reduction in dietary cholesterol in both sexes. Among women, an increase in total calorie intake with reduced consumption of vegetables and calories from sweets were observed. Despite increased intake of total dietary fat, there was a decrease in cholesterol intake and an increase in oleic and linoleic acids, fruit, and calcium. However, calcium and vegetable consumption is still short of international recommendations.

Accelerated solvent extraction for quantitative measurement of fatty acids in plasma and erythrocytes

Consumption of fish rich in n-3 highly unsaturated FAs (i.e., EPA and DHA) has been suggested to decrease the risk of lifestyle-related diseases such as coronary heart disease, cancer, diabetes, and dementia. Blood levels of those FA are known appropriate biomarkers of both the corresponding dietary FA intakes and fish consumption. In place of traditional handwork methods for extracting FA, we performed an accelerated solvent extraction (ASE) for at least 13 selected FA in plasma and erythrocytes to measure them by GLC. The FA levels (concentrations and compositions) in 35-50 microL of plasma or erythrocytes were extracted by ASE and measured by GLC. Intra- and interassay coefficients of variation were < or = 6.0% for both blood materials, except with a minor group of FA (< or = 1.0% of total FA). When ASE was compared with two traditional handwork methods, FA levels in plasma from 18 healthy subjects were all coincident with very high Pearson's correlation coefficients for the three sets of the same 18 samples (r > or = 0.85 to 0.95, P < 0.0001), except for 18:0 (r = 0.59, P < 0.01). Using ASE and GLC, we have developed a new method for determination the levels of FA in plasma and erythrocytes as biomarkers for dietary intake of fish, fat, and FA. This new method makes it feasible to measure small volumes of samples, automatically, quantitatively, routinely, easily, rapidly and cheaply, with acceptable precision and accuracy.

Influência do consumo alimentar de ácidos graxos trans no perfil de lipídios séricos em nipo-brasileiros de Bauru, São Paulo, Brasil

A influência da alteração do consumo de ácidos graxos trans nos níveis de lipídios séricos foi avaliada em 328 nipo-brasileiros de primeira (issei) e segunda geração (nisei), entre 40 e 79 anos, em 1993, participantes de dois inquéritos de saúde e nutrição realizados em 1993 e 2000. A relação entre a diferença do consumo de ácidos graxos trans e a diferença entre os níveis de lipídios séricos entre os dois inquéritos foi analisada em modelos de regressão linear múltiplos. Em ambos os gêneros, observou-se redução estatisticamente significante no consumo total de gordura trans, acompanhado de redução dos níveis séricos de LDL colesterol e aumento do HDL colesterol em sete anos de seguimento. Os valores médios de ingestão de gordura trans (percentual das calorias totais) em 1993 e 2000 foram: 5,1% e 3,4% para mulheres e 4,7% e 3,3% para homens, respectivamente. Apesar da ausência de associação entre as alterações do consumo de ácidos graxos trans e alterações no perfil de lipídios séricos, o nível de ingestão de gordura trans foi acima do recomendado pela OMS (até 1% das calorias totais).

Association of Dietary Fiber with Temporal Changes in Serum Cholesterol in Japanese-Brazilians

To examine dietary intakes in relation to long-term serum lipoprotein changes in a prospective cohort study with 7 y of follow-up, serum lipids were analyzed by enzymatic methods, while food intake was calculated from validated food frequency questionnaires. First- and second-generation Japanese-Brazilians (n = 316) living in Bauru, São Paulo/Brazil, of both genders, aged 40 to 79 y were assessed at baseline in 1993. Multiple linear regression models were used with changes in serum lipoproteins as the dependent variable and changes in dietary intakes as the independent variables, adjusted for confounding factors. In energy-adjusted analyses, changes in serum total cholesterol were inversely associated with changes in total dietary fiber, fruits/fruit juices and vegetables after adjustment for age and gender. Each increase of 10 g in the consumption of total dietary fiber was associated with a reduction of 12.5 mg/dL in the serum total cholesterol (p<0.05). Our results highlight the importance of increased intakes of total fiber, fruits and vegetables to prevent and control dyslipidemia in Japanese migrants.

Dietary approaches that delay age-related diseases

Reducing food intake in lower animals such as the rat decreases body weight, retards many aging processes, delays the onset of most diseases of old age, and prolongs life. A number of clinical trials of food restriction in healthy adult human subjects running over 2-15 years show significant reductions in body weight, blood cholesterol, blood glucose, and blood pressure, which are risk factors for the development of cardiovascular disease and diabetes. Lifestyle interventions that lower energy balance by reducing body weight such as physical exercise can also delay the development of diabetes and cardiovascular disease. In general, clinical trials are suggesting that diets high in calories or fat along with overweight are associated with increased risk for cardiovascular disease, type 2 diabetes, some cancers, and dementia. There is a growing literature indicating that specific dietary constituents are able to influence the development of age-related diseases, including certain fats (trans fatty acids, saturated, and polyunsaturated fats) and cholesterol for cardiovascular disease, glycemic index and fiber for diabetes, fruits and vegetables for cardiovascular disease, and calcium and vitamin D for osteoporosis and bone fracture. In addition, there are dietary compounds from different functional foods, herbs, and neutraceuticals such as ginseng, nuts, grains, and polyphenols that may affect the development of age-related diseases. Long-term prospective clinical trials will be needed to confirm these diet-disease relationships. On the basis of current research, the best diet to delay age-related disease onset is one low in calories and saturated fat and high in wholegrain cereals, legumes, fruits and vegetables, and which maintains a lean body weight. Such a diet should become a key component of healthy aging, delaying age-related diseases and perhaps intervening in the aging process itself. Furthermore, there are studies suggesting that nutrition in childhood and even in the fetus may influence the later development of aging diseases and lifespan.

Association of endothelial lipase gene (LIPG) haplotypes with high-density lipoprotein cholesterol subfractions and apolipoprotein AI plasma levels in Japanese Americans

The LIPG gene on chromosome 18 encodes for endothelial lipase, a member of the triglyceride lipase family. Mouse models suggest that variation in LIPG influences high-density lipoprotein (HDL) metabolism, but only limited data are available in humans. This study examined associations of LIPG haplotypes, comprising a single nucleotide polymorphism (SNP) in the promoter region (-384A>C), and a nonsynonymous SNP in exon 3 (Thr111Ile or 584C>T), with lipoprotein risk factors in 541 adult Japanese Americans. A marginal association was found between LIPG diplotypes and HDL cholesterol (p=0.045). Stronger associations were seen for HDL3 cholesterol (p=0.005) and Apolipoprotein AI plasma levels (p=0.002). After adjustment for age, gender, smoking and medications, individuals homozygous for the minor allele at both SNPs (*4 haplotype) had a more favorable risk factor profile, compared to other haplotype combinations. No relationship was seen for plasma triglyceride levels or low-density lipoprotein (LDL) size, but the homozygous *4 diplotype was also associated with lower Apolipoprotein B and LDL cholesterol levels (p=0.001 and 0.015, respectively). In conclusion, this community-based family study of Japanese Americans demonstrates that LIPG variants are associated with HDL related risk factors, and may play a role in susceptibility to cardiovascular disease in this population.

Dietary fat is associated with metabolic syndrome in Japanese Brazilians

OBJECTIVE

The aim of this study was to examine the association of nutrient intakes with metabolic syndrome in a Japanese descendant population at high risk for metabolic abnormalities.

RESEARCH DESIGN AND METHODS

In a population-based study of Japanese Brazilians aged > or =30 years, 412 men and 465 women were studied. The diagnosis of metabolic syndrome was based on the National Cholesterol Education Program criteria modified for Asians. Food intake was assessed by a validated food frequency questionnaire.

RESULTS

Men and women showed similar mean ages (55.7 +/- 12.7 and 54.4 +/- 11.9 years) and 49% (95% CI 44.8-54.6) and 43% (38.4-47.6) had metabolic syndrome, respectively. As expected, clinical parameters were less favorable in the subset of subjects with metabolic syndrome. Men with metabolic syndrome showed higher cholesterol (233.2 +/- 116.3 vs. 211.7 +/- 5.8 g/day, P < 0.05) and lower carbohydrate (288.5 +/- 45.8 vs. 300.1 +/- 39.8 g/day, P < 0.001) intakes than those without metabolic syndrome, but no difference was observed among the women. After adjusting for sex, age, smoking, education level, generation, physical activity, total energy, and dietary fiber intake, a positive association between metabolic syndrome and total fat intake was detected. Comparing people in the highest quintile of total fat consumption with those in the lowest quintile, odds ratio (OR) of metabolic syndrome was 5.0 ([95% CI 1.58-16.00]; P < 0.005). In contrast, linoleic acid intake was inversely associated with metabolic syndrome (OR 0.50 [95% CI 0.26-0.98]; P < 0.05). Considering food groups, after adjustments only fried food intake was shown to be associated with increased risk of metabolic syndrome.

CONCLUSIONS

Despite the limitation of such a study design in investigating cause-effect relationships, our findings favor the hypothesis that dietary total fat may increase whereas linoleic acid intake may reduce the risk of metabolic syndrome in Japanese descendants living in Brazil.

A reduced-fat diet and aerobic exercise in Japanese Americans with impaired glucose tolerance decreases intra-abdominal fat and improves insulin sensitivity but not beta-cell function

Lifestyle modification reduces the risk of developing type 2 diabetes and may have its effect through improving insulin sensitivity, beta-cell function, or both. To determine whether diet and exercise improve insulin sensitivity and/or beta-cell function and to evaluate these effects over time, we quantified insulin sensitivity and the acute insulin response to glucose (AIRg) in 62 Japanese Americans (age 56.5 +/- 1.3 years; mean +/- SE) with impaired glucose tolerance (IGT) who were randomized to the American Heart Association (AHA) Step 2 diet plus endurance exercise (n = 30) versus the AHA Step 1 diet plus stretching (n = 32) for 24 months. beta-Cell function (disposition index [DI]) was calculated as S(i) x AIRg, where S(i) is the insulin sensitivity index. The incremental area under the curve for glucose (incAUCg) was calculated from a 75-g oral glucose tolerance test. Intra-abdominal fat (IAF) and subcutaneous fat (SCF) areas were measured by computed tomography. At 24 months, the Step 2/endurance group had lower weight (63.1 +/- 2.4 vs. 71.3 +/- 2.9 kg; P = 0.004) and IAF (75.0 +/- 7.9 vs. 112.7 +/- 10.4 cm(2); P = 0.03) and SCF (196.5 +/- 18.0 vs. 227.7 +/- 19.9 cm(2); P < 0.001) areas, greater S(i) (4.7 +/- 0.5 vs. 3.3 +/- 0.3 x 10(-5) min . pmol(-1) . l(-1); P = 0.01), and a trend toward lower AIRg (294.9 +/- 50.0 vs. 305.4 +/- 30.0 pmol/l; P = 0.06) and incAUCg (8,217.3 +/- 350.7 vs. 8,902.0 +/- 367.2 mg . dl(-1) . 2 h(-1); P = 0.08) compared with the Step 1/stretching group after adjusting for baseline values. There was no difference in the DI (P = 0.7) between the groups. S(i) was associated with changes in weight (r = -0.426, P = 0.001) and IAF (r = -0.395, P = 0.003) and SCF (r = -0.341, P = 0.01) areas. Thus, the lifestyle modifications decreased weight and central adiposity and improved insulin sensitivity in Japanese Americans with IGT. However, such changes did not improve beta-cell function, suggesting that this degree of lifestyle modifications may be limited in preventing type 2 diabetes over the long term.

Effects of dietary fatty acids on insulin sensitivity and secretion

Globalization and global market have contributed to increased consumption of high-fat, energy-dense diets, particularly rich in saturated fatty acids( SFAs). Polyunsaturated fatty acids (PUFAs) regulate fuel partitioning within the cells by inducing their own oxidation through the reduction of lipogenic gene expression and the enhancement of the expression of those genes controlling lipid oxidation and thermogenesis. Moreover, PUFAs prevent insulin resistance by increasing membrane fluidity and GLUT4 transport. In contrast, SFAs are stored in non-adipocyte cells as triglycerides (TG) leading to cellular damage as a sequence of their lipotoxicity. Triglyceride accumulation in skeletal muscle cells (IMTG) derives from increased FA uptake coupled with deficient FA oxidation. High levels of circulating FAs enhance the expression of FA translocase the FA transport proteins within the myocites. The biochemical mechanisms responsible for lower fatty acid oxidation involve reduced carnitine palmitoyl transferase (CPT) activity, as a likely consequence of increased intracellular concentrations of malonyl-CoA; reduced glycogen synthase activity; and impairment of insulin signalling and glucose transport. The depletion of IMTG depots is strictly associated with an improvement of insulin sensitivity, via a reduced acetyl-CoA carboxylase (ACC) mRNA expression and an increased GLUT4 expression and pyruvate dehydrogenase (PDH) activity. In pancreatic islets, TG accumulation causes impairment of insulin secretion. In rat models, beta-cell dysfunction is related to increased triacylglycerol content in islets, increased production of nitric oxide, ceramide synthesis and beta-cell apoptosis. The decreased insulin gene promoter activity and binding of the pancreas-duodenum homeobox-1 (PDX-1) transcription factor to the insulin gene seem to mediate TG effect in islets. In humans, acute and prolonged effects of FAs on glucose-stimulated insulin secretion have been widely investigated as well as the effect of high-fat diets on insulin sensitivity and secretion and on the development of type 2 diabetes.

Impact of the Bienestar school-based diabetes mellitus prevention program on fasting capillary glucose levels: a randomized controlled trial

OBJECTIVE

To evaluate the impact of a school-based diabetes mellitus prevention program on low-income fourth-grade Mexican American children.

DESIGN

A randomized controlled trial with 13 intervention and 14 control schools.

SETTING

Elementary schools in inner-city neighborhoods in San Antonio, Tex.

PARTICIPANTS

Eighty percent of participants were Mexican American and 94% were from economically disadvantaged households. Baseline and follow-up measures were collected from 1419 (713 intervention and 706 control) and 1221 (619 intervention and 602 control) fourth-grade children, respectively.

INTERVENTION

The Bienestar Health Program consists of a health class and physical education curriculum, a family program, a school cafeteria program, and an after-school health club. The objectives are to decrease dietary saturated fat intake, increase dietary fiber intake, and increase physical activity.

MAIN OUTCOME MEASURES

The primary end point was fasting capillary glucose level, and the secondary end points were percentage of body fat, physical fitness level, dietary fiber intake, and dietary saturated fat intake. Fasting capillary glucose level, bioelectric impedance, modified Harvard step test, three 24-hour dietary recalls, weight, and height were collected at baseline and 8 months later.

RESULTS

Children in the intervention arm attended an average of 32 Bienestar sessions. Mean fasting capillary glucose levels decreased in intervention schools and increased in control schools after adjusting for covariates (-2.24 mg/dL [0.12 mmol/L]; 95% confidence interval, -6.53 to 2.05 [-0.36 to 0.11 mmol/L]; P =.03). Fitness scores (P =.04) and dietary fiber intake (P =.009) significantly increased in intervention children and decreased in control children. Percentage of body fat (P =.56) and dietary saturated fat intake (P =.52) did not differ significantly between intervention and control children.

CONCLUSION

This intervention showed some positive results, but additional research is needed to examine long-term benefits, translation, and cost-effectiveness.

Plasma fatty acid composition and incidence of diabetes in middle-aged adults: the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

The results of some epidemiologic studies conducted by using questionnaires suggest that dietary fat composition influences diabetes risk. Confirmation of this finding with use of a biomarker is warranted.

OBJECTIVE

We prospectively investigated the relation of plasma cholesterol ester (CE) and phospholipid (PL) fatty acid composition with the incidence of diabetes mellitus.

DESIGN

In 2909 adults aged 45-64 y, plasma fatty acid composition was quantified by using gas-liquid chromatography and was expressed as a percentage of total fatty acids. Incident diabetes (n = 252) was identified during 9 y of follow-up.

RESULTS

After adjustment for age, sex, baseline body mass index, waist-to-hip ratio, alcohol intake, cigarette smoking, physical activity, education, and parental history of diabetes, diabetes incidence was significantly and positively associated with the proportions of total saturated fatty acids in plasma CE and PL. The rate ratios of incident diabetes across quintiles of saturated fatty acids were 1.00, 1.36, 1.16, 1.60, and 2.08 (P = 0.0013) in CE and 1.00, 1.75, 1.87, 2.40, and 3.37 (P < 0.0001) in PL. In CE, the incidence of diabetes was also positively associated with the proportions of palmitic (16:0), palmitoleic (16:1n-7), and dihomo-gamma-linolenic (20:3n-6) acids and inversely associated with the proportion of linoleic acid (18:2n-6). In PL, incident diabetes was positively associated with the proportions of 16:0 and stearic acid (18:0).

CONCLUSIONS

The proportional saturated fatty acid composition of plasma is positively associated with the development of diabetes. Our findings with the use of this biomarker suggest indirectly that the dietary fat profile, particularly that of saturated fat, may contribute to the etiology of diabetes.

Improvement of BMI, body composition, and body fat distribution with lifestyle modification in Japanese Americans with impaired glucose tolerance

OBJECTIVE

To determine whether diet and endurance exercise improved adiposity-related measurements in Japanese Americans with impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS

This study compared the effects of an American Heart Association (AHA) step 2 diet (<30% of total calories as fat, <7% saturated fat, 55% carbohydrate, and < 200 mg cholesterol daily) plus endurance exercise for 1 h three times a week (treatment group) with an AHA step 1 diet (30% of total calories as fat, 10% saturated fat, 50% carbohydrate, and <300 mg cholesterol) plus stretching exercise three times a week (control group) on BMI, body composition (% fat), and body fat distribution at 6 and 24 months of follow-up in 64 Japanese American men and women with IGT, 58 of whom completed the study.

RESULTS

At 6 months, the treatment group showed significantly greater reduction in percent, body fat (-1.4 +/- 0.4 vs. -0.3 +/- 0.3%); BMI (-1.1 +/- 0.2 vs. -0.4 +/- 0.1 kg/m(2)); subcutaneous fat by computed tomography at the abdomen (-29.3 +/- 4.2 vs. -5.7 +/- 5.9 cm(2)), thigh (-13.2 +/- 3.6 vs. -3.6 +/- 3.0 cm(2)), and thorax (-19.6 +/- 3.6 vs. -8.9 +/- 2.6 cm(2)); and skinfold thickness at the bicep (-2.0 +/- 0.6 vs. 1.1 +/- 0.6 mm) and tricep (-3.7 +/- 0.8 vs. -0.9 +/- 0.6 mm), which continued despite moving to home-based exercise for the last 18 months.

CONCLUSIONS

Diet and endurance exercise improved BMI, body composition, and body fat distribution and, thus, may delay or prevent type 2 diabetes in Japanese Americans with IGT.

Dietary fat and incidence of type 2 diabetes in older Iowa women

OBJECTIVE

To examine the associations between reported intakes of dietary fat and incident type 2 diabetes.

RESEARCH DESIGN AND METHODS

We studied the relation between dietary fatty acids and diabetes in a prospective cohort study of 35,988 older women who initially did not have diabetes. Diet was assessed with a food frequency questionnaire at baseline, and 1,890 incident cases of diabetes occurred during 11 years of follow-up.

RESULTS

After adjusting for age, smoking, alcohol consumption, BMI, waist-to-hip ratio, physical activity, demographic factors, and dietary magnesium and cereal fiber, diabetes incidence was negatively associated with dietary polyunsaturated fatty acids, vegetable fat, and trans fatty acids and positively associated with omega-3 fatty acids, cholesterol, and the Keys score. After simultaneous adjustment for other dietary fat, only vegetable fat remained clearly related to diabetes risk. Relative risks across quintiles of vegetable fat intake were 1.00, 0.90, 0.87, 0.84, and 0.82 (P = 0.02). Diabetes risk was also inversely related to substituting polyunsaturated fatty acids for saturated fatty acids and positively correlated to the Keys dietary score.

CONCLUSIONS

These data support an inverse relation between incident type 2 diabetes and vegetable fat and substituting polyunsaturated fatty acids for saturated fatty acids and cholesterol.

Type 2 diabetes and the metabolic syndrome in Japanese Americans

Japanese Americans have experienced a higher prevalence of type 2 diabetes than in Japan. Research conducted in Seattle suggests that lifestyle factors associated with 'westernization' play a role in bringing out this susceptibility to diabetes. These lifestyle factors include consumption of a diet higher in saturated fat and reduced physical activity. A consequence of this is the development of central (visceral) adiposity, insulin resistance, and other features associated with this insulin resistance metabolic syndrome, such as dyslipidemia (high triglycerides, low HDL-cholesterol, and small and dense LDL particles), hypertension, and coronary heart disease. We have postulated that the superimposition of insulin resistance upon a genetic background of reduced beta-cell reserve results in hyperglycemia and diabetes among Japanese Americans. This article reviews evidence that support this view.