A comparison between Japanese-Americans living in Hawaii and Los Angeles and native Japanese: the impact of lifestyle westernization on diabetes mellitus

Dietary Vitamins A, C, and Potassium Intake Is Associated With Narrower Retinal Venular Caliber

Introduction

The retinal vasculature, a surrogate for the systemic microvasculature, can be observed non-invasively, providing an opportunity to examine the effects of modifiable factors, such as nutrient intake, on microcirculation. We aimed to investigate the possible associations of dietary nutrient intake with the retinal vessel caliber.

Methods

In this cross-sectional study, a total of 584 participants in a medical survey of Japanese descendants living in Los Angeles in 2015 underwent a dietary assessment, fundus photographic examination, and comprehensive physical and blood examinations. Retinal vessel caliber was measured using fundus photographs with a semi-automated computer system and summarized as central retinal artery and vein equivalents (CRAE and CRVE). The association between dietary nutrient intake and retinal vessel caliber was analyzed using a multivariate linear regression model adjusted for two models including potential confounders. The first model was adjusted for age and sex. The second model was adjusted for age, sex, smoking status, body mass index, hypertension, diabetes, dyslipidemia, history of coronary heart disease, and history of stroke.

Results

After adjustment of potential confounders, compared to the quartile with the lowest intake, the difference in CRVE for the highest quartile was −5.33 μm [95% confidence interval (CI): −9.91 to −0.76, P for trend = 0.02] for vitamin A, −4.93 μm (95% CI: −9.54 to −0.32, P for trend = 0.02) for vitamin C and −3.90 μm (95% CI: −8.48 to 0.69, P for trend = 0.04) for potassium.

Conclusions

A significant association was observed between higher vitamins A, C and potassium intakes and narrower retinal venular caliber.

Factors Associated with Lower Cognitive Performance Scores Among Older Japanese Men in Hawaii and Japan

BACKGROUND

Few studies have compared factors related to cognitive function among people with similar genetic backgrounds but different lifestyles.

OBJECTIVE

We aimed to identify factors related to lower cognitive scores among older Japanese men in two genetically similar cohorts exposed to different lifestyle factors.

METHODS

This cross-sectional study of community-dwelling Japanese men aged 71-81 years included 2,628 men enrolled in the Kuakini Honolulu-Asia Aging Study based in Hawaii and 349 men in the Shiga Epidemiological Study of Subclinical Atherosclerosis based in Japan. We compared participant performance through Cognitive Abilities Screening Instrument (CASI) assessment in Hawaii (1991-1993) and Japan (2009-2014). Factors related to low cognitive scores (history of cardiovascular disease, cardiometabolic factors, and lifestyle factors) were identified with questionnaires and measurements. Multivariable logistic regression analysis was used to calculate the adjusted odds ratios (ORs) of a low (< 82) CASI score based on different factors.

RESULTS

CASI scores were lower in Hawaii than in Japan [21.2%(n = 556) versus 12.3%(n = 43), p < 0.001], though this was not significant when adjusted for age and educational attainment (Hawaii 20.3%versus Japan 17.9%, p = 0.328). History of stroke (OR = 1.65, 95%confidence interval = 1.19-2.29) was positively associated with low cognitive scores in Hawaii. Body mass index ≥25 kg/m2 tended to be associated with low cognitive scores in Japan; there was a significant interaction between the cohorts.

CONCLUSION

Cognitive scores differences between cohorts were mostly explained by differences in educational attainment. Conversely, cardiovascular diseases and cardiometabolic factors differentially impacted cognitive scores among genetically similar older men exposed to different lifestyle factors.

Postprandial Metabolism and Physical Activity in Asians: A Narrative Review

The widespread benefits of physical activity in enhancing health and lowering the risk of non-communicable chronic diseases are well established across populations globally. Nevertheless, the prevalence of several lifestyle-related chronic diseases, including cardiovascular disease, varies markedly across countries and ethnicities. Direct ethnic comparative studies on the health benefits of physical activity are sparse and evidence-based physical activity guidelines are not ethnicity-specific. Indeed, physical activity guidelines in some Asian countries were developed primarily based on data from Western populations even though the magnitude of potential benefit may not be the same among different ethnic groups. Unfavorable diurnal perturbations in postprandial triglycerides and glucose are risk factors for cardiovascular disease. This narrative review summarizes differences in these risk factors primarily between individuals of Asian and white European descent but also within different Asian groups. Moreover, the variable effects of physical activity on mitigating risk factors among these ethnic groups are highlighted along with the underlying metabolic and hormonal factors that potentially account for these differences. Future ethnic comparative studies should include investigations in understudied ethnic groups, such as those of East Asian origin, given that the effectiveness of physical activity for ameliorating cardiovascular disease varies even among Asian groups.

Epidemiology of diabetes among South Asians in the United States: lessons from the MASALA study

South Asian individuals in the United States are at an increased risk of type 2 diabetes (T2DM); however, the mechanisms behind this are not well understood. The Mediators of Atherosclerosis in South Asians Living in America (MASALA) study is the only longitudinal cohort of South Asians in the United States and provides key insights as to the epidemiology of T2DM in South Asians. Evidence from the MASALA study suggests that South Asians experience a disproportionately high burden of prevalent and incident T2DM compared with members of other race/ethnic groups. Higher insulin resistance in South Asians, even with low body mass index (BMI), more impairment in insulin secretion, and greater deposition of ectopic fat likely play a role in T2DM etiology. Furthermore, South Asian migrants to the United States experience a range of factors related to acculturation, social networks, and religious beliefs, which may impact physical activity and dietary practices. Interventions to prevent T2DM in South Asians should include a focus on cultural factors related to health and should consider the complete mechanistic pathway and the relative contributions of insulin resistance, β cell dysfunction, and ectopic fat deposition on T2DM development in South Asians, particularly in those with lower BMI.

Variation in plasma glucagon levels according to obesity status in Japanese Americans with normal glucose tolerance

Japanese Americans living in the United States are genetically identical to Japanese people, but have undergone a rapid and intense westernization of their lifestyle. This study investigated variability in glucagon secretion after glucose loading among Japanese Americans with normal glucose tolerance (NGT) according to obesity status. The 75-g oral glucose tolerance test (OGTT) was performed for 138 Japanese Americans (aged 40-75 years) living in Los Angeles. Plasma glucagon levels measured using the sandwich enzyme-linked immunosorbent assay were compared according to body mass index (BMI) categories among 119 individuals with NGT. The individuals were classified into three categories according to their BMI values: <22 kg/m² (n = 37), 22-24.9 kg/m² (n = 46), and ≥25 kg/m² (n = 36). Fasting plasma glucagon levels and glucagon-area under the curve levels during the OGTT were the highest in the BMI ≥25 kg/m² group. Fasting glucagon levels were correlated with BMI (r = 0.399, p < 0.001), fasting insulin levels (r = 0.275, p = 0.003) and the homeostasis model assessment-insulin resistance (r = 0.262, p = 0.004). In conclusion, our findings suggest that fasting hyperglucagonemia is associated with obesity and insulin resistance even during the NGT stage in the Japanese American population.

Early combination versus initial metformin monotherapy in the management of newly diagnosed type 2 diabetes: An East Asian perspective

Type 2 diabetes (T2D) in the East Asian population is characterized by phenotypes such as low body mass index, an index of β-cell dysfunction, and higher percentage of body fat, an index of insulin resistance. These phenotypes/pathologies may predispose people to early onset of diabetes with increased risk of stroke and renal disease. Less than 50% of patients with T2D in East Asia achieve glycaemic targets recommended by national or regional guidelines, which may be attributable to knowledge and/or implementation gaps. Herein, we review the latest evidence with special reference to East Asian patients with T2D and present arguments for the need to use early combination therapy to intensify glycaemic control. This strategy is supported by the 5-year worldwide VERIFY study, which reported better glycaemic durability in newly diagnosed patients with T2D with a mean HbA1c of 6.9% treated with early combination therapy of vildagliptin plus metformin versus those treated with initial metformin monotherapy followed by addition of vildagliptin only with worsening glycaemic control. This paradigm shift of early intensified treatment is now recommended by the American Diabetes Association and the European Association for the Study of Diabetes. In order to translate these evidence to practice, increased awareness and strengthening of the healthcare system are needed to diagnose and manage patients with T2D early for combination therapy.

Cultural Influences on Dietary Self-Management of Type 2 Diabetes in East Asian Americans: A Mixed-Methods Systematic Review

Purpose: Many East Asian Americans (EAAs) (populations originating from China, Korea, Japan, and Taiwan) with type 2 diabetes mellitus (T2DM) experience unique challenges in managing their disease, including language barriers and traditional cultural beliefs, particularly among first-generation immigrants.. The purpose of this mixed-methods systematic review was to examine cultural perspectives of EAAs that influence dietary self-management of T2DM and identify education interventions and their approaches to enhance EAAs' dietary self-management of diabetes. Methods: A mixed-methods systematic review was conducted to examine EAAs' perspectives from qualitative studies and to identify education interventions and their approaches from quantitative studies. A literature search was conducted using PubMed/MEDLINE, SCOPUS, CINAHL, and Web of Science from 1995 to 2018. Sixteen studies (10 qualitative and 6 quantitative) met criteria for analysis. Thematic synthesis of qualitative data was conducted using a line-by-line coding strategy. Extracted quantitative data were assessed for cultural approaches used in the interventions and diabetes-related outcomes. Results: In the qualitative studies, beliefs about food impacted EAAs' abilities to adopt appropriate dietary recommendations for diabetes management. Requiring a specialized diet disrupted social harmony and made EAAs feel burdensome to others. Having bilingual and bicultural resources eased the stress of making dietary modifications. The most commonly incorporated approaches in diabetes education interventions were bilingual education and culturally specific dietary recommendations. Social roles and harmony were not discussed. Significant reductions in hemoglobin A1c and increases in diabetes knowledge were reported post-intervention. Conclusions: Beliefs about food, beliefs about social roles, and access to culturally competent care play an important role in dietary self-management of T2DM among EAAs. Understanding the cultural influences on dietary self-management of T2DM and tailoring interventions to meet the needs of EAAs are essential in effort to address the growing epidemic and improve patient outcomes.

Associations of nutrient intakes with glaucoma among Japanese Americans

The aim of this study was to investigate possible associations of nutrient intake on glaucoma in subjects of Japanese descent living in Los Angeles, CA.In this cross-sectional study, 581 Japanese American participants in Los Angeles underwent an interview, fundus photography, comprehensive physical, and blood examinations, along with determining the body mass index status and any confounding factors. CDSketch was used to measure the cup-disc ratio and rim width of each fundus in the retinal photographs. A multivariate logistic regression test with adjustment for confounding factors was used to assess the association between glaucoma and nutrient intake.A total of 61 of 581 participants were diagnosed with glaucoma in this study. Multivariate logistic regression analysis showed that a high intake of iron (odds ratio [OR]: 1.303, P = .004), low intake of vitamin A (OR: 0.365, P = .019), and vegetable fat (OR: 0.957, P = .004) were associated with an increased risk of glaucoma.Current findings showed that high iron intake and low vitamin A and vegetable fat intake appeared to be associated with an increased risk of glaucoma in subjects of Japanese descent living in the Los Angeles populations.

Influence of Timing of Insulin Initiation on Long-term Glycemic Control in Japanese Patients with Type 2 Diabetes: A Retrospective Cohort Study

Objective Delays in insulin initiation can lead to the development of complications in the management of type 2 diabetes. Methods In this study, the effects of the timing of insulin initiation on glycemic control in patients with type 2 diabetes were evaluated retrospectively. Changes in the HbA1c levels of 237 patients were analyzed after insulin initiation. Results The patients were divided into 4 groups according to the duration of diabetes at the time of insulin initiation: ≤3 years, 4 to 6 years, 7 to 9 years, or ≥10 years. Patients with a diabetes duration of ≤3 years were more frequently hospitalized at the time of insulin initiation, had a higher HbA1c level before insulin initiation and a lower HbA1c level at 1 year after insulin initiation and exhibited significant decreases in HbA1c at 1, 3, or 5 years after insulin initiation than those in the other 3 groups with longer durations of diabetes. In the group receiving 4 insulin injections per day, the reduction in HbA1c after 5 years of treatment was larger in patients with a diabetes duration at the time of insulin initiation of ≤3 years than in those with a duration of 7 to 9 years or ≥10 years. Conclusion Our results suggested that an earlier initiation of insulin therapy was crucial for sustaining glycemic control in Japanese patients with type 2 diabetes, particularly in those with a history of obesity or receiving multiple insulin injections daily.

Alteration of gut microbiota by a Westernized lifestyle and its correlation with insulin resistance in non-diabetic Japanese men

AIMS/INTRODUCTION

The severity of insulin resistance is higher in Japanese-American people with American lifestyles than in native Japanese people with Japanese lifestyles. Recently, the role of gut microbiota in the control of host metabolic homeostasis and organ physiology has been recognized. In addition, gut microbiota alterations have been suggested to contribute to pathogenesis of insulin resistance. The principle aim of the present study was to evaluate the impact of a Westernized lifestyle on the gut microbiota of Japanese-Americans versus native Japanese, and its correlation with insulin resistance.

MATERIALS AND METHODS

A total of 14 native Japanese men living in Hiroshima, Japan, and 14 Japanese-American men living in Los Angeles, USA, were included. A 75-g oral glucose tolerance test was carried out for all participants to assess their glucose tolerance, and normal glucose tolerance was observed. We compared the insulin response with oral glucose load, the Matsuda Index, and the composition of the gut microbiota between the native Japanese and Japanese-American men.

RESULTS

Japanese-American men showed higher area under the curve values for serum insulin concentrations during the oral glucose tolerance test and lower Matsuda Index than native Japanese men. Gut microbiota composition of the Japanese-American men was different; in particular, they showed a relatively lower abundance of Odoribacter than native Japanese men. The ratio between relative abundance of Odoribacter and Matsuda Index was positively correlated between the two groups.

CONCLUSIONS

Our findings suggest that Westernized lifestyles alter gut microbiota, and its alteration might induce insulin resistance in non-diabetic Japanese men.

Associations of nutrient intakes with obesity and diabetes mellitus in the longitudinal medical surveys of Japanese Americans

AIMS/INTRODUCTION

Our previous survey of two Japanese populations, with different lifestyles but identical genetic dispositions, showed that Japanese Americans had different dietary intakes and higher prevalences of obesity and diabetes mellitus, compared with the native Japanese population. The present study examined whether Westernized dietary habits could affect the development of obesity or diabetes.

MATERIALS AND METHODS

This study included 765 individuals with normal glucose tolerance at baseline medical examinations (1986 or 1989 in Los Angeles and in 1988 or 1992 in Hawaii) who subsequently completed follow-up medical examinations several years later. The participants were categorized at baseline as "lean" (576 individuals, body mass index of <25 kg/m2 ) or "obese" (189 individuals, body mass index of ≥25 kg/m2 ). Nutrient intakes were analyzed for associations with the development of obesity or diabetes using Cox's proportional hazard model.

RESULTS

A total of 41 lean participants developed diabetes, which was not associated with any nutrient intakes (mean follow up 10.8 ± 6.6 years). A total of 36 obese participants developed diabetes, which was positively associated with intakes of animal protein, animal fat and saturated fatty acid (mean follow up 10.7 ± 6.3 years). A total of 85 lean participants became obese, which was positively associated with intakes of simple carbohydrates, sugar and fructose, as well as inversely associated with intakes of vegetable protein and complex carbohydrates (mean follow up 10.4 ± 6.5 years).

CONCLUSIONS

In the Japanese Americans, different nutrient intakes affected the development of obesity and diabetes. Furthermore, the associations of nutrient intakes with diabetes development varied according to the presence or absence of obesity.

Mechanism and Potential of Egg Consumption and Egg Bioactive Components on Type-2 Diabetes

Type-2 diabetes (T2D) is one of the major global health challenges and a substantial economic burden. Egg and egg-derived components have been indicated to possess antioxidant, anti-inflammatory, anti-hypertensive, immunomodulatory, and anti-cancer activities. However, the scientific evidence about the benefits of egg on T2D is debatable. The relationship between egg consumption and the risk of T2D from observational epidemiological studies is not consistent. Interventional clinical studies, however, provide promising evidence that egg consumption ameliorates the risk of T2D. Current research progress also indicates that some egg components and egg-derived peptides might be beneficial in the context of T2D, in terms of insulin secretion and sensitivity, oxidative stress, and inflammation, suggesting possible application on T2D management. The current review summarizes recent clinical investigations related to the influence of egg consumption on T2D risk and in vivo and in vitro studies on the effect and mechanism of egg components and egg-derived peptides on T2D.

Characterization of changes in HbA1c in patients with and without secondary failure after metformin treatments by a population pharmacodynamic analysis using mixture models

The objective of the present study was to develop a population pharmacodynamic (PPD) model to describe the glycated hemoglobin (HbA1c)-lowering effects of metformin in type 2 diabetes mellitus patients with and without secondary failure and to characterize changes in HbA1c levels in the two subpopulations using a mixture model. Information on patients was collected retrospectively from electronic medical records. In this study, the mixture model was used to characterize the bimodal effects of metformin. A PPD analysis was performed using NONMEM 7.3.0. A physiological indirect response model, based on 829 HbA1c levels of 69 patients, described the time course for the HbA1c-lowering effects of metformin. Evidence for the different effectiveness of metformin subpopulations was provided using the mixture model. In the final PPD model, the inhibition effect was constant over a study duration in a patient subpopulation without secondary failure. In contrast, the inhibition effect decreased as a function of time after start of metformin treatment in a subpopulation with secondary failure. These results indicated that HbA1c improvements appeared to deteriorate over time in patients with secondary failure. In a PPD analysis of metformin, it was possible to assign patients with secondary failure using the mixture model.

Association of lifestyle and body structure to ocular axial length in Japanese elementary school children

BACKGROUND

The purpose of this study is to determine whether the lifestyle and body stature are significantly associated with the axial length (AL) of the eyes of Japanese third grade students.

METHODS

A prospective, cross sectional, observational study was performed on 122 third grade students consisting of 61 boys and 61 girls ages 8 to 9 years. The AL, body height, body weight, and body mass index (BMI) were measured. The lifestyle was determined by activities such as the daily duration of indoor studying, television viewing, use of computers and smart phones, outdoor activity time, bed time, Japanese or Western dietary habits, and parental myopia were investigated by a questionnaire with three or five grade levels. The relationship between AL and the questionnaire variables were analyzed by Spearman's correlation analyses.

RESULTS

Westernized dietary habits (r = -0.24, P = 0.01), duration of computer and smart phone use (r = 0.24, P = 0.008), parental myopia (r = 0.39, P < 0.001), body weight (r = 0.26, P = 0.005), and BMI (r = 0.23, P = 0.011) were significantly correlated with the AL. Multiple logistic regression analyses showed that the sex [r = -0.48; 95% confidence interval (CI) -0.80 to -0.17, P = 0.003], body weight (r = 0.04; 95% CI 0.02 to 0.07, P = 0.038), westernized dietary habits (r = -0.30; 95% CI -0.55 to -0.05, P = 0.021), and parental myopia (r = 0.40; 95% CI 0.20 to 0.61, P < 0.001) were significantly and independently correlated with the AL.

CONCLUSIONS

The body weight and parental myopia and westernized dietary habits are factors significantly associated with myopia. Changing from Japanese food style to westernized food style might increase the risk of progression of school myopia.

Westernization of lifestyle affects quantitative and qualitative changes in adiponectin

Background

Although Japanese–Americans and native Japanese share the same genetic predispositions, they live different lifestyles, resulting in insulin resistance in Japanese–Americans. We investigated whether the quantitative and qualitative changes in adiponectin (APN) due to differences in lifestyle contribute to the development of insulin resistance.

Methods

We evaluated 325 native Japanese in Hiroshima, Japan and 304 Japanese–Americans in Los Angeles, the United States, who were aged between 30 and 70 years and underwent medical examinations between 2009 and 2010. All participants underwent a 75-g oral glucose tolerance test (OGTT) to assess their glucose tolerance. The insulin response to oral glucose load, the Matsuda index, total APN levels, and C1q-APN/total-APN ratios were compared between native Japanese and Japanese–Americans.

Results

Compared with the native Japanese, the Japanese–Americans had significantly lower Matsuda index and higher area under the curve values for serum insulin concentration during OGTT in the normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) groups, but not in the diabetes mellitus (DM) group. Furthermore, the Japanese–Americans had significantly lower total APN levels and higher C1q-APN/total-APN ratios than the native Japanese in the NGT and IGT groups, but not in the DM group.

Conclusions

This study suggested that, in Japanese people, the westernization of their lifestyle might affect quantitative and qualitative changes in APN and induce insulin resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0565-z) contains supplementary material, which is available to authorized users.

Association between Serum Elaidic Acid Concentration and Insulin Resistance in Two Japanese Cohorts with Different Lifestyles

Aim: Many cohort studies have shown that increased trans fatty acid (TFA) intake increases the risk of developing coronary heart disease. However, whether TFA intake is directly associated with the development of diabetes mellitus (DM) remains unknown.

Methods: We performed the 75-g oral glucose tolerance test in two Japanese cohorts: a cohort of 454 native Japanese living in Hiroshima, Japan, and a cohort of 426 Japanese-Americans living in Los Angeles, USA, who shared identical genetic predispositions but had different lifestyles. Serum elaidic acid concentration was measured and compared, and its association with insulin resistance was assessed.

Results: Serum elaidic acid concentrations were significantly higher in the Japanese-Americans (median, 18.2 µmol/L) than in the native Japanese (median, 11.0 µmol/L). The serum elaidic acid concentrations in the native Japanese DM group (16.0 µmol/L) were significantly higher compared with those in the normal glucose tolerance (10.8 µmol/L) and impaired glucose tolerance (11.7 µmol/L) groups. Multiple linear regression analyses showed that serum elaidic acid concentrations were significantly positively associated with homeostasis model assessment for insulin resistance (HOMA-IR) values after adjusting for various factors.

Conclusions: These results suggest that excessive TFA intake worsens insulin resistance and increases the risk of developing DM even in the native Japanese, whose intakes of animal fat and simple carbohydrates were presumed to be lower than those of the Japanese-Americans.

Progression of Carotid Atherosclerosis in Two Japanese Populations with Different Lifestyles

Aim: We have conducted medical surveys on two Japanese populations (Japanese Americans living in the US and native Japanese living in Japan) to investigate the impact of westernization of lifestyles on diseases in Japanese people. A 1998 survey revealed that the progression of carotid intima-media wall thickness (IMT) was faster by approximately 20 years in Japanese Americans than in native Japanese. In this study, we compared the progression of atherosclerosis in native Japanese versus that in Japanese Americans using carotid IMT data from medical examinations conducted in the 2010s.

Methods: This study included 115 native Japanese living in Hiroshima who underwent a medical examination in 2014 and 112 Japanese Americans living in Hawaii who underwent a medical examination in 2012, excluding those receiving medication for diabetes mellitus (DM) or dyslipidemia. Carotid IMT was compared between the two Japanese populations.

Results: Serum total and low-density lipoprotein cholesterol levels were significantly higher in native Japanese than in Japanese Americans. The median carotid IMT was significantly greater in Japanese Americans than in native Japanese [median (25^th–75^th percentile): 1.27 (0.86–2.02) mm vs. 1.00 (0.80–1.30) mm, P = 0.001]. Regression curves showed that the age at which IMT exceeded 1.1 mm was estimated at > 50 years in Japanese Americans and at approximately 60 years in native Japanese.

Conclusions: According to surveys conducted in 2012 and 2014, carotid IMT was still greater in Japanese Americans than in native Japanese. However, a comparison with data from the 1998 survey showed that current native Japanese had higher serum lipid levels and more advanced atherosclerosis.

Effect of race and ethnicity on vildagliptin efficacy: A pooled analysis of phase II and III studies

AIMS

To determine the impact of race and ethnicity on the efficacy, body weight and hypoglycaemia incidence with vildagliptin treatment in patients with type 2 diabetes mellitus using patient-level data from the vildagliptin clinical trial programme.

METHODS

Data from 22 randomized, placebo-controlled global and local (Japan, China) registration studies of vildagliptin (50 mg once-daily or twice-daily) of ≥12-week duration were analysed by race (Caucasian [n = 2764] and Asian [n = 2232]) and by ethnicity (Japanese, Chinese, and Indian). The placebo-subtracted differences in the change in glycated haemoglobin (HbA1c) and body weight from baseline to week 12 or week 24 were evaluated by race or ethnicity using repeated measure analysis of unstructured covariance. Hypoglycaemia incidences were summarized using descriptive statistics.

RESULTS

The HbA1c reduction from baseline with vildagliptin was similar across the racial/ethnic subgroups (-0.83% ± 0.02% to -1.01% ± 0.05%). Placebo-corrected HbA1c reduction was similar between Caucasian (-0.68% ± 0.03%) and Asian (-0.80% ± 0.03%) patients ( P value for interaction = .56); analysis by race and ethnicity showed better efficacy ( P < .02) in Japanese patients. Japanese patients were drug-naïve and treated with a single oral anti-diabetes drug only; they showed no response to placebo. Weight neutrality of vildagliptin was demonstrated in all groups (0.47 ± 0.11 kg to -0.29 ± 0.08 kg). Hypoglycaemic events (≥1) were infrequent in all ethnic subgroups.

CONCLUSIONS

The glycaemic efficacy of vildagliptin was similar in Caucasian and Asian patients. The slightly better efficacy observed in Japanese patients was driven by the absence of placebo effect and might be explained by their earlier stage of diabetes compared to other subgroups.

A comparison of the prevalence of the metabolic syndrome and its components among native Japanese and Japanese Brazilians residing in Japan and Brazil

Background

This study investigated the prevalence of risk factors associated with the metabolic syndrome (MetSyn) among individuals of Japanese descent exposed to different cultural environments.

Design

A cross-sectional study to assess component risk factors for the diagnosis of MetSyn was undertaken in urban areas in Japan and Brazil. A total of 773 men and women aged 35 years or over were included in three groups: 249 native Japanese, 269 Brazilian individuals of Japanese ancestry residing in Japan, and 255 Brazilian individuals of Japanese ancestry residing in Brazil.

Results

Higher rates of metabolic abnormalities with respect to central obesity and serum lipid profiles were observed among Brazilian individuals of Japanese ancestry residing in Brazil compared with those residing in Japan and native Japanese. Likewise, an increased risk of hypertension was observed among Japanese Brazilian individuals residing in Japan. The prevalence of MetSyn in men was significantly higher among Brazilians of Japanese ancestry residing in Brazil (37.5%) compared with those residing in Japan (25.3%) or native Japanese (21.4%), whereas no significant difference was observed among women. In the logistic model, Brazilian individuals of Japanese ancestry residinginBrazil weretwice as likely to develop MetSyn compared with native Japanese, whereas no significant differences were found among those residing in Japan.

Conclusions

These findings underscore the significant heterogeneity in risk factors among communities of Japanese ancestry residing in Brazil and Japan, and suggest that immigrants exposed to the Brazilian cultural environment are more susceptible to the development of risk factors associated with MetSyn than native Japanese.

Changing Clinical Characteristics according to Insulin Resistance and Insulin Secretion in Newly Diagnosed Type 2 Diabetic Patients in Korea

BACKGROUND

The role of increased insulin resistance in the pathogenesis of type 2 diabetes has been emphasized in Asian populations. Thus, we evaluated the proportion of insulin resistance and the insulin secretory capacity in patients with early phase type 2 diabetes in Korea.

METHODS

We performed a cross-sectional analysis of 1,314 drug-naive patients with newly diagnosed diabetes from primary care clinics nationwide. The homeostasis model assessment of insulin resistance (HOMA-IR) was used as an index to measure insulin resistance, which was defined as a HOMA-IR ≥2.5. Insulin secretory defects were classified based on fasting plasma C-peptide levels: severe (<1.1 ng/mL), moderate (1.1 to 1.7 ng/mL) and mild to non-insulin secretory defect (≥1.7 ng/mL).

RESULTS

The mean body mass index (BMI) was 25.2 kg/m(2); 77% of patients had BMIs >23.0 kg/m(2). Up to 50% of patients had central obesity based on their waist circumference (≥90 cm in men and 85 cm in women), and 70.6% had metabolic syndrome. Overall, 59.5% of subjects had insulin resistance, and 20.2% demonstrated a moderate to severe insulin secretory defect. Among those with insulin resistance, a high proportion of subjects (79.0%) had a mild or no insulin secretory defect. Only 2.6% of the men and 1.9% of the women had both insulin resistance and a moderate to severe insulin secretory defect.

CONCLUSION

In this study, patients with early phase type 2 diabetes demonstrated increased insulin resistance, but preserved insulin secretion, with a high prevalence of obesity and metabolic syndrome.

β cell dysfunction versus insulin resistance in the pathogenesis of type 2 diabetes in East Asians

Type 2 diabetes (T2DM) is one of the most serious global health problems and is mainly a result of the drastic increase in East Asia, which includes over a fourth of the global diabetes population. Lifestyle factors and ethnicity are two determinants in the etiology of T2DM, and lifestyle changes such as higher fat intake and less physical activity link readily to T2DM in East Asians. It is widely recognized that T2DM in East Asians is characterized primarily by β cell dysfunction, which is evident immediately after ingestion of glucose or meal, and less adiposity compared to the disease in Caucasians. These pathophysiological differences have an important impact on therapeutic approaches. Here, we revisit the pathogenesis of T2DM in light of β cell dysfunction versus insulin resistance in East Asians and discuss ethnic differences in the contributions of insulin secretion and insulin resistance, together with incretin secretin and action, to glucose intolerance.

Hypothesis of Long-Term Outcome after Coronary Revascularization in Japanese Patients Compared to Multiethnic Groups in the US

BACKGROUND

Ethnicity has a significant impact on coronary artery disease (CAD). This study investigated the long-term outcomes of Japanese patients undergoing revascularization compared with US patients belonging to multiple ethnic groups.

METHODS AND RESULTS

We evaluated clinical outcomes, based on ethnicity, of patients included in the Coronary Revascularization Demonstrating Outcome (CREDO-Kyoto) and the Texas (US) Heart Institute Research Database (THIRDBase) registries. For the analysis, we included 8871 patients from the CREDO-Kyoto registry (median follow-up period [FU], 3.5 years; interquartile range [IQR], 2.6-4.3) and 6717 patients from the THIRDBase registry (FU, 5.2 years; IQR, 3.8-6.5) who underwent percutaneous coronary intervention or bypass surgery. Cox proportional hazard models were constructed to compare the adjusted long-term outcomes for each ethnic group. A total of 8871 Japanese, 5170 Caucasians, 648 African-Americans, 817 Hispanics, and 82 Asian-Americans were identified. When adjusted, Japanese patients had significantly better outcomes than US patients, classified by ethnicity (Caucasians: hazard ratio [HR], 1.56; 95% confidence interval [CI], 1.35-1.79; Hispanics: HR, 1.53; 95% CI, 1.22-1.93; African-Americans: HR, 2.03; 95% CI, 1.62-2.56), except for Asian-Americans (HR, 0.84; 95% CI. 0.38-1.89) who had outcomes similar to Japanese patients.

CONCLUSION

Our findings indicate better survival outcomes in re-vascularized Japanese CAD patients compared to major ethnic groups in the US, including Caucasian, Hispanic, and African-American CAD patients. The characteristics and outcomes of Japanese CAD patients were similar to those of Asian-Americans, despite the sample size limitations in the US dataset.

Japanese lifestyle during childhood prevents the future development of obesity among Japanese-Americans

OBJECTIVE

To evaluate whether a Japanese lifestyle during childhood could protect against the future development of obesity-associated metabolic diseases by comparing native Japanese with Japanese-Americans in whom genetic factors are the same.

METHODS

Study subjects were 516 native Japanese and 781 Japanese-Americans who underwent medical examinations between 2007 and 2010. Japanese-Americans were divided into 444 first-generation immigrants (JA-1), who were born in Japan, and 337 second- or later-generation descendants (JA-2), who were born in the United States. The JA-2 group was then divided into the kibei subgroup (N = 79), who had moved to Japan before the age of 18 years and later returned to the United States, and the non-kibei subgroup (N = 258), who had never lived in Japan.

RESULTS

The JA-2 group had the highest percentages of obesity, metabolic syndrome, and type 2 diabetes compared with native Japanese and JA-1. Furthermore, among JA-2, the prevalence of obesity and metabolic syndrome in the kibei subgroup was significantly lower than that in the non-kibei subgroup. The prevalence of diabetes in the kibei subgroup also tended to be lower than in the non-kibei subgroup.

CONCLUSIONS

The prevalence of obesity and metabolic diseases differed with residence in Japan during childhood among Japanese-Americans. These findings indicate the possibility that Japanese lifestyle during childhood could reduce the future risks for obesity-associated metabolic diseases.

Regardless of central obesity, metabolic syndrome is a significant predictor of type 2 diabetes in Japanese Americans

AIMS/INTRODUCTION

The impact of metabolic syndrome (MetS) on the development of type 2 diabetes has been reported in different ethnic populations. However, whether central obesity is an essential component as a diagnostic criterion for MetS remains a controversial topic. The aim of the present study was to investigate the association between MetS and the incidence of type 2 diabetes with or without central obesity in a Japanese American population.

MATERIALS AND METHODS

We examined whether MetS predicts incident type 2 diabetes among 928 Japanese American participants who did not have diabetes enrolled in an ongoing medical survey between 1992 and 2007. MetS was defined on the basis of American Heart Association/National Heart, Lung, and Blood Institute criteria. The average follow-up period was approximately 6.8 years.

RESULTS

During the follow-up period, 116 new cases of diabetes were diagnosed. Compared to the participants without MetS, the hazard ratio (HR) for incident type 2 diabetes was significantly higher in participants with MetS, after adjustment for sex, age and impaired glucose tolerance (HR 1.64, 95% CI 1.11-2.42). The risk of type 2 diabetes was found to be significantly higher in participants with MetS but without central obesity (HR 2.07, 95% CI 1.25-3.41), as well as in participants with MetS and with central obesity (HR 2.46, 95% CI 1.51-4.01) than in participants with neither MetS nor central obesity, after adjustment for sex, age and impaired glucose tolerance.

CONCLUSIONS

These results show that the presence of MetS, with or without central obesity, could independently predict the development of type 2 diabetes in Japanese Americans.

Comparison of HOMA-IR, HOMA-β% and disposition index between US white men and Japanese men in Japan: the ERA JUMP study

AIMS/HYPOTHESIS

At the same level of BMI, white people have less visceral adipose tissue (VAT) and are less susceptible to developing type 2 diabetes than Japanese people. No previous population-based studies have compared insulin resistance and insulin secretion between these two races in a standardised manner that accounts for VAT. We compared HOMA-IR, HOMA of beta cell function (HOMA-β%) and disposition index (DI) in US white men and Japanese men in Japan.

METHODS

We conducted a population-based, cross-sectional study, comprising 298 white men and 294 Japanese men aged 40-49 years without diabetes. Insulin, glucose, VAT and other measurements were performed at the University of Pittsburgh. We used ANCOVA to compare geometric means of HOMA-IR, HOMA-β% and DI, adjusting for VAT and other covariates.

RESULTS

White men had higher HOMA-IR, HOMA-β% and DI than Japanese men, and the difference remained significant (p < 0.01) after adjusting for VAT (geometric mean [95% CI]): 3.1 (2.9, 3.2) vs 2.5 (2.4, 2.6), 130.8 (124.6, 137.3) vs 86.7 (82.5, 91.0), and 42.4 (41.0, 44.0) vs 34.8 (33.6, 36.0), respectively. Moreover, HOMA-IR, HOMA-β% and DI were significantly higher in white men even after further adjustment for BMI, impaired fasting glucose and other risk factors.

CONCLUSIONS/INTERPRETATION

The higher VAT-adjusted DI in white men than Japanese men may partly explain lower susceptibility of white people than Japanese people to developing type 2 diabetes. The results, however, should be interpreted with caution because the assessment of insulin indices was made using fasting samples and adjustment was not made for baseline glucose tolerance. Further studies using formal methods to evaluate insulin indices are warranted.

Active and passive exposure to tobacco smoke in relation to insulin sensitivity and pancreatic β-cell function in Japanese subjects

AIM

Several studies have suggested that cigarette-smoking affects insulin sensitivity in Western populations. The present study evaluated glucose tolerance, pancreatic β-cell function and insulin sensitivity in relation to active and passive smoking among the Japanese.

METHODS

A total of 411 men and 586 women were recruited into a community-based cross-sectional study in Gifu, Japan. Diabetes, impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) were screened for by a 75g oral glucose tolerance test. HOMA and insulinogenic (ΔI0-30/ΔG0-30) indexes were used to estimate insulin secretion and sensitivity. To assess the possible association of self-reported smoking status and parameters of glucose metabolism, logistic regression was applied after adjusting for potential confounders.

RESULTS

Currently smoking women were more likely to have diabetes, IGT or IFG compared with never-smoking women (OR: 2.26, 95% CI: 1.05-4.84). Heavy-smoking men (≥25 cigarettes/day) were likely to be in the lowest tertile group of ΔI0-30/ΔG0-30 compared with never-smoking men (OR: 2.64, 95% CI: 1.05-6.68, Ptrend=0.04). The number of cigarettes/day was borderline significantly associated with diabetes in men. Also with borderline significance, never-smoking women with smoking husbands were more likely to have diabetes, IGT or IFG (OR: 1.62, 95% CI: 1.00-2.62) and significantly more likely to have lower HOMA-β (OR: 2.17, 95% CI: 1.36-3.48) than those without smoking husbands.

CONCLUSION

The greater the number of cigarettes smoked per day appears to be associated with diabetes among men whereas, among women, both active and passive smoking appear to be associated with diabetic states, including IGT and IFG. An association between smoking status and insulin secretion is also suggested, whereas no significant association was observed with HOMA-IR in this Japanese subjects, suggesting that the influence of smoking on glucose metabolism may differ among races.

Relationship between serum cholesterol efflux capacity and glucose intolerance in Japanese-Americans

AIM

Serum cholesterol efflux has been suggested to be a key anti-atherogenic function of reverse cholesterol transport. Meanwhile, the quantitative and qualitative alteration of the levels of lipoproteins in the serum has been reported in patients with diabetes, although it remains unclear whether the serum cholesterol efflux capacity is impaired in cases of newly diagnosed glucose intolerance. We thus assessed the relationship between the serum cholesterol efflux capacity and glucose intolerance as detected using oral glucose tolerance tests (OGTTs).

METHODS

We measured the capacity of whole serum to mediate cholesterol efflux from human THP-1 macrophages in a cohort of 439 Japanese-Americans who underwent 75-g OGTTs. A multiple regression analysis was performed to examine the relationship between the serum cholesterol efflux capacity and glucose intolerance.

RESULTS

The serum cholesterol efflux capacity was found to be negatively correlated with the area under the curve for the serum glucose concentration during the 75-g OGTTs in all subjects. In addition, the serum cholesterol efflux capacity was found to be modestly but significantly lower in the glucose intolerance group (31.4 ± 6.2%) than in the normal glucose tolerance group (33.2 ± 6.1%). There was also a negative association between the serum cholesterol efflux capacity and glucose intolerance after adjusting for age and sex. Moreover, this association remained significant even after further adjustments for serum total cholesterol, high-density lipoprotein cholesterol, apolipoprotein AI and C-reactive protein.

CONCLUSIONS

The serum cholesterol efflux capacity is impaired in Japanese-Americans newly diagnosed with glucose intolerance. This impairment may contribute in some manner to increasing the risk of atherosclerotic disease in subjects with glucose intolerance.

[Food consumption and dietary factors involved in health and disease in Nikkeis: systematic review]

OBJECTIVE

To analyze food consumption and dietary factors involved in the Nikkei population's health and disease processes

METHODS

A systematic review of observational studies that described Nikkeis' food intake was carried out in electronic databases Lilacs, SciELO and PubMed/Medline databases, from 1997 to 2012. Initially, 137 titles and abstracts were analyzed, excluding intervention studies, those which only presented metabolite and vitamin plasma levels and those which did not meet the objective of this study. Of these, 38 studies were selected and evaluated using a method based on Downs & Black (1998), adapted for observational studies, leaving 33 studies to be analyzed.

RESULTS

Few studies about Nikkei food intake were found outside of Hawaii, in the United States, and Sao Paulo (mainly in the city of Bauru) in Brazil. The total energy intake of Japanese-Brazilians had an elevated fat contribution, decreasing carbohydrate and protein intake. In the United States, the prevalence of Japanese-Americans who consumed high density energy food was elevated. The Niseis (children of immigrants) presented, on average, higher intake of Japanese food products, while the Sanseis (grandchildren of immigrants) showed more Westernized dietary habits.

CONCLUSIONS

Although some Japanese food habits have been maintained, the Nikkeis' dietary intake reveals a high prevalence of typical Westernized food intake (high in processed food, fat and sodium, and poor in fiber), that may be contributing to the increasing development of chronic disease in this population.

Consumption patterns of sweetened food and drink products in a Catholic Middle Eastern Canadian community

OBJECTIVE

The present study describes the consumption patterns of sweetened food and drink products in a Catholic Middle Eastern Canadian community and examines its associations with physical activity, sedentary behaviours and BMI.

DESIGN

A two-stage cross-sectional design was used. In Stage 1 (n 42), 24 h recalls enabled the identification of sweetened products. In Stage 2 (n 192), an FFQ was administered to measure the daily consumption of these products and to collect sociodemographic and behavioural data. Sweetened products were defined as processed culinary ingredients and ultra-processed products for which total sugar content exceeded 20% of total energy.

SETTING

Three Catholic Middle Eastern churches located in Montreal, Canada.

SUBJECTS

Normoglycaemic men and women (18-60 years old).

RESULTS

Twenty-six sweetened products represented an average consumption of 75·4 g total sugars/d or 15·1% of daily energy intake (n 190, 56% women). Soft drinks, juices, sweetened coffee, chocolate, cookies, cakes and muffins were the main sources of consumption and mostly consumed between meals. Age (exp (β) = 0·99; P < 0·01), physical activity (exp (β) = 1·08; P < 0·01) and recreational computer use (exp (β) = 1·17; P < 0·01) were independently associated with sweetened product consumption. The association between sweetened product consumption and physical activity was U-shaped. BMI was not significantly associated with sweetened product consumption but all participants regardless of BMI were above the WHO recommendation for free sugars.

CONCLUSIONS

Being physically active and spending less time using a computer may favour a reduced consumption of sweetened products. Very active individuals may, however, overconsume such products.

Forecasting the burden of type 2 diabetes in Singapore using a demographic epidemiological model of Singapore

OBJECTIVE

Singapore is a microcosm of Asia as a whole, and its rapidly ageing, increasingly sedentary population heralds the chronic health problems other Asian countries are starting to face and will likely face in the decades ahead. Forecasting the changing burden of chronic diseases such as type 2 diabetes in Singapore is vital to plan the resources needed and motivate preventive efforts.

METHODS

This paper describes an individual-level simulation model that uses evidence synthesis from multiple data streams-national statistics, national health surveys, and four cohort studies, and known risk factors-aging, obesity, ethnicity, and genetics-to forecast the prevalence of type 2 diabetes in Singapore. This comprises submodels for mortality, fertility, migration, body mass index trajectories, genetics, and workforce participation, parameterized using Markov chain Monte Carlo methods, and permits forecasts by ethnicity and employment status.

RESULTS

We forecast that the obesity prevalence will quadruple from 4.3% in 1990 to 15.9% in 2050, while the prevalence of type 2 diabetes (diagnosed and undiagnosed) among Singapore adults aged 18-69 will double from 7.3% in 1990 to 15% in 2050, that ethnic Indians and Malays will bear a disproportionate burden compared with the Chinese majority, and that the number of patients with diabetes in the workforce will grow markedly.

CONCLUSIONS

If the recent rise in obesity prevalence continues, the lifetime risk of type 2 diabetes in Singapore will be one in two by 2050 with concomitant implications for greater healthcare expenditure, productivity losses, and the targeting of health promotion programmes.

Body composition is the main determinant for the difference in type 2 diabetes pathophysiology between Japanese and Caucasians

OBJECTIVE This cross-sectional clinical study compared the pathophysiology of type 2 diabetes in Japanese and Caucasians and investigated the role of demographic, genetic, and lifestyle-related risk factors for insulin resistance and β-cell response. RESEARCH DESIGN AND METHODS A total of 120 Japanese and 150 Caucasians were enrolled to obtain comparable distributions of high/low BMI values across glucose tolerance states (normal glucose tolerance, impaired glucose tolerance, and type 2 diabetes), which were assessed by oral glucose tolerance tests. BMI in the two cohorts was distributed around the two regional cutoff values for obesity. RESULTS Insulin sensitivity was higher in Japanese compared with Caucasians, as indicated by the homeostatic model assessment of insulin resistance and Matsuda indices, whereas β-cell response was higher in Caucasians, as measured by homeostatic model assessment of β-cell function, the insulinogenic indices, and insulin secretion ratios. Disposition indices were similar for Japanese and Caucasians at all glucose tolerance states, indicating similar β-cell response relative to the degree of insulin resistance. The main determinants for differences in metabolic indices were measures of body composition, such as BMI and distribution of adipose tissue. Differences in β-cell response between Japanese and Caucasians were not statistically significant following adjustment by differences in BMI. CONCLUSIONS Our study showed similar disposition indices in Japanese and Caucasians and that the major part of the differences in insulin sensitivity and β-cell response between Japanese and Caucasians can be explained by differences in body composition.

The architecture of risk for type 2 diabetes: understanding Asia in the context of global findings

The prevalence of Type 2 diabetes is rising rapidly in both developed and developing countries. Asia is developing as the epicentre of the escalating pandemic, reflecting rapid transitions in demography, migration, diet, and lifestyle patterns. The effective management of Type 2 diabetes in Asia may be complicated by differences in prevalence, risk factor profiles, genetic risk allele frequencies, and gene-environment interactions between different Asian countries, and between Asian and other continental populations. To reduce the worldwide burden of T2D, it will be important to understand the architecture of T2D susceptibility both within and between populations. This review will provide an overview of known genetic and nongenetic risk factors for T2D, placing the results from Asian studies in the context of broader global research. Given recent evidence from large-scale genetic studies of T2D, we place special emphasis on emerging knowledge about the genetic architecture of T2D and the potential contribution of genetic effects to population differences in risk.

Low high-density lipoprotein cholesterol level is a significant risk factor for development of type 2 diabetes: Data from the Hawaii-Los Angeles-Hiroshima study

Aims/Introduction

A low level of high‐density lipoprotein cholesterol (HDLC) is a common feature of metabolic syndrome. We have reported that Japanese–Americans who share a virtually identical genetic makeup with native Japanese, but who have lived Westernized lifestyles for decades, have lower HDLC levels and a high prevalence of type 2 diabetes compared with native Japanese. However, the impact of low HDLC level on type 2 diabetes is unclear. The aims of the present study were to evaluate whether serum HDLC level was associated with development of type 2 diabetes and if the effect might be modified by lifestyle.

Materials and Methods

We examined 1,133 non‐diabetic Japanese–Americans and 1,072 non‐diabetic Japanese, who underwent the 75‐g oral glucose tolerance test (OGTT) and were followed for an average of 8.8 and 7.0 years, respectively. We analyzed whether serum HDLC level is a risk factor for development of type 2 diabetes based on the Cox proportional hazards model.

Results

After adjustment for age and sex, hazard ratios for development of type 2 diabetes per unit of serum HDLC level (mmol/L) were 0.292 (95% confidence interval [CI] 0.186–0.458, P < 0.0001) among Japanese–Americans and 0.551 (95% CI 0.375–0.88, P = 0.0023) among native Japanese. Comparable hazard ratios after further adjustment for category of OGTT and body mass index were 0.981 (95% CI 0.970–0.993, P = 0.0018) and 0.991 (95% CI 0.980–1.002, P = 0.112), respectively.

Conclusions

HDLC level was associated with development of type 2 diabetes in both Japanese–Americans and native Japanese. However, these results suggest that the impact of high‐density lipoprotein on glucose metabolism might be affected by lifestyle.

Red meat consumption is associated with the risk of type 2 diabetes in men but not in women: a Japan Public Health Center-based Prospective Study

The relationship between different types of meat intake and the risk of type 2 diabetes remains unclear. We prospectively examined the association between total meat, total red meat, unprocessed red meat, processed meat and poultry intake and the incidence of type 2 diabetes. Subjects were 27 425 men and 36 424 women aged 45–75 years who participated in the second survey of the Japan Public Health Center-based Prospective Study, and had no history of type 2 diabetes, cancer, stroke, IHD, chronic liver disease or kidney disease. Meat intake was estimated using a validated 147-item FFQ. OR of self-reported, physician-diagnosed type 2 diabetes over 5 years were estimated using a multiple logistic regression. A total of 1178 newly diagnosed cases of type 2 diabetes were self-reported. Intakes of total meat and total red meat were associated with the increased risk of type 2 diabetes in men but not in women. The multivariate-adjusted OR for the highest quartile compared with the lowest quartile of total meat and total red meat intake were 1·36 (95% CI 1·07, 1·73; P for trend=0·006) and 1·48 (95% CI 1·15, 1·90; P for trend=0·003) for men, respectively, and 0·82 (95% CI 0·62, 1·09; P for trend=0·14) and 0·77 (95% CI 0·57, 1·02; P for trend=0·08) for women, respectively. Intakes of processed red meat and poultry were not associated with the increased risk of diabetes in either men or women. In conclusion, elevated intake of red meat is associated with the increased risk of type 2 diabetes in Japanese men but not in women.

Psychological distress mediates the association between daytime sleepiness and consumption of sweetened products: cross-sectional findings in a Catholic Middle-Eastern Canadian community

OBJECTIVE

To examine the associations between consumption of sweetened products, daytime sleepiness (DS) and psychological distress (PD) in a Catholic Middle-Eastern Canadian community, and to test the hypothesis that the association between DS and consumption of sweetened products is mediated by PD.

DESIGN

A cross-sectional study.

SETTING

A Catholic Middle-Eastern Canadian community.

PARTICIPANTS

186 men and women aged between 18 and 60 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Sweetened product consumption was measured using a food frequency questionnaire (total sugars/day). DS and PD were measured using standardised questionnaires. The generalised linear model was used to estimate associations between sweetened product consumption, age, sex, self-reported body mass index, DS and PD. Baron and Kenny's four-step approach in addition to the Sobel test were used to establish mediation.

RESULTS

Average DS score was 8.2 (SD=4.5) with 19.5% having excessive scores (>12). Mean PD score was 20.8 (SD=6.2) with 11.8% having high distress scores. Average consumption of sweetened products was 15.5 g/day (SD=13.9). Baron and Kenny's three steps to establish partial mediation were confirmed. First, DS was associated with consumption of sweetened products (p<0.03). Second, DS and PD were correlated (r=0.197; p<0.04). Third, PD was associated with consumption of sweetened products (p<0.01) when both PD and DS were entered as predictors in a multivariate regression. However, Baron and Kenny's fourth step to establish complete mediation was not met. The effect of DS on consumption of sweetened products controlling for PD was reduced, but it was not zero. Finally, the Sobel test was significant (2.14; p<0.03).

CONCLUSIONS

The association between DS and consumption of sweetened products in the Catholic Middle-Eastern Canadian community is partially mediated by psychological distress. Further work should test this mediation relationship in larger samples and verify the potential effects of other sleep variables in this relationship.

Impact of glucose excursion and mean glucose concentration in oral glucose-tolerance test on oxidative stress among Japanese Americans

AIM

To evaluate the impact of glucose excursion (GE) and mean glucose concentration (MGC) on oxidative stress among persons with or without diabetes.

MATERIALS AND METHODS

We examined 775 Japanese Americans who had normal glucose tolerance (NGT), impaired glucose tolerance, or diabetes according to the 75 g oral glucose-tolerance test, using fasting, 1-hour, and 2-hour glucose data. We calculated GE by subtracting the minimum from the maximum glucose level among three points and calculated MGC using these measurements. We investigated the relationship between GE or MGC and urinary isoprostane as a marker of oxidative stress.

RESULTS

According to tertiles of GE or MGC, GE was associated with isoprostane levels among subjects with NGT as well as those with diabetes (P=0.004 and 0.033 for trend, respectively). However, MGC was associated with isoprostane only among NGT subjects (P=0.001 for trend). Association between GE and isoprostane was significant when adjustment was made for age, sex, smoking status, body mass index, C-reactive protein, glucose tolerance status, and homeostatic model assessment (P=0.029), but the association with MGC was not significant.

CONCLUSION

Our results suggest the possibility that GE might result in oxidative stress, and the relationship is stronger than that for MGC.

Describing the situational contexts of sweetened product consumption in a Middle Eastern Canadian community: application of a mixed method design

Little is known about the situational contexts in which individuals consume processed sources of dietary sugars. This study aimed to describe the situational contexts associated with the consumption of sweetened food and drink products in a Catholic Middle Eastern Canadian community. A two-stage exploratory sequential mixed-method design was employed with a rationale of triangulation. In stage 1 (n = 62), items and themes describing the situational contexts of sweetened food and drink product consumption were identified from semi-structured interviews and were used to develop the content for the Situational Context Instrument for Sweetened Product Consumption (SCISPC). Face validity, readability and cultural relevance of the instrument were assessed. In stage 2 (n = 192), a cross-sectional study was conducted and exploratory factor analysis was used to examine the structure of themes that emerged from the qualitative analysis as a means of furthering construct validation. The SCISPC reliability and predictive validity on the daily consumption of sweetened products were also assessed. In stage 1, six themes and 40-items describing the situational contexts of sweetened product consumption emerged from the qualitative analysis and were used to construct the first draft of the SCISPC. In stage 2, factor analysis enabled the clarification and/or expansion of the instrument's initial thematic structure. The revised SCISPC has seven factors and 31 items describing the situational contexts of sweetened product consumption. Initial validation of the instrument indicated it has excellent internal consistency and adequate test-retest reliability. Two factors of the SCISPC had predictive validity for the daily consumption of total sugar from sweetened products (Snacking and Energy demands) while the other factors (Socialization, Indulgence, Constraints, Visual Stimuli and Emotional needs) were rather associated to occasional consumption of these products.

Type 2 diabetes in Asians: prevalence, risk factors, and effectiveness of behavioral intervention at individual and population levels

This review summarizes the current data on diabetes risk factors, prevalence, and prevention efforts in Asia and Asian migrant populations. Studies indicate that type 2 diabetes mellitus is a large and growing threat to public health in Asian populations. Furthermore, Asian subgroups (e.g., South Asians/Asian Indians, Chinese) have unique risk factor profiles for developing diabetes, which differ from other populations and between Asian ethnic groups. Lifestyle intervention programs are effective in preventing diabetes in Asians, as with other ethnicities. The strength of these findings is lessened by the lack of systematically collected data using objective measurements. Large epidemiologic studies of diabetes prevalence and risk factor profiles and translational trials identifying sustainable and culturally acceptable lifestyle programs for Asian subgroups are needed.

Associations between small dense LDL, HDL subfractions (HDL2, HDL3) and risk of atherosclerosis in Japanese-Americans

AIM

Small dense low-density lipoprotein (sdLDL) has been suggested to be more atherogenic than large buoyant LDL. High-density lipoprotein (HDL) consists of two major subfractions (HDL2, HDL3), and just as controversy remains regarding which of the two is the more powerful negative risk factor for atherosclerosis, associations between sdLDL and these HDL subfractions are unclear.

METHODS

We measured sdLDL cholesterol (sdLDL-C), HDL2 cholesterol (HDL2-C) and HDL3 cholesterol (HDL3-C) by a newly developed method in 481 Japanese-Americans who were not using lipid-lowering medication, and examined the associations of these cholesterol concentrations with variables related to atherosclerosis.

RESULTS

In multivariate analysis, sdLDL-C was positively correlated with the body mass index (BMI), fasting glucose and insulin, 2-h glucose, HOMA-IR, high sensitivity C-reactive protein (hsCRP), and carotid artery intima-media thickness (IMT) after adjustment for age and sex. In particular, sdLDL-C was positively correlated with IMT, even after adjustment for sex, age, smoking status, hypertension, diabetes mellitus and hsCRP. HDL2-C was more closely inversely correlated than total HDL-C with BMI, fasting glucose and insulin, 2-h glucose, HOMA-IR, and hsCRP, whereas HDL3-C was not correlated with these factors. Additionally, HDL2-C was more closely correlated than total HDL-C or HDL3-C with sdLDL-C, LDL-C, triglycerides (TG), and apolipoprotein B (apoB).

CONCLUSIONS

SdLDL-C was closely associated with insulin resistance and glucose tolerance, lending credence to its potential as a useful risk marker in assessing carotid artery IMT and the present degree of atherosclerosis in Japanese-Americans. The findings also suggest that subjects with higher HDL2-C levels were better protected from atherosclerosis.

Association of genetic variants for susceptibility to obesity with type 2 diabetes in Japanese individuals

AIMS/HYPOTHESIS

In populations of East Asian descent, we performed a replication study of loci previously identified in populations of European descent as being associated with obesity measures such as BMI and type 2 diabetes.

METHODS

We genotyped 14 single nucleotide polymorphisms (SNPs) from 13 candidate loci that had previously been identified by genome-wide association meta-analyses for obesity measures in Europeans. Genotyping was done in 18,264 participants from two general Japanese populations. For SNPs showing an obesity association in Japanese individuals, we further examined diabetes associations in up to 6,781 cases and 7,307 controls from a subset of the original, as well as from additional populations.

RESULTS

Significant obesity associations (p < 0.1 two-tailed, concordant direction with previous reports) were replicated for 11 SNPs from the following ten loci in Japanese participants: SEC16B, TMEM18, GNPDA2, BDNF, MTCH2, BCDIN3D-FAIM2, SH2B1-ATP2A1, FTO, MC4R and KCTD15. The strongest effect was observed at TMEM18 rs4854344 (p = 7.1 × 10(-7) for BMI). Among the 11 SNPs showing significant obesity association, six were also associated with diabetes (OR 1.05-1.17; p = 0.04-2.4 × 10(-7)) after adjustment for BMI in the Japanese. When meta-analysed with data from the previous reports, the BMI-adjusted diabetes association was found to be highly significant for the FTO locus in East Asians (OR 1.13; 95% CI 1.09-1.18; p = 7.8 × 10(-10)) with substantial inter-ethnic heterogeneity (p = 0.003).

CONCLUSIONS/INTERPRETATION

We confirmed that ten candidate loci are associated with obesity measures in the general Japanese populations. Six (of ten) loci exert diabetogenic effects in the Japanese, although relatively modest in size, and independently of increased adiposity.

Increasing frequency and burden of cerebral artery atherosclerosis in Korean stroke patients

PURPOSE

Koreans have been undergoing rapid lifestyle changes that may have an effect on patterns of cerebral artery atherosclerosis. This study was aimed at determining the frequency and distribution of atherosclerosis in the cerebral arteries and associated temporal changes over the past eight-year period among Korean stroke patients.

MATERIALS AND METHODS

By using stroke registry data registered between April 1999 and March 2007, we investigated the presence, severity, and location of cerebral artery atherosclerosis as determined by angiographic findings. Their annual patterns and association with vascular risk factors were investigated.

RESULTS

Of 1,955 patients, 1,517 patients (77.6%) demonstrated atherosclerosis in one or more arteries. A significantly increasing trend of atherosclerosis was observed during the past eight years, which was ascribed to an increase of combined extracranial (EC) and intracranial (IC) atherosclerosis. The number of atherosclerotic arteries increased as the number of risk factors increased. In the multivariate analysis, the year and vascular risk factors were independent predictors of the presence of atherosclerosis.

CONCLUSION

We found that the atherosclerotic burden has been increasing for the past eight years in Korean stroke patients, particularly the combined EC and IC subtype. Lifestyle changes and increase in vascular risk factors may be contributing factors.

Dietary fiber, magnesium, and glycemic load alter risk of type 2 diabetes in a multiethnic cohort in Hawaii

The influence of dietary fiber, magnesium (Mg), and glycemic load (GL) on diabetes was examined in the Hawaii component of the Multiethnic Cohort. The 75,512 Caucasian, Japanese American, and Native Hawaiian participants aged 45-75 y at baseline completed a FFQ. After 14 y of follow-up, 8587 incident diabetes cases were identified through self-reports and health plans. We applied Cox regression stratified for age at cohort entry and adjusted for ethnicity, BMI, physical activity, education, and total energy with further stratifications by sex and ethnicity. When comparing extreme quintiles, total fiber intake was associated with reduced diabetes risk among all men [hazard ratio (HR): 0.75; 95% CI: 0.67, 0.84; P-trend < 0.001) and women (HR: 0.95; 95% CI: 0.85, 1.06; P-trend = 0.05). High intake of grain fiber reduced diabetes risk significantly by 10% in men and women. High vegetable fiber intake lowered risk by 22% in all men but not women. Mg intake reduced risk (HR = 0.77 and 0.84 for men and women, respectively) and, due to its strong correlation with fiber (r = 0.83; P < 0.001), may explain the protective effect of fiber. The top GL quintile was associated with a significantly elevated diabetes incidence in Caucasian men and in all women except Japanese Americans. Overall, several associations were more pronounced in Caucasians than in the other groups. These findings suggest that protection against diabetes can be achieved through food choices after taking into account body weight, but, due to differences in commonly consumed foods, risk estimates may differ by ethnic group.

Ethnic difference in patients with type 2 diabetes mellitus in inter-East Asian populations: a systematic review and meta-analysis focusing on gene polymorphism

BACKGROUND

We previously reported that the fasting serum insulin level was significantly lower in Japanese patients than in Korean and Chinese patients, and showed evidence that a difference in the dietary component would be one of the most influential factors for the ethnic difference. However, it is well known that type 2 diabetes mellitus (T2DM) results from the interaction between genetic predispositions and environmental risk factors. Therefore, we investigated ethnic differences by focusing on gene polymorphism, possibly related to T2DM in Japanese, Korean, and Chinese subjects.

METHODS

Data sources included MEDLINE and EMBASE between January 2001 and October 2008. We conducted a search for articles containing minor allele frequency (MAF) in the gene polymorphisms of peroxisome proliferator-activated receptor-γ (PPARG), inward-rectifying potassium channel Kir6.2 (KCNJ11), Calpain 10 (CAPN10), and transcription factor 7-like 2 (TCF7L2). The pooled odds ratio was calculated by using a fixed-effects model with the Mantel-Haenszel method after confirming statistical evidence of homogeneity across the ethnicities using the Breslow-Day test.

RESULTS

The Breslow-Day test revealed that there were no statistically significant differences between ethnicities in pooled odds ratios for the gene polymorphisms in PPARG (P = 0.828), KCNJ11 (P = 0.194), CAPN10 (P = 0.090), and TCF7L2 (P = 0.376). Also, pooled odds ratios of each gene polymorphism in East Asians were 0.645 for PPARG (P = 0.000), 1.168 for KCNJ11 (P = 0.000), 0.967 for CAPN10 (P = 0.759), and 1.386 for TCF7L2 (P = 0.000).

CONCLUSION

The results of this study and our previous studies suggest that behavioral and environmental risk factors have a more significant impact on ethnic difference in East Asian patients with T2DM compared with genetic predispositions.

Diabetes in Japan: a review of disease burden and approaches to treatment

In recent years there has been rapid growth in diabetes in Japan which now is one of the nations most affected by the worldwide diabetes epidemic. Diabetes has been identified as a healthcare priority by the Ministry of Health, Labour and Welfare (MHLW). Type 1 diabetes is rare in Japan, and type 2 diabetes predominates in both adults and children. The growth in diabetes is due to increases in the number of people with type 2 diabetes associated with increased longevity and lifestyle changes. Approximately 13.5% of the Japanese population now has either type 2 diabetes or impaired glucose tolerance. This high prevalence of type 2 diabetes is associated with a significant economic burden, with diabetes accounting for up to 6% of the total healthcare budget. The costs of diabetes are increased in patients with co-morbidities such as hypertension and hyperlipidaemia and in patients who develop complications, of which retinopathy has the highest cost. Costs increase with increasing number of complications. Current guidelines from the Japan Diabetes Society (JDS) recommend a target HbA(1c) of 6.5% for glycaemic control. This is achieved in approximately one third of patients with type 2 diabetes, and Japanese patients typically have lower HbA(1c) than patients in Western countries (e.g. US, UK). Japanese patients with type 2 diabetes have better adherence with diet and exercise recommendations than their peers in Western countries. Sulfonylureas have been the most widely prescribed first-line treatment for type 2 diabetes, although there is increasing use of combination therapy and of insulin.

Evaluation of the 24-hour profiles of physiological insulin, glucose, and C-peptide in healthy Japanese volunteers

BACKGROUND

Some studies have demonstrated the benefit of blood glucose control as close as possible to physiological conditions. Not enough reports have investigated in detail the 24-h plasma profiles of insulin/glucose/C-peptide. Here we investigated the 24-h plasma profiles of physiological insulin/glucose/C-peptide in healthy Japanese adults.

METHODS

In order to evaluate the 24-h profiles of physiological insulin/glucose/C-peptide profiles, 42 blood samples were taken from each subject in our group of healthy Japanese volunteers to measure the 24-h profile with three standardized meals.

RESULTS

Plasma glucose and insulin increased rapidly followed by a rapid decrease after each meal with little variation at night. The average peak values of insulin after each meal were as follows: 426.20 pmol/L (breakfast), 373.75 pmol/L (lunch), and 410.28 pmol/L (dinner). The average times to peak insulin were 0.651 h (breakfast), 0.677 h (lunch), and 0.689 h (dinner). The corresponding average maximum postprandial plasma glucose levels were 8.39 mmol/L (breakfast), 8.77 mmol/L (lunch), and 8.74 mmol/L (dinner). The average times to peak glucose were 0.738 h (breakfast), 0.650 h (lunch), and 0.625 h (dinner). The average maximum postprandial C-peptide levels were 2.64 nmol/L (breakfast), 2.55 nmol/L (lunch), and 2.67 nmol/L (dinner). No major differences were found in these parameters between the Caucasian and Japanese populations.

CONCLUSIONS

This is the first investigation to measure the 24-h profiles of insulin/glucose/C-peptide in healthy Japanese volunteers with standardized meals. It is hoped this information will provide useful reference for future research and clinical management.

Uncovering disparities in survival after non-small-cell lung cancer among Asian/Pacific Islander ethnic populations in California

Asians may have better survival after non-small-cell lung cancer (NSCLC) than non-Asians. However, it is unknown whether survival varies among the heterogeneous U.S. Asian/Pacific Islander (API) populations. Therefore, this study aimed to quantify survival differences among APIs with NSCLC. Differences in overall and disease-specific survival were analyzed in the California Cancer Registry among 16,577 API patients diagnosed with incident NSCLC between 1988 and 2007. Adjusted hazard ratios (HR) with 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression models with separate baseline hazards by disease stage. Despite better overall and disease-specific survival among APIs compared with non-Hispanic Whites, differences were evident across API populations. Among women, Japanese (overall survival HR, 1.16; 95% CI, 1.06-1.27) and APIs other than those in the six largest ethnic groups (other APIs; HR, 1.19; 95% CI, 1.07-1.33) had significantly poorer overall and disease-specific survival than Chinese. By contrast, South Asian women had significantly better survival than Chinese (HR, 0.79; 95% CI, 0.63-0.97). Among men, Japanese (HR, 1.15; 95% CI, 1.07-1.24), Vietnamese (HR, 1.07; 95% CI, 1.00-1.16), and other APIs (HR, 1.18; 95% CI, 1.08-1.28) had significantly poorer overall and disease-specific survival than Chinese. Other factors independently associated with poorer survival were lower neighborhood socioeconomic status, involvement with a non-university hospital, unmarried status, older age, and earlier year of diagnosis. APIs have significant ethnic differences in NSCLC survival that may be related to disparate lifestyles, biology, and especially health care access or use. To reduce the nationwide burden of lung cancer mortality, it is critical to identify and ameliorate hidden survival disparities such as those among APIs.

Confirmation of multiple risk Loci and genetic impacts by a genome-wide association study of type 2 diabetes in the Japanese population

OBJECTIVE

To identify novel type 2 diabetes gene variants and confirm previously identified ones, a three-staged genome-wide association study was performed in the Japanese population.

RESEARCH DESIGN AND METHODS

In the stage 1 scan, we genotyped 519 case and 503 control subjects with 482,625 single nucleotide polymorphism (SNP) markers; in the stage 2 panel comprising 1,110 case subjects and 1,014 control subjects, we assessed 1,456 SNPs (P < 0.0025, stage 1); additionally to direct genotyping, 964 healthy control subjects formed the in silico control panel. Along with genome-wide exploration, we aimed to replicate the disease association of 17 SNPs from 16 candidate loci previously identified in Europeans. The associated and/or replicated loci (23 SNPs; P < 7 x 10(-5) for genome-wide exploration and P < 0.05 for replication) were examined in the stage 3 panel comprising 4,000 case subjects and 12,569 population-based samples, from which 4,889 nondiabetic control subjects were preselected. The 12,569 subjects were used for overall risk assessment in the general population.

RESULTS

Four loci-1 novel with suggestive evidence (PEPD on 19q13, P = 1.4 x 10(-5)) and three previously reported-were identified; the association of CDKAL1, CDKN2A/CDKN2B, and KCNQ1 were confirmed (P < 10(-19)). Moreover, significant associations were replicated in five other candidate loci: TCF7L2, IGF2BP2, SLC30A8, HHEX, and KCNJ11. There was substantial overlap of type 2 diabetes susceptibility genes between the two populations, whereas effect size and explained variance tended to be higher in the Japanese population.

CONCLUSIONS

The strength of association was more prominent in the Japanese population than in Europeans for more than half of the confirmed type 2 diabetes loci.