Body mass index and weight change since 20 years of age and risk of coronary heart disease among Japanese: the Japan Public Health Center-Based Study

Body mass index trajectories and mortality risk in Japan using a population-based prospective cohort study: the Japan Public Health Center-based Prospective Study

BACKGROUND

Recent studies have found that long-term changes in weight during adulthood are associated with a high risk of mortality. The objective of this study was to characterize body mass index (BMI) trajectories during adulthood and to examine the association between BMI trajectories and risk of death in the Japanese population.

METHODS

The data were extracted from Japan Public Health Center-based Prospective Study-a population-based prospective cohort study in Japan with participants aged 40-69 years followed over 20 years. The participants were categorized into multiple BMI trajectory groups using the latent class growth model. The Cox proportional-hazards model was conducted using all-cause mortality and cause-specific mortality as outcomes and the identified BMI trajectory groups as a predictor. In total, 65 520 participants were included in the analysis.

RESULTS

Six BMI trajectory groups were identified: underweight stable (Group 1), low-to-high normal (Group 2), high-to-low normal (Group 3), normal to overweight (Group 4), overweight to normal (Group 5) and normal to obese (Group 6). Our Cox models showed a higher hazard (risk) of all-cause mortality among participants in the BMI-declining groups [Group 3, adjusted hazard ratio (aHR): 1.10, 95% CI: 1.05-1.16; Group 5, aHR: 1.16, 95% CI: 1.08-1.26], underweight stable group (Group 1, aHR: 1.27, 95% CI: 1.21-1.33) and normal to obese group (Group 6, aHR: 1.22, 95% CI: 1.13-1.33) than Group 2 (low-to-high normal BMI trajectory).

CONCLUSIONS

Stable underweight and weight loss were associated with a high risk of mortality, both of which were uniquely observed in a Japanese population.

Association of health behaviors, dietary habits, and oral health with weight gain after 20 years of age in community-dwelling Japanese individuals aged 40 years and older: a cross-sectional study

OBJECTIVES

This cross-sectional study investigated the factors associated with weight gain ≥ 10 kg after 20 years of age in the general Japanese population, with a focus on the number of teeth.

MATERIALS AND METHODS

We included individuals aged ≥ 40 years from Yamagata prefecture, Japan from 2017-2021. A postal survey was conducted using a self-administered questionnaire; 5,940 participants were included in the final analysis. The questionnaire included items on lifestyle factors, medical history, physical and mental conditions, oral health, and dietary intake. A multivariate logistic regression analysis was used to identify independent associations between weight gain ≥ 10 kg after 20 years of age and various parameters; adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated.

RESULTS

Less than 20 teeth, male sex, drinking habit frequency, eating very fast or fast, and a higher frequency of eating-away-from-home were significant factors associated with weight gain ≥ 10 kg after 20 years of age; individuals with < 20 versus > 20 teeth exhibited a 1.35-fold higher OR (95% CI 1.15-1.59; p < 0.01).

CONCLUSIONS

Our results suggest that having < 20 teeth may affect weight gain ≥ 10 kg after 20 years of age. However, owing to the cross-sectional study design, causality could not be determined. Therefore, maintaining healthy lifestyle behaviors to avoid tooth loss may also affect weight gain ≥ 10 kg after 20 years of age.

CLINICAL RELEVANCE

Having < 20 teeth has the potential to affect long-term weight gain after 20 years of age.

Dissecting the mediating and moderating effects of depression on the associations between traits and coronary artery disease: A two-step Mendelian randomization and phenome-wide interaction study

Background

Depression is often present concurrently with coronary artery disease (CAD), a disease with which it shares many risk factors. However, the manner in which depression mediates and moderates the association between traits (including biomarkers, anthropometric indicators, lifestyle behaviors, etc.) and CAD is largely unknown.

Methods

In our causal mediation analyses using two-step Mendelian randomization (MR), univariable MR was first used to investigate the causal effects of 108 traits on liability to depression and CAD. The traits with significant causal effects on both depression and CAD, but not causally modulated by depression, were selected for the second-step analyses. Multivariable MR was used to estimate the direct effects (independent of liability to depression) of these traits on CAD, and the indirect effects (mediated via liability to depression) were calculated. To investigate the moderating effect of depression on the association between 364 traits and CAD, a cross-sectional phenome-wide interaction study (PheWIS) was conducted in a study population from UK Biobank (UKBB) (N=275,257). Additionally, if the relationship between traits and CAD was moderated by both phenotypic and genetically predicted depression at a suggestive level of significance (Pinteraction≤0.05) in the PheWIS, the results were further verified by a cohort study using Cox proportional hazards regression.

Results

Univariable MR indicated that 10 of 108 traits under investigation were significantly associated with both depression and CAD, which showed a similar direct effect compared to the total effect for most traits. However, the traits "drive faster than speed limit" and "past tobacco smoking" were both exceptions, with the proportions mediated by depression at 24.6% and 7.2%, respectively. In the moderation analyses, suggestive evidence of several traits was found for moderating effects of phenotypic depression or susceptibility to depression, as estimated by polygenic risk score, including chest pain when hurrying, reason of smoking quitting and weight change. Consistent results were observed in survival analyses and Cox regression.

Conclusion

The independent role of traits in CAD pathogenesis regardless of depression was highlighted in our mediation analyses, and the moderating effects of depression observed in our study may be helpful for CAD risk stratification and optimized allocation of scarce medical resources.

Trends for the Association between Body Mass Index and Risk of Cardiovascular Disease among the Japanese Population: The Circulatory Risk in Communities Study (CIRCS)

AIM

This study aimed to investigate whether the impact of body mass index (BMI) on the risk of cardiovascular disease (CVD) has changed among the 1960s, 1970s, 1980s, 1990s, and early 2000s in Japan.

METHODS

The study population consisted of residents in Japan aged 40-69 years who had no history of CVD. The baseline surveys have been conducted every year since 1963. We defined the first, second, third, fourth, and fifth cohorts as 1963-1969 (n=4,248), 1970-1979 (n=6,742), 1980-1989 (n=12,789), 1990-1999 (n=12,537), and 2000-2005 (n=9,140) respectively. The participants were followed up for a median of 15 years for each cohort to determine the incidence of CVD. We classified them into four categories (BMI ＜21.0, 21.0-＜23.0, 23.0-＜25.0, and ≥ 25.0 kg/m ²).

RESULTS

From 1963-1969 to 2000-2005, the prevalence of BMI ≥ 25.0 increased over time. Compared with BMI 23.0-＜25.0, the age-, sex- and community-adjusted hazard ratios (95% confidence interval [CIs]) of CVD for BMI ≥ 25.0 were 1.10 (0.77-1.57), 0.89 (0.68-1.18), 1.03 (0.85-1.26), 1.28 (1.04-1.58), and 1.36 (1.04-1.78)in the first, second, third, fourth, and fifth cohorts, respectively. The corresponding population attributable fractions were 2.0% (nonsignificant), -2.6% (nonsignificant), 0.9% (nonsignificant), 7.6%, and 10.9%. Further adjustment for systolic blood pressure and antihypertensive medication use in the fourth and fifth cohorts attenuated the associations, which may reflect that blood pressure may mediate the BMI-CVD association.

CONCLUSION

The proportion of CVD attributable to overweight/obesity has increased during the periods between 1963-1969 and 2000-2005. The significant associations between overweight/obesity and risk of CVD after the 1990s were mediated by blood pressure levels.

Effect of diabetes and prediabetes on the development of disability and mortality among middle-aged adult Japanese: a 22-year follow-up of NIPPON DATA90

Aims/Introduction

To examine the association between diabetes and prediabetes at baseline, and disability, mortality over a 22‐year period among middle‐aged Japanese adults.

Materials and Methods

Participants consisted of 1,788 adults aged 45–64 years at baseline from the cohort study National Integrated Project for Prospective Observation of Non‐communicable Disease and its Trends in the Aged 1990 (NIPPON DATA90). Disability, defined as having a decline in activities of daily living (ADL), was assessed by a modified Katz questionnaire at four time points. Disability and death without disability for 22‐year follow up were used as outcomes to test the association with a diagnosis of diabetes or prediabetes at baseline, using multinomial logistic regression. Adjusted odds ratios (ORs) were obtained from four models that contained appropriate adjustment factors, such as age, sex, smoking status, drinking status, body mass index and cardiovascular risk factors (hypertension, hypercholesterolemia, triglycerides, low serum high‐density lipoprotein), at baseline.

Results

In the present study, 334 participants (18.7%) reported at least one disability, and 350 (19.6%) were reported dead without observation of disability during follow up. Adjusting sex and other risk factors, participants with diabetes and prediabetes had a higher risk for disability (OR 1.43, 95% confidence interval [CI] 1.07–1.91 and OR 1.66, 95% CI 1.10–2.50, respectively) and for mortality (OR 1.56, 95% CI 1.16–2.08 and OR 1.77, 95% CI 1.18–2.65, respectively) than individuals with normal glucose tolerance.

Conclusions

In middle‐aged Japanese adults, individuals with diabetes and prediabetes were more likely to be associated with disability and mortality. Our findings suggest that prediabetes and diabetes in middle‐aged adults should be paid more attention, and requires more intervention to prevent disability and mortality in later life.

Relationship between body mass index and masticatory factors evaluated with a wearable device

Numerous studies have evaluated the relationship between eating behavior and obesity, however few studies have objectively assessed eating behavior. Additionally, the association of masticatory behaviors with masticatory performance remains unclear. This study aimed to verify the relationship between masticatory performance and behavior measured by a wearable masticatory counter, and BMI. 365 healthy adults participated. Mastication behaviors, i.e. number of chews and bites, chewing rate, and chewing time, were measured using wearable masticatory counter while consuming one rice ball (100 g). Masticatory performance was evaluated using testing gummy jelly. Lifestyle habits including exercise, walking, and breakfast, were surveyed by questionnaire. The correlation coefficients between masticatory behaviors and performance and BMI were analyzed. Furthermore, multiple regression analysis was performed. The number of chews showed positive correlation with chewing rate, number of bites and chewing time, but no correlation with masticatory performance. BMI had weak but significant negative correlation with number of chews, bites, chewing time, and masticatory performance, but had no correlation with chewing rate. Multiple regression analysis revealed that BMI was associated with sex, age, number of chews, bites, masticatory performance, and walking speed. In conclusion, masticatory behavior and performance were not interrelated, but both were independently associated with BMI weakly.

The Impact of Obesity on Sudden Cardiac Death Risk

PURPOSE OF REVIEW

We aimed to describe the epidemiology of sudden cardiac death (SCD) in the obese, elaborating on the potential pathophysiological mechanisms linking obesity, SCD, and the outcomes in SCD survivors, as well as looking into the intriguing "obesity paradox" in these patients.

RECENT FINDINGS

Several studies show increased mortality in patients with BMI > 30 kg/m² admitted to the hospital following SCD. At the same time, other studies have implied that the "obesity paradox," described in various cardiovascular conditions, applies to patients admitted after SCD, showing lower mortality in the obese compared to normal weight and underweight patients. We found a significant body of evidence to support that while obesity increases the risk for SCD, the outcomes of obese patients post SCD are better. These findings should not be interpreted as supporting weight gain, as it is always better to prevent the "disaster" from happening than to improve your chances of surviving it. Obesity is shown to be significantly associated with increased risk for SCD; however, there is a growing body of evidence, supporting the "obesity paradox" in the survival of SCD victims. Prospectively, well-designed studies are needed to confirm these findings.

Clinical Significance of Lifetime Maximum Body Mass Index in Predicting the Development of T2DM: A Prospective Study in Beijing

BACKGROUND

Overweight and obesity are well-known risk factors for type 2 diabetes mellitus (T2DM). The effect of the maximum body mass index (BMImax), which indicates the highest body weight before the diagnosis of T2DM, is not fully understood. This study aimed to explore the predictive value of BMImax in the progression of diabetes.

METHODS

This prospective study recruited 2018 subjects with normal glucose tolerance in Beijing, China. The subjects were followed up for eight years, and the association between BMImax and glucose outcomes was evaluated.

RESULTS

Ninety-seven of the 2,018 participants developed diabetes by the end of the study. Compared to individuals with normal glucose tolerance, those who developed diabetes were characterized by higher levels of fasting plasma glucose (FPG), 2 h postload glucose (PBG), glycosylated hemoglobin (HbA_1c), systolic blood pressure (SBP), and low-density lipoprotein cholesterol (LDL-c), a higher prevalence of a familial history of diabetes and a lower level of high-density lipoprotein cholesterol (HDL-c). Multivariate regression analysis of sex-stratified groups suggested that FPG, HbA_1c, SBP and familial history of diabetes were independent risk factors for diabetes, but that BMImax was a unique indicator for female patients.

CONCLUSIONS

BMImax might be an independent predictor of T2DM in females, but it does not seem to be associated with the risk of diabetes in males. BMImax could be regarded as an indicator in the prevention and management of diabetes.

Trajectories of body mass index and risk for coronary heart disease: A 38-year follow-up study

Objective

Obesity is a well-known risk factor for coronary heart disease (CHD), but there is little evidence on the effect of long-term trajectories of body mass index (BMI) over the life course. By using repeated assessments, the aim was to study the risk of CHD in adults during 38 years in different trajectories of BMI.

Methods

A sample of 2129 men and women, aged 20–59 years at baseline, took part in four repeated interviews between 1980 and 2005. Data on BMI, medical history, lifestyle and socioeconomy were collected. Based on the World Health Organization categories of BMI, life course trajectories of stable normal weight, stable overweight, stable obesity, increasing BMI and fluctuating BMI were created. The individuals were followed through national registers for first hospitalization of CHD (389 events) until the end of 2017, and Hazard Ratios (HRs) were calculated, adjusted for age, sex, socioeconomic factors, lifestyle factors and metabolic comorbidities.

Results

Stable normal weight in all assessments was the reference group. Those who had an increase in BMI from normal weight in the first assessment to overweight or obesity in later assessments had no increased risk of CHD, HR 1.04 (95% CI: 0.70–1.53). The HR for individuals with fluctuating BMI was 1.25 (0.97–1.61), for stable overweight 1.43 (1.03–1.98), for stable obesity 1.50 (0.92–2.55), and for stable overweight or obesity 1.45 (1.07–1.97), after full adjustments.

Conclusion

Having a stable overweight or obesity throughout adult life was associated with increased CHD risk but changing from normal weight at baseline to overweight or obesity was not associated with increased CHD risk. Prevention of obesity early in life may be particularly important to reduce CHD risk.

Efficacy of Additional Intervention to the Specific Health Guidance in Japan: The Takahata GENKI Project

Purpose

A tailored approach to individual risk factors for developing lifestyle-related diseases would help induce behavioral changes toward intervention acceptability. The addition of preventive healthcare programs to nationwide specific health guidance in Japan is adapted in a given region.

Patients and Methods

We conducted a prospective parallel-group comparison study on 195 eligible residents from Takahata, Japan, with a high risk of lifestyle-related diseases from 2014 to 2017 to examine whether such an intervention could improve the body mass index (BMI) and estimated glomerular filtration rate (eGFR).

Results

Of the 195 enrolled residents, 117 were assigned to the control group and 78 to the intervention group. They were ≤65 years old and had a BMI ≥25 kg/m² and an eGFR ≤90 mL/kg/1.73 m². We conducted certain interventions for each group, including additional blood testing, regular health guidance, and specific health guidance. After one year, neither BMI (intervention: 26.7 ± 2.17 kg/m² vs control: 27.3 ± 2.12 kg/m², p = 0.076) nor eGFR (intervention: 72.2 ± 11.1 mL/kg/1.73 m² vs control: 73.1 ± 10.5 mL/kg/1.73 m², p = 0.608) differed significantly between groups. However, after three years, the BMI in the intervention group (26.4 ± 2.05 kg/m²) was significantly reduced compared to that in the control group (27.4 ± 2.26 kg/m²; p = 0.005).

Conclusion

The additional interventions might have contributed to a reduction in metabolic syndrome.

Trial Registration

This study was registered in the UMIN-Clinical Trials Registry (ID:000013581). More information: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000015868. The registration date was 31/03/2014.

Weight Change and the Onset of Cardiovascular Diseases: Emulating Trials Using Electronic Health Records

BACKGROUND

Cross-sectional measures of body mass index (BMI) are associated with cardiovascular disease (CVD) incidence, but less is known about whether weight change affects the risk of CVD.

METHODS

We estimated the effect of 2-y weight change interventions on 7-y risk of CVD (CVD death, myocardial infarction, stroke, hospitalization from coronary heart disease, and heart failure) by emulating hypothetical interventions using electronic health records. We identified 138,567 individuals with 45-69 years of age without chronic disease in England from 1998 to 2016. We performed pooled logistic regression, using inverse-probability weighting to adjust for baseline and time-varying confounders. We categorized each individual into a weight loss, maintenance, or gain group.

RESULTS

Among those of normal weight, both weight loss [risk difference (RD) vs. weight maintenance = 1.5% (0.3% to 3.0%)] and gain [RD = 1.3% (0.5% to 2.2%)] were associated with increased risk for CVD compared with weight maintenance. Among overweight individuals, we observed moderately higher risk of CVD in both the weight loss [RD = 0.7% (-0.2% to 1.7%)] and the weight gain group [RD = 0.7% (-0.1% to 1.7%)], compared with maintenance. In the obese, those losing weight showed lower risk of coronary heart disease [RD = -1.4% (-2.4% to -0.6%)] but not of stroke. When we assumed that chronic disease occurred 1-3 years before the recorded date, estimates for weight loss and gain were attenuated among overweight individuals; estimates for loss were lower among obese individuals.

CONCLUSION

Among individuals with obesity, the weight-loss group had a lower risk of coronary heart disease but not of stroke. Weight gain was associated with increased risk of CVD across BMI groups. See video abstract at, http://links.lww.com/EDE/B838.

Interaction between the genetic variant of rs696217-ghrelin and food intake and obesity and dyslipidemia

In this study, we aimed to investigate the relationship between the genetic variant of rs696217-ghrelin and fasted lipid profile, indices of obesity, and environmental parameters. Amplification refractory mutation system-polymerase chain reaction (ARMs-PCR) was used for genotyping 1118 individuals recruited as part of the Mashhad Stroke and Heart Atherosclerotic Disorder (MASHAD) cohort study. The interaction between the presence of the genetic variant of rs696217-ghrelin and nutritional intake and other major determinants of obesity and lipid profile was examined in the MASHAD study population. Individuals with the TT genotype at the locus had the lowest prevalence of obesity compared to other genotypes among the individuals. No significant relationship was found between the two groups regarding the lipid profile and TT genotype. Furthermore, no significant association was found between dietary intake and the genetic variant of rs696217-ghrelin in the population under study. Individuals with a TT or GT genotype appear to be at a higher risk of obesity, compared to those with a GG genotype. The results of the current study revealed a significant association between the genetic variant of rs696217-ghrelin and obesity; however, this gene did not correlate with the risk factors of cardiovascular diseases and dyslipidemia in the Iranian population.

Impact of Body Weight Gain on the Incidence of Nonalcoholic Fatty Liver Disease in Nonobese Japanese Individuals

INTRODUCTION

We aimed to investigate the effect of recent short-term weight gain on the incidence of nonalcoholic fatty liver disease (NAFLD) in nonobese (body mass index < 25 kg/m) participants.

METHODS

This retrospective cohort study included nonobese individuals who participated in an annual health checkup between 2008 and 2018 in Tokyo, Japan. We estimated the multivariable adjusted hazard ratio for the development of NAFLD diagnosed via ultrasound after a 3-kg unit gain in weight measured at a 2-year landmark time point postbaseline. Multivariable adjustments included weight change from the age of 20 and other relevant confounding factors. Sensitivity analyses using additional landmark time points at 1, 3, 4, and 5 years postbaseline and time-dependent Cox proportional hazards regressions were performed.

RESULTS

Among the 27,064 nonobese participants (142,699 person years of follow-up), 2,895 were diagnosed with NAFLD. Approximately 90% of the patients with NAFLD maintained their nonobese status before disease diagnosis. The adjusted hazard ratio for the development of NAFLD (for a 3-kg unit of weight gain) at the 2-year landmark time point postbaseline was 1.60 (95% confidence interval, 1.46-1.76) in nonobese men and 1.66 (95% confidence interval, 1.51-1.83) in nonobese women. This association was maintained in the sensitivity analyses.

DISCUSSION

Recent short-term weight gain is an independent risk factor for NAFLD development in nonobese men and women. Clinicians should be mindful of the association between weight gain and NAFLD onset, even in the nonobese population.

Incidence of cardiovascular disease and mortality in underweight individuals

BACKGROUND

Few studies have evaluated the association between being underweight and having cardiovascular disease in the general population. We investigated the incidence of stroke, myocardial infarction (MI), and all-cause mortality according to detailed underweight categories in a large population cohort.

METHODS

We included 4 164 364 individuals who underwent a health examination that was conducted as part of the Korean National Health Insurance Service between January 2009 and December 2012 and followed them up to determine the incidence of stroke, MI, and all-cause mortality until 31 December 2016. Based on the body mass index, the study population was categorized into normal (18.50-22.99), mild (17.00-18.49), moderate (16.00-16.99), and severe underweight (<16.00) groups. Cox proportional hazards analyses were performed to calculate the hazard ratio for stroke, MI, and mortality according to the severity of underweight in reference to the normal weight. We adjusted for age, sex, lifestyle, economic status, co-morbidity, blood pressure, glucose, lipid level, and waist circumference.

RESULTS

The mean age of the 4 164 364 eligible subjects in this study cohort was 44.4 ± 14.3 years, and 46.1% of the participants were male; 46 728 strokes, 30 074 MIs, and 121 080 deaths occurred during 27 449 902 person-years. The incidence of stroke, MI, and all-cause mortality increased proportionally with the severity of underweight in the multivariate model. This proportional association became more evident when the waist circumference was additionally adjusted. The respective hazard ratios (95% confidence intervals) for mild, moderate, and severe underweight were 1.10 (1.06-1.15), 1.11 (1.02-1.20), and 1.38 (1.24-1.53) for stroke; 1.19 (1.14-1.25), 1.40 (1.27-1.53), and 1.86 (1.64-2.11) for MI; and 1.63 (1.60-1.67), 2.10 (2.02-2.17), and 2.98 (2.85-3.11) for all-cause mortality. In stratified analyses based on waist circumference, the severity of underweight was consistently associated with a higher risk of stroke, MI, and death.

CONCLUSIONS

The severity of underweight was associated with a higher risk of stroke, MI, and all-cause mortality.

Weight change during middle age and risk of stroke and coronary heart disease: The Japan Public Health Center-based Prospective Study

BACKGROUND AND AIMS

The impact of weight changes in middle age on the incidence of cardiovascular disease has not been well elucidated. We investigated whether a 5-year weight change was associated with risk of stroke and coronary heart disease (CHD) in middle-aged individuals.

METHODS

We analyzed data of 74,928 participants aged 40-69 years who provided responses to the baseline and 5-year follow-up questionnaires in the Japan Public Health Center-based Prospective Study. Weight change was calculated by subtracting self-reported weight at baseline from that at 5-year follow-up. Stroke and CHD events were confirmed by reviewing hospital records.

RESULTS

During 997,406 person-years of follow-up, we documented 3,975 stroke and 914 CHD events. The multivariable HRs of stroke for losing ≥5 kg compared to stable weight (change ≤2 kg) was 1.17 (95% CI, 1.01-1.37) in men versus 1.33 (1.13-1.57) for losing ≥5 kg and 1.61 (1.36-1.92) for gaining ≥5 kg in women (U-shaped association). These associations did not change after the exclusion of early events. The multivariable HR of CHD for gaining ≥5 kg was 1.22 (0.95-1.58) in men. After exclusion of early events within another 5 years, that positive association became stronger [multivariable HR 1.34 (1.00-1.82)].

CONCLUSIONS

Weight gain during middle age was associated with an increased risk of stroke in women and an increased risk of CHD in men. Weight loss was associated with an increased risk of stroke in both men and women.

Relationship of Weight Change Patterns From Young to Middle Adulthood With Incident Cardiovascular Diseases

CONTEXT

The effect of weight change patterns on cardiovascular diseases (CVD) remains uncertain.

OBJECTIVE

We aim to examine the relation of weight change patterns and absolute weight change from young adulthood to midlife with incident CVD.

DESIGN

Retrospective cohort study.

SETTING

National Health and Nutrition Examination Survey 1999-2016.

PARTICIPANTS

A total of 20 715 US adults aged 40 through 79 with recalled weight at young adulthood (25 years) and midlife (10 years before baseline).

MAIN OUTCOME MEASURE

CVD status was determined by self-report of a prior diagnosis, and age at diagnosis was used to establish time of CVD onset. CVD events was defined as the first occurrence of a congestive heart failure, coronary heart disease, angina pectoris, heart attack, or stroke.

RESULTS

After 9.76 years of follow-up, compared with participants who remained at normal weight, those in maximum overweight, changing from nonobese to obese, changing from obese to nonobese, maintaining obesity between young and middle adulthood had a 39% (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.19-1.62), 93% (HR, 1.93; 95% CI, 1.64-2.28), 125% (HR, 2.25; 95% CI, 1.29-3.94), and 132% (HR, 2.32; 95% CI, 1.68-3.20) higher risk of CVD, respectively. In addition, compared with weight change within 2.5 kg, weight gain ≥ 10.0 kg was associated with higher risk of CVD.

CONCLUSIONS

Both nonobese to obese, obese to nonobese, and stable obese from young to middle adulthood were associated with increased risks of CVD. The findings emphasize the importance of maintaining normal weight throughout the adulthood for preventing CVD in later life.

Low BMI and weight loss aggravate COPD mortality in men, findings from a large prospective cohort: the JACC study

To clarify how low BMI and weight loss were associated with risk of chronic obstructive pulmonary disease (COPD) mortality, in a large prospective cohort of the general population across Japan, the Japan Collaborative Cohort Study, conducted between 1988 and 2009. A total of 45,837 male residents were observed for a median period of 19.1 years. Self-administered questionnaires, collecting information on BMI, weight loss since the age of 20, lifestyles, history of diseases, as well as records of COPD mortality, were analysed at 2019. During follow-up, 268 participants died from COPD. The multivariate-adjusted hazard ratio (95% confidence interval) of COPD mortality associated with a 1-SD increment of body mass index (BMI) was 0.48 (0.41–0.57), while for weight change from age of 20 (+ 2.0 kg) it was 0.63 (0.59–0.68). These associations were persistently observed after stratifications with smoking status, excluding those having airway symptoms in the baseline survey, and excluding early COPD deaths within 5, 10 and 15 years. Our study suggests that BMI and weight change since the age of 20 could be markers for COPD prognosis, indicated by risk of COPD mortality.

Weight Gain After 20 Years of Age is Associated with Unfavorable Lifestyle and Increased Prevalence of Metabolic Disorders

PURPOSE

It is unclear what kind of modifiable lifestyle factors are associated with long-time weight gain in adulthood. To clarify the lifestyle behavior related to body weight gain since the age of 20 years, we explored the lifestyle risk factor, independently associated with excessive weight gain after 20 years of age as compared to those in subjects with a stable weight, with matching of age, gender, and the current body mass index (BMI).

PATIENTS AND METHODS

From baseline data of a general population-based cohort study, we designed a cross-sectional analysis collecting individual data of medical health check-ups and a questionnaire related to lifestyle, including amount of sleep, frequency of eating breakfast, average times per day engaged in walking and sitting in the prior year, and smoking habits. These data were compared between the subjects with weight gain ≥10kg (n=3601) and <10kg (n=3601) after age 20, matched by a propensity score model which included current BMI, age and gender. We used multivariable logistic regressions to assess the lifestyle factor's association with high weight gain.

RESULTS

Participants who gained ≥10 kg were significantly more likely to sleep <5 hours or ≥9 hours per night, skip breakfast, engage in walking <1 hour per day, and sit ≥5 hours per day than those who gained <10kg. Multivariable logistic regressions analyses showed that, with adjusting for potential confounder, the lifestyles with the positive association with high weight gain were skipping breakfast (OR 1.252; 95% CI 1.053-1.489, vs regularly), long sleeping duration (9 hours/day≤ OR 1.613; 95% CI 1.018-2.557 vs 5≤-<7 hours/day), and former smoker (OR 1.163; 95% CI 1.008-1.343 vs never smoker), while walking duration was negatively associated with high weight gain. Furthermore, despite similar current BMI, participants with weight gain ≥10kg had significantly higher values for waist circumference, blood pressure, HbA1c, LDL-C, triglycerides, and hepatic enzyme levels than those with weight gain <10kg. Similarly, the prevalence rates of hypertension, dyslipidemia, metabolic syndrome (MetS), and former smoker were higher in the participants with weight gain ≥10kg.

CONCLUSION

Major weight gain after 20 years of age was associated with unfavorable lifestyle factors and greater waist circumference, possibly leading to elevated risk for MetS and other non-communicable diseases. These findings highlight the importance of maintaining both weight at age 20 and a favorable lifestyle throughout adulthood.

Long-term Body Weight Gain After Maturity is Associated With the Incidence of Chronic Kidney Disease (CKD), Independent of Current Body Weight, in Middle-aged and Older Men

BACKGROUND

This study investigated the relationship between long-term body weight gain after maturity and the incidence of chronic kidney disease (CKD).

METHODS

The participants were 303 men without a history of cardiovascular and cerebrovascular diseases, kidney dysfunction, or dialysis treatment. Their body weight gain after maturity was examined using a standardized self-administered questionnaire. The participants were divided into two groups based on the presence/absence of a body weight gain of ≥10 kg since 20 years of age.

RESULTS

After a 6-year follow-up, the cumulative incidence of CKD was significantly higher in participants with a body weight gain of ≥10 kg than in participants without body weight a body weight gain of ≥10 kg since 20 years of age (log-rank test: P = 0.041). After adjusting for the age, body mass index, estimated glomerular filtration rate levels, smoking and drinking habits, and the presence of hypertension, dyslipidemia, and hyperglycemia at baseline, the normal body weight participants with a body weight gain of ≥10 kg since 20 years of age was significantly related to the incidence of CKD (hazard ratio 2.47; 95% confidence of interval, 1.02-6.01, P = 0.045).

CONCLUSIONS

These results suggest that long-term body weight gain after maturity in normal body weight participants may be associated with the incidence of CKD, independent of current body weight.

Association of night eating habits with metabolic syndrome and its components: a longitudinal study

Background

Night time eating is a risk factor for metabolic syndrome and obesity. The aim of this study was to investigate whether dinner immediately before bed, snacks after dinner, or combinations of both were associated with metabolic syndrome and its components in a large Japanese cohort.

Methods

We enrolled 8153 adults aged 40–54 years who participated in specific medical checkups in an Okayama facility from 2009 to 2010 and from 2013 to 2014. Age-adjusted and multivariable-adjusted odds ratios of metabolic syndrome and its components in participants with both night eating habits for an average of 3.9 years were evaluated. The relative excess risk due to interaction (RERI) was utilized to determine the supra-additive interaction of both eating habits on metabolic syndrome and its components.

Results

The multivariable-adjusted odds ratio for obesity for those with both eating habits compared to those with neither habit was 2.11 (95% confidence interval [CI], 1.42–3.15) for men and 3.02 (95%CI, 1.72–5.29) for women. Both habits had a supra-additive interaction effect on obesity development in women (RERI, 1.67; RERI%, 85.0; p = 0.058), although this result was not significant. In women, there was an association between eating habits at night and metabolic syndrome, but in men it was unrelated. Both night eating habits were associated with dyslipidemia in men and women.

Conclusions

These findings suggest the need for intervention and awareness among individuals with night eating habits to mitigate further complications.

Body mass index, abdominal fatness, and the risk of sudden cardiac death: a systematic review and dose-response meta-analysis of prospective studies

Although overweight and obesity are established risk factors for some types of heart disease including ischemic heart disease, heart failure and atrial fibrillation, less is known about the association between adiposity and sudden cardiac death. We conducted a systematic review and meta-analysis of prospective studies to clarify the association between adiposity and risk of sudden cardiac death. PubMed and Embase databases were searched up to July 20th 2017. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random effects models. The summary RR was 1.16 (95% CI 1.05-1.28, I2 = 68%, n = 14) per 5 unit increment in BMI, and 1.82 (95% CI 1.61-2.07, I2 = 0%, n = 3) per 0.1 unit increase in waist-to-hip ratio, and 1.03 (95% CI 0.93-1.15, I2 = 0%, n = 2) per 10 cm increase in waist circumference. The heterogeneity in the analysis of BMI and sudden cardiac death persisted across most subgroup analyses. The association was stronger among studies with longer follow-up compared to short follow-up and was observed in the European and American studies, but not in the Asian studies. There was a J-shaped association between BMI and sudden cardiac death and the lowest risk was observed in the normal weight range, however, the increased risk with a low BMI was attenuated among studies with a longer duration of follow-up. This meta-analysis suggest an increased risk of sudden cardiac death with increasing BMI and waist-to-hip ratio, however, further studies with stratification for smoking status are needed of waist circumference, weight changes and adiposity at younger ages.

Men who were thin during early adulthood exhibited greater weight gain-associated visceral fat accumulation in a study of middle-aged Japanese men

OBJECTIVE

This study aimed to assess the relationship between weight gain from early adulthood and visceral fat accumulation.

METHODS

The participants were 549 men aged 42 to 64 years who were randomly selected from the local resident registry for the National Institute for Longevity Sciences' neighbourhood. They were asked to recall their weight at 18 years of age, and then, post-18 weight-change values were calculated for each participant (their current weight minus their weight at 18). The participants were divided according to their median body mass index (BMI) at 18 years of age (initial BMI) (<20.14 and ≥20.14 kg m-2). Visceral fat area (VFA) and subcutaneous fat area (SFA) were measured on computed tomography scans.

RESULTS

The participants with initial BMI of <20.14 kg m-2 exhibited greater post-18 weight changes than those with initial BMI of ≥20.14 kg m-2. The participants' post-18 weight-change values were negatively correlated with their initial BMI and positively correlated with both VFA and SFA. The slope of the regression line for the relationship between post-18 weight change and VFA was steeper in the participants with initial BMI of <20.14 kg m-2 (β = 4.36) than in those with initial BMI of ≥20.14 kg m-2 (β = 3.23).

CONCLUSIONS

Visceral fat accumulation is affected not only by an individual's post-18 weight gain but also by their initial BMI. Men who were thin in early adulthood experienced greater weight gain-associated VFA increases, but the same was not true for SFA.

Weight gain since age of 20 as risk of metabolic syndrome even in non-overweight individuals

PURPOSE

Metabolic syndrome (MetS), regardless of the presence of obesity, is known as a risk of diabetes and cardiovascular disease. Weight gain after age 20 reported to be associated with these diseases. Impact of the difference between the body mass index (BMI) at examination and BMI at age 20 (ΔBMI_exa-20y) on MetS, especially in non-overweight individuals, remains to be elucidated.

METHODS

We analyzed the data of 24,363 individuals (14,301 men and 10,062 women) in this cross-sectional study. The diagnosis of MetS was diagnosed when three or more of the following criteria were present: hypertension, hyperglycemia, hypertriglyceridemia, low HDL-cholesterol level, and abdominal obesity. Logistic regression was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) adjusting for age, alcohol, smoking, exercise, and BMI at examination.

RESULTS

Compared to the lowest ΔBMI_exa-20y tertile (ΔBMI_exa-20y < 1.2 kg/m² in men and ≤0 kg/m² in women), the highest tertile (ΔBMI_exa-20y ≥ 3.2 kg/m² in men and ≥2.0 kg/m² in women) was associated with the risk of the presence of MetS (multivariate OR = 1.80, 95%CI 1.53-2.11, p < 0.001 in men and OR = 3.27, 95%CI 2.22-4.96, p < 0.001 in women). This result was also applicable in non-overweight individuals (multivariate OR = 2.06, 95%CI 1.46-2.92, p < 0.001 in men and OR = 2.49, 95%CI 1.40-4.64, p < 0.001 in women).

CONCLUSIONS

Our analyses showed that ΔBMI_exa-20y is associated with the risk of the presence of MetS, even in non-overweight individuals. It is thus important to check weight changes from early adulthood, even in non-overweight individuals.

Atherosclerotic Cardiovascular Risk in Japan

Increased global mortality is associated with atherosclerosis, which appears to be independent of race. Cardiovascular disease is one of the leading causes of mortality and morbidity in Japan. Atherosclerosis, an inflammatory disease characterized by abnormal lipid accumulation and inflammation in the arterial wall, is the main underlying cause of cardiovascular disease. Numerous cardiovascular risk scores have been developed and are used to prioritize patients' treatment needs. The predictive performance of risk scores established in Western nations needs to be examined in Japanese populations. For secondary prevention, it is imperative to control hypertension, hyperlipidemia, diabetes mellitus, smoking, and local interventions. In this review, we present a historical overview of atherosclerotic risk research and the risk factors for atherosclerosis in Japan and compare the situation in Japan with that in Western nations. In addition, we discuss relevant cardiovascular risk assessment tools in the context of clinical practice in Japan.

Relationship between 8-year weight change, body size, and health in a large cohort of adults in Thailand

Background

Overweight and obesity have been shown to be risk factors for a range of non-communicable diseases, especially cardio-metabolic conditions, worldwide. But less is known about the effects of weight change on adults' overall health and wellbeing, particularly in transitional low- and middle-income countries. This study aimed to assess the relationship between 8-year weight change and measures of self-assessed health among Thai adults.

Methods

Data were collected from Thai adults aged 25–40 years (n = 27,003) enrolled in the Thai cohort Study and surveyed in 2005, 2009, and 2013. We used self-reported weight and height measurements at baseline and 2013, as well as three standard health questions regarding overall health, energy, and emotion asked at the two time points, to investigate the effects of weight change on health.

Results

Between 2005 and 2013, 6.0% of participants lost more than 5% of their baseline weight; 38.5% were stable (<5% loss to 5% gain); 23.0% slightly gained weight (>5%–10%); 22.8% gained moderate weight (>10%–20%); and 9.4% had heavy weight gain (>20%). Moderate (>10%–20%) and heavy weight gain (>20%) were both associated with an increased risk of reporting ‘poor or very poor‘ overall health in 2013 among participants who had a normal body mass index (BMI) (adjusted odds ratio [AOR] 1.39; 95% confidence interval [CI], 1.13–1.71 and AOR 1.44; 95% CI, 1.09–1.90, respectively), were overweight (AOR 1.53; 955 CI, 1.01–2.29 and AOR 1.82; 95% CI, 1.04–3.19, respectively) or had obesity (AOR 2.47; 95% CI, 1.74–3.51 and AOR 3.20; 95% CI, 2.00–5.16, respectively) in 2005. Weight gain of over 20% also had a negative impact on energy level among cohort members with a normal BMI in 2005 (AOR 1.36; 95% CI, 1.11–1.65) and among participants with obesity in 2005 (AOR 1.93; 95% CI, 1.38–2.71). For those who were underweight, had a normal BMI, or had obesity at baseline, weight loss of more than 5% was associated with reporting emotional problems. Excessive weight gain adversely impacted participants who were underweight or had obesity at baseline.

Conclusion

Our study found that weight change, in particular weight gain, was associated with negative health outcomes, and this effect appeared to increase at higher levels of body size. The present findings may be useful to promote weight maintenance and healthy lifestyles.

•

This study investigated 8-year weight change and overall health among Thai adults.

•

Weight gain was associated with poor emotional well-being and lower levels of energy.

•

Findings highlight the importance of monitoring weight change and health effects.

BMI history and risk of incident fatty liver: a population-based large-scale cohort study

BACKGROUND AND AIMS

Most physicians might consider that fatty liver would develop along with increasing body weight; however, an association between BMI history and incident fatty liver has not been clarified as yet.

METHODS

We carried out a population-based cohort study that included 4427 healthy Japanese individuals who received yearly health-checkup programs over a decade. Fatty liver was diagnosed using ultrasonography.

RESULTS

During the observational period, 38.7% (case/N=1002/2588) of men and 17.3% (319/1847) of women were diagnosed with fatty liver. Among these, only 18.9% (189 of 1002 participants) of men and 18.5% (59 of 319) of women developed fatty liver when they reached the lifetime maximum BMI. Adjusted odds ratio of the difference between lifetime maximum BMI and BMI at age 20 years (ΔBMImax-20 years) for incident fatty liver was 1.33 [95% confidence interval (CI) 1.28-1.39, P<0.001] in men or 1.40 (95% CI 1.33-1.49, P<0.001) in women. According to receiver operator characteristic (ROC) analysis, the optimal cut-off points of ΔBMImax-20 years for incident fatty liver were 4.82 kg/m [area under ROC curve 0.70 (95% CI 0.68-0.72), P<0.001] in men and 4.11 kg/m [area under ROC curve 0.76 (95% CI 0.73-0.79), P<0.001] in women.

CONCLUSION

The ΔBMImax-20 years was associated with an increased risk of incident fatty liver. In addition, more patients developed fatty liver not at the maximum point of BMI history, but after that. Therefore, it is useful to check ΔBMImax-20 years and to continue observing the individuals for detection of fatty liver.

Maximum BMI and microvascular complications in a cohort of Japanese patients with type 2 diabetes: the Japan Diabetes Complications Study

AIMS

The aim of this study was to examine the associations between possible indices of obesity based on information on weight history and the incidence of microvascular complications.

METHODS

A cohort of individuals with type 2 diabetes from 59 institutes in Japan was followed for 8years. Patients were classified into three categories according to weight at entrance and past maximum weight: normal (BMI at baseline <25kg/m(2) and maximum BMI <25kg/m(2)), past obesity (BMI at baseline <25kg/m(2) and maximum BMI ≥25kg/m(2)), and current obesity (BMI at baseline ≥25kg/m(2)) groups. The outcomes were diabetic retinopathy and overt nephropathy.

RESULTS

BMI at maximum and baseline of the 1809 patients was 26.5±3.5 and 23.1±3.0kg/m(2) (p<0.01), respectively (23.0±1.6 and 20.6±1.9kg/m(2) for normal, 27.4±2.0 and 22.8±1.4kg/m(2) for past obesity, and 30.1±2.9 and 27.0±1.8kg/m(2) for current obesity). The hazard ratios of past and current obesity compared to normal were 1.92 (95% CI, 1.08-3.41; p=0.03) and 2.21 (1.16-4.22; p=0.02), respectively, for overt nephropathy and 1.38 (1.05-1.83; p=0.02) and 1.64 (1.18-2.28; p<0.01), respectively, for diabetic retinopathy after adjustment for confounders.

CONCLUSIONS

Past obesity as well as current obesity were associated with increased risks of microvascular complications. Further identification of high-risk populations may be possible by classifying normal weight patients by past obesity.

The impact of body weight gain on nonalcoholic fatty liver disease and metabolic syndrome during earlier and later adulthood

AIM

Body weight gain adds risk for metabolic disorders and there are different metabolic changes in earlier and later adulthood. However, its impact on non-alcoholic fatty liver disease (NAFLD) was indeterminate. The aim of current study was to evaluate the impact of body weight gain on NAFLD and metabolic syndrome (MetS) during overall, earlier (25-40y) and later (over 40y) adulthood.

METHODS

1119 subjects were selected to calculate changes in body weight (ΔBW), body mass index (BMI) (ΔBMI) and bodyweight per year (ΔBW/y) to analysis their impact on NAFLD and MetS in multi-variable regression models, and explored the potential mediators that associated ΔBMI with NAFLD by mediation analysis.

RESULTS

ΔBMI, ΔBW and ΔBW/y in whole adulthood were all positively associated with NAFLD and MetS. Body weight gain during earlier adulthood was more strongly associated with NAFLD than those during later adulthood. In NAFLD, the ORs of ΔBMI (third trisection), ΔBW and ΔBW/y were 3.86 (2.25, 6.57), 1.05 (1.02, 1.09) and 2.05 (1.29, 3.24) during earlier adulthood, and 1.47 (1.09, 2.02), 1.02 (1.00, 1.06), and 1.04 (.99, 1.13) over 40y. Insulin and HOMA-IR were important intermediates that associated ΔBMI with NAFLD. ΔBMI in earlier adulthood increased higher insulin and insulin resistance (IR) than later adulthood.

CONCLUSIONS

Body weight gain in adulthood was positively associated with NAFLD and MetS, and the association was stronger in earlier than later adulthood. Insulin and IR were important mediators that contributed to the association.

The sex-specific association between BMI and coronary heart disease: a systematic review and meta-analysis of 95 cohorts with 1·2 million participants

BACKGROUND

The risk of developing coronary heart disease differs by sex, and accumulating evidence suggests that sex differences exist in the effect of coronary risk factors on vascular risk. So far, the existence of a sex difference in the association between BMI and coronary heart disease has not been systematically studied. Since sexual dimorphisms in body composition exist, we postulated that the association between BMI and coronary heart disease would differ between women and men.

METHODS

We did systematic searches of PubMed and Embase up to Feb 20, 2015, for studies of the longitudinal association between BMI and coronary heart disease in women and men from population-based cohorts. We excluded studies if they contained duplicate data from the same study, reported estimates only for Z scores or percentiles of BMI, did not report estimate uncertainty, did not report sex-specific estimates, recruited mainly individuals with a previous history of cardiovascular disease or from within selected populations, and those for which the full text was not available in English. We also included individual participant data from four large studies. Study results were pooled using random-effect models with inverse variance weighting. Our predefined primary endpoint was the pooled women-to-men ratio of the age-adjusted hazard ratios (HRs), or equivalent, relating (continuous and categorical) BMI to coronary heart disease.

FINDINGS

We reviewed a total of 8561 original entries twice for inclusion in the analysis, of which 32 published studies were eligible for inclusion. Data from 95 cohorts, 1,219,187 participants, and 37,488 incident cases of coronary heart disease were included. Higher BMI was significantly associated with age-adjusted coronary heart disease: for a one-unit (kg/m(2)) increment in BMI; the HR was 1·04 (95% CI 1·03-1·05) in women and 1·05 (1·04-1·07) in men. Compared with people of a normal weight, the age-adjusted HR of coronary heart disease for the underweight group was 1·25 (1·05-1·49) in women and 1·09 (0·91-1·23) in men; for the overweight group 1·20 (1·12-1·29) in women and 1·22 (1·12-1·32) in men; and for the obese group 1·61 (1·42-1·82) in women and 1·60 (1·43-1·79) in men. Overall, these associations did not differ between the sexes. The women-to-men ratios of the HRs were 0·99 (95% CI 0·98-1·00) for a one-unit increment in BMI, 1·10 (0·91-1·32) for the underweight group, 0·99 (0·92-1·07) for the overweight group, and 1·06 (0·95-1·17) for the obese group, relative to the normal weight group. Similar results were obtained after multiple adjustment and in a range of sensitivity analyses.

INTERPRETATION

Increased BMI, measured either continuously or categorically, has the same deleterious effects on the risk of coronary heart disease in women and men across diverse populations.

FUNDING

None.

Association of weight gain since age 20 with non-alcoholic fatty liver disease in normal weight individuals

BACKGROUND AND AIMS

Interventions for lifestyle diseases including non-alcoholic fatty liver disease (NAFLD) have focused on overweight and obese populations. The impact of adult weight gain on NAFLD development among normal weight individuals remains unclear.

METHODS

In this cross-sectional study, we collected data from participants presenting to a health check-up program. Ultrasound-diagnosed NAFLD prevalence was examined over 1-kg increments of weight change since age 20. Relative risks were calculated in men and women stratified by current weight (normal, overweight, and obese). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusting for potential confounders.

RESULTS

Among 21 496 participants, 3498 cases of NAFLD (16.3%) were observed. Prevalence of NAFLD increased with weight gain since age 20; among the 10.1-11.0 kg weight gain group, 41.6% of men and 24.8% of women had NAFLD. Multivariate analysis by quartiles showed that weight change was significantly associated with NAFLD risk in men and women. Risk of NAFLD associated with weight change (10-kg increments) was significantly higher in normal weight individuals (men: OR 7.53, 95% CI: 4.99-11.36, women: OR 12.20, 95% CI: 7.45-19.98) than overweight (men: OR 1.61, 95% CI: 0.91-2.85, women: OR 2.90, 95% CI: 0.99-8.54) and obese (men: OR 4.0, 95% CI: 2.97-5.39, women: OR 2.68, 95% CI: 2.00-3.60).

CONCLUSIONS

NAFLD is robustly associated with weight change since age 20. This effect appears particularly strong in individuals at normal weight, suggesting an important role for early and longitudinal weight monitoring, even among healthy individuals at normal weight.

Improvement in endothelial function by lifestyle modification focused on exercise training is associated with insulin resistance in obese patients

A new method to evaluate endothelial function, namely, reactive hyperemia peripheral arterial tonometry (RH-PAT), has been developed. RH-PAT is an index of endothelial function, indicating initial atherosclerotic lesions. The present study aimed to investigate the effect of lifestyle modification with a focus on exercise training on RH-PAT in obese patients. We studied 43 obese patients (body mass index ≥ 30). RH-PAT was measured, and the RH-PAT index was calculated as a ratio of the digital pulse volume during reactive hyperemia divided by that at baseline. Further, we assessed body composition, arterial stiffness, insulin resistance, adipocytokine levels, and exercise tolerance. The exercise program consisted of 30 min on a cycle ergometer or treadmill, 3 times per week for 6 months. Training intensity was adjusted to the anaerobic threshold. Significant improvements were observed in the RH-PAT index following exercise training. We noted a significant reduction in weight, body fat percentage, and leptin values, and a significant increase in adiponectin levels and exercise tolerance. An abnormal baseline RH-PAT index was observed in 24 patients (55.8%); however, the improvement rate was higher in these patients than in patients with normal RH-PAT index values. Stepwise multiple regression analysis revealed that changes in insulin resistance (Δ”HOMA-IR) were independently correlated with changes in the RH-PAT index. Our results indicate that lifestyle modification with a focus on exercise training improved the RH-PAT index in obese patients. Patients with abnormal RH-PAT index values before lifestyle modification with exercise training demonstrated a high rate of improvement following exercise. Further, our results suggest that insulin resistance was the only independent factor influencing improvement in endothelial function.

Overweight in early adulthood, adult weight change, and risk of type 2 diabetes, cardiovascular diseases, and certain cancers in men: a cohort study

The relative importance of overweight after childhood and excess weight gain during adulthood remains unclear. In 39,909 male participants of the Health Professionals Follow-Up Study who were 40-75 years of age in 1986 and were followed until 2008, we documented 8,755 incident cases of obesity-related chronic diseases (type 2 diabetes mellitus, cardiovascular diseases, and colorectal, renal, pancreatic, and esophageal cancers). We calculated composite and cause-specific hazard ratios using a model that included body mass index (BMI; weight (kg)/height (m)(2)) at 21 years of age, weight change since age 21 years, smoking, alcohol consumption, and family histories of myocardial infarction, colon cancer, and diabetes. Compared with a BMI at 21 years of 18.5-22.9, the composite hazard ratio for a BMI of 23-24.9 was 1.22 (95% confidence interval (CI): 1.16, 1.29), that for a BMI of 25.0-27.4 was 1.57 (95% CI: 1.48, 1.67), that for a BMI of 27.5-29.9 was 2.40 (95% CI: 2.17, 2.65), and that for a BMI ≥30.0 was 3.15 (95% CI: 2.76, 3.60). The composite hazard ratios for adult weight gain compared with a stable weight were 1.12 (95% CI: 1.03, 1.22) for a gain of 2.5-4.9 kg, 1.41 (95% CI: 1.31, 1.52) for a gain of 5-9.9 kg, 1.72 (95% CI: 1.59, 1.86) for a gain of 10-14.9 kg, and 2.45 (95% CI: 2.27, 2.63) for a gain ≥15 kg. Adiposity in early adulthood and adult weight gain were both associated with marked increases in the risk of major chronic diseases in middle-aged and older men, and these associations were already apparent at modest levels of overweight and weight gain.

Association between body mass index and cardiovascular disease mortality in east Asians and south Asians: pooled analysis of prospective data from the Asia Cohort Consortium

OBJECTIVE

To evaluate the association between body mass index and mortality from overall cardiovascular disease and specific subtypes of cardiovascular disease in east and south Asians.

DESIGN

Pooled analyses of 20 prospective cohorts in Asia, including data from 835,082 east Asians and 289,815 south Asians. Cohorts were identified through a systematic search of the literature in early 2008, followed by a survey that was sent to each cohort to assess data availability.

SETTING

General populations in east Asia (China, Taiwan, Singapore, Japan, and Korea) and south Asia (India and Bangladesh).

PARTICIPANTS

1,124,897 men and women (mean age 53.4 years at baseline).

MAIN OUTCOME MEASURES

Risk of death from overall cardiovascular disease, coronary heart disease, stroke, and (in east Asians only) stroke subtypes.

RESULTS

49,184 cardiovascular deaths (40,791 in east Asians and 8393 in south Asians) were identified during a mean follow-up of 9.7 years. East Asians with a body mass index of 25 or above had a raised risk of death from overall cardiovascular disease, compared with the reference range of body mass index (values 22.5-24.9; hazard ratio 1.09 (95% confidence interval 1.03 to 1.15), 1.27 (1.20 to 1.35), 1.59 (1.43 to 1.76), 1.74 (1.47 to 2.06), and 1.97 (1.44 to 2.71) for body mass index ranges 25.0-27.4, 27.5-29.9, 30.0-32.4, 32.5-34.9, and 35.0-50.0, respectively). This association was similar for risk of death from coronary heart disease and ischaemic stroke; for haemorrhagic stroke, the risk of death was higher at body mass index values of 27.5 and above. Elevated risk of death from cardiovascular disease was also observed at lower categories of body mass index (hazard ratio 1.19 (95% confidence interval 1.02 to 1.39) and 2.16 (1.37 to 3.40) for body mass index ranges 15.0-17.4 and <15.0, respectively), compared with the reference range. In south Asians, the association between body mass index and mortality from cardiovascular disease was less pronounced than that in east Asians. South Asians had an increased risk of death observed for coronary heart disease only in individuals with a body mass index greater than 35 (hazard ratio 1.90, 95% confidence interval 1.15 to 3.12).

CONCLUSIONS

Body mass index shows a U shaped association with death from overall cardiovascular disease among east Asians: increased risk of death from cardiovascular disease is observed at lower and higher ranges of body mass index. A high body mass index is a risk factor for mortality from overall cardiovascular disease and for specific diseases, including coronary heart disease, ischaemic stroke, and haemorrhagic stroke in east Asians. Higher body mass index is a weak risk factor for mortality from cardiovascular disease in south Asians.

Long- and short-term weight change and incident coronary heart disease and ischemic stroke: the Atherosclerosis Risk in Communities Study

Weight gain increases the prevalence of obesity, a risk factor for cardiovascular disease. Nevertheless, unintentional weight loss can be a harbinger of health problems. The Atherosclerosis Risk in Communities Study (1987-2009) included 15,792 US adults aged 45-64 years at baseline and was used to compare associations of long-term (30 years) and short-term (3 years) weight change with the risks of coronary heart disease (CHD) and ischemic stroke. Age-, gender-, and race-standardized incidence rates were 4.9 (95% confidence interval (CI): 4.6, 5.2) per 1,000 person-years for CHD and 2.5 (95% CI: 2.3, 2.8) per 1,000 person-years for stroke. After controlling for baseline body mass index and other covariates, long-term weight gain (since age 25 years) of more than 2.7% was associated with elevated CHD risk, and any long-term weight gain was associated with increased stroke risk. Among middle-aged adults, short-term (3-year) weight loss of more than 3% was associated with elevated immediate CHD risk (hazard ratio = 1.46, 95% CI: 1.18, 1.81) and stroke risk (hazard ratio = 1.45, 95% CI: 1.10, 1.92). Risk tended to be larger in adults whose weight loss did not occur through dieting. Avoidance of weight gain between early and middle adulthood can reduce risks of CHD and stroke, but short-term, unintentional weight loss in middle adulthood may be an indicator of immediate elevated risk that has not previously been well recognized.

Prospective study on waist circumference and risk of all-cause and cardiovascular mortality: pooled analysis of Japanese community-based studies

BACKGROUND

The aim of the present study was to clarify the association between waist circumference and all-cause and cardiovascular disease (CVD) mortality risk in relatively lean Japanese subjects.

METHODS AND RESULTS

A total of 3,554 men and 4,472 women who had no history of CVD were examined and their waist circumference measured at baseline. The subjects were aged ≥40 years and were obtained from 3 prospective cohort studies during 1988-1996. Hazard ratios for all-cause and CVD mortality were analyzed over a follow-up period of 14.7 years using a Cox proportional hazards model and penalized spline method, after adjustment for study cohort, age, smoking, alcohol drinking, hypertension, dyslipidemia, and diabetes. Compared with the lowest quintile, the highest quintile of waist circumference in men was associated with a linear reduction in all-cause mortality risk (multivariate-adjusted hazard ratio, 0.73; 95% confidence interval: 0.60-0.89; P for trend=0.001). CVD mortality risk was increased in men aged ≤65 years with a higher waist circumference. This relationship was U-shaped. Waist circumference was not associated with all-cause or CVD mortality risk in women.

CONCLUSIONS

Waist circumference was associated inversely with increased risk of all-cause death in men, but not in women. Middle-aged men with a greater waist circumference potentially have an increased risk of CVD mortality.

Weight gain after 20 years of age is associated with prevalence of chronic kidney disease

BACKGROUND

Weight gain after maturity is a risk factor for diabetes, coronary heart disease, and stroke, even in individuals with a normal body mass index; however, there is little information about the influence of weight gain after maturity on chronic kidney disease (CKD). Therefore, we examined the association between weight gain after 20 years of age and the prevalence of CKD.

METHODS

A cross-sectional study was performed on 28,151 women and 21,110 men aged between 40 and 59 years who participated in the specific health check and guidance system of Japan in 2008. We compared prevalence of CKD between participants with and without weight gain of at least 10 kg after 20 years of age. Multivariate logistic regression models and stratified analyses were used to adjust for possible confounding factors.

RESULTS

The prevalence of CKD among participants with weight gain was significantly higher than among those without weight gain both in women (11.8 vs 8.3%, p < 0.0001) and in men (12.2 vs 9.2%, p < 0.0001). After adjustment for age, smoking, regular exercise, alcohol intake, history of kidney disease, hypertension, diabetes, and hypercholesterolemia, the odds ratio (95% confidence interval) for CKD was 1.24 (1.14-1.36) in women and 1.15 (1.05-1.26) in men with weight gain of at least 10 kg after the age of 20 years. Even in participants without metabolic syndrome, weight gain was independently associated with CKD in both genders.

CONCLUSIONS

Weight gain after 20 years of age is associated with CKD among Japanese, even those without metabolic syndrome.

Body mass index and mortality from all causes and major causes in Japanese: results of a pooled analysis of 7 large-scale cohort studies

BACKGROUND

We pooled data from 7 ongoing cohorts in Japan involving 353 422 adults (162 092 men and 191 330 women) to quantify the effect of body mass index (BMI) on total and cause-specific (cancer, heart disease, and cerebrovascular disease) mortality and identify optimal BMI ranges for middle-aged and elderly Japanese.

METHODS

During a mean follow-up of 12.5 years, 41 260 deaths occurred. The Cox proportional hazards model was used to estimate hazard ratios (HRs) for each BMI category, after controlling for age, area of residence, smoking, drinking, history of hypertension, diabetes, and physical activity in each study. A random-effects model was used to obtain summary measures.

RESULTS

A reverse-J pattern was seen for all-cause and cancer mortality (elevated risk only for high BMI in women) and a U- or J-shaped association was seen for heart disease and cerebrovascular disease mortality. For total mortality, as compared with a BMI of 23 to 25, the HR was 1.78 for 14 to 19, 1.27 for 19 to 21, 1.11 for 21 to 23, and 1.36 for 30 to 40 in men, and 1.61 for 14 to 19, 1.17 for 19 to 21, 1.08 for 27 to 30, and 1.37 for 30 to 40 in women. High BMI (≥27) accounted for 0.9% and 1.5% of total mortality in men and women, respectively.

CONCLUSIONS

The lowest risk of total mortality and mortality from major causes of disease was observed for a BMI of 21 to 27 kg/m(2) in middle-aged and elderly Japanese.