Body mass index and cardiovascular disease mortality in Japan: the Ohsaki Study

Association between underweight and risk of heart failure in diabetes patients

BACKGROUND

The risk of heart failure (HF) in underweight diabetes mellitus (DM) patients has rarely been studied. We conducted a cohort study to investigate the association between underweight (BMI < 18.5 kg/m2) and BMI change over time and the risk of HF in patients with type 2 DM.

METHODS

We utilized the health screening data from the National Health Insurance Service and the Korean National Health Screening database from 2009 to 2012, with follow-up until December 2018. Participants with DM were categorized into four groups based on their BMI at 4 years before study inclusion and BMI at the study entry: (1) Always Normal Weight (BMI at 4 years ago/BMI at study entry ≥18.5/≥18.5 kg/m2, reference group); (2) Transitioned to Underweight (≥18.5/<18.5 kg/m2); (3) Transitioned to Normal Weight (<18.5/≥18.5 kg/m2) and (4) Always Underweight (<18.5/<18.5 kg/m2). Participants were followed until the development of HF or at the end of the follow-up. Initial screening data included participants with DM who had the health screening during the study period (n = 2,746,079). Participants aged <20 years (n = 390), those who did not undergo health examination 4 years prior (n = 1,306,520), and those with missing data (n = 77,410) were excluded. Participants diagnosed with HF before study participation (n = 81,645) and within 1 year of study enrolment (n = 11,731) were excluded. After applying exclusion criteria, 1,268,383 participants were finally included in the analysis. The primary outcome was the development of HF. We employed Cox proportional hazards models, adjusting for various confounding factors, to assess the risk of developing HF.

RESULTS

Median follow-up duration was 6.88 years and men were 63.16%. The mean ages of each groups were as follows: Always Normal Weight (57.92 ± 11.64 years), Transitioned to Underweight (62 ± 13.5 years), Transitioned to Normal Weight (56.6 ± 15.29 years) and Always Underweight (57.76 ± 15.35 years). In comparison with the Always Normal Weight group (n = 1,245,381, HF = 76,360), Transitioned to Underweight group (≥18.5/<18.5 kg/m2, n = 9304, HF = 880, adjusted Hazard Ratio (aHR)1.389, 95% confidence interval (CI) 1.3-1.485) or Transitioned to Normal Weight (<18.5/≥18.5 kg/m2, n = 6024, HF = 478, aHR 1.385, 95% CI 1.266-1.515) exhibited an increased risk of HF. The highest risk was observed in the Always Underweight group (<18.5/<18.5 kg/m2, n = 7674, HF = 665, aHR 1.612, 95% CI 1.493-1.740).

CONCLUSIONS

Underweight was significantly associated with the risk of HF in the DM population. Active surveillance for HF in an underweight DM population is needed.

Obesity paradox and stroke outcomes according to stroke subtype: a propensity score-matched analysis

OBJECTIVE

Obesity has traditionally been considered a risk factor for ischemic stroke. However, some clinical observations have reported a complex relationship between patients who are overweight or obese with paradoxically better stroke outcomes. Stroke subtypes have differing distributions of risk factors, so this study aimed to explain the relationship between body mass index (BMI) and functional prognosis according to stroke subtype.

METHODS

A prospective institutional database on stroke was accessed between March 2014 and December 2021, and consecutive patients with ischemic stroke were retrospectively selected. BMI was categorized into five groups (underweight, normal weight, overweight, obese, and morbid obesity). The outcome of interest in this study was the modified Rankin Scale (mRS) at 90 d, which was divided into favorable (mRS = 0-2) and unfavorable (mRS ≥ 3) groups. The relationship between functional outcome and BMI was analyzed according to stroke subtype.

RESULTS

Among 2779 patients with stroke, 913 (32.9%) had unfavorable outcomes. After a propensity score-matched analysis, obesity was inversely associated with unfavorable outcomes (adjusted odds ratio [aOR] = 0.61, 95% confidence interval [95% CI]: 0.46-0.80) in all patients with stroke. Among the stroke subtypes, overweight (aOR = 0.38, 95% CI: 0.20-0.74) and obese (aOR = 0.40, 95% CI: 0.21-0.76) groups were inversely associated with unfavorable outcomes in the cardioembolism subtype. Obesity (aOR = 0.55, 95% CI: 0.32-0.95) was inversely associated with unfavorable outcomes in the small vessel disease subtype. There was no significant relationship between stroke outcome and BMI classification in the large artery disease subtype.

CONCLUSIONS

These findings suggest that the obesity paradox in ischemic stroke outcomes might differ according to the stroke subtype.

The Obesity Paradox in Real-World Nation-Wide Cohort of Patients Admitted for a Stroke in the U.S

Background: Obesity has been associated with increased incidence and severity of various cardiovascular risk factors and increased risk for stroke. However, the evidence of its effect on outcomes in stroke victims have been equivocal. We aimed to investigate the distribution of BMI in a nation-wide cohort of individuals, admitted for a stroke, and the relationship between BMI and in-hospital mortality. Methods: Data from the U.S. National Inpatient Sample (NIS) was collected, to identify hospitalizations for stroke, between October 2015 and December 2016. The patients were sub-divided into six groups based on their BMI: underweight, normal weight, overweight, obese I, obese II and extremely obese groups. Various sociodemographic and clinical parameters were gathered, and incidence of mortality and the length of hospital stay were analyzed. Multivariable analysis was performed to identify independent predictors of in-hospital mortality. Results: A weighted total of 84,185 hospitalizations for stroke were included in the analysis. The approximate mean patients aged was 65.5 ± 31 years, the majority being female (55.3%) and white (63.1%). The overall in-hospital mortality during the study period was 3.6%. A reverse J-shaped relationship between the body mass index and in-hospital mortality was documented, while patients with elevated BMI showed significantly lower in-hospital mortality compared to the underweight and normal weight study participants, 2.8% vs. 7.4%, respectively, p < 0.001. Age and several comorbidities, as well as the Deyo Comorbidity Index, were found to predict mortality in a multivariable analysis. Conclusion: A reverse J-shaped relationship between body mass index and in-hospital mortality was documented in patients admitted for a stroke in the U.S. during the study period. The above findings support the existence of an “obesity paradox” in patients hospitalized following a stroke, similar to that described in other cardiovascular conditions.

The Lifelong Health Support 10: a Japanese prescription for a long and healthy life

BACKGROUND

Although the age-adjusted incidence and mortality of cancer and cardiovascular disease (CVD) have been decreasing steadily in Japan, both diseases remain major contributors to morbidity and mortality along with the aging society. Herein, we aim to provide a prescription of 10 health tips for long and healthy life named the "Lifelong Health Support 10 (LHS10)."

METHOD

The LHS10 was developed by the preventive medicine specialists at the National Cerebral and Cardiovascular Center in Suita, where it has been used for health guidance to prevent CVD, cancer, and cognitive decline in addition to their major risk factors such as hypertension, diabetes, and obesity. It consisted of the lifestyle modification recommendations of the 2014 Japanese Society of Hypertension guidelines and the 2017 Japan Atherosclerosis Society Guidelines for preventing atherosclerotic CVD. Further, it came in line with other international lifestyle modification guidelines. In this narrative review, we summarized the results of several Japanese epidemiological studies investigating the association between the LHS10 items and the risk of cancer, CVD, and other chronic diseases including dementia, diabetes, and chronic kidney disease.

RESULTS

The LHS10 included avoiding smoking and secondhand smoke exposure, engaging in physical activity, refraining from excessive alcohol drinking, reducing fried foods and sugary soft drinks, cutting salt in food, consuming more vegetables, fruits, fish, soy foods, and fibers, and maintaining proper body weight. All items of the LHS10 were shown to reduce the risk of cancer, CVD, and other chronic diseases.

CONCLUSIONS

The LHS10 can be a helpful tool for health guidance.

Insomnia with physiological hyperarousal is associated with lower weight: a novel finding and its clinical implications

Previous studies on the association of insomnia with body mass index (BMI) have been controversial. Physiological hyperarousal, the key pathological mechanism of insomnia, may be an important reason for different findings. We explored whether insomnia with physiological hyperarousal measured by the multiple sleep latency test (MSLT) is associated with body-weight differences. A total of 185 normal sleepers and 440 insomniacs were included in this study. Insomnia was defined by standard diagnostic criteria with symptoms lasting ≥6 months. All subjects underwent one night of laboratory polysomnography followed by a standard MSLT. We used the median MSLT value (i.e., ≥14 min) to define physiological hyperarousal. BMI was based on measured height (cm) and weight (kg) during the subjects' sleep laboratory visit. BMI > 25 kg/m² was defined as overweight, while BMI < 18.5 kg/m² was defined as underweight. After controlling for confounders, the odds of lower weight rather than overweight were significantly increased among insomnia patients with increased MSLT: insomnia with MSLT 14-17 min and MSLT > 17 min increased the odds of lower weight by approximately 89% (OR = 1.89, 95% CI 1.00-4.85) and 273% (OR = 3.73, 95% CI 1.51-9.22) compared with normal sleepers, respectively. In contrast, insomnia in patients with MSLT 11-14 min and 8-11 min was not different from normal sleepers in terms of body weight. Insomnia associated with physiological hyperarousal, the most severe phenotype of chronic insomnia, is associated with higher odds of lower weight and underweight compared with normal sleepers. This is a novel finding consistent with previous physiologic data and has significant clinical implications.

Caution, "normal" BMI: health risks associated with potentially masked individual underweight-EPMA Position Paper 2021

An increasing interest in a healthy lifestyle raises questions about optimal body weight. Evidently, it should be clearly discriminated between the standardised "normal" body weight and individually optimal weight. To this end, the basic principle of personalised medicine "one size does not fit all" has to be applied. Contextually, "normal" but e.g. borderline body mass index might be optimal for one person but apparently suboptimal for another one strongly depending on the individual genetic predisposition, geographic origin, cultural and nutritional habits and relevant lifestyle parameters-all included into comprehensive individual patient profile. Even if only slightly deviant, both overweight and underweight are acknowledged risk factors for a shifted metabolism which, if being not optimised, may strongly contribute to the development and progression of severe pathologies. Development of innovative screening programmes is essential to promote population health by application of health risks assessment, individualised patient profiling and multi-parametric analysis, further used for cost-effective targeted prevention and treatments tailored to the person. The following healthcare areas are considered to be potentially strongly benefiting from the above proposed measures: suboptimal health conditions, sports medicine, stress overload and associated complications, planned pregnancies, periodontal health and dentistry, sleep medicine, eye health and disorders, inflammatory disorders, healing and pain management, metabolic disorders, cardiovascular disease, cancers, psychiatric and neurologic disorders, stroke of known and unknown aetiology, improved individual and population outcomes under pandemic conditions such as COVID-19. In a long-term way, a significantly improved healthcare economy is one of benefits of the proposed paradigm shift from reactive to Predictive, Preventive and Personalised Medicine (PPPM/3PM). A tight collaboration between all stakeholders including scientific community, healthcare givers, patient organisations, policy-makers and educators is essential for the smooth implementation of 3PM concepts in daily practice.

BMI and Medically Certified Long-Term Sickness Absence Among Japanese Employees

OBJECTIVE

In contrast to the association between excess weight and sickness absence (SA), the association in relation to underweight has been under-researched. This study aimed to examine the effects of BMI at both extremes of its distribution on SA.

METHODS

Data came from the Japan Epidemiology Collaboration on Occupational Health study of 77,760 workers aged 20 to 59 years (66,166 males, 11,594 females). Information was collected on medically certified long-term SA (LTSA) (i.e., SA lasting ≥ 30 consecutive days) from April 2012 to March 2017. A sex-specific Cox proportional hazards model was used to investigate the associations.

RESULTS

Among males, both obesity (hazard ratio [HR] = 1.81, 95% CI: 1.50-2.17) and underweight (HR = 1.56, 95% CI: 1.23-1.96) were significantly associated with LTSA compared with normal weight. This U-shaped association between BMI categories and LTSA was observed both for mental and physical disorders. Among females, an elevated risk was observed among those with overweight (HR = 1.54, 95% CI: 1.16-2.05).

CONCLUSIONS

In a cohort of the Japanese working-age population, both obesity and underweight were associated with a greater risk of LTSA in males. Future research should not overlook the excess risk of LTSA associated with underweight.

Coronary artery disease and body mass index: What is the relationship?

INTRODUCTION

Nowadays, obesity is considered an independent risk factor for the development of cardiovascular diseases (CVD), which has been presented as an important cause of worldwide morbidity and mortality, especially coronary artery disease (CAD). The objective of the study was to verify the association between body mass index (BMI) and severity of CAD, its risk factors and surgical and percutaneous treatment in patients hospitalized in cardiological units.

METHODS

An ambispective, cross-sectional study was performed with patients older than 18 years attended by nutrition in the cardiology units, who underwent coronary angiography. The severity of CAD was categorized into two distinct classifications (CAD Class I and II), considering the presence of CAD as lesions ≥50% and ≥70%. The nutritional status of the patient was established based on BMI according to the World Health Organization (WHO) for the total sample and group of adults, and according to the Pan American Health Organization (PAHO) for the elderly. Age, gender, presence of associated comorbidities, history of smoking, and performed procedures were collected in patients' records. For statistical analysis Kruskal Wallis and Chi-square tests were used, and Hodges-Lehmann estimate was used for the median. Comparisons and associations were considered significant when p < 0.05.

RESULTS

A total of 703 patients were included, of which 495 had arterial lesions ≥70% and 513 patients' lesions ≥50%. The average age was 61 years, women were older (63 vs 61; p = 0.008), had a higher BMI (28.16 kg/m² vs 26.68 kg/m², p = 0.001) and were more likely to have diabetes mellitus (DM) (p < 0.001), dyslipidemia (DSLP) (p < 0.001), and hypertension (HTN) (p = 0.001). The majority of the sample consisted of men, who more often underwent percutaneous coronary intervention (PCI) (53,9% vs 39%, p < 0.001), and were more likely to present more severe CAD (p < 0.001 and p = 0.003). In patients diagnosed with CAD the increase in BMI was positively associated with the presence of DM (p < 0.001), DSLP (p < 0.001) and HTN (p < 0.001), and negatively with age (p = 0.007). Patients with obesity III, were diagnosed with CAD, in average, 11 years earlier than patients with normal BMI (p = 0.05). Therefore, the higher the BMI, the lower the age at the moment of the examination in the total sample, and in the group of elderly, and this association was not found in adults. There was no significant association of BMI with the severity of CAD, or with PCI and coronary artery bypass grafting (CABG). The greater severity of CAD was positively associated with the presence of DM (p = 0.012 and p = 0.001), HTN (p = 0.033 and p = 0.003) and older age (p = 0.005 and p = 0.015). Patients who underwent CABG had a higher incidence of and HTN (p = 0.003), DM (p = 0.006), whereas patients who had PCI had a lower incidence of HTN (p = 0.021) and DM (p = 0.004).

CONCLUSION

Obesity was showed to be as an independent risk factor for the early incidence of CAD, which is strongly associated with the presence of comorbidities such as DM, HTN and DSLP. The greater severity of CAD and coronary interventions were associated with the presence of risk factors for CAD.

A J-shaped relation of BMI and stroke: Systematic review and dose-response meta-analysis of 4.43 million participants

BACKGROUND AND AIM

Many studies have shown increased risk of stroke with greater adiposity as measured by body mass index (BMI), but questions remain about the shape of the dose-response relation. We conducted a systematic review and meta-analysis of prospective studies to clarify the strength and shape of the dose-response relation between BMI and risk of stroke.

METHODS AND RESULTS

PubMed and Embase databases were searched for articles published up to May 11, 2018. Random-effects generalized least-squares regression models were used to estimate study-specific dose-response association, and restricted cubic splines were used to model the association. We included reports of 44 prospective cohort studies describing 102 466 incident cases among 4 432 475 participants. With a 5-unit increment in BMI, the summary relative risk for stroke incidence was 1.10 (95% confidence interval, 1.06 to 1.13; I² = 88.0%). The dose-response relation was J-shaped (P_{non-linearity} <0.001). The risk was not increased at the low BMI range (<24 kg/m²), but was increased within the high BMI range (>25 kg/m²).

CONCLUSION

Both overweight and obesity increase the risk of stroke with a J-shaped dose-response relation, and the nadir of the curve was observed at BMI 23-24 kg/m².

Predictive Value of Underweight Status for Patients With Peripheral Artery Disease With Claudication

We evaluated whether underweight status is associated with poor prognosis in patients with peripheral artery disease (PAD) with claudication, excluding critical limb ischemia. We identified 441 claudicants hospitalized for cardiovascular disease between 2005 and 2012. Patients were divided into 4 groups according to body mass index (BMI): an underweight group (BMI < 18.5 kg/m2; n = 48), a normal group (BMI = 18.5-25.0 kg/m2; n = 286), an overweight group (BMI = 25.0-30.0 kg/m2; n = 92), and an obese group (BMI ≥ 30.0 kg/m2; n = 15). The mean follow-up period was 3.5 ± 1.9 years. The underweight group had significantly lower levels of hemoglobin, albumin, estimated glomerular filtration rate, triglycerides, and hemoglobin A1c; higher levels of C-reactive protein and B-type natriuretic peptide; and a higher prevalence of hemodialysis. The incidence of all-cause death and cardiovascular death was significantly higher in the underweight group (underweight vs normal, 77.1% vs 33.0%; P < .001 and 43.3% vs 14.4%; P < .001, respectively). In a multivariate Cox analysis, underweight status was an independent predictor of all-cause death (hazard ratio, 2.53; 95% confidence interval, 1.58-4.18; P < .001). Therefore, promoting weight gain, as well as managing cardiovascular disease, may be important for underweight patients with PAD.

Body mass index and stroke incidence in Japanese community residents: The Jichi Medical School (JMS) Cohort Study

BACKGROUND

High body mass index (BMI) has been reported as a risk factor for cardiovascular events in Western countries, while low BMI has been reported as a risk factor for cardiovascular death in Asian countries, including Japan. Although stroke is a major cause of death and disability in Japan, few cohort studies have examined the association between BMI and stroke incidence in Japan. This study aimed to examine the association between BMI and stroke incidence using prospective data from Japanese community residents.

METHODS

Data were analyzed from 12,490 participants in the Jichi Medical School Cohort Study. Participants were categorized into five BMI groups: ≤18.5, 18.6-21.9, 22.0-24.9, 25.0-29.9, and ≥30.0 kg/m². Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using the Cox proportional hazard model. The group with a BMI of 22.0-24.9 kg/m² was used as the reference category.

RESULTS

During mean follow-up of 10.8 years, 395 participants (207 men and 188 women) experienced stroke, including 249 cerebral infarctions and 92 cerebral hemorrhages. Men with a BMI ≤18.5 kg/m² (HR 2.11; 95% CI, 1.17-3.82) and women with a BMI ≥30.0 kg/m² (HR 2.25; 95% CI, 1.28-5.08) were at significantly higher risk for all-stroke. Men with a BMI ≤18.5 kg/m² were at significantly higher risk for cerebral infarction (HR 2.15; 95% CI, 1.07-4.33).

CONCLUSIONS

The association between BMI and stroke incidence observed in this population was different than those previously reported: low BMI was a risk factor for all-stroke and cerebral infarction in men, while high BMI was a risk factor for all-stroke in women.

Alcoholic beverage consumption contributes to caloric and moisture intakes and body weight status

OBJECTIVES

This study provides cross-sectional information on alcoholic beverages as potential sources of moisture and calories for drinkers in the United States. Associations between number of drinks per day and body weight status were also studied.

METHODS

Multivariable regression models were used to ascertain associations while controlling for potential confounders.

RESULTS

Compared to nondrinkers, daily moisture intake increased as the number of drinks increased. Increase in daily moisture intake of drinkers remained significant even after correcting for diuretic effects of ethanol (men: 270.6 g [95% confidence interval (CI), 115.7-425.4], P = 0.001) and (women: 193.0 g [95% CI, 76.8-309.4], P = 0.002). The increase in daily moisture intake after correcting for diuretic losses were men: 3.9% to 9.6%; and women: 4.1% to 12.8% depending on number of drinks. The increase in calorie intake was 6.7% to 16.2% of men's, and 6.4% to 16.0% of women's daily intake. Compared to nondrinking counterparts, men who consumed 2 or more drinks per day were more likely to be overweight whereas men who consumed 4 or more drinks per day were more likely to be obese (odds ratio: 1.63 [95% CI, 1.10-2.40], P = 0.015). Women at all levels of drinking were less likely to be obese (odds ratio: 0.70 [95% CI, 0.55-0.88], P = 0.004) compared to nondrinking counterparts.

CONCLUSION

Alcoholic beverages contribute to moisture intake despite the diuretic effect of their ethanol content. Calorie intake increase with increasing alcohol intake among men and women but only men associate with increased likelihood of overweight and obesity. Women drinkers associate with lower body mass index and are less likely to be overweight or obese.

Heart Disease Is Associated With Anthropometric Indices and Change in Body Size Perception Over the Life Course: The Golestan Cohort Study

BACKGROUND

Cardiovascular disease and obesity are now becoming leading causes of morbidity and mortality in low- and middle-income countries.

OBJECTIVES

We investigated the relationship between prevalent heart disease (HD) and current anthropometric indices and body size perception over time from adolescence to adulthood in Iran.

METHODS

We present a cross-sectional analysis of baseline data from a prospective study of adults in Golestan Province, Iran. Demographics, cardiac history, and current anthropometric indices-body mass index, waist circumference, and waist to hip ratio-were recorded. Body size perception for ages 15 years, 30 years, and at the time of interview was assessed via pictograms. Associations of these factors and temporal change in perceived body size with HD were evaluated using multivariable logistic regression models.

RESULTS

Complete data were available for 50,044 participants; 6.1% of which reported having HD. Higher body mass index, waist circumference, and waist to hip ratio were associated with HD (p < 0.001). Men had a U-shaped relationship between HD and body size perception at younger ages. For change in body size perception, men and women demonstrated a U-shaped relationship with prevalent HD from adolescence to early adulthood, but a J-shaped pattern from early to late adulthood.

CONCLUSIONS

HD was associated with anthropometric indices and change in body size perception over time for men and women in Iran. Due to the increasing prevalence of overweight and obesity in low- and middle-income countries, interventions focused on decreasing the cumulative burden of risk factors throughout the life course may be an important component of cardiovascular risk reduction.

The effect of age on the shape of the BMI-mortality relation and BMI associated with minimum all-cause mortality in a large Austrian cohort

BACKGROUND

It is unclear if the body mass index (BMI) associated with minimum all-cause mortality is constant throughout adult life or increasing with age.

METHODS

We applied multivariable fractional polynomials to the data of the Vorarlberg Health Monitoring and Prevention Program to quantify the BMI associated with minimum mortality over age. The analysis included data of 129,904 never-smoking women and men (mean age: 45.4 years) who were followed for a median of 18.6 years.

RESULTS

Optimum BMI in women increased with age, lying within the normal BMI category (according to the World Health Organization definition) from the age of 20 years (23.3 kg m(-2), 95% confidence interval (CI): 22.2-24.3) to the age of 54 years and in the lower half of the overweight category from the age of 55 years onwards, reaching 26.2 kg m(-2) (95% CI: 25.1-27.3) at the age of 69 years. In men, optimum BMI increased slightly from 23.7 kg m(-2) (95% CI: 22.1-25.2) at the age of 20 years until the age of 59 years, reaching a BMI of 25.4 kg m(-2) (95% CI: 24.8-26.0) and decreased afterwards to 22.7 kg m(-2) (95% CI: 20.9-24.6) at the age of 80 years.

CONCLUSIONS

Our results indicate that BMI associated with minimum all-cause mortality changes with age and that patterns differ by sex. Sex- and age-independent BMI recommendations might therefore be inappropriate. Further studies using flexible methods instead of predefined categories are necessary to revise BMI recommendations.

Factors influencing the decline in stroke mortality: a statement from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

Stroke mortality has been declining since the early 20th century. The reasons for this are not completely understood, although the decline is welcome. As a result of recent striking and more accelerated decreases in stroke mortality, stroke has fallen from the third to the fourth leading cause of death in the United States. This has prompted a detailed assessment of the factors associated with the change in stroke risk and mortality. This statement considers the evidence for factors that have contributed to the decline and how they can be used in the design of future interventions for this major public health burden.

METHODS

Writing group members were nominated by the committee chair and co-chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council's Scientific Statements Oversight Committee and the American Heart Association Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiological studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize evidence and to indicate gaps in current knowledge. All members of the writing group had the opportunity to comment on this document and approved the final version. The document underwent extensive American Heart Association internal peer review, Stroke Council leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

The decline in stroke mortality over the past decades represents a major improvement in population health and is observed for both sexes and for all racial/ethnic and age groups. In addition to the overall impact on fewer lives lost to stroke, the major decline in stroke mortality seen among people <65 years of age represents a reduction in years of potential life lost. The decline in mortality results from reduced incidence of stroke and lower case-fatality rates. These significant improvements in stroke outcomes are concurrent with cardiovascular risk factor control interventions. Although it is difficult to calculate specific attributable risk estimates, efforts in hypertension control initiated in the 1970s appear to have had the most substantial influence on the accelerated decline in stroke mortality. Although implemented later, diabetes mellitus and dyslipidemia control and smoking cessation programs, particularly in combination with treatment of hypertension, also appear to have contributed to the decline in stroke mortality. The potential effects of telemedicine and stroke systems of care appear to be strong but have not been in place long enough to indicate their influence on the decline. Other factors had probable effects, but additional studies are needed to determine their contributions.

CONCLUSIONS

The decline in stroke mortality is real and represents a major public health and clinical medicine success story. The repositioning of stroke from third to fourth leading cause of death is the result of true mortality decline and not an increase in mortality from chronic lung disease, which is now the third leading cause of death in the United States. There is strong evidence that the decline can be attributed to a combination of interventions and programs based on scientific findings and implemented with the purpose of reducing stroke risks, the most likely being improved control of hypertension. Thus, research studies and the application of their findings in developing intervention programs have improved the health of the population. The continued application of aggressive evidence-based public health programs and clinical interventions is expected to result in further declines in stroke mortality.

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.

Why Has the BMI gone up so drastically in the last 35 years?

OBJECTIVES

We attempted to answer the following questions: Why has the body mass index (BMI) increased so dramatically in the last 35 years? Are some food groups or additives more responsible than others?

METHODS

Data for per capita food production available for consumption after spoilage for different food groups and additives from the US Department of Agriculture were used as independent variables to predict BMI increases. The heights and weights were taken from the Centers for Disease Control and the US Census Bureau for the years 1970 to 2004.

RESULTS

The additives of fats and sugars in combination, not separately, best predicted increases in BMI accounting for 97% of the variance in the linear regression analyses. When all food groups were entered into regressions to predict increases in BMI, fats and sugars in combination accounted for 96% of the variance for women and 97% for men, with the other food groups adding very little. Path analyses showed that fat and sweeteners had direct effects on BMI and were also the mediators of increased caloric consumption.

CONCLUSIONS

In line with the major physiological theories emphasizing palatability as the addictive stimulus in models of incentives and addiction, fats and sugars in combination rather than calories per se or particular food groups accounted for the increases in BMI. These empirically based theories and data suggest that one should focus on palatability and addictive models in dealing with the increasing problem of obesity in the United States.

Morbidity patterns among the underweight, overweight and obese between 2 and 18 years: population-based cross-sectional analyses

CONTEXT

No study has documented how symptomatic morbidity varies across the body mass index (BMI) spectrum (underweight, normal weight, overweight and obese) or across the entire child and adolescent age range.

OBJECTIVE

To (1) quantify physical and psychosocial morbidities experienced by 2-18-year-olds according to BMI status and (2) explore morbidity patterns by age.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional data from two Australian population studies (the Longitudinal Study of Australian Children and the Health of Young Victorians Study) were collected during 2000-2006. Participants were grouped into five age bands: 2-3 (n=4606), 4-5 (n=4983), 6-7 (n=4464), 8-12 (n=1541) and 13-18 (n=928) years.

MAIN MEASURES

Outcomes-Parent- and self-reported global health; physical, psychosocial and mental health; special health-care needs; wheeze; asthma and sleep problems. Exposure-measured BMI (kg m(-2)) categorised using standard international cutpoints.

ANALYSES

The variation in comorbidities across BMI categories within and between age bands was examined using linear and logistic regression models.

RESULTS

Comorbidities varied with BMI category for all except sleep problems, generally showing the highest levels for the obese category. However, patterns differed markedly between age groups. In particular, poorer global health and special health-care needs were associated with underweight in young children, but obesity in older children. Prevalence of poorer physical health varied little by BMI in 2-5-year-olds, but from 6 to 7 years was increasingly associated with obesity. Normal-weight children tended to experience the best psychosocial and mental health, with little evidence that the U-shaped associations of these variables with BMI status varied by age. Wheeze and asthma increased slightly with BMI at all ages.

CONCLUSIONS

Deviation from normal weight is associated with health differences in children and adolescents that vary by morbidity and age. As well as lowering risks for later disease, promoting normal body weight appears central to improving the health and well-being of the young.

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.

Lack of leisure-time physical activity in non-obese Japanese men with components of metabolic syndrome

A focus exclusively on waist circumference, the main component used in the diagnosis of metabolic syndrome (MetS), may lead to ignoring non-obese individuals with other MetS components, including high levels of blood pressure, fasting blood glucose, and triglycerides and low levels of high-density lipoprotein. This study investigated lifestyles and eating behaviors among non-obese individuals with components of MetS. Of the 918 Japanese male workers, 151 subjects (16.4%) had a waist circumference < 85 cm with more than one MetS component. This non-obese high-risk group for MetS gained weight in adulthood, consume alcohol, and engage in less leisure-time physical activity compared to 317 subjects (34.5%) with a waist circumference < 85 cm and without MetS components (p < 0.05). The remaining 450 subjects (49%) were obese with a waist circumference ≥ 85, including 93 men with MetS. A lack of leisure-time physical activity was associated with the non-obese high-risk group for MetS [odds ratio 1.59, 95% confidence interval 1.02 - 2.49] compared to the 317 non-obese men without MetS (reference group). Such a difference in physical activity was not found between the 450 obese subjects and the reference group. Instead, eating behaviors, such as eating rapidly, preference for fatty foods, and eating out for dinner, were significantly associated with MetS. Thus, men with smaller waist circumferences and any MetS component should be carefully monitored for physical activity to prevent further development of MetS, while men with larger waist circumferences including MetS need to be monitored for unfavorable eating behaviors.

Effect of age on the association between body mass index and all-cause mortality: the Ohsaki cohort study

Background

To clarify the effect of age on the association between body mass index (BMI) and all-cause mortality.

Methods

We followed 43 972 Japanese participants aged 40 to 79 years for 12 years. Cox proportional hazards regression analysis was used to estimate hazard ratios (HRs), using the following BMI categories: <18.5 (underweight), 18.5–20.9, 21.0–22.9, 23.0–24.9 (reference), 25.0–27.4, 27.5–29.9, and ≥30.0 kg/m² (obese). Analyses were stratified by age group: middle-aged (40–64 years) vs elderly (65–79 years).

Results

We observed a significantly increased risk of mortality in underweight elderly men: the multivariate HR was 1.26 (0.92–1.73) in middle-aged men and 1.49 (1.26–1.76) in elderly men. In addition, we observed a significantly increased risk of mortality in obese middle-aged men: the multivariate HR was 1.71 (1.17–2.50) in middle-aged men and 1.25 (0.87–1.80) in elderly men. In women, there was an increased risk of mortality irrespective of age group in the underweight: the multivariate HR was 1.46 (0.96–2.22) in middle-aged women and 1.47 (1.19–1.82) in elderly women. There was no excess risk of mortality with age in obese women: the multivariate HR was 1.47 (0.94–2.27) in middle-aged women and 1.26 (0.95–1.68) in elderly women.

Conclusions

As compared with the reference category, obesity was associated with a high mortality risk in middle-aged men, whereas underweight, rather than obesity, was associated with a high mortality risk in elderly men. In women, obesity was associated with a high mortality risk during middle age; underweight was associated with a high mortality risk irrespective of age. The mortality risk due to underweight and obesity may be related to sex and age.

Body mass index, weight change and risk of stroke and stroke subtypes: the Japan Public Health Center-based prospective (JPHC) study

OBJECTIVE

The Japan Public Health Center-based prospective Study examined the association of body mass index (BMI) and weight change with incident stroke in Japanese individuals, for whom BMI levels are generally low.

METHODS

We used initial data from 1990 to 1994 and 5-year follow-up surveys from 1995 to 1999. We calculated weight change over a 5-year period for 32,847 men and 38,875 women, aged 45-74 years, with no history of cardiovascular disease or cancer. Subjects were followed from the 1995-1999 survey to the end of 2005, and hazard ratios of self-reported BMI levels and weight change for incident stroke were estimated using Cox's proportional hazard models adjusted for potential confounders.

RESULTS

During the follow-up period (median 7.9 years) there were 2019 incident strokes, including subtypes. Multivariable-adjusted hazard ratios for all stroke events by BMI levels of 27.0-29.9 and ≥ 30 kg m(-2) versus 23.0-24.9 kg m(-2) were 1.09 (95% confidence interval 0.88, 1.36) and 1.25 (0.86, 1.84) in men (P for trend=0.22), and 1.29 (1.01, 1.65) and 2.16 (1.60, 2.93) in women (P for trend <0.001), respectively. A weight change of ≥ 10% in the previous 5 years was associated with total strokes and ischemic strokes in women.

CONCLUSION

Higher BMI levels and a weight gain of ≥ 10% over 5 years were associated with an increased risk of stroke in women, whereas this association was weak in men.

Total energy intake and intake of three major nutrients by body mass index in Japan: NIPPON DATA80 and NIPPON DATA90

Background

This paper investigated the relationship between body mass index (BMI) and total energy intake as well as intake of three major nutrients in representative Japanese populations enrolled in the National Nutrition Surveys of Japan in 1980 and 1990.

Methods

A total of 10 422 participants (4585 men and 5837 women) and 8342 participants (3488 men and 4854 women) aged 30 or older from 300 randomly selected districts participated in the National Survey of Circulatory Disorders and the National Nutrition Survey in Japan in 1980 and 1990, respectively. The nutrition surveys were performed with weighing record method for three consecutive days to each household. Individually estimated total energy intake and intakes of three major nutrients (carbohydrate, protein, and fat) were compared by the categories of BMI and by 10-year age groups.

Results

In men, total energy intake (kcal/day), intakes of three major nutrients (g/day) and energy intake ratio from protein and fat (%) increased as BMI increased in each age group, whereas energy intake ratio from carbohydrate (%) decreased. In women, total energy intake, intakes of three major nutrients, and energy intake ratio from protein increased as BMI increased. Energy intake ratio from carbohydrate and fat decreased as BMI increased in women in 1990. When participants were categorized into quartiles according to total energy intake in each sex group, BMI increased as total energy intake increased in men in both 1980 and 1990.

Conclusions

A positive relationship was observed between body mass index and total energy intake in Japanese men. The relationship was weaker in Japanese women.

Excess body weight and incidence of stroke: meta-analysis of prospective studies with 2 million participants

BACKGROUND AND PURPOSE

A systematic review of the prospective studies addressing the relationship of overweight and obesity to major stroke subtypes is lacking. We evaluated the occurrence of a graded association between overweight, obesity, and incidence of ischemic and hemorrhagic stroke by a meta-analysis of cohort studies.

METHODS

A search of online databases and relevant reviews was performed. Inclusion criteria were original article in English, prospective study design, follow-up > or = 4 years, indication of number of subjects exposed, and number of events across body mass index categories. Crude unadjusted relative risk (RR) and 95% CI were calculated for each study for overweight or obese compared with normal-weight categories. Log-transformed values and SE were used to calculate the pooled RR with random effects models; publication bias was checked. Additional analyses were performed using the multivariate estimates of risk reported in the individual studies.

RESULTS

Twenty-five studies were included, with 2 274 961 participants and 30 757 events. RR for ischemic stroke was 1.22 (95% CI, 1.05-1.41) for overweight and 1.64 (95% CI, 1.36-1.99) for obesity, whereas RR for hemorrhagic stroke was 1.01 (95% CI, 0.88-1.17) and 1.24 (95% CI, 0.99-1.54), respectively. Subgroup and meta-regression analyses ruled out gender, population average age, body mass index and blood pressure, year of recruitment, year of study publication, and length of follow-up as significant sources of heterogeneity. The additional analyses relying on the published multivariate estimates of risk provided qualitatively similar results.

CONCLUSIONS

Overweight and obesity are associated with progressively increasing risk of ischemic stroke, at least in part, independently from age, lifestyle, and other cardiovascular risk factors.

Issues in obesity monitoring, screening and subsequent treatment

PURPOSE OF REVIEW

Despite intense policy, media and research interest, childhood obesity rates continue to rise in most countries. Screening may seem a logical response to a situation in which obesity does not usually resolve spontaneously, yet most obese children do not present for treatment. This article explores recent evidence for and against monitoring and screening of children's BMI.

RECENT FINDINGS

Whether conducted in primary care or school settings, population screening of children's BMI can be feasible, acceptable and not intrinsically harmful. However, it incurs a substantial cost, and randomized controlled trials do not suggest that it improves BMI outcomes. Population trends in BMI are more complex than a simple rise in obesity; birth cohorts with higher rates of childhood overweight are not inevitably more overweight as young adults. The consequences of a concomitant increase in thinness are uncertain.

SUMMARY

Systematic monitoring of BMI is essential, but need not be continuous, and could involve representative samples rather than all individuals in a population. In contrast, BMI screening cannot be recommended until more effective management becomes available for overweight and mildly obese children. Research into prevention and intervention should, therefore, be prioritized over population screening at this point in time.

Liver transplantation at the extremes of the body mass index

Controversies exist regarding the morbidity and mortality of patients undergoing liver transplantation at the extremes of the body mass index (BMI). A review of the United Network for Organ Sharing database from 1987 through 2007 revealed 73,538 adult liver transplants. Patients were stratified into 6 BMI categories established by the World Health Organization: underweight, <18.5 kg/m(2); normal weight, 18.5 to <25 kg/m(2); overweight, 25 to <30 kg/m(2); obese, 30 to <35 kg/m(2); severely obese, 35 to <40 kg/m(2); and very severely obese, > or =40 kg/m(2). Survival rates were compared among these 6 categories via Kaplan-Meier survival curves with the log-rank test. The underweight and very severely obese groups had significantly lower survival. There were 1827 patients in the underweight group, 1447 patients in the very severely obese group, and 68,172 patients in the other groups, which became the control. Groups with extreme BMI (<18.5 and > or =40) were compared to the control to assess significant differences. Underweight patients were more likely to die from hemorrhagic complications (P < 0.002) and cerebrovascular accidents (P < 0.04). When compared with the control, the very severely obese patients had a higher number of infectious complications and cancer events (P = 0.02) leading to death. In 3 different eras of liver transplantation, multivariable analysis showed that underweight and very severe obesity were significant predictors of death. In conclusion, liver transplantation holds increased risk for patients at the extremes of BMI. Identifying these patients and instituting aggressive new policies may improve outcomes. Liver Transpl 15:968-977, 2009. (c) 2009 AASLD.