Intention to lose weight, weight changes, and 18-y mortality in overweight individuals without co-morbidities

Association of change in fat and lean mass with incident cardiovascular events for women in midlife and beyond: A prospective study using dual-energy x-ray absorptiometry (DXA)

OBJECTIVE

To determine whether changes in fat and lean mass over time, quantified using dual-energy x-ray absorptiometry (DXA), are related to incident cardiovascular events. Previous studies using surrogate anthropometric methods have had inconsistent findings.

STUDY DESIGN

Prospective, longitudinal observational study of women aged 40 to 80 randomly selected from the electoral roll and stratified into decades: 40-49, 50-59, 60-69 and 70-79 years.

MAIN OUTCOME MEASURES

Changes in anthropometric measurements (body mass index and waist-to-hip ratio) and DXA-quantified fat mass and lean mass between the first and fifth years of the study. Incident cardiovascular events recorded from the sixth to the 12th year.

RESULTS

In total 449 participants (87.9 %) were analyzed. A 10 % or greater decrease in total fat mass index was associated with a 67 % lower likelihood of any cardiovascular event (OR = 0.33, 95%CI 0.15-0.71); no association was observed for an increase. A 10 % or greater decrease in abdominal fat mass index was associated with a 62 % lower likelihood of incident stroke (OR = 0.38, 95%CI 0.16-0.91); no association was observed for an increase. A 10 % or greater decrease in appendicular lean mass index resulted in increased odds ratio of 2.91 for incident peripheral artery events (OR = 2.91, 95%CI 1.18-7.20).

CONCLUSIONS

Reducing fat mass for women in midlife and beyond may decrease the risk of cardiovascular events. An increase in fat mass may not contribute to additional cardiovascular events. A reduction in limb muscle mass may provide an independent marker for cardiometabolic risk and peripheral artery disease. No independent association was found using anthropometric measurements and incident cardiovascular events.

Association of body mass index and long-term mortality in patients from nationwide LIPIDOGRAM 2004-2015 cohort studies: no obesity paradox?

BACKGROUND

An obesity paradox has been described in relation to adverse clinical outcomes (e.g., mortality) with lower body mass index (BMI).

AIMS

We sought to evaluate the association between BMI and weight loss with long-term all-cause mortality in adult populations under the care of family physicians.

METHODS

LIPIDOGRAM studies were conducted in primary care in Poland in 2004, 2006, and 2015 and enrolled a total of 45,615 patients. The LIPIDOGRAM Plus study included 1627 patients recruited in the LIPIDOGRAM 2004 and repeated measurements in 2006 edition. Patients were classified by BMI categories as underweight, normal weight, overweight and class I, II, or III (obesity). Follow-up data up to December 2021 were obtained from the Central Statistical Office. Differences in all-cause mortality were analyzed using Kaplan‒Meier and Cox regression analyses.

RESULTS

Of 45,615 patients, 10,987 (24.1%) were normal weight, 320 (0.7%) were underweight, 19,134 (41.9%) were overweight, and 15,174 (33.2%) lived with obesity. Follow-up was available for 44,620 patients (97.8%, median duration 15.3 years, 61.7% females). In the crude analysis, long-term all-cause mortality was lowest for the normal-weight group (14%) compared with other categories. After adjusting for comorbidities, the highest risk of death was observed for the class III obesity and underweight categories (hazard ratio, HR 1.79, 95% CI [1.55-2.05] and HR 1.57, 95% CI [1.22-2.04]), respectively. The LIPIDOGRAM Plus analysis revealed that a decrease in body weight (by 5 and 10%) over 2 years was associated with a significantly increased risk of death during long-term follow-up-HR 1.45 (95% CI 1.05-2.02, p = 0.03) and HR 1.67 (95% CI 1.02-2.74, p < 0.001). Patients who experienced weight loss were older and more burdened with comorbidities.

CONCLUSIONS

Being underweight, overweight or obese is associated with a higher mortality risk in a population of patients in primary care. Patients who lost weight were older and more burdened with cardiometabolic diseases, which may suggest unintentional weight loss, and were at higher risk of death in the long-term follow-up. In nonsmoking patients without comorbidities, the lowest mortality was observed in those with a BMI < 25 kg/m2, and no U-curve relationship was observed.

Body mass index trajectories and their predictors in undergraduate students from Canada: Results from the GENEiUS study

Objective: To explore the patterns and predictors of body mass index (BMI) change among undergraduate students from Ontario (Canada). Participants: 68 undergraduate students were followed longitudinally for 3 years with anthropometric data collected bi-annually. Methods: BMI measurements were plotted to generate individual BMI trajectory curves, which were categorized, based on the observed trajectory pattern. Within and between group comparisons of BMI were conducted via nonparametric paired tests. The association of baseline BMI, sex, and ethnicity with BMI trajectory type was assessed using multinomial logistic regression. Results: Four BMI trajectory types were observed: "stable weight" (n = 15, 22.1%), "weight gain" (n = 30, 44.1%), "weight loss" (n = 12, 17.6%), and "weight cycling" (n = 11, 16.2%) trajectories. Higher baseline BMI was significantly associated with the "weight gain," "weight loss," and the "weight cycling" trajectories as compared to the "stable weight" trajectory type. Conclusions: Our findings demonstrate an association between high baseline BMI and "nonstable" subsequent BMI change patterns among Canadian students.

Weight Change During the Postintervention Follow-up of Look AHEAD

OBJECTIVE

Patients with type 2 diabetes are encouraged to lose weight, but excessive weight loss in older adults may be a marker of poor health and subsequent mortality. We examined weight change during the postintervention period of Look AHEAD, a randomized trial comparing intensive lifestyle intervention (ILI) with diabetes support and education (DSE) (control) in overweight/obese individuals with type 2 diabetes and sought to identify predictors of excessive postintervention weight loss and its association with mortality.

RESEARCH DESIGN AND METHODS

These secondary analyses compared postintervention weight change (year 8 to final visit; median 16 years) in ILI and DSE in 3,999 Look AHEAD participants. Using empirically derived trajectory categories, we compared four subgroups: weight gainers (n = 307), weight stable (n = 1,561), steady losers (n = 1,731), and steep losers (n = 380), on postintervention mortality, demographic variables, and health status at randomization and year 8.

RESULTS

Postintervention weight change averaged -3.7 ± 9.5%, with greater weight loss in the DSE than the ILI group. The steep weight loss trajectory subgroup lost on average 17.7 ± 6.6%; 30% of steep losers died during postintervention follow-up versus 10-18% in other trajectories (P < 0001). The following variables distinguished steep losers from weight stable: baseline, older, longer diabetes duration, higher BMI, and greater multimorbidity; intervention, randomization to control group and less weight loss in years 1-8; and year 8, higher prevalence of frailty, multimorbidity, and depressive symptoms and lower use of weight control strategies.

CONCLUSIONS

Steep weight loss postintervention was associated with increased risk of mortality. Older individuals with longer duration of diabetes and multimorbidity should be monitored for excessive unintentional weight loss.

Effects of Intensive Lifestyle Intervention on All-Cause Mortality in Older Adults With Type 2 Diabetes and Overweight/Obesity: Results From the Look AHEAD Study

OBJECTIVE

Look AHEAD, a randomized trial comparing intensive lifestyle intervention (ILI) and diabetes support and education (DSE) (control) in 5,145 individuals with overweight/obesity and type 2 diabetes, found no significant differences in all-cause or cardiovascular mortality or morbidity during 9.6 (median) years of intervention. Participants in ILI who lost ≥10% at 1 year had lower risk of composite cardiovascular outcomes relative to DSE. Since effects of ILI may take many years to emerge, we conducted intent-to-treat analyses comparing mortality in ILI over 16.7 years (9.6 years of intervention and then observation) to DSE. In a secondary exploratory analysis, we compared mortality by magnitude of weight loss in ILI relative to DSE.

RESEARCH DESIGN AND METHODS

Primary outcome was all-cause mortality from randomization to 16.7 years. Other outcomes included cause-specific mortality, interactions by subgroups (age, sex, race/ethnicity, and cardiovascular disease history), and an exploratory analysis by magnitude of weight loss in ILI versus DSE as reference. Analyses used proportional hazards regression and likelihood ratio.

RESULTS

The incidence of all-cause mortality did not differ significantly in ILI and DSE (549 and 589 participants, respectively) (hazard ratio [HR] 0.91 [95% CI 0.81, 1.02]; P = 0.11). There were no significant differences between treatments in cause-specific mortality or within prespecified subgroups. ILI participants who lost ≥10% at 1 year had a 21% reduced risk of mortality (HR 0.79 [95% CI 0.67, 0.94]; P = 0.007) relative to DSE.

CONCLUSIONS

ILI focused on weight loss did not significantly affect mortality risk. However, ILI participants who lost ≥10% had reduced mortality relative to DSE.

High-fat meals do not affect thrombin formation and fibrin clot lysis in individuals with obesity during intentional weight loss

Repeated weight loss cycles are associated with increased cardiovascular morbidity. Meal-induced thrombin formation, measured as prothrombin fragment 1+2 (F1+2), is observed in individuals with overweight after weight loss, and postprandial effects can be one of the mechanisms underlying harmful effects during intentional weight loss. We hypothesize that consumption of high-fat meals during intentional weight loss triggers a prothrombotic state by increasing postprandial F1+2 or decreasing fibrin clot lysis in individuals with obesity, and that the response associates with the gut bacteria composition. A cross-over meal study was conducted in patients admitted to bariatric surgery during dietary weight loss (N = 20) and surgical weight loss (N = 16) (weight loss groups). High-fat (67 E%) and low-fat (16 E%) meals were served at 08:15 and 10:00 on 2 study days. Blood samples collected at 08:00 (fasting), 12:00, and 14:00 were analyzed for triglycerides, activated factor VII (FVIIa), F1+2, D-dimer, fibrinogen, tissue factor , and fibrin clot lysis. The proportion of Gram-negative bacteria and bacterial diversity were analyzed in fecal samples obtained less than 24 hours before the meal test. Triglyceride and FVIIa increased after high-fat meals in both weight loss groups, whereas D-dimer (dietary group) and F1+2 decreased and tissue factor and fibrin clot lysis did not change. There was a negative association between the proportion of Gram-negative bacteria and changes in FVIIa in the surgery group. Postprandial FVII activation after high-fat meals is not accompanied by increased F1+2, irrespective of the weight loss intervention, but might be associated with the proportion of Gram-negative gut bacteria.

Maternal weight change from prepregnancy to 18 months postpartum and subsequent risk of hypertension and cardiovascular disease in Danish women: A cohort study

BACKGROUND

One-fourth of women experience substantially higher weight years after childbirth. We examined weight change from prepregnancy to 18 months postpartum according to subsequent maternal risk of hypertension and cardiovascular disease (CVD).

METHODS AND FINDINGS

We conducted a cohort study of 47,966 women with a live-born singleton within the Danish National Birth Cohort (DNBC; 1997-2002). Interviews during pregnancy and 6 and 18 months postpartum provided information on height, gestational weight gain (GWG), postpartum weights, and maternal characteristics. Information on pregnancy complications, incident hypertension, and CVD was obtained from the National Patient Register. Using Cox regression, we estimated adjusted hazard ratios (HRs; 95% confidence interval [CI]) for hypertension and CVD through 16 years of follow-up. During this period, 2,011 women were diagnosed at the hospital with hypertension and 1,321 with CVD. The women were on average 32.3 years old (range 18.0-49.2) at start of follow-up, 73% had a prepregnancy BMI <25, and 27% a prepregnancy BMI ≥25. Compared with a stable weight (±1 BMI unit), weight gains from prepregnancy to 18 months postpartum of >1-2 and >2 BMI units were associated with 25% (10%-42%), P = 0.001 and 31% (14%-52%), P < 0.001 higher risks of hypertension, respectively. These risks were similar whether weight gain presented postpartum weight retention or a new gain from 6 months to 18 months postpartum and whether GWG was below, within, or above the recommendations. For CVD, findings differed according to prepregnancy BMI. In women with normal-/underweight, weight gain >2 BMI units and weight loss >1 BMI unit were associated with 48% (17%-87%), P = 0.001 and 28% (6%-55%), P = 0.01 higher risks of CVD, respectively. Further, weight loss >1 BMI unit combined with a GWG below recommended was associated with a 70% (24%-135%), P = 0.001 higher risk of CVD. No such increased risks were observed among women with overweight/obesity (interaction by prepregnancy BMI, P = 0.01, 0.03, and 0.03, respectively). The limitations of this observational study include potential confounding by prepregnancy metabolic health and self-reported maternal weights, which may lead to some misclassification.

CONCLUSIONS

Postpartum weight retention/new gain in all mothers and postpartum weight loss in mothers with normal-/underweight may be associated with later adverse cardiovascular health.

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.

Body mass index trajectories among people with obesity and association with mortality: Evidence from a large Israeli database

Objective

Previous studies using longitudinal weight data to characterize obesity are based on populations of limited size and mostly include individuals of all body mass index (BMI) levels, without focusing on weight changes among people with obesity. This study aimed to identify BMI trajectories over 5 years in a large population with obesity, and to determine the trajectories' association with mortality.

Methods

For inclusion, individuals aged 30–74 years at index date (1 January 2013) with continuous membership in Clalit Health Services from 2008 to 2012 were required to have ≥1 BMI measurement per year in ≥3 calendar years during this period, of which at least one was ≥30 kg/m². Latent class analysis was used to generate BMI trajectories over 5 years (2008–2012). Cox proportional hazards models were used to assess the association between BMI trajectories and all‐cause mortality during follow‐up (2013–2017).

Results

In total, 367,141 individuals met all inclusion criteria. Mean age was 57.2 years; 41% were men. The optimal model was a quadratic model with four classes of BMI clusters. Most individuals (90.0%) had stable high BMI over time. Individuals in this cluster had significantly lower mortality than individuals in the other trajectory clusters (p < 0.01), including clusters of people with dynamic weight trajectories.

Conclusions

The results of the current study show that people with stable high weight had the lowest mortality of all four BMI trajectories identified. These findings help to expand the scientific understanding of the impact that weight trajectories have on health outcomes, while demonstrating the challenges of discerning the cumulative effects of obesity and weight change, and suggest that dynamic historical measures of BMI should be considered when assessing patients' future risk of obesity‐related morbidity and mortality, and when choosing a treatment strategy.

The body in isolation: The physical health impacts of incarceration in solitary confinement

We examine how solitary confinement correlates with self-reported adverse physical health outcomes, and how such outcomes extend the understanding of the health disparities associated with incarceration. Using a mixed methods approach, we find that solitary confinement is associated not just with mental, but also with physical health problems. Given the disproportionate use of solitary among incarcerated people of color, these symptoms are most likely to affect those populations. Drawing from a random sample of prisoners (n = 106) in long-term solitary confinement in the Washington State Department of Corrections in 2017, we conducted semi-structured, in-depth interviews; Brief Psychiatric Rating Scale (BPRS) assessments; and systematic reviews of medical and disciplinary files for these subjects. We also conducted a paper survey of the entire long-term solitary confinement population (n = 225 respondents) and analyzed administrative data for the entire population of prisoners in the state in 2017 (n = 17,943). Results reflect qualitative content and descriptive statistical analysis. BPRS scores reflect clinically significant somatic concerns in 15% of sample. Objective specification of medical conditions is generally elusive, but that, itself, is a highly informative finding. Using subjective reports, we specify and analyze a range of physical symptoms experienced in solitary confinement: (1) skin irritations and weight fluctuation associated with the restrictive conditions of solitary confinement; (2) un-treated and mis-treated chronic conditions associated with the restrictive policies of solitary confinement; (3) musculoskeletal pain exacerbated by both restrictive conditions and policies. Administrative data analyses reveal disproportionate rates of racial/ethnic minorities in solitary confinement. This analysis raises the stakes for future studies to evaluate comparative prevalence of objective medical diagnoses and potential causal mechanisms for the physical symptoms specified here, and for understanding differential use of solitary confinement and its medically harmful sequelae.

Intentional weight loss as a predictor of type 2 diabetes occurrence in a general adult population

INTRODUCTION

Observational and intervention studies have verified that weight loss predicts a reduced type 2 diabetes (T2D) risk. At the population level, knowledge on the prediction of self-report intentional weight loss (IWL) on T2D incidence is, however, sparse. We studied the prediction of self-report IWL on T2D incidence during a 15-year follow-up in a general adult population.

RESEARCH DESIGN AND METHODS

The study sample from the representative Finnish Health 2000 Survey comprised 4270 individuals, aged 30-69 years. IWL was determined with questions concerning dieting attempts and weight loss during the year prior to baseline. Incident T2D cases during a 15-year follow-up were drawn from national health registers. The strength of the association between IWL and T2D incidence was estimated with the Cox model.

RESULTS

During the follow-up, 417 incident cases of T2D occurred. IWL predicted an increased risk of T2D incidence (HR 1.44; 95% CI 1.11 to 1.87, p=0.008) in a multivariable model. In interaction analyses comparing individuals with and without IWL, a suggestively elevated risk emerged in men, the younger age group, among less-educated people and in individuals with unfavorable values in several lifestyle factors.

CONCLUSIONS

Self-report IWL may predict an increased risk of T2D in long-term, probably due to self-implemented IWL tending to fail. The initial prevention of weight gain and support for weight maintenance after weight loss deserve greater emphasis in order to prevent T2D.

Change in Body Weight and Long-Term Risk of Stroke and Death in Healthy Men

Background and Purpose—

The importance of weight change for the risk of stroke is not well known. We examined the associations between early- and mid-life weight change and risks of stroke and death during long-term follow-up of healthy men.

Methods—

We recruited healthy men aged between 40 and 59 years and performed a cardiovascular examination at baseline and again at 7 years. We collected data on weight change since the age of 25 (early-life weight change) and measured weight change from baseline to the visit at 7 years (mid-life weight change). For both weight change periods, participants were divided into the following categories: weight loss, weight gain 0 to 4.9 kg, weight gain 5 to 9.9 kg, and weight gain ≥10 kg. Data on stroke and death were collected up to 35 years, from study visits, hospital records, and the National Cause of Death Registry. We used Cox regression to analyze the associations between weight change during early-life and mid-life and risks of stroke and death.

Results—

Of the 2014 participants, 2014 (100%) had data on early-life weight change and were followed for a median of 30.1 years, while 1403 had data on mid-life weight change and were followed for a median of 24.6 years. During early-life, compared with those who had weight gain 0 to 4.9 kg, hazard ratio for stroke was 1.46 (95% CI, 1.09–1.95) among those with weight gain 5 to 9.9 kg, 1.39 (95% CI, 1.03–1.87) for those with weight gain ≥10 kg, and 1.46 (95% CI, 0.99–2.11) among those with weight loss. For all-cause death, the hazard ratios were 1.08 (95% CI, 0.92–1.23), 1.14 (95% CI, 0.98–1.33), and 1.29 (95% CI, 1.06–1.56), respectively. During mid-life, there were no significant differences in risk of stroke or death between the groups.

Conclusions—

Weight increase during early-life, but not mid-life, seems to be associated with increased long-term risk of stroke in healthy men. If these findings can be confirmed, efforts to prevent weight increase should target the younger population.

Attitudes to and experiences with body weight control and changes in body weight in relation to all-cause mortality in the general population

Background and aims

Increased body mass index (BMI = weight/height²; kg/m²) and weight gain is associated with increased mortality, wherefore weight loss and avoided weight gain should be followed by lower mortality. This is achieved in clinical settings, but in the general population weight loss appears associated with increased mortality, possibly related to the struggles with body weight control (BWC). We investigated whether attitudes to and experiences with BWC in combination with recent changes in body weight influenced long-term mortality among normal weight and overweight individuals.

Population and methods

The study population included 6,740 individuals attending the 3^rd cycle in 1991–94 of the Copenhagen City Heart Study, providing information on BMI, educational level, health behaviours, well-being, weight half-a-year earlier, and answers to four BWC questions about caring for body weight, assumed benefit of weight loss, current and past slimming experiences. Participants reporting previous unintended weight loss (> 4 kg during one year) were excluded. Cox regression models estimated the associations of prior changes in BMI and responses to the BWC questions with approximately 22 years all-cause mortality with age as ‘time scale’. Participants with normal weight (BMI < 25.0 kg/m²) and overweight (BMI ≥ 25.0 kg/m²) were analysed separately, and stratified by gender and educational level, health behaviours and well-being as co-variables.

Results

Compared with stable weight, weight loss was associated with significantly increased mortality in the normal weight group, but not in the overweight group, and weight gain was not significantly associated with mortality in either group. Participants with normal weight who claimed that it would be good for their health to lose weight or that they were currently trying to lose weight had significantly higher mortality than those denying it. There were no other significant associations with the responses to the BWC questions in either the normal weight or the overweight group. When combining the responses to the BWC questions with the weight changes, using the weight change as either a continuous or categorical variable, there were no significant interaction in their relation to mortality in either the normal weight or the overweight group.

Conclusion

Attitudes to and experiences with BWC did not notably modify the association of changes in body weight with mortality in either people with normal weight or people with overweight.

Impact of weight variability on mortality among Korean men and women: a population based study

The health consequences of weight fluctuation have been controversial and little-studied within Asian populations. We aimed to determine the effect of weight variability on mortality using Korean National Health Insurance Service – National Health Screening Cohort. Weight variability was defined as the average successive variability of body mass index (BMI) of the first (2002 and 2003), second (2004 and 2005), and third (2006 and 2007) health examinations. Then, we used Cox regression models to estimate the effect of weight variability on mortality. Compared to participants within the first quintile (lowest) of weight variability, those within the fifth quintile (highest) had increased the risk of death from all causes (hazard ratio, HR 1.33, 95% confidence interval, CI 1.26–1.41), cardiovascular disease (HR 1.31, 95% CI 1.12–1.53), cancer (HR 1.11, 95% CI 1.02–1.22), and other causes (HR 1.58, 95% CI 1.45–1.73). The risk-increasing effect of weight variability on mortality was preserved after excluding past and current smokers as well as those with pre-existing cardiovascular disease or cancer. In conclusion, high weight variability may lead to elevated risk of death even among healthy never smokers. Therefore, maintaining a steady weight should be recommended to benefit from reduced risk of death.

The Complex Interactions Between Obesity, Metabolism and the Brain

Obesity is increasing at unprecedented levels globally, and the overall impact of obesity on the various organ systems of the body is only beginning to be fully appreciated. Because of the myriad of direct and indirect effects of obesity causing dysfunction of multiple tissues and organs, it is likely that there will be heterogeneity in the presentation of obesity effects in any given population. Taken together, these realities make it increasingly difficult to understand the complex interplay between obesity effects on different organs, including the brain. The focus of this review is to provide a comprehensive view of metabolic disturbances present in obesity, their direct and indirect effects on the different organ systems of the body, and to discuss the interaction of these effects in the context of brain aging and the development of neurodegenerative diseases.

Changes in Cardiovascular Disease Risk Factors with Unintentional Versus Intentional Weight Loss: The Coronary Artery Risk Development in Young Adults Study

BACKGROUND

It is well known that total and intentional weight loss (IWL) are associated with reductions in cardiovascular disease (CVD) risk factors, however, associations with unintentional weight loss (UWL) have not been studied.

METHODS

We examined annual changes in blood pressure and lipids associated with UWL versus IWL in 576 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study who had lost weight over one of two time intervals (i.e., study years 5-7 or 7-10) and reported whether the weight loss was intentional at the end of the interval.

RESULTS

After adjusting for age, sex, race, and field center, an annual weight loss smaller than 6% resulted in small improvements in lipids that were similar regardless of intentionality. When annual weight loss was ≥6%, UWL was associated with less reduction in total cholesterol (-0.2 vs. -10.4 mg/dL), low-density lipoprotein cholesterol (-3.2 vs. -9.4 mg/dL), and triglycerides (-0.5 vs. -19.0 mg/dL) compared with IWL. Intentionality was not associated with the size of changes in blood pressure (systolic blood pressure: -2.7 vs. -2.0 mmHg; diastolic blood pressure: -2.2 vs. -1.3 mmHg) and high-density lipoprotein cholesterol (3.2 vs. 2.7 mg/dL).

CONCLUSIONS

Substantial UWL may be accompanied or preceded by other biological changes in this young adult population that alter changes in CVD risk factors that are associated with IWL.

Maintenance of body weight is an important determinant for the risk of ischemic stroke: A nationwide population-based cohort study

Background

Overweight is known as a risk factor for ischemic stroke. However, the effect of weight change on the development of ischemic stroke remains controversial. We investigated the relationship between weight change and the risk of ischemic stroke using a nationwide population-based cohort.

Methods

Our study enrolled 11,084,683 participants (Mean age 49.7±13.5 years, range 20–114 years) in the Korean National Health Screening Program from 2009 to 2012. Weight change was calculated using the difference between the baseline weight and the weight at health screening four years prior to the baseline. The occurrence of newly-diagnosed ischemic stroke was observed until the end of 2015. We categorized the study population according to weight change and performed multivariable analysis to compare the risk.

Results

Ischemic stroke was newly diagnosed in 113,591 subjects. The crude incidence rates of ischemic stroke per 1000 person-years according to the change in body weight were 3.059, 1.906, and 1.491 in the <-5%, ±5%, and ≥+5% groups, respectively. After adjusting all variables, the hazard ratio (HR) of ischemic stroke was higher in subjects who underwent weight loss (HR 1.152) or weight gain (HR 1.087) than in those who maintained their weight. When analyzed by eight groups of 5% intervals, the risk showed a U-shaped curve with those who maintained their weight showing the lowest risk.

Conclusions

The risk of ischemic stroke was gradually increased in those who lost or gained more than 5% of their weight over four years, after adjusting for confounders. We should be aware of the increased risk of ischemic stroke in people who undergo weight change and should identify and manage the cause of weight change.

Observational Evidence for Unintentional Weight Loss in All-Cause Mortality and Major Cardiovascular Events: A Systematic Review and Meta-Analysis

The obesity paradox has been described in several observational cohorts and meta-analysis. However, evidence of the intentionality of weight loss in all-cause deaths and major cardiovascular events (MACE) in prospective cohorts is unclear. We analysed whether involuntary weight loss is associated with increased cardiovascular events and mortality. In a systematic review, we searched multiple electronic databases for observational studies published up to October 2016. Studies reporting risk estimates for unintentional weight loss compared with stable weight in MACE and mortality were included. Fifteen studies met the selection criteria, with a total of 178,644 participants. For unintentional weight loss, we found adjusted risk ratios (RRs) with confidence intervals (CIs) of 1.38 (95% CI: 1.23, 1.53) and 1.17 (95% CI: 0.98, 1.37) for all-cause mortality and MACE, respectively. Participants with comorbidities, overweight and obese populations, and older adults yielded RRs (95% CI) of 1.49 (1.30, 1.68), 1.11 (1.04, 1.18), and 1.81 (1.59, 2.03), respectively. Unintentional weight loss had a significant impact on all-cause mortality. We found no protective effect of being overweight or obese for unintentional weight loss and MACE.

Behavioral and Pharmacotherapy Weight Loss Interventions to Prevent Obesity-Related Morbidity and Mortality in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Overweight and obesity have been associated with adverse health effects.

OBJECTIVE

To systematically review evidence on benefits and harms of behavioral and pharmacotherapy weight loss and weight loss maintenance interventions in adults to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed Publisher-Supplied Records, PsycINFO, and the Cochrane Central Register of Controlled Trials for studies published through June 6, 2017; ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials through August 2017; and ongoing surveillance in targeted publications through March 23, 2018. Studies from previous reviews were reevaluated for inclusion.

STUDY SELECTION

Randomized clinical trials (RCTs) focusing on weight loss or weight loss maintenance in adults.

DATA EXTRACTION AND SYNTHESIS

Data were abstracted by one reviewer and confirmed by another. Random-effects meta-analyses were conducted for weight loss outcomes in behavior-based interventions.

MAIN OUTCOMES AND MEASURES

Health outcomes, weight loss or weight loss maintenance, reduction in obesity-related conditions, and adverse events.

RESULTS

A total of 122 RCTs (N = 62 533) and 2 observational studies (N = 209 993) were identified. Compared with controls, participants in behavior-based interventions had greater mean weight loss at 12 to 18 months (-2.39 kg [95% CI, -2.86 to -1.93]; 67 studies [n = 22065]) and less weight regain (-1.59 kg [95% CI, -2.38 to -0.79]; 8 studies [n = 1408]). Studies of medication-based weight loss and maintenance interventions also reported greater weight loss or less weight regain in intervention compared with placebo groups at 12 to 18 months (range, -0.6 to -5.8 kg; no meta-analysis). Participants with prediabetes in weight loss interventions had a lower risk of developing diabetes compared with controls (relative risk, 0.67 [95% CI, 0.51 to 0.89]). There was no evidence of other benefits, but most health outcomes such as mortality, cardiovascular disease, and cancer were infrequently reported. Small improvements in quality of life in some medication trials were noted but were of unclear clinical significance. There was no evidence of harm such as cardiovascular disease from behavior-based interventions; higher rates of adverse events were associated with higher dropout rates in medication groups than in placebo groups.

CONCLUSIONS AND RELEVANCE

Behavior-based weight loss interventions with or without weight loss medications were associated with more weight loss and a lower risk of developing diabetes than control conditions. Weight loss medications, but not behavior-based interventions, were associated with higher rates of harms. Long-term weight and health outcomes data, as well as data on important subgroups, were limited.

Is weight cycling associated with adverse health outcomes? A cohort study

Evidence about the health effects of weight cycling is not consistent, with some studies suggesting it is harmful for health. Here we investigated whether weight cycling was associated with weight change and mental health outcomes in 10,428 participants in the mid-age cohort of The Australian Longitudinal Study of Women's Health (ALSWH) over 12years. In 1998 the women were asked how many times they had ever intentionally lost at least 5kg and how many times had they regained this amount. Women were categorised into four weight pattern groups: frequent weight cyclers (FWC, three or more weight cycles), low frequency weight cyclers (LFWC, one or two weight cycles), non-weight cyclers (NWC), and weight loss only (WL). We used generalised linear modelling to investigate relationships between weight pattern group, weight change and mental health outcomes. In 1998, 15% of the women were FWC, 24% LFWC, 46% NWC and 15% were WL. Weight change was similar across weight pattern groups in women with obesity, however healthy weight and overweight FWC gained more weight than women who did not weight cycle. We found no difference in overall mental health scores between groups, but both LFWC and FWC had higher odds of depressive symptoms (adjusted OR 1.5, 95%CI: 1.1 to 1.9 and 1.7, 95%CI: 1.1 to 2.4, respectively) than NWC. Our results suggest that, although weight cycling is not associated with greater weight gain in women with obesity, it may increase depressive symptoms.

Exercise training and weight loss, not always a happy marriage: single blind exercise trials in females with diverse BMI

Individuals show high variability in body weight responses to exercise training. Expectations and motivation towards effects of exercise on body weight might influence eating behaviour and could conceal regulatory mechanisms. We conducted 2 single-blind exercise trials (4 weeks (study 1) and 8 weeks (study 2)) with concealed objectives and exclusion of individuals with weight loss intention. Circuit exercise training programs (3 times a week (45-90 min), intensity 50%-90% peak oxygen uptake for 4 and 8 weeks) were conducted. Thirty-four females finished the 4-week intervention and 36 females the 8-week intervention. Overweight/obese (OV/OB) and lean female participants' weight/body composition responses were assessed and fasting and postprandial appetite hormone levels (PYY, insulin, amylin, leptin, ghrelin) were measured before and after the intervention for understanding potential contribution to individuals' body weight response to exercise training (study 2). Exercise training in both studies did not lead to a significant reduction of weight/body mass index (BMI) in the participants' groups; however, lean participants gained muscle mass. Appetite hormones levels were significantly (p < 0.05) altered in the OV/OB group, affecting fasting (-24%) and postprandial amylin (-14%) levels. Investigation of individuals' BMI responses using multiple regression analysis revealed that levels of fasting leptin, postprandial amylin increase, and BMI were significant predictors of BMI change, explaining about 43% of the variance. In conclusion, tested exercise training did not lead to weight loss in female participants, while a considerable proportion of variance in body weight response to training could be explained by individuals' appetite hormone levels and BMI.

Maintaining a clinical weight loss after intensive lifestyle intervention is the key to cardiometabolic health

OBJECTIVE

Intensive lifestyle interventions (ILI) are criticised for ineffective obesity treatment because weight loss over time is modest and thus of limited clinical relevance. However, a subgroup (5-30%) maintains a clinical weight loss >10%, but it is not clear if cardiometabolic health follows this pattern. The aim was to study the effect of different magnitudes of weight loss maintenance after ILI on cardiometabolic health.

METHODS

Eighty out of 2420 former participants (age: 36±1, BMI: 38±1, (means ±SE)) in an 11-12-week ILI were recruited into 3 groups; clinical weight loss maintenance (>10% weight loss), moderate maintenance (1-10%), and weight regain based on weight loss at follow-up (5.3±0.4years). Weight loss during the ILI was achieved by increased physical activity and hypo-caloric diet. Dual X-ray Absorptiometry, blood sample, skeletal muscle biopsy and VO_2max test were used to determine cardiometabolic health at follow-up.

RESULTS

At follow-up, the clinical weight loss maintenance group scored better in the following variables compared to the other groups: BMI (31±1, 33±2, 43±2kg/m²), composition (34±2, 40±1, 49±1% fat), visceral adipose tissue (0.8±0.2, 1.7±0.5, 2.4±0.4kg), plasma triglycerides (0.8±0.2, 1.3±0.4, 1.6±0.3mmol/L), plasma glucose (4.9±0.1, 5.9±0.4, 5.9±0.1mmol/L), Hb1Ac (5.1±0.0, 5.6±0.2, 5.8±0.2%), protein content in skeletal muscle of GLUT4 (1.5±0.2, 0.9±0.1, 1.0±0.1 AU) and hexokinase II (1.6±0.2, 1.0±0.2, 0.7±0.1 AU), citrate synthase activity (155±6, 130±5, 113±5μmol/g/min) and VO_2max (49±1, 43±1, 41±1mL/min/FFM) (p<0.05).

CONCLUSION

Cardiometabolic health is better in participants who have maintained >10% weight loss compared to moderate weight loss and weight regain.

Uptake of the centers for medicare and medicaid obesity benefit: 2012-2013

OBJECTIVE

To assess the use of the Medicare Obesity Benefit (MOB) by a licensed physician or associate provider in an outpatient setting in older adults.

METHODS

A serial cross-sectional analysis of fee-for-service Medicare claims (2012 and 2013) was used to assess the use of the MOB. Number and proportion of Medicare beneficiaries over age 65 using the benefit were assessed. Correlation between state-obesity rates and MOB uptake was determined based on state-specific obesity prevalence data from the Behavioral Risk Factor Surveillance System. Results There were 27,338 (0.10%) Medicare beneficiaries over age 65 in 2012 using the MOB and slightly more in 2013 (n = 46,821 [0.17%]). Mean age of MOB users in both years was 73 years, and 62% were females. Use declined with older age and was highest in the Northeast and lowest in the Midwest. High state obesity prevalence was not correlated with higher uptake of the MOB. Estimated proportion of persons with obesity using the MOB was 0.35% and 0.60% in successive years. A mean of 1.99 and 2.16 claims/MOB user was observed.

CONCLUSIONS

While the rate of MOB use increased in the second full year of its implementation, few were availing themselves of this benefit.

The Effectiveness of Screening for Obesity in Primary Care: Weighing the Evidence

In response to growing alarm about the increase in the prevalence of obesity in the United States, several organizations have recommended that physicians screen their adult patients for this condition and initiate treatment. Screening can be an effective intervention when the condition is grave and prevalent, when an accurate test exists, when effective treatment exists, when the screening program itself does not pose undue risks, and when early detection and treatment improve outcomes. This article critically reviews the evidence supporting these criteria in the case of obesity in adults. It extends previous reviews by assessing the potential impact that uncertainties in the evidence base may have on the effectiveness a screening program. It also examines the feasibility of such a program. We conclude that following the recommendation to screen all adults for obesity is unlikely to improve outcomes.

'Adipaging': ageing and obesity share biological hallmarks related to a dysfunctional adipose tissue

The increasing ageing of our societies is accompanied by a pandemic of obesity and related cardiometabolic disorders. Progressive dysfunction of the white adipose tissue is increasingly recognized as an important hallmark of the ageing process, which in turn contributes to metabolic alterations, multi-organ damage and a systemic pro-inflammatory state ('inflammageing'). On the other hand, obesity, the paradigm of adipose tissue dysfunction, shares numerous biological similarities with the normal ageing process such as chronic inflammation and multi-system alterations. Accordingly, understanding the interplay between accelerated ageing related to obesity and adipose tissue dysfunction is critical to gain insight into the ageing process in general as well as into the pathophysiology of obesity and other related conditions. Here we postulate the concept of 'adipaging' to illustrate the common links between ageing and obesity and the fact that, to a great extent, obese adults are prematurely aged individuals.

Development and Efficacy Testing of a Social Network-Based Competitive Application for Weight Loss

INTRODUCTION

Although a lot of people continuously try to lose weight, the obesity rate has remained high: 36.9% of males and 38.0% of females worldwide in 2013. This suggests the need for a new intervention.

MATERIALS AND METHODS

In this study, we designed a smartphone application, With U, to aid weight loss by using an offline social network of friends and an online social network, Facebook. To determine the effects of With U, this study was designed as a one-group pretest-posttest design. Overweight, obese, and severely obese adults 20-40 years old, along with their friends, participated in this study. A total of 10 pairs attempted to lose weight for 4 weeks. We used a questionnaire to measure general characteristics, motivation, and intent to continue to use With U, and the Inbody720 (Biospace, Seoul, Republic of Korea) body composition analyzer was used to measure physical characteristics. In addition, we briefly interviewed the participants about their experience.

RESULTS

We observed statistically significant effects in terms of motivation to lose weight and the amount of weight loss. Changes in physical characteristics beyond weight loss also showed positive trends. Also, we discovered some interesting facts during the interviews. The weight loss effect was greater when the team members met more and the relationship between the challengers was more direct and intimate.

CONCLUSIONS

The application With U, designed and developed to allow friends to challenge each other to lose weight, affected both motivation to lose weight and the amount of weight loss. In the future, effects of smartphone applications for health management with social networks need to be studied further.

Trajectories of Body Mass Index and Their Associations With Mortality Among Older Japanese: Do They Differ From Those of Western Populations?

Few studies have focused on the relationship between the trajectories of long-term changes in body mass index (BMI; weight (kg)/height (m)(2)) and all-cause mortality in old age, particularly in non-Western populations. We evaluated this association by applying group-based mixture models to data derived from the National Survey of the Japanese Elderly, which included 4,869 adults aged 60 or more years, with up to 7 repeated observations between 1987 and 2006. Four distinct BMI trajectories were identified: "low-normal weight, decreasing" (baseline BMI = 18.7; 23.8% of sample); "mid-normal weight, decreasing" (baseline BMI = 21.9; 44.6% of sample); "high-normal weight, decreasing" (baseline BMI = 24.8; 26.5% of sample); and "overweight, stable" (baseline BMI = 28.7; 5.2% of sample). Survival analysis with an average follow-up of 13.8 years showed that trajectories of higher BMI were associated with lower mortality. In particular, relative to those with a mid-normal weight, decreasing BMI trajectory, those with an overweight, stable BMI trajectory had the lowest mortality, and those with a low-normal, decreasing BMI trajectory had the highest mortality. In sharp contrast with prior observations from Western populations, BMI changes lie primarily within the normal-weight range, and virtually no older Japanese are obese. The association between BMI trajectories and mortality varies according to the distribution of BMI within the population.

Body Mass Index: Obesity, BMI, and Health: A Critical Review

The body mass index (BMI) is the metric currently in use for defining anthropometric height/weight characteristics in adults and for classifying (categorizing) them into groups. The common interpretation is that it represents an index of an individual's fatness. It also is widely used as a risk factor for the development of or the prevalence of several health issues. In addition, it is widely used in determining public health policies.The BMI has been useful in population-based studies by virtue of its wide acceptance in defining specific categories of body mass as a health issue. However, it is increasingly clear that BMI is a rather poor indicator of percent of body fat. Importantly, the BMI also does not capture information on the mass of fat in different body sites. The latter is related not only to untoward health issues but to social issues as well. Lastly, current evidence indicates there is a wide range of BMIs over which mortality risk is modest, and this is age related. All of these issues are discussed in this brief review.

Intentional weight loss and all-cause mortality: a meta-analysis of randomized clinical trials

BACKGROUND

Obesity is associated with increased mortality, and weight loss trials show rapid improvement in many mortality risk factors. Yet, observational studies typically associate weight loss with higher mortality risk. The purpose of this meta-analysis of randomized controlled trials (RCTs) of weight loss was to clarify the effects of intentional weight loss on mortality.

METHODS

2,484 abstracts were identified and reviewed in PUBMED, yielding 15 RCTs reporting (1) randomization to weight loss or non-weight loss arms, (2) duration of ≥18 months, and (3) deaths by intervention arm. Weight loss interventions were all lifestyle-based. Relative risks (RR) and 95% confidence intervals (95% CI) were estimated for each trial. For trials reporting at least one death (n = 12), a summary estimate was calculated using the Mantel-Haenszel method. Sensitivity analysis using sparse data methods included remaining trials.

RESULTS

Trials enrolled 17,186 participants (53% female, mean age at randomization = 52 years). Mean body mass indices ranged from 30-46 kg/m2, follow-up times ranged from 18 months to 12.6 years (mean: 27 months), and average weight loss in reported trials was 5.5±4.0 kg. A total of 264 deaths were reported in weight loss groups and 310 in non-weight loss groups. The weight loss groups experienced a 15% lower all-cause mortality risk (RR = 0.85; 95% CI: 0.73-1.00). There was no evidence for heterogeneity of effect (Cochran's Q = 5.59 (11 d.f.; p = 0.90); I2 = 0). Results were similar in trials with a mean age at randomization ≥55 years (RR = 0.84; 95% CI 0.71-0.99) and a follow-up time of ≥4 years (RR = 0.85; 95% CI 0.72-1.00).

CONCLUSIONS

In obese adults, intentional weight loss may be associated with approximately a 15% reduction in all-cause mortality.

Consequences of obesity and weight loss: a devil's advocate position

Obesity is associated with multiple negative health consequences and current weight management guidelines recommend all obese persons to lose weight. However, recent evidence suggests that not all obese persons are negatively affected by their weight and that weight loss does not necessarily always improve health. The purpose of this review is not to trivialize the significant health risks associated with obesity, but to discuss subpopulations of obese people who are not adversely affected, or may even benefit from higher adiposity, and in who weight loss per se may not always be the most appropriate recommendation. More specifically, this review will take a devil's advocate position when discussing the consequences of obesity and weight loss for adults with established cardiovascular disease and type 2 diabetes, weight cyclers, metabolically healthy obese adults, youth, older adults and obese individuals who are highly fit.

Changes in body mass index, waist and hip circumferences, waist to hip ratio and risk of all-cause mortality in men

BACKGROUND

There is a paucity of data about the impact of changes in anthropometric measurements on the risk of mortality events, especially in men.

METHODS

The study sample consists of 1805 Iranian men, aged ⩾ 30 years, free from cardiovascular disease at baseline; they had undergone health examinations in both phases I (1999-2001) and II (2001-2003) and were followed up until March 2010. Participants were categorized by changes in anthropometric measurements into four groups: Group 1, change percentage<-5%; Group 2, -5% ⩽ change percentages<+5%; Group 3, 5% ⩽ change percentage<10%; and Group 4, change percentage ⩾ 10%. Cox proportional hazard regression was performed to assess the hazard ratios (HRs) of the anthropometric changes for all-cause mortality, given group 2 as the reference.

RESULTS

During 6.6 years of follow-up, 88 cases of mortality events occurred. The confounder-adjusted multivariate HRs for the first, third and fourth groups of hip circumference (HC) changes were 3.13(1.28-7.64), 0.75(0.43-1.31) and 0.82(0.23-2.99); the corresponding values for waist to hip ratio (WHR) change were 1.80(0.75-4.33), 1.21(0.70-2.1) and 2.32(1.25-4.3). After further adjustment for mediator covariates, results did not change. The equivalent values for body mass index and waist circumference did not reach statistical significance.

CONCLUSIONS

In Middle Eastern Caucasian men, increase in WHR was associated with incident mortality, which was more prominent in those with ⩾ 10% increase in the ratio. Moreover, decrease in HC was highly associated with excess risk of mortality.

Impact of weight cycling on risk of morbidity and mortality

Unintentional weight gain is commonly observed in adult humans, often provoking intentional weight loss attempts followed by unintentional weight regain. This episodic variation in body weight over a period of time has been referred to as 'weight cycling'. Over the last two decades, weight cycling has been associated with a number of morbid health conditions and increased mortality. This article provides a comprehensive evaluation of recent weight-cycling evidence, looks to understand design differences between studies and study outcomes, assesses the need for further research on particular health outcomes, and proposes alternative methodologies that will bridge the needs and capabilities of research. Searches were conducted per PRISMA guidelines. Articles on weight cycling in the literature were initially identified using search strings in PubMed. Eligibility assessment of the remaining articles was performed independently by three reviewers to identify publications that presented direct evidence. Twenty human studies (in addition to seven animal studies) were selected and retained; 12 accounted for the intentionality of weight loss. Although weight regain following successful weight loss remains one of the most challenging aspects of body-weight regulation, evidence for an adverse effect of weight cycling appears sparse, if it exists at all.

Weight status in young adulthood and survival after cardiovascular diseases and cancer

BACKGROUND

Some studies have suggested that overweight is associated with lower mortality, but these results may be affected by reverse causality. We analysed how body mass index (BMI) in young adulthood is associated with mortality in the general population and after the diagnoses of coronary heart disease (CHD), stroke and cancer.

METHODS

BMI was measured at an average age of 18 years in 734 438 Swedish men born in 1950-65. Diagnoses of CHD, stroke and cancer as well as all-cause mortality were derived from registers covering the whole population, up to 31 December 2010. The follow-up of 24.56 million person-years included 33 067 cases of mortality and 19 843 CHD, 13 578 stroke and 27 365 cancer diagnoses. Hazard ratios (HR) [with 95% confidence intervals (CI)] were estimated by the Cox proportional hazards model.

RESULTS

Higher mortality in the whole cohort (HR = 1.26, 1.21-1.32) as well as after the diagnosis of CHD (HR = 1.33, 1.09-1.63) or cancer (HR = 1.13, 1.01-1.25) was found in moderately overweight men (BMI 25.0-27.4 kg/m(2)) as compared with normal weight men (BMI 20.1-22.4 kg/m(2)); for stroke patients the result for the same BMI categories was not statistically significant (HR = 1.17, 0.94-1.45). Mortality increased with increasing weight status and was highest in obese men (BMI >30 kg/m(2)): HR = 2.17 (2.02-2.34) for the whole cohort, 2.35 (1.81-3.05) after the diagnosis of CHD, 2.08 (1.56-2.77) after stroke and 1.68 (1.40-2.01) after cancer.

CONCLUSIONS

Even moderate overweight in young adulthood increases all-cause mortality and mortality after the diagnosis of CHD, stroke and cancer in men. Preventing overweight in young adulthood remains as an important public health issue.

Public health ethics and obesity prevention: the trouble with data and ethics

In recent years policy makers and public health professionals have described obesity and its associated diseases as a major global public health problem. Bioethicists have tried to address the normative implications of proposed public health interventions by developing guidelines or proposing ethical principles that ethically grounded health policy responses should take into consideration. We are reviewing here relevant literature and conclude that while there are clearly health (and health care cost) implications resulting from the increasing number of seriously obese people across the globe, there appear to be legitimate questions about the scope of the problem as well as questions about whether particular demonstrable correlations are indicative of causations. These empirical questions require further clinical and epidemiological research. We then review currently discussed public health ethics guidance documents and proposals. Suffering from the same conceptual problems that are known features of principle-based bioethics, insofar as their capacity to ground ethically justifiable policies is concerned, they are unsuitable for actual policy development. Even if the empirical questions were resolved, health policy makers could not rely on currently existing prominent public health ethics guidance documents to develop ethically defensible policies. Further empirical and ethics research is necessary to develop ethically defensible public health policies targeting obesity.

Obesity and mortality risk: new findings from body mass index trajectories

Little research has addressed the heterogeneity and mortality risk in body mass index (BMI) trajectories among older populations. Applying latent class trajectory models to 9,538 adults aged 51 to 77 years from the US Health and Retirement Study (1992-2008), we defined 6 latent BMI trajectories: normal weight downward, normal weight upward, overweight stable, overweight obesity, class I obese upward, and class II/III obese upward. Using survival analysis, we found that people in the overweight stable trajectory had the highest survival rate, followed by those in the overweight obesity, normal weight upward, class I obese upward, normal weight downward, and class II/III obese upward trajectories. The results were robust after controlling for baseline demographic and socioeconomic characteristics, smoking status, limitations in activities of daily living, a wide range of chronic illnesses, and self-rated health. Further analysis suggested that BMI trajectories were more predictive of mortality risk than was static BMI status. Using attributable risk analysis, we found that approximately 7.2% of deaths after 51 years of age among the 1931-1941 birth cohort were due to class I and class II/III obese upward trajectories. This suggests that trajectories of increasing obesity past 51 years of age pose a substantive threat to future gains in life expectancy.

Changes in body mass index following newly diagnosed type 2 diabetes and risk of cardiovascular mortality: a cohort study of 8486 primary-care patients

AIMS

Elevated body mass index (BMI) is associated with an increased risk of type 2 diabetes and cardiovascular disease (CVD). This study explored the association between BMI changes in the first 18 months of newly diagnosed type 2 diabetes and the risk of long-term CVD mortality.

METHODS

A total of 8486 patients with newly diagnosed type 2 diabetes and no previous history of CVD or cancer were identified from 84 primary-care centres in Sweden. During the first year after diagnosis, patients were grouped according to BMI change: 'Increase', or ≥+1 BMI unit; 'unchanged', or between +1 and-1 BMI unit; and 'decrease', or ≤-1 BMI unit. Associations between BMI change and CVD mortality, defined as death from stroke, myocardial infarction or sudden death, were estimated using adjusted Cox proportional hazards models (NCT 01121315).

RESULTS

Baseline mean age was 60.0 years and mean BMI was 30.2kg/m(2). Patients were followed for up to 9 years (median: 4.6 years). During the first 18 months, 53.4% had no change in their BMI, while 32.2% decreased and 14.4% increased. Compared with patients with unchanged BMI, those with an increased BMI had higher risks of CVD mortality (hazard ratio: 1.63, 95% CI: 1.11-2.39) and all-cause mortality (1.33, 1.01-1.76). BMI decreases had no association with these risks compared with unchanged BMI: 1.06 (0.76-1.48) and 1.06 (0.85-1.33), respectively.

CONCLUSION

Increased BMI within the first 18 months of type 2 diabetes diagnosis was associated with an increased long-term risk of CVD mortality. However, BMI decrease did not lower the long-term risk of mortality.

Modeling obesity histories in cohort analyses of health and mortality

There is great interest in understanding the role of weight dynamics over the life cycle in predicting the incidence of disease and death. Beginning with a Medline search, we identify, classify, and evaluate the major approaches that have been used to study these dynamics. We identify four types of models: additive models, duration-of-obesity models, additive-weight-change models, and interactive models. We develop a framework that integrates the major approaches and shows that they are often nested in one another, a property that facilitates statistical comparisons. Our criteria for evaluating models are two-fold: the model's interpretability and its ability to account for observed variation in health outcomes. We apply two sets of nested models to data on adults age 50-74 years at baseline in two national probability samples drawn from National Health and Nutrition Examination Survey. One set of models treats obesity as a dichotomous variable and the other treats it as a continuous variable. In three of four applications, a fully interactive model does not add significant explanatory power to the simple additive model. In all four applications, little explanatory power is lost by simplifying the additive model to a duration model in which the coefficients of weight at different ages are set equal to one another. Other versions of a duration-of-obesity model also perform well, underscoring the importance of obesity at early adult ages for mortality at older ages.

Body weight variability in midlife and risk for dementia in old age

OBJECTIVE

To analyze the relationship between body weight variability and dementia more than 3 decades later.

METHODS

The measurement of body weight variability was based on 3 successive weight recordings taken from over 10,000 apparently healthy tenured working men participating in the Israel Ischemic Heart Disease study, in which cardiovascular risk factors and clinical status were assessed in 1963, 1965, and 1968, when subjects were 40-70 years of age. Groups of men were stratified according to quartiles of SD of weight change among 3 measurements (1963/1965/1968): ≤ 1.15 kg, 1.16-1.73 kg, 1.74-2.65 kg, and ≥ 2.66 kg. The prevalence of dementia was assessed more than 36 years later in approximately one-sixth of them who survived until 1999/2000 (minimum age 76 years) and underwent cognitive evaluation (n = 1,620).

RESULTS

Survivors' dementia prevalence rates were 13.4%, 18.4%, 20.1%, and 19.2% in the first to fourth quartiles of weight change SD, respectively (p for trend = 0.034). Compared to the first quartile of weight change SD and adjusted for diabetes mellitus, body height, and socioeconomic status, a multivariate analysis demonstrated that the odds ratio for dementia was 1.42 (95% confidence interval [CI] 0.95-2.13), 1.59 (95% CI 1.05-2.37), and 1.74 (95% CI 1.14-2.64) in quartiles 2-4 of weight change SD respectively. This relationship was independent of the direction of weight changes.

CONCLUSION

Midlife variations in weight may antecede late-life dementia.

Obesity and the occurrence of bronchitis in adolescents

OBJECTIVE

Previous studies have shown that an elevated BMI was associated with higher risks of bronchitis among children. The magnitude of how increase in BMI influencing the risk of incident bronchitis remained unexplored. The objective of this study is to assess the association between BMI and the incidence of bronchitis in the Taiwan Children Health Study.

DESIGN

A school-based prospective cohort study.

METHODS

We conducted a population-based prospective cohort study among seventh-grade school children in 14 Taiwanese communities. A total of 3,634 adolescents completed follow-up questionnaire in 2009. Associations between BMI and incident bronchitis were analyzed by multiple Poisson regression models, taking overdispersion into account.

RESULTS

Among eligible cohort participants without bronchitis at study entry, the proportion of overweight and obesity were 32.1% and 17.9%. Overweight was 40.7% and obesity was 27.7% among those with incident bronchitis. The BMI percentile categories showed significant increasing trends for bronchitis in total eligible children and in girls (P for trend <0.001). Overweight and obesity were both associated with increased risks of incident bronchitis. This association was significant in girls only while stratified by gender.

CONCLUSIONS

Our data showed that the BMI percentile and weight status were associated with higher risks of incident bronchitis in adolescents, especially in girls.

Predictors of body mass index change from 11 to 15 years of age: the 1993 Pelotas (Brazil) birth cohort study

PURPOSE

We explored predictors of nutritional status change from 11 to 15 years of age by analyzing prospective data.

METHODS

We collected data at 11 and 15 years of age from individuals born in 1993 in Pelotas, Brazil. We assessed nutritional status using body mass index (BMI) for age in z-score according to the World Health Organization 2007 standards. Independent variables collected at 11 years of age were socioeconomic position, adolescent's perception of own weight, body dissatisfaction, and weight loss dieting.

RESULTS

Of the 4,032 adolescents whose nutritional status could be evaluated in the two follow-ups, 93% maintained their nutritional status classification from 11 to 15 years. A total of 102 (2.8%) became obese and 181 (4.5%) ceased to be obese in the 4-year period. The prevalence of obesity decreased from 11 to 15 years of age in both boys and girls. Low-income girls were more likely to become obese from 11 to 15 years of age compared with high-income ones. Among boys, those with high income were more likely to cease being obese compared those with low income. Those who perceived themselves to be obese, who wished to have a smaller silhouette, and who were on diets to lose weight were more likely to become obese or to achieve a normal BMI category at 15 years of age.

CONCLUSIONS

BMI tracks strongly in early adolescence. This finding suggests that interventions to more effectively change nutritional status should be implemented in childhood and should consider emotional aspects as well as social and biological ones.

Obesity: a disease or a biological adaptation? An update

Obesity is characterized by the accumulation of excess body fat and can be conceptualized as the physical manifestation of chronic energy excess. An important challenge of today's world is that our so-called obesogenic environment is conducive to the consumption of energy and unfavourable to the expenditure of energy. The modern, computer-dependent, sleep-deprived, physically inactive humans live chronically stressed in a society of food abundance. From a physiological standpoint, the excess weight gain observed in prone individuals is perceived as a normal consequence to a changed environment rather than a pathological process. In other words, weight gain is a sign of our contemporary way of living or a 'collateral damage' in the physiological struggle against modernity. Additionally, substantial body fat loss can complicate appetite control, decrease energy expenditure to a greater extent than predicted, increase the proneness to hypoglycaemia and its related risk towards depressive symptoms, increase the plasma and tissue levels of persistent organic pollutants that promote hormone disruption and metabolic complications, all of which are adaptations that can increase the risk of weight regain. In contrast, body fat gain generally provides the opposite adaptations, emphasizing that obesity may realistically be perceived as an a priori biological adaptation for most individuals. Accordingly, prevention and treatment strategies for obesity should ideally target the main drivers or root causes of body fat gain in order to be able to improve the health of the population.

A critical review of major mortality risk factors for all-cause mortality in first-episode schizophrenia: clinical and research implications

A bibliographical search was performed to identify and evaluate the impact in first-episode schizophrenia of the major mortality risk factors as described by the World Health Organisation (2009). We found that at first diagnosis rates of diabetes were only slightly increased, although lipid abnormalities, mild hypertension and being overweight were commonly reported. Levels of drug and alcohol abuse were high, as were pre-diagnosis rates of smoking, physical inactivity and poor cardiorespiratory fitness. During the first year of antipsychotic treatment, there were significant increases in the rates of hyperglycaemia/diabetes, obesity, lipid abnormalities and hypertension, but no changes in fitness levels, smoking or drug and alcohol abuse. In chronic schizophrenia, excess cancer and cardiac deaths seem linked in part to availability and quality of care. Innate risk factors such as abnormal reelin and raised prolactin may also be important. New evidence, such as an inverse relationship between body mass index and suicide in the general population, suggests accepted wisdom may not apply to patients at high risk of ending their own lives. With current knowledge emphasis needs to be placed by early intervention services on physical fitness, smoking and other substance misuse, diabetes and hypertension, as well as focusing on weight reduction only in the obese.

The downside of weight loss: realistic intervention in body-weight trajectory

OBJECTIVE

To explore the reasons why long-term weight loss is seldom achieved and to evaluate the consequences of various weight trajectories, including stability, loss, and gain.

QUALITY OF EVIDENCE

Studies evaluating population weight metrics were mainly observational. Level I evidence was available to evaluate the influence of weight interventions on mortality and quality of life.

MAIN MESSAGE

Sustained weight loss is achieved by a small percentage of those intending to lose weight. Mortality is lowest in the high-normal and overweight range. The safest body-size trajectory is stable weight with optimization of physical and metabolic fitness. With weight loss there is evidence for lower mortality in those with obesity-related comorbidities. There is also evidence for improved health-related quality of life in obese individuals who lose weight. Weight loss in the healthy obese, however, is associated with increased mortality.

CONCLUSION

Weight loss is advisable only for those with obesity-related comorbidities. Healthy obese people wishing to lose weight should be informed that there might be associated risks. A strategy that leads to a stable body mass index with optimized physical and metabolic fitness at any size is the safest weight intervention option.

Repeated measures of body mass index and risk of health related outcomes

Most studies examining the association between body mass index (BMI) and mortality neglected changes in weight over time, which may have led to underestimation of the true association. The aim of this study is to examine the relationship between BMI and health related outcomes while accounting for variations of BMI over time. The association between BMI and both mortality and occupational disability was examined in a follow-up of 5,554 male construction workers in Württemberg/Germany, who participated at least two times in routine occupational health examinations between 1986 and 2005. Using Cox proportional hazards model with time dependent variables, hazard ratios were calculated with normal weight (<25 kg/m²) as reference after adjustment for potential confounding factors. Overall, an U-shaped association between baseline BMI and mortality (370 events) as well as occupational disability (658 events) was observed, with lowest risk at BMI levels between 25 and 30 kg/m². Men with a baseline BMI ≥ 30 kg/m² experienced a 10% higher mortality and disability risk than normal weight men. The association between BMI and occupational disability became stronger after accounting for temporal variability of BMI with a significant increased risk of 1.26 (95% confidence interval: 1.01-1.56) among obese men. In contrast, the association between BMI and mortality did not materially change after accounting for time dependent effects. Stable obesity as defined by a BMI of 30 kg/m² and above increases risk of disability in male construction workers. Accounting for changes of BMI over time is crucial for disclosing full impact of obesity.

Long-term effects of changes in cardiorespiratory fitness and body mass index on all-cause and cardiovascular disease mortality in men: the Aerobics Center Longitudinal Study

BACKGROUND

The combined associations of changes in cardiorespiratory fitness and body mass index (BMI) with mortality remain controversial and uncertain.

METHODS AND RESULTS

We examined the independent and combined associations of changes in fitness and BMI with all-cause and cardiovascular disease (CVD) mortality in 14 345 men (mean age 44 years) with at least 2 medical examinations. Fitness, in metabolic equivalents (METs), was estimated from a maximal treadmill test. BMI was calculated using measured weight and height. Changes in fitness and BMI between the baseline and last examinations over 6.3 years were classified into loss, stable, or gain groups. During 11.4 years of follow-up after the last examination, 914 all-cause and 300 CVD deaths occurred. The hazard ratios (95% confidence intervals) of all-cause and CVD mortality were 0.70 (0.59-0.83) and 0.73 (0.54-0.98) for stable fitness, and 0.61 (0.51-0.73) and 0.58 (0.42-0.80) for fitness gain, respectively, compared with fitness loss in multivariable analyses including BMI change. Every 1-MET improvement was associated with 15% and 19% lower risk of all-cause and CVD mortality, respectively. BMI change was not associated with all-cause or CVD mortality after adjusting for possible confounders and fitness change. In the combined analyses, men who lost fitness had higher all-cause and CVD mortality risks regardless of BMI change.

CONCLUSIONS

Maintaining or improving fitness is associated with a lower risk of all-cause and CVD mortality in men. Preventing age-associated fitness loss is important for longevity regardless of BMI change.