Effects of Intended Weight Loss on Morbidity and Mortality: Possible Explanations of Controversial Results

Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy decreases lean body mass and appendicular skeletal muscle mass index even until one year after the final treatment in patients with B-cell non-Hodgkin lymphoma

Sarcopenia is an independent prognostic factor for several solid cancers, including B-cell non-Hodgkin lymphoma (B-NHL). However, previous reports have measured the parameters of loss of skeletal muscle as sarcopenia only once before chemotherapy and have predicted poor outcomes. In this study, changes in body composition were measured in patients who received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy for B-NHL using the InBody 720 analyzer throughout the therapy. Twenty-seven patients who achieved complete remission and survived for one year after the last cycle were included in the study. Body composition was evaluated immediately before initiation and fourth cycle, and one month and one year after the last cycle. Throughout the follow-up period, the lean body mass index (LBMI) and appendicular skeletal muscle mass index (ASMI) showed significant transient decreases even one year following the last cycle (p < 0.001, p = 0.002, respectively). Body fat index (BFI) and body fat percentage (BF%) decreased until one month after the last cycle; however, they reached levels higher than the baseline levels, +22.1% and +15.9%, respectively, at 1 year from the last cycle. The loss of skeletal muscle mass did not recover even one year after the last cycle. Interventions in nutritional management are needed to prevent sarcopenia in patients treated with R-CHOP therapy.

High prevalence of pre-existing sarcopenia in critically ill patients with hematologic malignancies admitted to the intensive care unit for sepsis or septic shock

BACKGROUND & AIMS

We aimed to evaluate body composition (BC) by computed tomography (CT) in hematologic malignancy (HM) patients admitted to the intensive care unit (ICU) for sepsis or septic shock.

METHODS

We retrospectively assessed BC and its impact on outcome of 186 patients at the 3rd lumbar (L3) and 12th thoracic vertebral levels (T12) using CT-scan performed before ICU admission.

RESULTS

The median patient age was 58.0 [47; 69] years. Patients displayed adverse clinical characteristics at admission with median [q1; q3] SAPS II and SOFA scores of 52 [40; 66] and 8 [5; 12], respectively. The mortality rate in the ICU was 45.7%. Overall survival rates at 1 month after admission in the pre-existing sarcopenic vs. non pre-existing sarcopenic patients were 47.9% (95% CI [37.6; 61.0]) and 55.0% (95% CI [41.6; 72.8]), p = 0.99), respectively, at the L3 level and 48.4% (95% CI [40.4; 58.0]) vs. 66.7% (95% CI [51.1; 87.0]), p = 0.062), respectively, at the T12 level.

CONCLUSIONS

Sarcopenia is assessable by CT scan at both the T12 and L3 levels and is highly prevalent in HM patients admitted to the ICU for severe infections. Sarcopenia may contribute to the high mortality rate in the ICU in this population.

Liraglutide changes body composition and lowers added sugar intake in overweight persons with insulin pump-treated type 1 diabetes

AIMS

To present secondary outcome analyses of liraglutide treatment in overweight adults with insulin pump-treated type 1 diabetes (T1D), focusing on changes in body composition and dimensions, and to evaluate changes in food intake to identify potential dietary drivers of liraglutide-associated weight loss.

MATERIALS AND METHODS

A 26-week randomized placebo-controlled study was conducted to investigate the efficacy and safety of liraglutide 1.8 mg daily in 44 overweight adults with insulin pump-treated T1D and glucose levels above target, and demonstrated significant glycated haemoglobin (HbA1c)- and body weight-reducing effects. For secondary outcome analysis, dual X-ray absorptiometry scans were completed at Weeks 0 and 26, and questionnaire-based food frequency recordings were obtained at Weeks 0, 13 and 26 to characterize liraglutide-induced changes in body composition and food intake.

RESULTS

Total fat and lean body mass decreased in liraglutide-treated participants (fat mass -4.6 kg [95% confidence interval {CI} -5.7; -3.5], P < 0.001; lean mass -2.5 kg [95% CI -3.2;-1.7], P < 0.001), but remained stable in placebo-treated participants (fat mass -0.3 kg [95% CI -1.3;0.8], P = 0.604; lean mass 0.0 kg [95% CI -0.7;0.7]; P = 0.965 [between-group P values <0.001]). Participants reduced their energy intake numerically more in the liraglutide arm (-1.1 MJ [95% CI -2.0;-0.02], P = 0.02) than in the placebo arm (-0.9 MJ [95% CI -2.0;0.1], P = 0.22), but the between-group difference was statistically insignificant (P = 0.42). However, energy derived from added sugars decreased by 27% in the liraglutide arm compared with an increase of 14% in the placebo arm (P = 0.004).

CONCLUSIONS

Liraglutide lowered fat and lean body mass compared with placebo. Further, liraglutide reduced intake of added sugars. However, no significant difference in total daily energy intake was detected between liraglutide- and placebo-treated participants.

Weight Change Since Age 20 and the Risk of Cardiovascular Disease Mortality: A Prospective Cohort Study

Aim: Weight change could have many health outcomes. This study aimed to investigate the association between weight change and mortality risk due to total cardiovascular disease (CVD), ischemic heart disease (IHD), and stroke among Japanese.

Methods: We used Suita Study data from 4,746 people aged 30-79 years in this prospective cohort study. Weight change was defined as the difference between baseline weight and weight at age 20. We used Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of total CVD, IHD, and stroke mortality for 1) participants with a weight change (＞10, 5 to 10, -5 to -10, and ＜-10 kg) compared to those with stable weight (-4.9 to 4.9 kg) and 2) participants who moved from one body mass index category (underweight, normal weight, or overweight) to another compared to those with normal weight at age 20 and baseline.

Results: Within a median follow-up period of 19.9 years, the numbers of total CVD, IHD, and stroke mortality were 268, 132, and 79, respectively. Weight loss of ＞10 kg was associated with the increased risk of total CVD mortality 2.07 (1.29, 3.32) and stroke mortality 3.02 (1.40, 6.52). Moving from normal weight at age 20 to underweight at baseline was associated with the increased risk of total CVD, IHD, and stroke mortality: 1.76 (1.12, 2.77), 2.10 (1.13, 3.92), and 2.25 (1.05, 4.83), respectively.

Conclusion: Weight loss, especially when moving from normal to underweight, was associated with the increased risk of CVD mortality.

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.

Life-long body mass index trajectories and mortality in two generations

PURPOSE

To identify life-long body mass index (BMI) trajectories across two related generations and estimate their associated mortality risks and population attributable deaths.

METHODS

We use prospective cohort data from the Framingham Heart Study (1948-2011) original (4576 individuals, 3913 deaths) and offspring (3753 individuals, 967 deaths) cohorts and latent trajectory models to model BMI trajectories from age 31 to 80 years. Survival models are used to estimate trajectory-specific mortality risk.

RESULTS

We define seven BMI trajectories among original cohort and six among offspring cohort. Among original cohort, people who are normal weight at age 31 years and gradually move to overweight status in middle or later adulthood have the lowest mortality risk even compared to those who maintain normal weight throughout adulthood, followed by overweight stable, lower level of normal weight, overweight downward, class I obese upward, and class II/III upward trajectories. Mortality risks associated with obesity trajectories have declined across cohorts, while the prevalence of high-risk trajectories has increased.

CONCLUSIONS

The mortality impact of weight gain depends on an individual's BMI trajectory. Population attributable deaths associated with unhealthy weight trajectories have grown over generations because the prevalence has increased, offsetting the decline in trajectory-specific mortality risks.

Variabilities in Weight and Waist Circumference and Risk of Myocardial Infarction, Stroke, and Mortality: A Nationwide Cohort Study

BACKGROUND

Evidence regarding the association between variabilities in obesity measures and health outcomes is limited. We aimed to examine the association between variabilities in obesity measures and cardiovascular outcomes and all-cause mortality.

METHODS

We identified 4,244,460 individuals who underwent health examination conducted by the Korean National Health Insurance Service during 2012, with ≥3 anthropometric measurements between 2009 and 2012. Variabilities in body weight (BW) and waist circumference (WC) were assessed using four indices including variability independent of the mean (VIM). We performed multivariable Cox proportional hazards regression analyses.

RESULTS

During follow-up of 4.4 years, 16,095, 18,957, and 30,200 cases of myocardial infarction (MI), stroke, and all-cause mortality were recorded. Compared to individuals with the lowest quartiles, incrementally higher risks of study outcomes and those of stroke and all-cause mortality were observed among individuals in higher quartiles of VIM for BW and VIM for WC, respectively. The multivariable adjusted hazard ratios and 95% confidence intervals comparing the highest versus lowest quartile groups of VIM for BW were 1.17 (1.12 to 1.22) for MI, 1.20 (1.16 to 1.25) for stroke, and 1.66 (1.60 to 1.71) for all-cause mortality; 1.07 (1.03 to 1.12) for stroke and 1.29 (1.25 to 1.33) for all-cause mortality regarding VIM for WC. These associations were similar with respect to the other indices for variability.

CONCLUSION

This study revealed positive associations between variabilities in BW and WC and cardiovascular outcomes and allcause mortality. Our findings suggest that variabilities in obesity measures are associated with adverse health outcomes in the general population.

Levels and changes in body mass index decomposed into fat and fat-free mass index: relation to long-term all-cause mortality in the general population

BACKGROUND

In the general population, body mass index (BMI = weight (kg)/(height (m))²) shows a U-shaped relation to mortality, which is attributable to a combination of an inverse association with fat-free mass index (FFMI) and a direct association with fat mass index (FMI). However, preceding changes in body composition related to diseases, health behaviors, or social conditions that are also influencing later mortality may confound these associations.

OBJECTIVE

To examine associations of FFMI and FMI, adjusted for preceding changes in FFMI and FMI over a 6 years period, with all-cause mortality in a healthy general population.

METHODS

The study population was a random subset of adult Danes, participating in the Danish MONICA project; 989 men and 962 women, born 1922, 1932, 1942, and 1952, and examined in 1987-88 and 1993-94. They had no known major co-morbidities until start of follow-up in 1993-94, and were followed up for 18 years. Measures included height, weight, and bio-impedance, from which BMI, FFMI, and FMI were calculated, and information on educational level, smoking, alcohol drinking, leisure-time physical activity, which were obtained by questionnaires. We analyzed the relation between body composition and all-cause mortality by Cox proportional hazards model with splines, stratified by birth cohorts, and with adjustment for preceding changes in body composition and for the covariates including gender. We estimated hazard ratios (HR) with 95% confidence intervals (CI) relative to HR = 1.00 at the median values of BMI, FMI, and FFMI.

RESULTS

During 18 years of follow-up, 286 men and 200 women died. BMI showed the well-known U-shaped association with mortality, and FMI was directly and FFMI inversely associated with mortality. Associations were not significantly modified by gender. Preceding changes in BMI, FMI, and FFMI were only weakly and not significantly associated with mortality. Associations for FMI and FFMI were monotonic, but curve-linear with a higher mortality above and below the respective median values of FMI and FFMI: at the 5th percentiles of FMI and FFMI, HRs were 0.80 (CI 0.57-1.13) and 2.01 (1.24-3.27), and at the 95th percentiles, HRs were 2.16 (1.38-3.38) and 0.81 (0.52-1.27), respectively.

CONCLUSIONS

In an apparently healthy general population, a large fat mass and a small fat-free mass are associated with greater risk of early mortality, also after adjusting for preceding changes in body composition, health behaviors, and educational level.

Weight loss in heart failure is associated with increased mortality only in non-obese patients without diabetes

BACKGROUND

Weight loss (WL) is an independent predictor of mortality in patients with heart failure (HF). Moderate WL is recommended for overweight or obese patients with type 2 diabetes mellitus (DM). The aim of this study was to assess the prognostic impact of body weight reduction on survival in patients with both HF with reduced ejection fraction (HFrEF) and DM.

METHODS

The study comprised patients with HFrEF at the outpatient clinic. WL was defined as a body weight reduction of at least 7.5% during at least 6 months. Clinical features and 1 year mortality were analysed in WL and DM groups. Multivariate regression model was chosen to assess the predictive role of WL in HF patients with and without DM. The analysis regarding obesity before HF was also performed.

RESULTS

The study comprised 777 patients with HFrEF. Mean age was 53.2 ± 9.2, 12.0% were women, mean EF was 23.7 ± 6.0 %, and New York Heart Association III or IV class, DM, and WL were found in 60.5%, 33.3%, and 47.1% patients, respectively. WL was more prevalent in diabetic patients, comparing with those without DM (53.7% vs. 43.8%, respectively, 0.01), and was associated with higher 1 year mortality only in non-diabetic group (17.6% for WL vs. 8.2% for non-WL, log-rank 0.001). In the multivariate analysis, WL was associated with a higher risk of 1 year mortality in non-diabetic patients: HR 1.76 (1.05-2.95), 0.03 and only in the subgroup without obesity: HR 2.35 (1.28-4.32), 0.006. In non-diabetic patients with obesity and in diabetic patients regardless of weight status, WL was not associated with worse prognosis (thereof, WL was excluded from the multivariate models).

CONCLUSIONS

Overall, WL in HFrEF has emerged as a predictor of unfavourable outcomes only in non-obese patients without DM. More importantly, this study has identified that the presence of DM (irrespective of weight status) or the presence of obesity in non-diabetic patients abolished the unfavourable impact of WL on long-term outcomes.

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.

Weight change and 15 year mortality: results from the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) cohort study

Studies have reported a higher mortality risk associated with weight loss, particularly in middle-aged and older adults, although some of these studies did find that gaining weight was also associated with an increased mortality risk. We examined changes in weight in relation to mortality in a prospective population-based cohort study of men and women, resident in Norfolk, UK. Participants were assessed at baseline (1993–1997) and at a second examination (1998–2000), as part of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) study, and followed up to 2015 for mortality. Participants with a self-reported history of cancer or cardiovascular disease, body mass index < 18.5 kg/m² or missing data on adjustment variables, at either time-point were excluded, leaving 12,580 participants, aged 39–78 in 1993–1997, eligible for analyses. Cox proportional hazards models were used to determine Hazard Ratios (HRs) for all-cause (2603 deaths), cardiovascular (749 deaths), cancer (981 deaths), respiratory (226 deaths) and other causes of mortality (647 deaths) by categories of weight change. After multivariate adjustment, the HRs (95% CIs) for all-cause mortality for men and women who lost more than 5 kg were 1.85 (1.48–2.31) and 1.64 (1.31–2.05) respectively. Higher hazards were also found for specific causes of mortality and weight loss > 5 kg. Similar associations were observed after excluding deaths in the first 5 years of follow-up. Results for weight gain were inconclusive. We conclude that objectively measured weight loss, but not weight gain, was associated with subsequent higher mortality risk in this population-based study of middle-aged and elderly men and women. However, undiagnosed, pre-existing disease and the inability to account for weight cycling need to be remembered when interpreting these results. Unravelling the causal pathways underlying this association will require more detailed studies, including that of changes in body composition.

Modified body adiposity index for body fat estimation in severe obesity

BACKGROUND

The body adiposity index (BAI) comprises a simple method for estimating body fat (BF) that needs to be validated in patients with severe obesity. The present study aimed to determine BAI accuracy with respect to the determination BF in patients with severe obesity.

METHODS

A cross-sectional prospective study comparing two methods for BF estimation was conducted in 433 patients with severe obesity between August 2012 to December 2014. BF was estimated by bioelectrical impedance analysis (BIA) with specific equations developed for BF estimation in patients with severe obesity and BAI. The BF estimation in 240 patients with severe obesity (Group 1: G1) was used to evaluate BAI limitations and to develop a specific equation in this population. The new equation proposed was validated in another 158 patients with severe obesity (Group 2: G2).

RESULTS

There was a significant difference between BF determination by BIA and BAI (P = 0.039). The mean (SD) BF in G1 was 52.3% (6.1%) determined by BIA and 51.6% (8.1%) determined by BAI. Sex, waist-hip ratio (WHR) and obesity grade determined significant errors on BF estimation by BAI. A new equation (modified body adiposity index; MBAI) was developed by linear regression to minimise these errors [MBAI% = 23.6 + 0.5 × (BAI); add 2.2 if body mass index ≥ 50 kg m^-2 and 2.4 if WHR ≥ 1.05]. The new equation reduced the difference [1.2% (5.9%), P < 0.001 to 0.4% (4.12%), P = 0.315] and improved the correlation (0.6-0.7) between methods.

CONCLUSIONS

BAI present significant limitations in severe obesity and MBAI was effective for BF estimation in this population.

Biology of upper-body and lower-body adipose tissue--link to whole-body phenotypes

The distribution of adipose tissue in the body has wide-ranging and reproducible associations with health and disease. Accumulation of adipose tissue in the upper body (abdominal obesity) is associated with the development of cardiovascular disease, insulin resistance, type 2 diabetes mellitus and even all-cause mortality. Conversely, accumulation of fat in the lower body (gluteofemoral obesity) shows opposite associations with cardiovascular disease and type 2 diabetes mellitus when adjusted for overall fat mass. The abdominal depots are characterized by rapid uptake of predominantly diet-derived fat and a high lipid turnover that is easily stimulated by adrenergic receptor activation. The lower-body fat stores have a reduced lipid turnover with a capacity to accommodate fat undergoing redistribution. Lower-body adipose tissue also seems to retain the capacity to recruit additional adipocytes as a result of weight gain and demonstrates fewer signs of inflammatory insult. New data suggest that the profound functional differences between the upper-body and lower-body tissues are controlled by site-specific sets of developmental genes, such as HOXA6, HOXA5, HOXA3, IRX2 and TBX5 in subcutaneous abdominal adipose tissue and HOTAIR, SHOX2 and HOXC11 in gluteofemoral adipose tissue, which are under epigenetic control. This Review discusses the developmental and functional differences between upper-body and lower-body fat depots and provides mechanistic insight into the disease-protective effects of lower-body fat.

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.

Change in body size and mortality: results from the Melbourne collaborative cohort study

BACKGROUND

The association between change in weight or body mass index, and mortality is widely reported, however, both measures fail to account for fat distribution. Change in waist circumference, a measure of central adiposity, in relation to mortality has not been studied extensively.

METHODS

We investigated the association between mortality and changes in directly measured waist circumference, hips circumference and weight from baseline (1990-1994) to wave 2 (2003-2007) in a prospective cohort study of people aged 40-69 years at baseline. Cox regression, with age as the time metric and follow-up starting at wave 2, adjusted for confounding variables, was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for change in body size in relation to mortality from all causes, cardiovascular disease and cancer.

RESULTS

There were 1465 deaths (109 cancer, 242 cardiovascular disease) identified during an average 7.7 years of follow-up from 21 298 participants. Compared to minimal increase in body size, loss of waist circumference (HR: 1.26; 95% CI: 1.09-1.47), weight (1.80; 1.54-2.11), or hips circumference (1.35; 1.15-1.57) were associated with an increased risk of all-cause mortality, particularly for older adults. Weight loss was associated with cardiovascular disease mortality (2.40; 1.57-3.65) but change in body size was not associated with obesity-related cancer mortality.

CONCLUSION

This study confirms the association between weight loss and increased mortality from all-causes for older adults. Based on evidence from observational cohort studies, weight stability may be the recommended option for most adults, especially older adults.

Changes of body mass index in relation to mortality: results of a cohort of 42,099 adults

BACKGROUND

High Body-Mass-Index (BMI) is associated with increased all-cause mortality, but little is known about the effect of short- and long-term BMI change on mortality. The aim of the study was to determine how long-term weight change affects mortality.

METHODS AND FINDINGS

Within a population-based prospective cohort of 42,099 Austrian men and women (mean age 43 years) with at least three BMI measurements we investigated the relationship of BMI at baseline and two subsequent BMI change intervals of five years each with all-cause mortality using Cox proportional Hazard models. During median follow-up of 12 years 4,119 deaths were identified. The lowest mortalities were found in persons with normal weight or overweight at baseline and stable BMI over 10 years. Weight gain (≥0.10 kg/m(2)/year) during the first five years was associated with increased mortality in overweight and obese people. For weight gain during both time intervals mortality risk remained significantly increased only in overweight (Hazard Ratio (HR): 1.39 (95% confidence interval: 1.01; 1.92)) and obese women (1.85 (95% confidence interval: 1.18; 2.89)). Weight loss (< -0.10 kg/m(2)/year) increased all-cause mortality in men and women consistently. BMI change over time assessed using accepted World Health Organisation BMI categories showed no increased mortality risk for people who remained in the normal or overweight category for all three measurements. In contrast, HRs for stable obese men and women were 1.57 (95% CI: 1.31; 1.87) and 1.46 (95% CI: 1.25; 1.71) respectively.

CONCLUSION

Our findings highlight the importance of weight stability and obesity avoidance in prevention strategy.

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.

Keap1-knockdown decreases fasting-induced fatty liver via altered lipid metabolism and decreased fatty acid mobilization from adipose tissue

AIMS

The purpose of this study was to determine whether Nrf2 activation, via Keap1-knockdown (Keap1-KD), regulates lipid metabolism and mobilization induced by food deprivation (e.g. fasting).

METHODS AND RESULTS

Male C57BL/6 (WT) and Keap1-KD mice were either fed ad libitum or food deprived for 24 hours. After fasting, WT mice exhibited a marked increase in hepatic lipid accumulation, but Keap1-KD mice had an attenuated increase of lipid accumulation, along with reduced expression of lipogenic genes (acetyl-coA carboxylase, stearoyl-CoA desaturase-1, and fatty acid synthase) and reduced expression of genes related to fatty acid transport, such as fatty acid translocase/CD36 (CD36) and Fatty acid transport protein (FATP) 2, which may attribute to the reduced induction of Peroxisome proliferator-activated receptor (Ppar) α signaling in the liver. Additionally, enhanced Nrf2 activity by Keap1-KD increased AMP-activated protein kinase (AMPK) phosphorylation in liver. In white adipose tissue, enhanced Nrf2 activity did not change the lipolysis rate by fasting, but reduced expression of fatty acid transporters--CD36 and FATP1, via a PPARα-dependent mechanism, which impaired fatty acid transport from white adipose tissue to periphery circulation system, and resulted in increased white adipose tissue fatty acid content. Moreover, enhanced Nrf2 activity increased glucose tolerance and Akt phosphorylation levels upon insulin administration, suggesting Nrf2 signaling pathway plays a key role in regulating insulin signaling and enhanced insulin sensitivity in skeletal muscle.

CONCLUSION

Enhanced Nrf2 activity via Keap1-KD decreased fasting-induced steatosis, pointing to an important function of Nrf2 on lipid metabolism under the condition of nutrient deprivation.

Harnessing the beneficial properties of adipogenic microbes for improving human health

Obesity is associated with numerous metabolic comorbidities. Weight loss is an effective measure for alleviating many of these metabolic abnormalities. However, considering the limited success of most medical weight-management approaches in producing a sustained weight loss, approaches that improve obesity-related metabolic abnormalities independent of weight loss would be extremely attractive and of practical benefit. Metabolically healthy obesity supports the notion that a better metabolic profile is possible despite obesity. Moreover, adequate expansion of adipose tissue appears to confer protection from obesity-induced metabolic comorbidities. To this end, the 10th Stock conference examined new approaches to improve metabolic comorbidities independent of weight loss. In particular, human adenovirus 36 (Ad36) and specific gut microbes were examined for their potential to influence lipid and glucose homeostasis in animals and humans. While these microbes possess some undesirable properties, research has identified attributes of adenovirus Ad36 and gut microbes that may be selectively harnessed to improve metabolic profile without the obligatory weight loss. Furthermore, identifying the host signalling pathways that these microbes recruit to improve the metabolic profile may offer new templates and targets, which may facilitate the development of novel treatment strategies for obesity-related metabolic conditions.

Effects of obesity on the impact of short-term changes in anthropometric measurements on coronary heart disease in women

OBJECTIVE

To assess the impact of short-term changes in body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio on the risk of future coronary heart disease (CHD) among women.

PARTICIPANTS AND METHODS

The study sample consisted of 2468 women aged 30 years or older without cardiovascular disease at baseline who underwent 2 consecutive examinations, the first between January 31, 1999, and August 21, 2001, and second between October 20, 2001, and September 22, 2005, and were followed up until March 31, 2010. Cox proportional hazard regression was performed to estimate the hazard ratios (HRs) of the anthropometric measures for CHD events.

RESULTS

During a mean follow-up of 6.6 years, CHD occurred in 127 of the study participants (5.1%). There were significant interactions between a BMI of 30 kg/m(2) or greater and anthropometric changes in prediction of CHD events (all P<.04). Among nonobese individuals, a 1-SD increase in HC changes, independent of WC and BMI changes, was inversely associated with risk of CHD events (HR, 0.60 [95% CI, 0.44-0.83]). Among obese individuals, a 1-SD increase in WC, independent of other changes, increased the risk of CHD. Conversely, a 1-SD increase in BMI decreased the risk of CHD by 35% (HR, 0.65 [95% CI, 0.45-0.94]).

CONCLUSION

In this study, the impact of changes in anthropometric measures on CHD was modified by obesity at baseline. Among nonobese women, increases in HC could significantly reduce the risk of CHD events. Among obese individuals, although increases in WC were associated with a higher risk of CHD, increases in BMI decreased the risk.

Maintained intentional weight loss reduces cardiovascular outcomes: results from the Sibutramine Cardiovascular OUTcomes (SCOUT) trial

AIM

The Sibutramine Cardiovascular OUTcomes trial showed that sibutramine produced greater mean weight loss than placebo but increased cardiovascular morbidity but not mortality. The relationship between 12-month weight loss and subsequent cardiovascular outcomes is explored.

METHODS

Overweight/obese subjects (N = 10 744), ≥55 years with cardiovascular disease and/or type 2 diabetes mellitus, received sibutramine plus weight management during a 6-week Lead-in Period before randomization to continue sibutramine (N = 4906) or to receive placebo (N = 4898). The primary endpoint was the time from randomization to first occurrence of a primary outcome event (non-fatal myocardial infarction, non-fatal stroke, resuscitated cardiac arrest or cardiovascular death).

RESULTS

For the total population, mean weight change during Lead-in Period (sibutramine) was -2.54 kg. Post-randomization, mean total weight change to Month 12 was -4.18 kg (sibutramine) or -1.87 kg (placebo). Degree of weight loss during Lead-in Period or through Month 12 was associated with a progressive reduction in risk for the total population in primary outcome events and cardiovascular mortality over the 5-year assessment. Although more events occurred in the randomized sibutramine group, on an average, a modest weight loss of approximately 3 kg achieved in the Lead-in Period appeared to offset this increased event rate. Moderate weight loss (3-10 kg) reduced cardiovascular deaths in those with severe, moderate or mild cardiovascular disease.

CONCLUSIONS

Modest weight loss over short-term (6 weeks) and longer-term (6-12 months) periods is associated with reduction in subsequent cardiovascular mortality for the following 4-5 years even in those with pre-existing cardiovascular disease. While the sibutramine group experienced more primary outcome events than the placebo group, greater weight loss reduced overall risk of these occurring in both groups.

Changes in waist circumference and the incidence of acute myocardial infarction in middle-aged men and women

Background

Waist circumference (WC) measured at one point in time is positively associated with the risk of acute myocardial infarction (MI), but the association with changes in WC (DWC) is not clear. We investigated the association between DWC and the risk of MI in middle-aged men and women, and evaluated the influence from concurrent changes in BMI (DBMI).

Methodology/Principal Findings

Data on 38,593 participants from the Danish Diet, Cancer and Health study was analysed. Anthropometry was assessed in 1993–97 and 1999–02. Information on fatal and non-fatal MI was obtained from National Registers. Cases were validated by review of the medical records. Hazard ratios (HR) were calculated from Cox proportional hazard models with individuals considered at risk from 1999–02 until December 30 2009. During 8.4 years of follow-up, 1,041 incident cases of MI occurred. WC was positively associated with the risk of MI, but weakly after adjustment for BMI. DWC was not associated with the risk of MI (HR per 5 cm change  = 1.01 (0.95, 1.09) with adjustment for covariates, baseline WC, BMI and DBMI). Associations with DWC were not notably different in sub-groups stratified according to baseline WC or DBMI, or when individuals with MI occurring within the first years of follow-up were excluded.

Conclusions/Significance

WC was positively associated with the risk of MI in middle-aged men and women, but changes in WC were not. These findings suggest that a reduction in WC may be an insufficient target for prevention of MI in middle-aged men and women.

Dynamic path analysis in life-course epidemiology

Life-course epidemiology seeks to better understand the mechanisms that lead to the development of chronic diseases. An example is the mechanism leading from body size to coronary heart disease (CHD); one way to acquire a better understanding of this mechanism is to investigate to what extent it works through other risk factors. In this paper, the dynamic path analysis model is presented as a tool to analyze these dynamic mechanisms in life-course epidemiology. A key feature of dynamic path analysis is its ability to decompose the total effect of a risk factor into a direct effect (not mediated by other variables) and indirect effects (mediated through other variables). This is illustrated by examining the associations between repeated measurements of body mass index (BMI) and systolic blood pressure (SBP) and the risk of CHD in a sample of Danish men between 1976 and 2006. The effect of baseline BMI on the risk of CHD is decomposed into a direct effect and indirect effects going through later BMI, concurrent SBP, or later SBP. In conclusion, dynamic path analysis is a flexible tool that by the decomposition of effects can be used to increase the understanding of mechanisms that underlie the etiology of chronic disease.

Mortality risk in older men associated with changes in weight, lean mass, and fat mass

OBJECTIVES

To evaluate risk of all-cause mortality associated with changes in body weight, total lean mass, and total fat mass in older men.

DESIGN

Longitudinal cohort study.

SETTING

Six U.S. clinical centers.

PARTICIPANTS

Four thousand three hundred thirty-one ambulatory men aged 65 to 93 at baseline.

MEASUREMENTS

Repeated measurements of body weight and total lean and fat mass were taken using dual-energy X-ray absorptiometry 4.6 ± 0.4 years apart. Percentage changes in these measures were categorized as gain (+5%), loss (-5%), or stable (-5% to +5%). Deaths were verified centrally according to death certificate reviews, and proportional hazard models were used to estimate the risk of mortality.

RESULTS

After accounting for baseline lifestyle factors and medical conditions, a higher risk of mortality was found for men with weight loss (hazard rat (HR)=1.84, 95% confidence interval (CI)=1.50-2.26), total lean mass loss (HR=1.78, 95% CI=1.45-2.19), and total fat mass loss (HR=1.72, 95% CI=1.34-2.20) than for men who were stable for each body composition measure. Men with total fat mass gain had a slightly greater mortality risk (HR=1.29, 95% CI=0.99-1.67) than those who remained stable. These associations did not differ according to baseline age, obesity, or self-reported health status (P for interactions >.10), although self-reported weight loss intent altered mortality risks with total fat mass (P for interaction=.04) and total lean mass (P for interaction=.09) change.

CONCLUSION

Older men who lost weight, total lean mass, or total fat mass had a higher risk of mortality than men who remained stable.

Changes in waist circumference and mortality in middle-aged men and women

Background

Waist circumference (WC) adjusted for body mass index (BMI) is positively associated with mortality, but the association with changes in WC is less clear. We investigated the association between changes in WC and mortality in middle-aged men and women, and evaluated the influence from concurrent changes in BMI.

Methodology/Principal Findings

Data on 26,625 healthy men and women from the Danish Diet, Cancer and Health study was analyzed. WC and BMI were assessed in 1993–97 and in 1999–02. Information on mortality was obtained by linkage to the Danish central Person Register. Hazard ratios (HR) were estimated with Cox regression models. During 6.7 years of follow-up, 568 and 361 deaths occurred among men and women, respectively. Changes in WC were positively associated with mortality (HR per 5 cm for the sexes combined  = 1.09 (1.02∶1.16) with adjustment for covariates, baseline WC, BMI and changes in BMI), whereas changes in BMI were inversely associated with mortality (HR per kg/m2 for the sexes combined  = 0.91 (0.86, 0.97) with adjustment for covariates, baseline WC, BMI and changes in WC). Associations between changes in WC and mortality were not notably different in sub-groups stratified according to changes in BMI, baseline WC or when smokers or deaths occurring within the first years of follow-up were excluded.

Conclusions/Significance

Changes in WC were positively associated with mortality in healthy middle-aged men and women throughout the range of concurrent changes in BMI. These findings suggest a need for development of prevention and treatment strategies targeted against redistribution of fat mass towards the abdominal region.

Fat mass protects hospitalized elderly persons against morbidity and mortality

BACKGROUND

It is well established that the combination of protein-energy malnutrition and low body mass index (BMI) increases the risk of death in elderly patients, but recent studies indicate that the risk of death may decrease with higher body weight. However, these studies did not perform direct, separate, and reliable measurements of fat and lean mass by using a reference technique.

OBJECTIVE

Our objective was to evaluate the relation between body composition, based on the 4-compartment model, and morbidity and mortality in hospitalized elderly patients.

DESIGN

This prospective study enrolled 125 elderly patients evaluated at admission for body composition on the basis of BMI plus fat mass, lean mass, appendicular skeletal muscle mass, and body cell mass indexes (calculated as the ratio of the mass to the square of the height) measured by X-ray absorptiometry and bioelectrical impedance analysis. Outcomes were assessed 6 mo later by using a score system that takes into account complications (pressure ulcers and/or infections) and 6-mo mortality.

RESULTS

The fat mass index correlated positively (r = 0.19 and P = 0.023 adjusted for sex; r = 0.18 and P = 0.043 adjusted for sex, albuminemia, and C-reactive protein) with outcome score (1: death, 2: complications, 3: no complications). There was no significant correlation between outcome score and BMI, lean mass, appendicular skeletal muscle mass, and body cell mass indexes.

CONCLUSIONS

This study clearly indicates that the generally accepted rule that overweight is associated with morbidity and mortality does not apply to hospitalized elderly patients, for whom fat mass is associated with a decreased risk of adverse events.

A review and meta-analysis of the effect of weight loss on all-cause mortality risk

Overweight and obesity are associated with increased morbidity and mortality, although the range of body weights that is optimal for health is controversial. It is less clear whether weight loss benefits longevity and hence whether weight reduction is justified as a prime goal for all individuals who are overweight (normally defined as BMI>25 kg/m2). The purpose of the present review was to examine the evidence base for recommending weight loss by diet and lifestyle change as a means of prolonging life. An electronic search identified twenty-six eligible prospective studies that monitored subsequent mortality risk following weight loss by lifestyle change, published up to 2008. Data were extracted and further analysed by meta-analysis, giving particular attention to the influence of confounders. Moderator variables such as reason for weight loss (intentional, unintentional), baseline health status (healthy, unhealthy), baseline BMI (normal, overweight, obese), method used to estimate weight loss (measured weight loss, reported weight loss) and whether models adjusted for physical activity (adjusted data, unadjusted data) were used to classify subgroups for separate analysis. Intentional weight loss per se had a neutral effect on all-cause mortality (relative risk (RR) 1·01; P = 0·89), while weight loss which was unintentional or ill-defined was associated with excess risk of 22 to 39 %. Intentional weight loss had a small benefit for individuals classified as unhealthy (with obesity-related risk factors) (RR 0·87 (95 % CI 0·77, 0·99); P = 0·028), especially unhealthy obese (RR 0·84 (95 % CI 0·73, 0·97); P = 0·018), but appeared to be associated with slightly increased mortality for healthy individuals (RR 1·11 (95 % CI 1·00, 1·22); P = 0·05), and for those who were overweight but not obese (RR 1·09 (95 % CI 1·02, 1·17); P = 0·008). There was no evidence for weight loss conferring either benefit or risk among healthy obese. In conclusion, the available evidence does not support solely advising overweight or obese individuals who are otherwise healthy to lose weight as a means of prolonging life. Other aspects of a healthy lifestyle, especially exercise and dietary quality, should be considered. However, well-designed intervention studies are needed clearly to disentangle the influence of physical activity, diet strategy and body composition, in order to define appropriate advice to those populations that might be expected to benefit.

Cachexia and aging: an update based on the Fourth International Cachexia Meeting

This manuscript highlights the new developments in the pathophysiology of anorexia, cachexia and sarcopenia, based on presentations given at the Fourth International Cachexia Meeting. It stresses the importance of these conditions in older persons.