The association of body mass index with mortality in the California Teachers Study

MPA alters metabolic phenotype of endometrial cancer-associated fibroblasts from obese women via IRS2 signaling

Obese women have a higher risk of developing endometrial cancer (EC) than lean women. Besides affecting EC progression, obesity also affects sensitivity of patients to treatment including medroxprogesterone acetate (MPA). Obese women have a lower response to MPA with an increased risk for tumor recurrence. While MPA inhibits the growth of normal fibroblasts, human endometrial cancer-associated fibroblasts (CAFs) were reported to be less responsive to MPA. However, it is still unknown how CAFs from obese women respond to progesterone. CAFs from the EC tissues of obese (CO) and non-obese (CN) women were established as primary cell models. MPA increased cell proliferation and downregulated stromal differentiation genes, including BMP2 in CO than in CN. Induction of IRS2 (a BMP2 regulator) mRNA expression by MPA led to activation of glucose metabolism in CO, with evidence of greater mRNA levels of GLUT6, GAPDH, PKM2, LDHA, and increased in GAPDH enzymatic activity. Concomitantly, MPA increased the mRNA expression of a fatty acid transporter, CD36 and lipid droplet formation in CO. MPA-mediated increase in glucose metabolism genes in CO was reversed with a progesterone receptor inhibitor, mifepristone (RU486), leading to a decreased proliferation. Our data suggests that PR signaling is aberrantly activated by MPA in CAFs isolated from endometrial tissues of obese women, leading to activation of IRS2 and glucose metabolism, which may lead to lower response and sensitivity to progesterone in obese women.

A Population-Based Cohort Study of Respiratory Disease and Long-Term Exposure to Iron and Copper in Fine Particulate Air Pollution and Their Combined Impact on Reactive Oxygen Species Generation in Human Lungs

Metal components in fine particulate matter (PM_2.5) from nontailpipe emissions may play an important role in underlying the adverse respiratory effects of PM_2.5. We investigated the associations between long-term exposure to iron (Fe) and copper (Cu) in PM_2.5 and their combined impact on reactive oxygen species (ROS) generation in human lungs, and the incidence of asthma, chronic obstructive pulmonary disease (COPD), COPD mortality, pneumonia mortality, and respiratory mortality. We conducted a population-based cohort study of ∼0.8 million adults in Toronto, Canada. Land-use regression models were used to estimate the concentrations of Fe, Cu, and ROS. Outcomes were ascertained using validated health administrative databases. We found positive associations between long-term exposure to Fe, Cu, and ROS and the risks of all five respiratory outcomes. The associations were more robust for COPD, pneumonia mortality, and respiratory mortality than for asthma incidence and COPD mortality. Stronger associations were observed for ROS than for either Fe or Cu. In two-pollutant models, adjustment for nitrogen dioxide somewhat attenuated the associations while adjustment for PM_2.5 had little influence. Long-term exposure to Fe and Cu in PM_2.5 and estimated ROS concentration in lung fluid was associated with increased incidence of respiratory diseases, suggesting the adverse respiratory effects of nontailpipe emissions.

Longitudinal analysis of Socioecological obesogenic factors in a National Sample of U.S. children

BACKGROUND

Childhood obesity is a serious public health threat. Although many researchers conducted research on socioecological determinants of childhood obesity, their longitudinal effects remain inconclusive especially among young children. This study examined socioecological factors and associated transitions of children's body mass index (BMI) status throughout children's kindergarten to elementary school years, using data from a national longitudinal sample.

METHODS

The baseline sample of this study included 1264 children (weighted N = 379,297) extracted from the Early Childhood Longitudinal Study (baseline mean age: 5.24 years). The socioecological framework guided selection of socioecological obesogenic variables (e.g., family activity and parental involvement). Longitudinal ordered logistic regressions were performed to determine the associations between socioecological obesogenic variables and unhealthy/healthy changes in BMI status that captured transitions between healthy and unhealthy weight status (i.e., overweight, obesity, and severe obesity).

RESULTS

Children with Hispanic ethnicity and nonwhite, less socioeconomic and environmental support, and living in households with fewer family members were more likely than their counterparts to have unhealthy BMI status changes over time (all ps < 0.05). Over the study period, girls were less likely than boys to experience transitions to unhealthy BMI status (all ps < 0.05).

CONCLUSION

As hypothesized a priori, the findings of the current affirmed multiple dimensions of how sociological obesogenic factors may influence children's BMI status changes in a longitudinal setting. In order to maintain children's long-term healthy weight, more attention should be paid to socioeconomic obesogenic factors surrounding children as well as individual determinants of obesity (e.g., being physically active and having well-balanced nutrition).

Ethnic and biological differences in the association between physical activity and survival after breast cancer

Physical activity is recommended for most cancer patients as a nonpharmacological therapy to improve prognosis. Few studies have investigated the association between physical activity and breast cancer prognosis by ethnicity, biological, and modifiable risk factors for mortality. We investigated the association between physical activity and long-term survival among breast cancer survivors. A total of 397 survivors (96 Hispanic and 301 non-Hispanic White (NHW)) from the New Mexico HEAL study contributed baseline and biological data approximately 6 months after diagnosis. Study outcomes included all-cause, breast cancer-specific, and non-breast cancer mortality. The exposure was self-reported physical activity within the past month. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox Proportional Hazards regression. A total of 133 deaths (53 breast cancer-specific deaths) were observed after a median follow-up time of 13 years. Engaging in >6.9 metabolic equivalent hours/week (MET-h/week) of moderate to vigorous physical activity (active) was inversely associated with all-cause mortality among all women (HR 0.66, 95% CI 0.43-0.99) and NHWs (HR 0.58, 95% CI 0.36-0.94). Active NHW women also had a reduced risk of non-breast cancer mortality (HR 0.56, 95% CI 0.31-0.99), compared to inactive women (0 MET-h/week). In subgroups, we observed the inverse associations with all-cause mortality among women >58 years old (p-interaction= 0.03) and with localized stage (p-interaction = 0.046). Our results confirm the protective association between physical activity and mortality after breast cancer diagnosis, and demonstrate that this association significantly differs by age and cancer stage. Larger studies are warranted to substantiate our findings.

Could Obesity be a Triggering Factor for Endometrial Tubal Metaplasia to be a Precancerous Lesion?

BACKGROUND & AIMS

Endometrial tubal metaplasia (ETM) is mostly described in conjunction with unopposed estrogen levels, and its association with endometrial hyperplasia and endometrial carcinoma (EC) is striking. Obesity is a risk factor for endometrial hyperplasia and EC development. The aim of this study is to investigate the impact of BMI and serum estradiol level on expression of PAX-2, H-TERT, P16, Ki-67, and P53 in studied ETM in reference to benign endometrium and EC.

METHODS

The study was conducted on the following groups: group (1) consists of 57 cases that had endometrial biopsies with histologically demonstrable ETM (typical or atypical) and all were subjected to serum estradiol levelling and body mass index (BMI) evaluation; group (2) had adjacent benign endometrial tissue as control; group (3) consists of 52 cases of conventional endometrial carcinoma and 16 serous carcinoma paraffin blocks which were collected and reevaluated. All included groups were immunostained for PAX-2, H-TERT, p16, ki67, and p53.

RESULTS

The relation between BMI and serum estradiol level in group 1 and PAX-2, H-TERT, P16, and p53 was statistically significant, while their relation with atypia and ki67 expression was insignificant. Twenty-three ETM cases (40.4%) out of group 1 were all (100%) obese, 87% had high serum estradiol level, and 73.9% were postmenopausal and had a similar immunohistochemical profile as EC cases (group 3).

CONCLUSIONS

The presence of ETM regardless of the histologic atypia in obese postmenopausal patients with high serum estradiol level is an alarming sign. This implies that ETM might not be as benign as generally accepted, as under certain clinical conditions, it may turn into a potential premalignant lesion.

Robotic surgery in obese patients with early-stage endometrial cancer

Aim

The objective of this study was to assess the clinical effectiveness of robotic surgery for obese patients (body mass index (BMI) ≥ 30 kg/m²) with early stage endometrial cancer.

Material and methods

This study is a retrospective review of women who underwent robotic surgery for early-stage endometrial cancer from 2008 to 2017. Patients were subdivided into those with BMI < 30 kg/m² (group 1), and those with BMI ≥ 30 kg/m² (group 2). Basic demographics and perioperative period outcomes were extracted from the medical records and compared.

Results

Group 1 included fifty patients and group 2 included 24 patients. There were no significant differences in surgical outcomes or complication rates between the two groups (p > 0.05 for all). There were no differences in pelvic nodal counts or length of stay.

Conclusions

Robotic surgery was found to be feasible and safe for obese patients with endometrial cancer. Its widespread application needs a larger sample with longer follow-up.

World Cancer Research Fund International: Continuous Update Project-systematic literature review and meta-analysis of observational cohort studies on physical activity, sedentary behavior, adiposity, and weight change and breast cancer risk

PURPOSE

The purpose of the present study was to systematically review the complex associations between energy balance-related factors and breast cancer risk, for which previous evidence has suggested different associations in the life course of women and by hormone receptor (HR) status of the tumor.

METHODS

Relevant publications on adulthood physical activity, sedentary behavior, body mass index (BMI), waist and hip circumferences, waist-to-hip ratio, and weight change and pre- and postmenopausal breast cancer risk were identified in PubMed up to 30 April 2017. Random-effects meta-analyses were conducted to summarize the relative risks across studies.

RESULTS

One hundred and twenty-six observational cohort studies comprising over 22,900 premenopausal and 103,000 postmenopausal breast cancer cases were meta-analyzed. Higher physical activity was inversely associated with both pre- and postmenopausal breast cancers, whereas increased sitting time was positively associated with postmenopausal breast cancer. Although higher early adult BMI (ages 18-30 years) was inversely associated with pre- and postmenopausal breast cancers, adult weight gain and greater body adiposity increased breast cancer risk in postmenopausal women, and the increased risk was evident for HR+ but not HR- breast cancers, and among never but not current users of postmenopausal hormones. The evidence was less consistent in premenopausal women. There were no associations with adult weight gain, inverse associations with adult BMI (study baseline) and hip circumference, and non-significant associations with waist circumference and waist-to-hip ratio that were reverted to positive associations on average in studies accounting for BMI. No significant associations were observed for HR-defined premenopausal breast cancers.

CONCLUSION

Better understanding on the impact of these factors on pre- and postmenopausal breast cancers and their subtypes along the life course is needed.

Weight control is vital for patients with early-stage endometrial cancer or complex atypical hyperplasia who have received progestin therapy to spare fertility: a systematic review and meta-analysis

Objectives: This study aimed to identify potential prognostic factors for patients with complex atypical hyperplasia (CAH) or early-stage endometrial cancer (EC) who received progestin therapy to spare fertility and, thus, improve the management of this patient group. Materials and methods: The PubMed, PMC, EMBASE, Web of Science, and Cochrane databases were searched for correlational studies published in English. Studies that evaluated the prognosis of patients with CAH or early-stage EC were pooled for a systematic review and meta-analysis. Results: In total, 31 eligible studies, including 8 prospective and 23 retrospective studies involving 1099 patients, were included in this analysis. The most commonly used progestin agents were medroxyprogesterone acetate (MPA, 47.0%) and megestrol acetate (MA, 25.5%). The total complete response (CR) rate was 75.8% (833/1099), and the median time to CR with first-line progestin therapy was 6 months. In total, 294 (26.8%) patients who achieved CR became pregnant spontaneously (28 cases) or through assisted reproductive technology (127 cases). During the median follow-up of 39 months, 245 (22.3%) women developed recurrence. Only one patient (0.09%) died of the disease. The meta-analysis showed that compared to a BMI<25 kg/m² and CAH, a body mass index (BMI) ≥25 kg/m² (P=0.0004, odds ratios (OR), 0.4; 95% confidence interval, 0.3-0.6) and EC (P=0.0000, OR, 0.3; 95% confidence interval, 0.2-0.6) were significantly associated with a higher likelihood of a CR. Patients with a BMI≥25 kg/m² (P=0.0007, OR, 2.5; 95% confidence interval, 1.4-4.3), PCOS (P=0.0006, OR, 3.4; 95% confidence interval, 1.5-7.9), and EC (P=0.0344, OR, 2.8; 95% confidence interval, 1.4-5.3) had a significantly higher risk of recurrence. Conclusion: In general, patients with CAH or early-stage EC who were treated with progesterone therapy had a favorable prognosis. However, the recurrence risk was not insignificant. Weight control is crucial for improving the clinical management of this patient group.

A meta-analysis but not a systematic review: an evaluation of the Global BMI Mortality Collaboration

Meta-analyses of individual participant data (MIPDs) offer many advantages and are considered the highest level of evidence. However, MIPDs can be seriously compromised when they are not solidly founded upon a systematic review. These data-intensive collaborative projects may be led by experts who already have deep knowledge of the literature in the field and of the results of published studies and how these results vary based on different analytical approaches. If investigators tailor the searches, eligibility criteria, and analysis plan of the MIPD, they run the risk of reaching foregone conclusions. We exemplify this potential bias in a MIPD on the association of body mass index with mortality conducted by a collaboration of outstanding and extremely knowledgeable investigators. Contrary to a previous meta-analysis of group data that used a systematic review approach, the MIPD did not seem to use a formal search: it considered 239 studies, of which the senior author was previously aware of at least 238, and it violated its own listed eligibility criteria to include those studies and exclude other studies. It also preferred an analysis plan that was also known to give a specific direction of effects in already published results of most of the included evidence. MIPDs where results of constituent studies are already largely known need safeguards to their validity. These may include careful systematic searches, adherence to the Preferred Reporting Items for Systematic Review and Meta-Analyses of individual participant data guidelines, and exploration of the robustness of results with different analyses. They should also avoid selective emphasis on foregone conclusions based on previously known results with specific analytical choices.

Accuracy of transvaginal ultrasonography compared to endometrial biopsy for the etiological diagnosis of abnormal perimenopausal bleeding

BACKGROUND AND AIMS

Perimenopause is marked by clinical manifestations which disturb everyday life and which may also hide a pathomorphological, more precisely endometrial, substrate. An accurate early diagnosis established by accessible, non-invasive methods is very important for the therapeutic management.

METHOD

The study included 103 patients aged between 41.5-55.11 years, divided into 3 age groups: 40-44 years (n=10), 45-49 years (n=54) and ≥50 years (n=39).

RESULTS

Certain risk factors of endometrial neoplasm or premalignant conditions were evidenced, their accurate identification being useful in limiting the number of patients with abnormal uterine bleeding (AUB) submitted to diagnostic screening. The most common cause of AUB in our study was fibroma, followed by functional causes.

CONCLUSIONS

Transvaginal ultrasound (TVUS) represents a minimally invasive method for the screening of perimenopausal patients with AUB, especially to rule out endometrial adenocarcinoma (EAC). TVUS sensitivity was higher than clinical diagnosis in case of leiomioma, polypi and EAC. TVUS was more accurate in the diagnosis of EAC, polypi and leiomioma.

BMI and all cause mortality: systematic review and non-linear dose-response meta-analysis of 230 cohort studies with 3.74 million deaths among 30.3 million participants

OBJECTIVE

To conduct a systematic review and meta-analysis of cohort studies of body mass index (BMI) and the risk of all cause mortality, and to clarify the shape and the nadir of the dose-response curve, and the influence on the results of confounding from smoking, weight loss associated with disease, and preclinical disease.

DATA SOURCES

PubMed and Embase databases searched up to 23 September 2015.

STUDY SELECTION

Cohort studies that reported adjusted risk estimates for at least three categories of BMI in relation to all cause mortality.

DATA SYNTHESIS

Summary relative risks were calculated with random effects models. Non-linear associations were explored with fractional polynomial models.

RESULTS

230 cohort studies (207 publications) were included. The analysis of never smokers included 53 cohort studies (44 risk estimates) with >738 144 deaths and >9 976 077 participants. The analysis of all participants included 228 cohort studies (198 risk estimates) with >3 744 722 deaths among 30 233 329 participants. The summary relative risk for a 5 unit increment in BMI was 1.18 (95% confidence interval 1.15 to 1.21; I(2)=95%, n=44) among never smokers, 1.21 (1.18 to 1.25; I(2)=93%, n=25) among healthy never smokers, 1.27 (1.21 to 1.33; I(2)=89%, n=11) among healthy never smokers with exclusion of early follow-up, and 1.05 (1.04 to 1.07; I(2)=97%, n=198) among all participants. There was a J shaped dose-response relation in never smokers (Pnon-linearity <0.001), and the lowest risk was observed at BMI 23-24 in never smokers, 22-23 in healthy never smokers, and 20-22 in studies of never smokers with ≥20 years' follow-up. In contrast there was a U shaped association between BMI and mortality in analyses with a greater potential for bias including all participants, current, former, or ever smokers, and in studies with a short duration of follow-up (<5 years or <10 years), or with moderate study quality scores.

CONCLUSION

Overweight and obesity is associated with increased risk of all cause mortality and the nadir of the curve was observed at BMI 23-24 among never smokers, 22-23 among healthy never smokers, and 20-22 with longer durations of follow-up. The increased risk of mortality observed in underweight people could at least partly be caused by residual confounding from prediagnostic disease. Lack of exclusion of ever smokers, people with prevalent and preclinical disease, and early follow-up could bias the results towards a more U shaped association.

Underweight and mortality

OBJECTIVE

According to most prospective studies, being underweight (BMI<18·5 kg/m2) is associated with significantly higher mortality than being of normal weight, especially among smokers. We aimed to explore in a generally lean population whether being underweight is significantly associated with increased all-cause mortality.

DESIGN

Prospective cohort study.

SETTING

Korea Medical Insurance Corporation study with 14 years of follow-up.

SUBJECTS

After excluding deaths within the first 5 years of follow-up (1993-1997) to minimize reverse causation and excluding participants without information about smoking and health status, 94 133 men and 48 496 women aged 35-59 years in 1990 were included.

RESULTS

We documented 5411 (5·7 %) deaths in men and 762 (1·6 %) in women. Among never smokers, hazard ratios (HR) for underweight individuals were not significantly higher than those for normal-weight individuals (BMI=18·5-22·9 kg/m2): HR=0·87 (95 % CI 0·41, 1·84, P=0·72) for underweight men and HR=1·12 (95 % CI 0·76, 1·65, P=0·58) for underweight women. Among ex-smokers, HR=0·86 (95 % CI 0·38, 1·93, P=0·72) for underweight men and HR=3·77 (95 % CI 0·42, 32·29, P=0·24) for underweight women. Among current smokers, HR=1·60 (95 % CI 1·28, 2·01, P<0·001) for underweight men and HR=2·07 (95 % CI 0·43, 9·94, P=0·36) for underweight women.

CONCLUSIONS

The present study does not support that being underweight per se is associated with increased all-cause mortality in Korean men and women.

Robotic surgery in supermorbidly obese patients with endometrial cancer

OBJECTIVE

Morbid obesity is a known risk factor for the development of endometrial cancer. Several studies have demonstrated the overall feasibility of robotic-assisted surgical staging for endometrial cancer as well as the benefits of robotics compared with laparotomy. However, there have been few reports that have evaluated robotic surgery for endometrial cancer in the supermorbidly obese population (body mass index [BMI], ≥50 kg/m(2)). We sought to evaluate safety, feasibility, and outcomes for supermorbidly obese patients who undergo robotic surgery for endometrial cancer, compared with patients with lower body mass indices.

STUDY DESIGN

We performed a retrospective chart review of 168 patients with suspected early-stage endometrial adenocarcinoma who underwent robotic surgery for the management of their disease. Analysis of variance and univariate logistic regression were used to compare patient characteristics and surgical variables across all body weights. Cox proportional hazard regression was used to determine the impact of body weight on recurrence-free and overall survival.

RESULTS

The mean BMI of our cohort was 40.9 kg/m(2). Median follow up was 31 months. Fifty-six patients, 30% of which had grade 2 or 3 tumors, were supermorbidly obese with a BMI of ≥50 kg/m(2) (mean, 56.3 kg/m(2)). A comparison between the supermorbidly obese and lower-weight patients demonstrated no differences in terms of length of hospital stay, blood loss, complication rates, numbers of pelvic and paraaortic lymph nodes retrieved, or recurrence and survival. There was a correlation between BMI and conversion to an open procedure, in which the odds of conversion increased with increasing BMI (P = .02).

CONCLUSION

Offering robotic surgery to supermorbidly obese patients with endometrial cancer is a safe and feasible surgical management option. When compared with patients with a lower BMI, the supermorbidly obese patient had a similar outcome, length of hospital stay, blood loss, complications, and numbers of lymph nodes retrieved.

The relation of weight to women's health: a matched sample study from Austria

While being underweight, overweight, or obese has been associated with higher rates of morbidity and mortality, such relations have not been studied in Austrian women. Therefore, the aim of this study was to analyze differences in health, health behaviors, and quality of life among women of various weight status categories, using data from the Austrian Health Interview (AT-HIS) 2006/07. First, women between 20 and 60 years of age, from four different weight status groups (underweight, normal weight, overweight, and obese) were matched case to case on age and socioeconomic status. After matching, the total number of women included in the analyses was 516 (N = 129 per). Differences in health status among women in different weight status categories were calculated using multiple conditional logistic regression analyses. Compared to females in the other three groups, women with normal weight had the best state of health: they had better self-reported health, suffered from fewer chronic conditions (e.g., sacrospinal complaints or migraines), and needed medical treatment less often. Moreover, they had better self-reported quality of life. In contrast, women who were underweight or obese showed worse health than women of normal weight. Appropriate health programs for weight risk groups are needed.

J-shapedness: an often missed, often miscalculated relation: the example of weight and mortality

We present three considerations in analysing the association between weight and mortality, as well as other relations that might be non-linear in nature. First, authors must graphically plot their independent and dependent variables in a continuous manner. Second, authors should assess the shape of that relation, and note its shape. If it is non-linear, and specifically, J-shaped or U-shaped, careful consideration should be given to using the 'best' statistical model, of which multivariate fractional polynomial regression is a reasonable choice. Authors should also refrain from truncating their data to avoid dealing with non-linear relations.

Body mass index and risk of death in Asian Americans

OBJECTIVES

We investigated the association between body mass index (BMI) and mortality among Asian Americans.

METHODS

We pooled data from prospective cohort studies with 20 672 Asian American adults with no baseline cancer or heart disease history. We estimated hazard ratios and 95% confidence intervals (CIs) with Cox proportional hazards models.

RESULTS

A high, but not low, BMI was associated with increased risk of total mortality among individuals aged 35 to 69 years. The BMI was not related to total mortality among individuals aged 70 years and older. With a BMI 22.5 to < 25 as the reference category among never-smokers aged 35 to 69 years, the hazard ratios for total mortality were 0.83 (95% CI = 0.47, 1.47) for BMI 15 to < 18.5; 0.91 (95% CI = 0.62, 1.32) for BMI 18.5 to < 20; 1.08 (95% CI = 0.86, 1.36) for BMI 20 to < 22.5; 1.14 (95% CI = 0.90, 1.44) for BMI 25 to < 27.5; 1.13 (95% CI = 0.79, 1.62) for BMI 27.5 to < 30; 1.82 (95% CI = 1.25, 2.64) for BMI 30 to < 35; and 2.09 (95% CI = 1.06, 4.11) for BMI 35 to 50. Higher BMI was also related to increased cardiovascular disease and cancer mortality.

CONCLUSIONS

High BMI is associated with increased mortality risk among Asian Americans.

Impact of obesity on cancer survivorship and the potential relevance of race and ethnicity

Evidence that obesity is associated with cancer incidence and mortality is compelling. By contrast, the role of obesity in cancer survival is less well understood. There is inconsistent support for the role of obesity in breast cancer survival, and evidence for other tumor sites is scant. The variability in findings may be due in part to comorbidities associated with obesity itself rather than with cancer, but it is also possible that obesity creates a physiological setting that meaningfully alters cancer treatment efficacy. In addition, the effects of obesity at diagnosis may be distinct from the effects of weight change after diagnosis. Obesity and related comorbid conditions may also increase risk for common adverse treatment effects, including breast cancer-related lymphedema, fatigue, poor health-related quality of life, and worse functional health. Racial and ethnic groups with worse cancer survival outcomes are also the groups for whom obesity and related comorbidities are more prevalent, but findings from the few studies that have addressed these complexities are inconsistent. We outline a broad theoretical framework for future research to clarify the specifics of the biological-social-environmental feedback loop for the combined and independent contributions of race, comorbid conditions, and obesity on cancer survival and adverse treatment effects. If upstream issues related to comorbidities, race, and ethnicity partly explain the purported link between obesity and cancer survival outcomes, these factors should be among those on which interventions are focused to reduce the burden of cancer.

Severe obesity in children and adolescents: identification, associated health risks, and treatment approaches: a scientific statement from the American Heart Association

Severe obesity afflicts between 4% and 6% of all youth in the United States, and the prevalence is increasing. Despite the serious immediate and long-term cardiovascular, metabolic, and other health consequences of severe pediatric obesity, current treatments are limited in effectiveness and lack widespread availability. Lifestyle modification/behavior-based treatment interventions in youth with severe obesity have demonstrated modest improvement in body mass index status, but participants have generally remained severely obese and often regained weight after the conclusion of the treatment programs. The role of medical management is minimal, because only 1 medication is currently approved for the treatment of obesity in adolescents. Bariatric surgery has generally been effective in reducing body mass index and improving cardiovascular and metabolic risk factors; however, reports of long-term outcomes are few, many youth with severe obesity do not qualify for surgery, and access is limited by lack of insurance coverage. To begin to address these challenges, the purposes of this scientific statement are to (1) provide justification for and recommend a standardized definition of severe obesity in children and adolescents; (2) raise awareness of this serious and growing problem by summarizing the current literature in this area in terms of the epidemiology and trends, associated health risks (immediate and long-term), and challenges and shortcomings of currently available treatment options; and (3) highlight areas in need of future research. Innovative behavior-based treatment, minimally invasive procedures, and medications currently under development all need to be evaluated for their efficacy and safety in this group of patients with high medical and psychosocial risks.

Obesity and risk of breast cancer mortality in Hispanic and Non-Hispanic white women: the New Mexico Women's Health Study

Obesity is reported to be associated with poorer survival in women with breast cancer, regardless of menopausal status. Our purpose was to determine if the associations of obesity with breast cancer-specific, all-cause, and non-breast cancer mortality differ between Hispanic and non-Hispanic white (NHW) women with breast cancer. Data on lifestyle and medical history were collected for incident primary breast cancer cases (298 NHW, 279 Hispanic) in the New Mexico Women's Health Study. Mortality was ascertained through the National Death Index and New Mexico Tumor Registry over 13 years of follow-up. Adjusted Cox regression models indicated a trend towards increased risk for breast cancer-specific mortality in obese NHW women (hazard ratio [HR] 2.07; 95% confidence interval [CI] 0.98-4.35) but not in Hispanic women (HR 1.32; 95% CI 0.64-2.74). Obese NHW women had a statistically significant increased risk for all-cause mortality (HR 2.12; 95% CI 1.15-3.90) while Hispanic women did not (HR 1.23; 95% CI 0.71-2.12). Results were similar for non-breast cancer mortality: NHW (HR 2.65; 95% CI 0.90-7.81); Hispanic (HR 2.18; 95% CI 0.77-6.10). Our results suggest that obesity is associated with increased risk for breast cancer-specific mortality in NHW women; however, this association is attenuated in Hispanic women.

Association of all-cause mortality with overweight and obesity using standard body mass index categories: a systematic review and meta-analysis

IMPORTANCE

Estimates of the relative mortality risks associated with normal weight, overweight, and obesity may help to inform decision making in the clinical setting.

OBJECTIVE

To perform a systematic review of reported hazard ratios (HRs) of all-cause mortality for overweight and obesity relative to normal weight in the general population.

DATA SOURCES

PubMed and EMBASE electronic databases were searched through September 30, 2012, without language restrictions.

STUDY SELECTION

Articles that reported HRs for all-cause mortality using standard body mass index (BMI) categories from prospective studies of general populations of adults were selected by consensus among multiple reviewers. Studies were excluded that used nonstandard categories or that were limited to adolescents or to those with specific medical conditions or to those undergoing specific procedures. PubMed searches yielded 7034 articles, of which 141 (2.0%) were eligible. An EMBASE search yielded 2 additional articles. After eliminating overlap, 97 studies were retained for analysis, providing a combined sample size of more than 2.88 million individuals and more than 270,000 deaths.

DATA EXTRACTION

Data were extracted by 1 reviewer and then reviewed by 3 independent reviewers. We selected the most complex model available for the full sample and used a variety of sensitivity analyses to address issues of possible overadjustment (adjusted for factors in causal pathway) or underadjustment (not adjusted for at least age, sex, and smoking).

RESULTS

Random-effects summary all-cause mortality HRs for overweight (BMI of 25-<30), obesity (BMI of ≥30), grade 1 obesity (BMI of 30-<35), and grades 2 and 3 obesity (BMI of ≥35) were calculated relative to normal weight (BMI of 18.5-<25). The summary HRs were 0.94 (95% CI, 0.91-0.96) for overweight, 1.18 (95% CI, 1.12-1.25) for obesity (all grades combined), 0.95 (95% CI, 0.88-1.01) for grade 1 obesity, and 1.29 (95% CI, 1.18-1.41) for grades 2 and 3 obesity. These findings persisted when limited to studies with measured weight and height that were considered to be adequately adjusted. The HRs tended to be higher when weight and height were self-reported rather than measured.

CONCLUSIONS AND RELEVANCE

Relative to normal weight, both obesity (all grades) and grades 2 and 3 obesity were associated with significantly higher all-cause mortality. Grade 1 obesity overall was not associated with higher mortality, and overweight was associated with significantly lower all-cause mortality. The use of predefined standard BMI groupings can facilitate between-study comparisons.

Catch it before it kills: progesterone, obesity, and the prevention of endometrial cancer

The lifetime risk for developing endometrial cancer, the fourth most common malignancy in women, is approximately 3%. Endometrial cancer is a hormone-driven cancer, with approximately 80% of endometrial cancers arising attributable to either an excess of estrogen or a lack of progesterone. In the normal endometrium, the proliferative effects of estrogen are normally countered by progesterone, but the absence of progesterone allows estrogen to induce oncogenesis, an effect that is amplified in situations of excess estrogen. One of the major emerging causes of the estrogen/progesterone imbalance is obesity. Obesity is associated with several hormonal derangements as well as dysregulation of insulin/insulin-like growth factor activity, which collectively contribute to hyperplasia and carcinogenesis in the endometrium. In this article, we provide an in-depth description of how obesity mechanistically promotes this hormone and growth factor imbalance. Given that endometrial cancer is clearly associated with obesity, we put forth the hypothesis that a large portion of these cancers might be prevented by treatment with progesterone.

Understanding obesity and endometrial cancer risk: opportunities for prevention

Worldwide, obesity has become a major public health crisis. Overweight and obesity not only increase the risk of cardiovascular disease and type-2 diabetes mellitus but also are now known risk factors for a variety of cancer types. Among all cancers, increasing body mass index is associated most strongly with endometrial cancer incidence and death. The molecular mechanisms underlying how adipose tissue and obesity contribute to the pathogenesis of endometrial cancer are becoming better understood and have revealed a number of rational strategies, both behavioral and pharmaceutical, for the prevention of both primary and recurrent disease.

Obesity and breast cancer survival in ethnically diverse postmenopausal women: the Multiethnic Cohort Study

Breast cancer survival has been found to be lower in obese women, but few studies have evaluated ethnic variations in this association. This study examined all-cause and breast cancer-specific survival by body mass index (BMI) in the Multiethnic Cohort (MEC) study for African American, Native Hawaiian, Japanese American, Latino, and Caucasian women. Female MEC participants free of breast cancer, aged ≥50 years at cohort entry, and diagnosed with primary invasive breast cancer during follow-up were included in the analyses (n = 3,842). Cox proportional hazards regression was used to estimate the effect of pre-diagnostic adult BMI (<22.5, 22.5-24.9, 25.0-29.9, ≥30 kg/m(2)) on the risk of mortality. Mean age at diagnosis was 68.8 years (range 50-89 years). During a mean follow-up of 6.2 ± 3.8 years after diagnosis, there were 804 deaths that included 376 breast cancer-specific deaths. After adjustment for breast cancer characteristics, including hormone receptor status, stage at diagnosis, and treatment, obese women had a higher risk of all-cause [hazard ratio (HR) = 1.54; 95% confidence interval (CI): 1.23, 1.91] and breast cancer-specific (HR = 1.45; 95% CI: 1.05, 2.00) mortality compared to women with high-normal BMI; however, being overweight did not affect survival. There was no evidence of ethnic differences in the BMI effect on all-cause (P (interaction) = 0.87) or breast cancer-specific (P (interaction) = 0.63) mortality. Our findings are consistent with the literature that maintaining moderate weight throughout adult life may be beneficial for breast cancer survival in women and this appears to hold for all ethnic groups.

Pro-inflammatory and tumour proliferative properties of excess visceral adipose tissue

Obesity has been associated with increased incidence and mortality of oesophageal and colorectal adenocarcinoma. Excess central adiposity may drive this association through an altered inflammatory milieu. Utilising a unique adipose tissue bioresource we aimed to determine the pro-tumour properties of visceral adipose tissue. Comparing subcutaneous and visceral adipose tissue depots, we observed significantly higher levels of VEGF and IL-6, along with significantly higher proportions of CD8(+) T cells and NKT cells in visceral adipose tissue. Significantly higher levels of VEGF were observed in the conditioned media from visceral adipose tissue of centrally obese compared to non-obese patients. We also report a significant increase in oesophageal and colorectal tumour cell proliferation following culture with conditioned media from visceral adipose tissue of centrally obese patients. Neutralising VEGF in the conditioned media significantly decreased tumour cell proliferation. This novel report highlights a potential mechanism whereby visceral adipose tissue from centrally obese cancer patients may drive tumour progression.