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

Joint association of sedentary behavior and vitamin D status with mortality among cancer survivors

BACKGROUND

Sedentary behavior and vitamin D deficiency are independent risk factors for mortality in cancer survivors, but their joint association with mortality has not been investigated.

METHODS

We analyzed data from 2914 cancer survivors who participated in the National Health and Nutrition Examination Survey (2007-2018) and followed up with them until December 31, 2019. Sedentary behavior was assessed by self-reported daily hours of sitting, and vitamin D status was measured by serum total 25-hydroxyvitamin D (25(OH)D) levels.

RESULTS

Among 2914 cancer survivors, vitamin D deficiency was more prevalent in those with prolonged daily sitting time. During up to 13.2 years (median, 5.6 years) of follow-up, there were 676 deaths (cancer, 226; cardiovascular disease, 142; other causes, 308). The prolonged sitting time was associated with a higher risk of all-cause and noncancer mortality, and vitamin D deficiency was associated with a higher risk of all-cause and cancer mortality. Furthermore, cancer survivors with both prolonged sitting time (≥ 6 h/day) and vitamin D deficiency had a significantly higher risk of all-cause (HR, 2.05; 95% CI: 1.54-2.72), cancer (HR, 2.33; 95% CI, 1.47-3.70), and noncancer mortality (HR, 1.91; 95% CI, 1.33-2.74) than those with neither risk factor after adjustment for potential confounders.

CONCLUSIONS

In a nationally representative sample of U.S. cancer survivors, the joint presence of sedentary behavior and vitamin D deficiency was significantly associated with an increased risk of all-cause and cancer-specific mortality.

Natural products targeting inflammation-related metabolic disorders: A comprehensive review

Currently, the incidence of metabolic disorders is increasing, setting a challenge to global health. With major advancement in the diagnostic tools and clinical procedures, much has been known in the etiology of metabolic disorders and their corresponding pathophysiologies. In addition, the use of in vitro and in vivo experimental models prior to clinical studies has promoted numerous biomedical breakthroughs, including in the discovery and development of drug candidates to treat metabolic disorders. Indeed, chemicals isolated from natural products have been extensively studied as prospective drug candidates to manage diabetes, obesity, heart-related diseases, and cancer, partly due to their antioxidant and anti-inflammatory properties. Continuous efforts have been made in parallel to improve their bioactivity and bioavailability using selected drug delivery approaches. Here, we provide insights on recent progress in the role of inflammatory-mediated responses on the initiation of metabolic disorders, with particular reference to diabetes mellitus, obesity, heart-related diseases, and cancer. In addition, we discussed the prospective role of natural products in the management of diabetes, obesity, heart-related diseases, and cancers and provide lists of potential biological targets for high throughput screening in drug discovery and development. Lastly, we discussed findings observed in the preclinical and clinical studies prior to identifying suitable approaches on the phytochemical drug delivery systems that are potential to be used in the treatment of metabolic disorders.

Comparison of obesity indices and triglyceride glucose-related parameters to predict type 2 diabetes mellitus among normal-weight elderly in China

PURPOSE

Although a significant proportion of type 2 diabetes mellitus (T2DM) cases arose from normal-weight individuals, studies on indicators of T2DM in normal-weight people are limited. Accordingly, this study aims to investigate the predictive value of obesity indices and triglyceride glucose-related parameters (TyG-related parameters) in T2DM among normal-weight Chinese elderly.

METHODS

A total of 24,215 normal-weight Chinese elderly (age ≥ 60 years) [body mass index-BMI (18.5-23.9 kg/m²)] were included. Obesity indices and triglyceride glucose-related parameters (TyG-related parameters) included waist circumference (WC), waist-to-height ratio (WHtR), visceral adiposity index (VAI), lipid accumulation product (LAP), and TyG-related parameters (TyG, TyG-BMI, TyG-WC, and TyG-WHtR). Multivariate logistic regression analysis was performed to examine the associations between obesity- and TyG-related indices and T2DM. The areas under the curve (AUC) of the receiver-operating characteristic (ROC) curve analyses were used to evaluate and compare the predictive value of the different indices.

RESULTS

The prevalence of T2DM was 14.2% in normal-weight individuals. Among the indices, TyG was significantly associated with T2DM among men and women, respectively, (adjusted odds ratio-aOR per SD 3.46; 95% CI 3.23-3.71) and (aOR per SD 3.64; 95% CI 3.43-3.86). Compared with other indices, TyG had the highest AUC value for T2DM in men (AUC: 0.818, 95% CI 0.810-0.825) and women (AUC: 0.824, 95% CI 0.814-0.833).

CONCLUSIONS

TyG is an effective marker and outperforms other indices when predicting T2DM in the normal-weight Chinese elderly population.

LEVEL OF EVIDENCE

Level V: Opinions of authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

Metabolic aspects of the relationship of asthma and obesity

Asthma and obesity are serious medical and social world problems, and their combined course is characterized by a decrease in the quality of life, an increase in the frequency and duration of hospitalization. The present review summarizes the current views on the mechanisms of formation of asthma phenotype combined with obesity, role of leptin and adiponectin imbalance in the development of systemic inflammation in obesity in the pathophysiology of asthma, its interrelations with metabolic syndrome. We present data that shows that syndrome is closely related not only to the debut of asthma, but also to a decrease in its control. Along with obesity, the role of other components of metabolic syndrome, in particular insulin resistance, as a predictor of asthma development is considered. Insulin resistance may be the most likely factor in the relationship between asthma and obesity, independent of other components of the metabolic syndrome. Insulin resistance associated with obesity can lead to disruption of nitric oxide synthesis. We reveal common mechanism of metabolic disorders of nitric oxide and arginine in metabolic syndrome and asthma and show that insulin resistance treatment can be therapeutically useful in patients with asthma in combination with obesity.

Change in body size and mortality: a systematic review and meta-analysis

Background

: Observational studies have reported that weight loss in later life is associated with an increased risk of mortality. However, the association with weight gain is unclear. We conducted a systematic review and meta-analysis of prospective studies assessing the association of weight gain and loss, and mortality.

Methods

: We searched PubMed, Scopus and Web of Science for articles published before 5 September 2015. We included prospective studies that reported enough information to extract hazard ratios (HRs) with the corresponding 95% confidence intervals (CIs) for the association between weight gain and/or weight loss, and all-cause and cause-specific mortality. The estimates were pooled using a random-effects model. Meta-regression models were fitted to explore sources of potential between-study heterogeneity.

Results

: A total of 25 (providing data from 437 772 participants with 34 038 deaths from all causes) and 24 studies (434 694 participants with 31 978 deaths) presented results for the exposures, weight loss and weight gain. Weight loss compared with a stable weight was associated with an increased risk of all-cause (pooled HR: 1.45; 95% CI: 1.34, 1.58), and cardiovascular disease (CVD) mortality (1.50; 1.32, 1.70) and a slightly increased risk of cancer mortality (1.19; 0.97, 1.46). Weight gain was associated with an increased risk of CVD mortality (1.21; 1.07, 1.36) and a slightly increased risk of all-cause mortality (1.07; 1.01, 1.13) and cancer mortality (1.04; 0.96, 1.13). Considerable heterogeneity was observed; the method used to ascertain body size and the proportion of the baseline sample included in the final analysis explained most of the heterogeneity.

Conclusion

: Weight loss and weight gain in midlife are associated with increased risk of all-cause and CVD mortality.

Influence of obesity and physical workload on disability benefits among construction workers followed up for 37 years

OBJECTIVES

The objectives of this study are to investigate the relation between obesity and labour force exit via diagnosis-specific disability benefits, and whether physical workload modifies this association.

METHODS

A longitudinal analysis was performed among 3 28 743 Swedish construction workers in the age of 15-65 years. Body weight and height were measured at a health examination and enriched with register information on disability benefits up to 37 years later. Diagnoses of disability benefits were categorised into cardiovascular diseases (CVDs), musculoskeletal diseases (MSDs), mental disorders and others. A job exposure matrix, based on self-reported lifting of heavy loads and working in bent forward or twisted position, was applied as a measure of physical workload. Cox proportional hazards regression analyses were performed, and the relative excess risk due to interaction (RERI) between obesity and physical workload was calculated.

RESULTS

Obese construction workers were at increased risk of receiving disability benefits (HR 1.70, 95% CI 1.65 to 2.76), mainly through CVD (HR 2.30) and MSD (HR 1.71). Construction workers with a high physical workload were also more likely to receive a disability benefit (HR 2.28, 95% CI 2.21 to 2.34), particularly via MSD (HR 3.02). Obesity in combination with a higher physical workload increased the risk of disability benefits (RERI 0.28) more than the sum of the risks of obesity and higher physical workload, particularly for MSD (RERI 0.44).

CONCLUSIONS

Obesity and a high physical workload are risk factors for disability benefit. Furthermore, these factors are synergistic risk factors for labour force exit via disability benefit through MSD. Comprehensive programmes that target health promotion to prevent obesity and ergonomic interventions to reduce physical workload are important to facilitate sustained employment.

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.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Maternal obesity during pregnancy and cardiovascular development and disease in the offspring

Maternal obesity during pregnancy is an important public health problem in Western countries. Currently, obesity prevalence rates in pregnant women are estimated to be as high as 30 %. In addition, approximately 40 % of women gain an excessive amount of weight during pregnancy in Western countries. An accumulating body of evidence suggests a long-term impact of maternal obesity and excessive weight gain during pregnancy on adiposity, cardiovascular and metabolic related health outcomes in the offspring in fetal life, childhood and adulthood. In this review, we discuss results from recent studies, potential underlying mechanisms and challenges for future epidemiological studies.

Atopic dermatitis is more severe in children over the age of two who have an increased body mass index

AIM

Childhood obesity increases the risk of developing atopic dermatitis, but no objective measuring tool has been used to determine whether it also affects the severity. Our aim was to determine whether an association existed between increased body mass index (BMI) or weight for length and severity of atopic dermatitis, as measured by the SCORing Atopic Dermatitis (SCORAD) index.

METHODS

Children with atopic dermatitis who presented to the emergency department at an urban children's hospital (n = 104) were assessed using the SCORAD index. We assessed the relationship between BMI percentile or weight for length percentile, based on age, and atopic dermatitis severity, using single-variable multinomial logistic regression with odds ratios.

RESULTS

A significant association was found between BMI >24 and atopic dermatitis severity for children older than 2 years. When analysed separately, a significant association between BMI percentile and SCORAD severity was found in boys but not in girls.

CONCLUSION

These data suggest that the severity of atopic dermatitis is associated with increased BMI percentile in children older than 2 years, although this association was not apparent in younger ages using weight for length. Our results indicate the need for new avenues in the prevention and treatment of these entities.

Estimating the Effects of Obesity and Weight Change on Mortality Using a Dynamic Causal Model

BACKGROUND

A well-known challenge in estimating the mortality risks of obesity is reverse causality attributable to illness-associated and smoking-associated weight loss. Given that the likelihood of chronic and acute illnesses rises with age, reverse causality is most threatening to estimates derived from elderly populations.

METHODS

I analyzed data from 12,523 respondents over 50 years old from a nationally representative longitudinal dataset, the Health and Retirement Study (HRS). The effects of both baseline body weight and time-varying weight change on mortality are estimated, adjusting for demographic and socio-economic variables, as well as time-varying confounders including illness and smoking. Body weight is measured by body mass index (BMI). In survival models for mortality, illness and smoking were lagged to minimize bias from reverse causality in estimates of the effect of weight change. Furthermore, because illness both causes and is caused by changes in BMI, I used a marginal structural model (MSM) rather than standard adjustment to control confounding by this and other time-dependent factors.

RESULTS

Overall, relative to normal weight, underweight and Class II/III at baseline are associated with hazard ratios that are 2.07 (95% confidence interval (CI): 1.28-3.37) and 1.82 (1.54-2.16) respectively, whereas overweight and Class I obesity do not significantly lower or raise the mortality risks. Furthermore, relative to stable weight change, all types of weight change lead to significantly increased risk of mortality. Specifically, large weight loss results in a mortality risk that is nearly 3.86 (3.26-4.58) times of staying in the stable weight range and small weight loss is about 1.81 (1.55-2.11 ) times riskier. In contrast, large weight gain and small weight gain are associated with hazard ratios that are 1.98 (1.67-2.35) and 1.20 (1.02-1.41) respectively.

CONCLUSIONS

Being underweight or severe obese at baseline is associated with excess mortality risk, and weight change tend to raise mortality risk. Both the confounding by illness and by smoking lead to overestimates of the effects of being underweight at baseline and of weight loss, but underestimates the effect of being obese at baseline.

The Generation R Study: Biobank update 2015

The Generation R Study is a population-based prospective cohort study from fetal life until adulthood. The study is designed to identify early environmental and genetic causes and causal pathways leading to normal and abnormal growth, development and health from fetal life, childhood and young adulthood. In total, 9,778 mothers were enrolled in the study. Data collection in children and their parents include questionnaires, interviews, detailed physical and ultrasound examinations, behavioural observations, Magnetic Resonance Imaging and biological samples. Efforts have been conducted for collecting biological samples including blood, hair, faeces, nasal swabs, saliva and urine samples and generating genomics data on DNA, RNA and microbiome. In this paper, we give an update of the collection, processing and storage of these biological samples and available measures. Together with detailed phenotype measurements, these biological samples provide a unique resource for epidemiological studies focused on environmental exposures, genetic and genomic determinants and their interactions in relation to growth, health and development from fetal life onwards.

Repeated measures of body mass index and C-reactive protein in relation to all-cause mortality and cardiovascular disease: results from the consortium on health and ageing network of cohorts in Europe and the United States (CHANCES)

Obesity has been linked with elevated levels of C-reactive protein (CRP), and both have been associated with increased risk of mortality and cardiovascular disease (CVD). Previous studies have used a single 'baseline' measurement and such analyses cannot account for possible changes in these which may lead to a biased estimation of risk. Using four cohorts from CHANCES which had repeated measures in participants 50 years and older, multivariate time-dependent Cox proportional hazards was used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) to examine the relationship between body mass index (BMI) and CRP with all-cause mortality and CVD. Being overweight (≥25-<30 kg/m(2)) or moderately obese (≥30-<35) tended to be associated with a lower risk of mortality compared to normal (≥18.5-<25): ESTHER, HR (95 % CI) 0.69 (0.58-0.82) and 0.78 (0.63-0.97); Rotterdam, 0.86 (0.79-0.94) and 0.80 (0.72-0.89). A similar relationship was found, but only for overweight in Glostrup, HR (95 % CI) 0.88 (0.76-1.02); and moderately obese in Tromsø, HR (95 % CI) 0.79 (0.62-1.01). Associations were not evident between repeated measures of BMI and CVD. Conversely, increasing CRP concentrations, measured on more than one occasion, were associated with an increasing risk of mortality and CVD. Being overweight or moderately obese is associated with a lower risk of mortality, while CRP, independent of BMI, is positively associated with mortality and CVD risk. If inflammation links CRP and BMI, they may participate in distinct/independent pathways. Accounting for independent changes in risk factors over time may be crucial for unveiling their effects on mortality and disease morbidity.

Associations between overweight, obesity, health measures and need for recovery in office employees: a cross-sectional analysis

Background

With both a high need for recovery (NFR) and overweight and obesity being a potential burden for organizations (e.g. productivity loss and sickness absence), the aim of this paper was to examine the associations between overweight and obesity and several other health measures and NFR in office workers.

Methods

Baseline data of 412 office employees participating in a randomised controlled trial aimed at improving NFR in office workers were used. Associations between self-reported BMI categories (normal body weight, overweight, obesity) and several other health measures (general health, mental health, sleep quality, stress and vitality) with NFR were examined. Unadjusted and adjusted linear regression analyses were performed and adjusted for age, education and job demands. In addition, we adjusted for general health in the association between overweight and obesity and NFR.

Results

A significant positive association was observed between stress and NFR (B = 18.04, 95%CI:14.53-21.56). General health, mental health, sleep quality and vitality were negatively associated with NFR (p < 0.001). Analyses also showed a significant positive association between obesity and NFR (B = 8.77, 95%CI:0.01-17.56), but not between overweight and NFR.

Conclusions

The findings suggest that self-reported stress is, and obesity may be, associated with a higher NFR. Additionally, the results imply that health measures that indicate a better health are associated with a lower NFR.

Trial registration

The trial is registered at the Dutch Trial Register (NTR) under trial registration number: NTR2553.

The Rotterdam Study: 2014 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Comparing life expectancy and health-adjusted life expectancy by body mass index category in adult Canadians: a descriptive study

BACKGROUND

While many studies have examined differences between body mass index (BMI) categories in terms of mortality risk and health-related quality of life (HRQL), little is known about the effect of body weight on health expectancy. We examined life expectancy (LE), health-adjusted life expectancy (HALE), and proportion of LE spent in nonoptimal (or poor) health by BMI category for the Canadian adult population (age ≥ 20).

METHODS

Respondents to the National Population Health Survey (NPHS) were followed for mortality outcomes from 1994 to 2009. Our study population at baseline (n=12,478) was 20 to 100 years old with an average age of 47. LE was produced by building abridged life tables by sex and BMI category using data from the NPHS and the Canadian Chronic Disease Surveillance System. HALE was estimated using the Health Utilities Index from the Canadian Community Health Survey as a measure of HRQL. The contribution of HRQL to loss of healthy life years for each BMI category was also assessed using two methods: by calculating differences between LE and HALE proportional to LE and by using a decomposition technique to separate out mortality and HRQL contributions to loss of HALE.

RESULTS

At age 20, for both sexes, LE is significantly lower in the underweight and obesity class 2+ categories, but significantly higher in the overweight category when compared to normal weight (obesity class 1 was nonsignificant). HALE at age 20 follows these same associations and is significantly lower for class 1 obesity in women. Proportion of life spent in nonoptimal health and decomposition of HALE demonstrate progressively higher losses of healthy life associated with lowered HRQL for BMI categories in excess of normal weight.

CONCLUSIONS

Although being in the overweight category for adults may be associated with a gain in life expectancy as compared to normal weight adults, overweight individuals also experience a higher proportion of these years of life in poorer health. Due to the descriptive nature of this study, further research is needed to explore the causal mechanisms which explain these results, including the important differences we observed between sexes and within obesity subcategories.