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Journal of the Academy of Nutrition and... Oct 2014Weight loss can reduce the health risks associated with being overweight or obese. However, the most effective method of weight loss remains unclear. Some programs... (Comparative Study)
Comparative Study Meta-Analysis Review
Weight loss can reduce the health risks associated with being overweight or obese. However, the most effective method of weight loss remains unclear. Some programs emphasize physical activity, others diet, but existing evidence is mixed as to whether these are more effective individually or in combination. We aimed to examine the clinical effectiveness of combined behavioral weight management programs (BWMPs) targeting weight loss in comparison to single component programs, using within study comparisons. We included randomized controlled trials of combined BWMPs compared with diet-only or physical activity-only programs with at least 12 months of follow-up, conducted in overweight and obese adults (body mass index ≥25). Systematic searches of nine databases were run and two reviewers extracted data independently. Random effects meta-analyses were conducted for mean difference in weight change at 3 to 6 months and 12 to 18 months using a baseline observation carried forward approach for combined BWMPs vs diet-only BWMPs and combined BWMPs vs physical activity-only BWMPs. In total, eight studies were included, representing 1,022 participants, the majority of whom were women. Six studies met the inclusion criteria for combined BWMP vs diet-only. Pooled results showed no significant difference in weight loss from baseline or at 3 to 6 months between the BWMPs and diet-only arms (-0.62 kg; 95% CI -1.67 to 0.44). However, at 12 months, a significantly greater weight-loss was detected in the combined BWMPs (-1.72 kg; 95% CI -2.80 to -0.64). Five studies met the inclusion criteria for combined BWMP vs physical activity-only. Pooled results showed significantly greater weight loss in the combined BWMPs at 3 to 6 months (-5.33 kg; 95% CI -7.61 to -3.04) and 12 to 18 months (-6.29 kg; 95% CI -7.33 to -5.25). Weight loss is similar in the short-term for diet-only and combined BWMPs but in the longer-term weight loss is increased when diet and physical activity are combined. Programs based on physical activity alone are less effective than combined BWMPs in both the short and long term.
Topics: Adult; Behavior Therapy; Combined Modality Therapy; Diet, Reducing; Energy Intake; Evidence-Based Medicine; Exercise; Humans; Motor Activity; Obesity; Overweight; Randomized Controlled Trials as Topic; Time Factors; Weight Loss
PubMed: 25257365
DOI: 10.1016/j.jand.2014.07.005 -
PloS One 2013Overweight and obesity are thought to significantly influence a person's risk of cardiovascular disease, possibly via its effect on the microvasculature. Retinal... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Overweight and obesity are thought to significantly influence a person's risk of cardiovascular disease, possibly via its effect on the microvasculature. Retinal vascular caliber is a surrogate marker of microvascular disease and a predictor of cardiovascular events. The aim of this systematic review and meta-analysis was to determine the association between body mass index (BMI) and retinal vascular caliber.
METHODS AND FINDINGS
Relevant studies were identified by searches of the MEDLINE and EMBASE databases from 1966 to August 2011. Standardized forms were used for data extraction. Among over 44,000 individuals, obese subjects had narrower arteriolar and wider venular calibers when compared with normal weight subjects, independent of conventional cardiovascular risk factors. In adults, a 1 kg/m(2) increase in BMI was associated with a difference of 0.07 μm [95% CI: -0.08; -0.06] in arteriolar caliber and 0.22 μm [95% CI: 0.21; 0.23] in venular caliber. Similar results were found for children.
CONCLUSIONS
Higher BMI is associated with narrower retinal arteriolar and wider venular calibers. Further prospective studies are needed to examine whether a causative relationship between BMI and retinal microcirculation exists.
Topics: Adolescent; Adult; Aged; Body Mass Index; Child; Humans; Microvessels; Middle Aged; Obesity; Retinal Vessels; Risk Factors
PubMed: 23405065
DOI: 10.1371/journal.pone.0052708 -
Respiratory Medicine Sep 2013Epidemiological data has established increasing adiposity as a risk factor for incident asthma. However, the mechanisms underlying the association between obesity and... (Review)
Review
BACKGROUND AND AIM
Epidemiological data has established increasing adiposity as a risk factor for incident asthma. However, the mechanisms underlying the association between obesity and asthma are incompletely understood. In the present paper, we review current knowledge of possible mechanisms mediating the observed association between obesity and asthma.
METHODS
Systematic literature review.
RESULTS
Obesity and asthma share some etiological factors, such as a common genetic predisposition and effects of in utero conditions, and may also have common predisposing factors such as physical activity and diet. Obesity results in important changes in the mechanical properties of the respiratory system which could explain the occurrence of asthma. However, there are also plausible biological mechanisms whereby obesity could be expected to either cause or worsen asthma. These include co-morbidities such as gastro-oesophageal reflux, complications from sleep-disordered breathing, breathing at low lung volumes, chronic systemic inflammation, and endocrine factors, including adipokines and reproductive hormones. Obesity related asthma is in general not associated with eosinophilic airway inflammation, and adipokines are likely to play important roles in the inflammatory pathogenesis of asthma in obese individuals.
CONCLUSION
The association between obesity and asthma is not straightforward, and further knowledge is clearly needed, as understanding the underlying mechanisms may lead to new therapeutic options for this high-risk part of the asthma population.
Topics: Adipokines; Adiposity; Adolescent; Adult; Aged; Asthma; Biomarkers; Body Mass Index; Dinoprost; Environment; Epigenesis, Genetic; Female; Genetic Predisposition to Disease; Humans; Life Style; Lung; Male; Middle Aged; Obesity; Oxidative Stress; Respiratory Function Tests; Sex Factors; Young Adult
PubMed: 23642708
DOI: 10.1016/j.rmed.2013.03.019 -
International Journal of Environmental... Oct 2017This systematic review and meta-analysis examined the associations between obesity and puberty timing based on scientific evidence. Eight electronic databases were... (Meta-Analysis)
Meta-Analysis Review
This systematic review and meta-analysis examined the associations between obesity and puberty timing based on scientific evidence. Eight electronic databases were searched up to February 2017 for eligible studies, and two reviewers screened the articles and extracted the data independently. A total of 11 cohort studies with 4841 subjects met the inclusion criteria. Compared with the group of normal-weight girls, the obese group had more girls with menarche (RR: 1.87, 95% CI: 1.59-2.19, 2 studies). The number of girls with early puberty was significantly higher in the obese group than the normal weight group (RR: 2.44, 95% CI: 1.32-4.52, 5 studies). However, no differences were detected between girls who were obese or normal weight at age of menarche (WMD: -0.53 years, 95% CI: -1.24-0.19, 2 studies). There is no consistent result in the relationship between obesity and timing of pubertal onset in boys. Obesity may contribute to early onset of puberty in girls, while in boys, there is insufficient data. Given the limited number of cohort studies included in this meta-analysis, high-quality studies with strong markers of puberty onset, as well as standardized criteria for defining obesity are needed.
Topics: Cohort Studies; Humans; Obesity; Puberty; Sexual Maturation
PubMed: 29064384
DOI: 10.3390/ijerph14101266 -
Einstein (Sao Paulo, Brazil) 2014Obesity is a chronic disease characterized by the excessive accumulation of body fat that is harmful to the individuals. Respiratory disorders are among the... (Review)
Review
Obesity is a chronic disease characterized by the excessive accumulation of body fat that is harmful to the individuals. Respiratory disorders are among the comorbidities associated with obesity. This study had the objective of investigating the alterations in respiratory function that affect obese individuals. A systematic review was performed, by selecting publications in the science databases MEDLINE and LILACS, using PubMed and SciELO. The articles that assessed pulmonary function by plethysmography and/or spirometry in obese individuals aged under 18 years were included. The results demonstrated that the obese individuals presented with a reduction in lung volume and capacity as compared to healthy individuals. Reduction of total lung capacity and reduction of forced vital capacity, accompanied by reduction of the forced expiratory volume after one second were the most representative findings in the samples. The articles analyzed proved the presence of a restrictive respiratory pattern associated with obesity.
Topics: Body Mass Index; Female; Humans; Lung; Male; Obesity; Plethysmography; Respiratory Function Tests; Respiratory Tract Diseases; Total Lung Capacity
PubMed: 24728258
DOI: 10.1590/s1679-45082014rw2691 -
Journal of Public Health (Oxford,... Sep 2016Maternal obesity is emerging as a public health problem, recently highlighted together with maternal under-nutrition as a 'double burden', especially in African... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Maternal obesity is emerging as a public health problem, recently highlighted together with maternal under-nutrition as a 'double burden', especially in African countries undergoing social and economic transition. This systematic review was conducted to investigate the current evidence on maternal obesity in Africa.
METHODS
MEDLINE, EMBASE, Scopus, CINAHL and PsycINFO were searched (up to August 2014) and identified 29 studies. Prevalence, associations with socio-demographic factors, labour, child and maternal consequences of maternal obesity were assessed. Pooled risk ratios comparing obese and non-obese groups were calculated.
RESULTS
Prevalence of maternal obesity across Africa ranged from 6.5 to 50.7%, with older and multiparous mothers more likely to be obese. Obese mothers had increased risks of adverse labour, child and maternal outcomes. However, non-obese mothers were more likely to have low-birthweight babies. The differences in measurement and timing of assessment of maternal obesity were found across studies. No studies were identified either on the knowledge or attitudes of pregnant women towards maternal obesity; or on interventions for obese pregnant women.
CONCLUSIONS
These results show that Africa's levels of maternal obesity are already having significant adverse effects. Culturally adaptable/sensitive interventions should be developed while monitoring to avoid undesired side effects.
Topics: Africa; Age Factors; Female; Humans; Mothers; Obesity; Parity; Prevalence; Risk Factors
PubMed: 26487702
DOI: 10.1093/pubmed/fdv138 -
BMJ Open Jan 2018It was repeatedly shown that lower income is associated with higher risks for subsequent obesity. However, the perspective of a potential reverse causality is often... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
It was repeatedly shown that lower income is associated with higher risks for subsequent obesity. However, the perspective of a potential reverse causality is often neglected, in which obesity is considered a cause for lower income, when obese people drift into lower-income jobs due to labour-market discrimination and public stigmatisation. This review was performed to explore the direction of the relation between income and obesity by specifically assessing the importance of social causation and reverse causality.
DESIGN
Systematic review and meta-analysis.
METHODS
A systematic literature search was conducted in January 2017. The databases Medline, PsycINFO, Sociological Abstracts, International Bibliography of Social Sciences and Sociological Index were screened to identify prospective cohort studies with quantitative data on the relation between income and obesity. Meta-analytic methods were applied using random-effect models, and the quality of studies assessed with the Newcastle-Ottawa Scale.
RESULTS
In total, 21 studies were eligible for meta-analysis. All included studies originated from either the USA (n=16), the UK (n=3) or Canada (n=2). From these, 14 studies on causation and 7 studies on reverse causality were found. Meta-analyses revealed that lower income is associated with subsequent obesity (OR 1.27, 95% CI 1.10 to 1.47; risk ratio 1.52, 95% CI 1.08 to 2.13), though the statistical significance vanished once adjusted for publication bias. Studies on reverse causality indicated a more consistent relation between obesity and subsequent income, even after taking publication bias into account (standardised mean difference -0.15, 95% CI -0.30 to 0.01). Sensitivity analyses implied that the association is influenced by obesity measurement, gender, length of observation and study quality.
CONCLUSIONS
Findings suggest that there is more consistent evidence for reverse causality. Therefore, there is a need to examine reverse causality processes in more detail to understand the relation between income and obesity.
PROSPERO REGISTRATION NUMBER
42016041296.
Topics: Health Knowledge, Attitudes, Practice; Humans; Income; Obesity; Prospective Studies; Qualitative Research; Risk Factors; Social Environment; Socioeconomic Factors
PubMed: 29306894
DOI: 10.1136/bmjopen-2017-019862 -
Antimicrobial Resistance and Infection... Nov 2022The role of obesity in catheter-related bloodstream infection has been reported in several studies, but it is still controversial. We conducted this meta-analysis to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The role of obesity in catheter-related bloodstream infection has been reported in several studies, but it is still controversial. We conducted this meta-analysis to summarize existing evidence to assess the relationship between obesity and the risk of catheter-related bloodstream infection.
METHODS
We searched MEDLINE, EMBASE, PubMed and Web of Science for the related studies published before January 2022. Meta-analysis was performed by use of a random-effects model.
RESULTS
A total of 5 articles were included in this meta-analysis. Patients with body mass index ≥ 25 kg/m had an increased risk of catheter-related bloodstream infection (OR 1.75, 95% CI 1.38-2.22) in overall analysis. Further analysis indicated that patients with overweight, obesity and severely obesity were all significantly associated with a higher risk of for catheter-related bloodstream infection (OR 1.51 [1.10-2.08], OR 1.43 [1.12-1.82] and OR 2.74 [1.85-4.05], respectively).
CONCLUSION
This meta-analysis provided evidence that obesity was significantly associated with a higher risk of catheter-related bloodstream infection. Close attention should be paid to the complications and prognosis of obese patients with vascular catheterization in clinical work.
Topics: Humans; Catheter-Related Infections; Sepsis; Obesity; Catheters
PubMed: 36371230
DOI: 10.1186/s13756-022-01166-z -
Obesity Reviews : An Official Journal... Dec 2013Although previous systematic reviews considered the relationship between socioeconomic status and obesity, almost 200 peer-reviewed articles have been published since... (Meta-Analysis)
Meta-Analysis Review
Although previous systematic reviews considered the relationship between socioeconomic status and obesity, almost 200 peer-reviewed articles have been published since the last review on that topic, and this paper focuses specifically on education, which has different implications. The authors systematically review the peer-reviewed literature from around the world considering the association between educational attainment and obesity. Databases from public health and medicine, education, psychology, economics, and other social sciences were searched, and articles published in English, French, Portuguese and Spanish were included. This paper includes 289 articles that report on 410 populations in 91 countries. The relationship between educational attainment and obesity was modified by both gender and the country's economic development level: an inverse association was more common in studies of higher-income countries and a positive association was more common in lower-income countries, with stronger social patterning among women. Relatively few studies reported on lower-income countries, controlled for a comprehensive set of potential confounding variables and/or attempted to assess causality through the use of quasi-experimental designs. Future research should address these gaps to understand if the relationship between educational attainment and obesity may be causal, thus supporting education policy as a tool for obesity prevention.
Topics: Adult; Child; Developed Countries; Developing Countries; Educational Status; Female; Health Policy; Humans; Male; Obesity; Social Class; Social Determinants of Health
PubMed: 23889851
DOI: 10.1111/obr.12062 -
Clinical Gastroenterology and... Mar 2016Obesity is associated with an increased risk for pancreatic cancer, but it is unclear whether it affects mortality. We performed a systematic review and meta-analysis to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND & AIMS
Obesity is associated with an increased risk for pancreatic cancer, but it is unclear whether it affects mortality. We performed a systematic review and meta-analysis to assess the association between premorbid obesity and mortality from pancreatic cancer.
METHODS
We performed a systematic search through January 2015 and identified studies of the association between premorbid obesity (at least 1 year prior to pancreatic cancer diagnosis) and pancreatic cancer-related mortality. We estimated summary adjusted hazard ratio (aHR) with 95% confidence interval (CI), comparing data from obese (body mass index [BMI] ≥30 kg/m(2)) and overweight subjects (BMI, 25.0-29.9 kg/m(2)) with those from individuals with a normal BMI (controls) by using random-effects model.
RESULTS
We identified 13 studies (including 3 studies that pooled multiple cohorts); 5 studies included only patients with pancreatic cancer, whereas 8 studies evaluated pancreatic cancer-related mortality in cancer-free individuals at inception. In the meta-analysis, we observed increase in pancreatic cancer-related mortality among overweight (aHR, 1.06; 95% CI, 1.02-1.11; I(2) = 0) and obese individuals (aHR, 1.31; 95% CI, 1.20-1.42; I(2) = 43%), compared with controls; the association remained when we analyzed data from only subjects with pancreatic cancer. Each 1 kg/m(2) increase in BMI was associated with 10% increase in mortality (aHR, 1.10; 95% CI, 1.05-1.15) with minimal heterogeneity (I(2) = 0). In the subgroup analysis, obesity was associated with increased mortality in Western populations (11 studies; aHR, 1.32; 95% CI, 1.22-1.42) but not in Asia-Pacific populations (2 studies; aHR, 0.98; 95% CI, 0.76-1.27).
CONCLUSIONS
In a systematic review and meta-analysis, we associated increasing level of obesity with increased mortality in patients with pancreatic cancer in Western but not Asia-Pacific populations. Strategies to reduce obesity-induced metabolic abnormalities might be developed to treat patients with pancreatic cancer.
Topics: Body Mass Index; Global Health; Humans; Obesity; Pancreatic Neoplasms
PubMed: 26460214
DOI: 10.1016/j.cgh.2015.09.036