Sarah A. Elliott

Is Obesity Associated with Altered Energy Expenditure

Historically, obese individuals were believed to have lower energy expenditure (EE) rates than nonobese individuals (normal and overweight), which, in the long term, would contribute to a positive energy balance and subsequent weight gain. The aim of this review was to critically appraise studies that compared measures of EE and its components, resting EE (REE), activity EE (AEE), and diet-induced thermogenesis (DIT), in obese and nonobese adults to elucidate whether obesity is associated with altered EE. Contrary to popular belief, research has shown that obese individuals have higher absolute REE and total EE. When body composition (namely the metabolically active component, fat-free mass) is taken into account, these differences between obese and nonobese individuals disappear, suggesting that EE in obese individuals is not altered. However, an important question is whether AEE is lower in obese individuals because of a decrease in overall physical activity or because of less energy expended while performing physical activity. AEE and DIT could be reduced in obese individuals, mostly because of unhealthy behavior (low physical activity, higher intake of fat). However, the current evidence does not support the hypothesis that obesity is sustained by lower daily EE or REE. Future studies, comparing EE between obese and nonobese and assessing potential physiologic abnormalities in obese individuals, should be able to better answer the question of whether these individuals have altered energy metabolism.

Impact of Body Weight and Body Composition on Ovarian Cancer Prognosis.

Measures of body weight and anthropometrics such as body mass index (BMI) are commonly used to assess nutritional status in clinical conditions including cancer. Extensive research has evaluated associations between body weight and prognosis in ovarian cancer patients, yet little is known about the potential impact of body composition (fat mass (FM) and fat-free mass (FFM)) in these patients. Thus, the purpose of this publication was to review the literature (using PubMed and EMBASE) evaluating the impact of body weight and particularly body composition on surgical complications, morbidity, chemotherapy dosing and toxicity (as predictors of prognosis), and survival in ovarian cancer patients. Body weight is rarely associated with intra-operative complications, but obesity predicts higher rates of venous thromboembolism and wound complications post-operatively in ovarian cancer patients. Low levels of FM and FFM are superior predictors of length of hospital stay compared to measures of body weight alone, but the role of body composition on other surgical morbidities is unknown. Obesity complicates chemotherapy dosing due to altered pharmacokinetics, imprecise dosing strategies, and wide variability in FM and FFM. Measurement of body composition has the potential to reduce toxicity if the results are incorporated into chemotherapy dosing calculations. Some findings suggest that excess body weight adversely affects survival, while others find no such association. Limited studies indicate that FM is a better predictor of survival than body weight in ovarian cancer patients, but the direction of this relationship has not been determined. In conclusion, body composition as an indicator of nutritional status is a better prognostic tool than body weight or BMI alone in ovarian cancer patients.

Body Composition, Strength, and Dietary Intake of Patients with Hip or Knee Osteoarthritis.

PURPOSE To describe body composition (fat mass (FM) and fat-free mass (FFM)), strength, and nutritional characteristics of patients with hip or knee osteoarthritis undergoing total joint arthroplasty. METHODS In this prospective pilot study, osteoarthritic patients underwent body composition assessment using bioelectrical impedance analysis, grip strength measurement, and completed a 24-h dietary recall during their pre-operative assessment. RESULTS Fifty-five patients were included (∼66% females, age 43-89 years). Mean ± SD body mass index (BMI) was 32.79 ± 6.48 kg/m(2) and 62% were obese. Compared with hip osteoarthritis patients, knee osteoarthritis patients had a higher BMI (P = 0.018) and males with knee osteoarthritis had a lower grip strength (P = 0.028). There was a wide range in FM and FFM values across the BMI spectrum. Patients with a higher FM index (FMI, FM/height in m(2)) had higher levels of pain (P = 0.036) and females with higher FMI had a lower grip strength (P = 0.048). Dietary under-reporting was common and many patients did not meet recommendations for protein, vitamins C and E, or omega-3 fatty acids. Those who consumed less protein than the recommended dietary allowance were older (P = 0.018). CONCLUSIONS A wide variability of body composition and dietary intake was observed which may impact strength and ultimately affect physical function. As such, patients with osteoarthritis may benefit from targeted nutrition and physical activity interventions before and after surgery.

Accuracy of a Portable Indirect Calorimeter for Measuring Resting Energy Expenditure in Individuals With Cancer

BACKGROUND Determining optimal caloric intake for an individual with cancer is complicated by metabolic changes that occur, namely, alterations in resting energy expenditure (REE). There is currently no validated clinically available equation or tool to measure energy expenditure in these patients. METHODS Patients with newly diagnosed solid tumors underwent REE assessments using the FitMate GS portable indirect calorimeter and reference VMax metabolic cart; both used canopy hoods. REE was also estimated from the Harris-Benedict, Mifflin St. Jeor, and Henry equations for comparison. Data were analyzed using paired samples t-test and the Bland-Altman approach to assess group-level and individual-level agreement compared with the metabolic cart. RESULTS A total 26 patients (19 males; body mass index: 27.8 ± 5.5 kg/m2 ; age: 62 ± 10 years) participated in the study. Biases for the FitMate GS and both equations were low (ranging from -44 to -92 kcal or -2.3% to -5.1%), indicating good group-level accuracy. The FitMate GS had low bias, but the widest limits of agreement (-28.0% to 21.2%) compared with the 3 equations (Harris-Benedict: -15.8% to 11.2%; Mifflin St. Jeor: -17.1% to 6.9%; Henry: -15.4% to 11.5%). These differences were not due to volume of oxygen, BMI category, or sex. CONCLUSION FitMate GS performed well on a group level, but its accuracy was poor on an individual level. Further research should develop better equations and validate tools to measure energy expenditure for accurate dietary recommendations for patients at nutrition risk.

A descriptive analysis of non-Cochrane child-relevant systematic reviews published in 2014

BackgroundConsumers, clinicians, policymakers and researchers require high quality evidence to guide decision-making in child health. Though Cochrane systematic reviews (SRs) are a well-established source of evidence, little is known about the characteristics of non-Cochrane child-relevant SRs. To complement published descriptions of Cochrane SRs, we aimed to characterize the epidemiologic, methodological, and reporting qualities of non-Cochrane child-relevant SRs published in 2014.MethodsEnglish-language child-relevant SRs of quantitative primary research published outside the Cochrane Library in 2014 were eligible for this descriptive analysis. A research librarian searched MEDLINE, CINAHL, Web of Science, and PubMed in August 2015. A single reviewer screened articles for inclusion; a second verified the excluded studies. Reviewers extracted: general characteristics of the review; included study characteristics; methodological approaches. We performed univariate analyses and presented the findings narratively.ResultsWe identified 1598 child-relevant SRs containing a median (IQR) 19 (11, 33) studies. These originated primarily from high-income countries (n = 1247, 78.0%) and spanned 47 of the 53 Cochrane Review Groups. Most synthesized therapeutic (n = 753, 47.1%) or epidemiologic (n = 701, 43.8%) evidence. Though 39.3% (n = 628) of SRs included evidence related to children only, few were published in pediatric-specific journals (n = 283, 17.7%). Reporting quality seemed poor based on the items we assessed; few reviews mentioned an a-priori protocol (n = 246, 15.4%) or registration (n = 111, 6.9%), and only 23.4% (n = 374) specified a primary outcome. Many SRs relied solely on evidence from non-RCTs (n = 796, 49.8%). Less than two-thirds (n = 953, 59.6%) appraised the quality of included studies and assessments of the certainty of the body of evidence were rare (n = 102, 6.4%).ConclusionsChild-relevant Cochrane SRs are a known source of high quality evidence in pediatrics. There exists, however, an abundance of evidence from non-Cochrane SRs that may be complementary. Our findings show that high-quality non-Cochrane SRs may not be practical nor easy for knowledge users to find. Improvements are needed to ensure that evidence syntheses published outside of the Cochrane Library adhere to the high standard of conduct and reporting characteristic of Cochrane SRs.