Dataset Information

Assessing Energy Requirements in Women With Polycystic Ovary Syndrome: A Comparison Against Doubly Labeled Water.

ABSTRACT: Context:Weight loss is prescribed to offset the deleterious consequences of polycystic ovary syndrome (PCOS), but a successful intervention requires an accurate assessment of energy requirements. Objective:Describe energy requirements in women with PCOS and evaluate common prediction equations compared with doubly labeled water (DLW). Design:Cross-sectional study. Setting:Academic research center. Participants:Twenty-eight weight-stable women with PCOS completed a 14-day DLW study along with measures of body composition and resting metabolic rate and assessment of physical activity by accelerometry. Main Outcome:Total daily energy expenditure (TDEE) determined by DLW. Results:TDEE was 2661 ± 373 kcal/d. TDEE estimated from four commonly used equations was within 4% to 6% of the TDEE measured by DLW. Hyperinsulinemia (fasting insulin and homeostatic model assessment of insulin resistance) was associated with TDEE estimates from all prediction equations (both r = 0.45; P = 0.02) but was not a significant covariate in a model that predicts TDEE. Similarly, hyperandrogenemia (total testosterone, free androgen index, and dehydroepiandrosterone sulfate) was not associated with TDEE. In weight-stable women with PCOS, the following equation derived from DLW can be used to determine energy requirements: TDEE (kcal/d) = 438 - [1.6 * Fat Mass (kg)] + [35.1 * Fat-Free Mass (kg)] + [16.2 * Age (y)]; R2 = 0.41; P = 0.005. Conclusions:Established equations using weight, height, and age performed well for predicting energy requirements in weight-stable women with PCOS, but more precise estimates require an accurate assessment of physical activity. Our equation derived from DLW data, which incorporates habitual physical activity, can also be used in women with PCOS; however, additional studies are needed for model validation.

SUBMITTER: Broskey NT

PROVIDER: S-EPMC5470767 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature

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Assessing Energy Requirements in Women With Polycystic Ovary Syndrome: A Comparison Against Doubly Labeled Water.

Broskey Nicholas T NT Klempel Monica C MC Gilmore L Anne LA Sutton Elizabeth F EF Altazan Abby D AD Burton Jeffrey H JH Ravussin Eric E Redman Leanne M LM

The Journal of clinical endocrinology and metabolism 20170601 6

<h4>Context</h4>Weight loss is prescribed to offset the deleterious consequences of polycystic ovary syndrome (PCOS), but a successful intervention requires an accurate assessment of energy requirements.<h4>Objective</h4>Describe energy requirements in women with PCOS and evaluate common prediction equations compared with doubly labeled water (DLW).<h4>Design</h4>Cross-sectional study.<h4>Setting</h4>Academic research center.<h4>Participants</h4>Twenty-eight weight-stable women with PCOS complet ...[more]

PMID: 28323951

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Project description:BACKGROUND:Low-carbohydrate diets have been reported to significantly increase human energy expenditure when measured using doubly labeled water (DLW) but not by respiratory chambers. Although DLW may reveal true physiological differences undetected by respiratory chambers, an alternative possibility is that the expenditure differences resulted from failure to correctly estimate the respiratory quotient (RQ) used in the DLW calculations. OBJECTIVE:To examine energy expenditure differences between isocaloric diets varying widely in carbohydrate and to quantitatively compare DLW data with respiratory chamber and body composition measurements within an energy balance framework. DESIGN:DLW measurements were obtained during the final 2 wk of month-long baseline (BD; 50% carbohydrate, 35% fat, 15% protein) and isocaloric ketogenic diets (KD; 5% carbohydrate, 80% fat, 15% protein) in 17 men with a BMI of 25-35 kg/m2. Subjects resided 2 d/wk in respiratory chambers to measure energy expenditure (EEchamber). DLW expenditure was calculated using chamber-determined RQ either unadjusted (EEDLW) or adjusted (EEDLW?RQ) for net energy imbalance using diet-specific coefficients. Accelerometers measured physical activity. Body composition changes were measured by dual-energy X-ray absorptiometry (DXA) which were combined with energy intake measurements to calculate energy expenditure by balance (EEbal). RESULTS:After transitioning from BD to KD, neither EEchamber nor EEbal were significantly changed (?EEchamber = 24 ± 30 kcal/d; P = 0.43 and ?EEbal = -141 ± 118 kcal/d; P = 0.25). Similarly, physical activity (-5.1 ± 4.8%; P = 0.3) and exercise efficiency (-1.6 ± 2.4%; P = 0.52) were not significantly changed. However, EEDLW was 209 ± 83 kcal/d higher during the KD (P = 0.023) but was not significantly increased when adjusted for energy balance (EEDLW?RQ = 139 ± 89 kcal/d; P = 0.14). After removing 2 outliers whose EEDLW were incompatible with other data, EEDLW was marginally increased during the KD by 126 ± 62 kcal/d (P = 0.063) and EEDLW?RQ was only 46 ± 65 kcal/d higher (P = 0.49). CONCLUSIONS:DLW calculations failing to account for diet-specific energy imbalance effects on RQ erroneously suggest that low-carbohydrate diets substantially increase energy expenditure. This trial was registered at clinicaltrials.gov as NCT01967563.

Project description:Several studies have reported the association between polycystic ovary syndrome (PCOS) and low-grade chronic inflammation to be of uncertain cause: obesity, insulin resistance, or PCOS itself. The aim of the study was to investigate the WBC (white blood cell) count and CRP (C-reactive protein) concentration in women with PCOS and to determine the factors that affect their concentration. The study included 200 women aged 18-40 with PCOS and 105 healthy women as the control group, recruited in the Department of Gynaecological Endocrinology of Medical University in Warsaw from 2016 to 2018. Each patient underwent clinical, biochemical, and ultrasonographic assessments. WBC and CRP were significantly higher in the PCOS group (Z = -2,353, p = 0,019 and Z = -2,453, p = 0,014). WBC positively correlated with serum insulin at 0, 60, and 120?min during the oral glucose tolerance test (INS0: r = 0,221, p = 0,001; INS1: r = 0,194, p = 0,003; INS2: r = 0,022, p = 0,001), testosterone (r = 0,130, p = 0,046), androstenedione (r = 0,212, p = 0,001), and DHEAS (r = 0,178, p = 0,006) and negatively correlated with progesterone (r = -0,204, p = 0,002), estradiol (r = -0,140, p = 0,032), and SHBG (r = -0,308, p < 0,001). CRP positively correlated with insulin concentration in 0, 60, and 120?min during the oral glucose tolerance test (INS0: r = 0,343, p < 0,001; INS1: r = 0,276, p = 0,001; INS2: r = 0,320, p < 001) and negatively correlated with progesterone (r = -0,194, p = 0,030) and SHBG (-0,244, p = 0,005). We also estimated positive correlation between BMI and serum CRP and WBC concentration. Multiple linear regression analysis showed that CRP values are positively associated with BMI (beta = 0,374, p < 0,001) and insulin level (INS1) (beta = 0,282, p = 0,004); and WBC results are negatively associated with SHGB (beta = -0,284, p < 0,001) but positively associated with testosterone (beta = 0,163, p = 0,024) and BMI (beta = 0,157, p = 0,047). PCOS is associated with increased WBC and CRP concentrations. The main predicting factors of increased CRP are BMI and insulin resistance, but there is also a relationship between WBC count in PCOS and androgen concentration itself so that inflammation may be mediated not only through adiposity but also through increased androgen concentration.

Project description:BACKGROUND:Polycystic ovary syndrome (PCOS) affects 8% to 13% of reproductive-aged women and is associated with reproductive and metabolic dysfunction. Obesity worsens the presentation of PCOS and weight management (weight loss, maintenance or prevention of excess weight gain) is proposed as an initial treatment strategy, best achieved through lifestyle changes incorporating diet, exercise and behavioural interventions. OBJECTIVES:To assess the effectiveness of lifestyle treatment in improving reproductive, anthropometric (weight and body composition), metabolic and quality of life factors in PCOS. SEARCH METHODS:We searched the Cochrane Gynaecology and Fertility Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO, CINAHL and AMED (date of last search March 2018). We also searched controlled trials registries, conference abstracts, relevant journals, reference lists of relevant papers and reviews, and grey literature databases, with no language restrictions applied. SELECTION CRITERIA:Randomised controlled trials (RCTs) comparing lifestyle treatment (diet, exercise, behavioural or combined treatments) to minimal or no treatment in women with PCOS. DATA COLLECTION AND ANALYSIS:Two authors independently selected trials, assessed evidence quality and risk of bias, and extracted data. Our primary outcomes were live birth, miscarriage and pregnancy. We used inverse variance and fixed-effect models in the meta-analyses. We reported dichotomous outcomes as an odds ratio and continuous outcomes as a mean difference (MD) or standardised mean difference (SMD). MAIN RESULTS:We included 15 studies with 498 participants. Ten studies compared physical activity to minimal dietary and behavioural intervention or no intervention. Five studies compared combined dietary, exercise and behavioural intervention to minimal intervention. One study compared behavioural intervention to minimal intervention. Risk of bias varied: eight studies had adequate sequence generation, seven had adequate clinician or outcome assessor blinding, seven had adequate allocation concealment, six had complete outcome data and six were free of selective reporting. No studies assessed the fertility primary outcomes of live birth or miscarriage. No studies reported the secondary reproductive outcome of menstrual regularity, as defined in this review.Lifestyle intervention may improve a secondary (endocrine) reproductive outcome, the free androgen index (FAI) (MD -1.11, 95% confidence interval (CI) -1.96 to -0.26, 6 RCTs, N = 204, I2 = 71%, low-quality evidence). Lifestyle intervention may reduce weight (kg) (MD -1.68 kg, 95% CI -2.66 to -0.70, 9 RCTs, N = 353, I2 = 47%, low-quality evidence). Lifestyle intervention may reduce body mass index (BMI) (kg/m2) (-0.34 kg/m2, 95% CI -0.68 to -0.01, 12 RCTs, N = 434, I2= 0%, low-quality evidence). We are uncertain of the effect of lifestyle intervention on glucose tolerance (glucose outcomes in oral glucose tolerance test) (mmol/L/minute) (SMD -0.02, 95% CI -0.38 to 0.33, 3 RCTs, N = 121, I2 = 0%, low-quality evidence). AUTHORS' CONCLUSIONS:Lifestyle intervention may improve the free androgen index (FAI), weight and BMI in women with PCOS. We are uncertain of the effect of lifestyle intervention on glucose tolerance. There were no studies that looked at the effect of lifestyle intervention on live birth, miscarriage or menstrual regularity. Most studies in this review were of low quality mainly due to high or unclear risk of bias across most domains and high heterogeneity for the FAI outcome.

Project description:IntroductionWrist-mounted motion sensors can quantify the volume and intensity of physical activities, but little is known about their long-term validity. Our aim was to validate a wrist motion sensor in estimating daily energy expenditure, including any change induced by long-term participation in endurance and strength training. Supplemental heart rate monitoring during weekly exercise was also investigated.MethodsA 13-day doubly labeled water (DLW) measurement of total energy expenditure (TEE) was performed twice in healthy male subjects: during two last weeks of a 12-week Control period (n = 15) and during two last weeks of a 12-week combined strength and aerobic Training period (n = 13). Resting energy expenditure was estimated using two equations: one with body weight and age, and another one with fat-free mass. TEE and activity induced energy expenditure (AEE) were determined from motion sensor alone, and from motions sensor combined with heart rate monitor, the latter being worn during exercise only.ResultsWhen body weight and age were used in the calculation of resting energy expenditure, the motion sensor data alone explained 78% and 62% of the variation in TEE assessed by DLW at the end of Control and Training periods, respectively, with a bias of +1.75 (p <.001) and +1.19 MJ/day (p = .002). When exercise heart rate data was added to the model, the combined wearable device approach explained 85% and 70% of the variation in TEE assessed by DLW with a bias of +1.89 and +1.75 MJ/day (p <.001 for both). While significant increases in TEE and AEE were detected by all methods as a result of participation in regular training, motion sensor approach underestimated the change measured by DLW: +1.13±0.66 by DLW, +0.59±0.69 (p = .004) by motion sensor, and +0.98±0.70 MJ/day by combination of motion sensor and heart rate. Use of fat-free mass in the estimation of resting energy expenditure removed the biases between the wearable device estimations and the golden standard reference method of TEE and demonstrated a training-induced increase in resting energy expenditure by +0.18±0.13 MJ/day (p <.001).ConclusionsWrist motion sensor combined with a heart rate monitor during exercise sessions, showed high agreement with the golden standard measurement of daily TEE and its change induced by participation in a long-term training protocol. The positive findings concerning the validity, especially the ability to follow-up the change associated with a lifestyle modification, can be considered significant because they partially determine the feasibility of wearable devices as quantifiers of health-related behavior.

Dataset Information

Assessing Energy Requirements in Women With Polycystic Ovary Syndrome: A Comparison Against Doubly Labeled Water.

Publications

Assessing Energy Requirements in Women With Polycystic Ovary Syndrome: A Comparison Against Doubly Labeled Water.

Similar Datasets

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