A systematic review of interventions to increase physical activity and reduce sedentary behaviour following bariatric surgery.

BACKGROUND: Bariatric surgery promotes weight loss and improves co-morbid conditions, with patients who are more physically active having better outcomes. However, levels of physical activity and sedentary behaviour often remain unchanged following surgery. OBJECTIVES: To identify interventions and components thereof that are able to facilitate changes in physical activity and sedentary behaviour. ELIGIBILITY: Physical activity and/or sedentary behaviour must have been measured, pre and post intervention, in patients who have undergone bariatric surgery. STUDY APPRAISAL AND SYNTHESIS METHODS: : Four databases were searched with key-words. Two researchers conducted paper screening, data extraction and risk-of-bias assessment. RESULTS: Twelve studies were included; eleven were randomised. Two were delivered presurgery and ten postsurgery; five found positive effect. Moderate to vigorous physical activity increased in three studies, two of which also found a significant increase in step count. The fourth found a significant increase in strenuous activity and the fifth a significant increase in metabolic equivalent of task/day and reduced time spent watching television. LIMITATIONS: Meta-analysis could not be conducted due to heterogeneity of outcomes and the tools used. CONCLUSION AND IMPLICATIONS OF KEY FINDINGS: This review has identified interventions and components thereof that were able to provoke positive effect. However, intervention and control conditions were not always well described particularly in terms of behaviour change techniques and the rationale for their use. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO (CRD42019121372

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Perceptions of antenatal exercise in pregnant females and the impact of COVID-19

Exercise during pregnancy presents many benefits for the mother and baby. Yet, pregnancy is characterised by a decrease in exercise. Studies have reported barriers to antenatal exercise. The coronavirus (COVID-19) pandemic may have further exacerbated barriers to antenatal exercise as pregnant females faced many challenges. Rich, in-depth exploration into pregnant female’s perceived barriers to antenatal exercise during COVID-19 is imperative. Questionnaires reporting physical activity levels were completed by all participants (n = 14). Semi-structured interviews were conducted between November 2020 and May 2021 in the UK. Interviews were analysed using thematic analysis and revealed four main themes: ‘Perceptions of being an active person shaping activity levels in pregnancy’, ‘How do I know what is right? Uncertainty, seeking validation and feeling informed’, ‘Motivators to antenatal exercise’ and ‘A process of adaptations and adjustment’. Findings indicate that the COVID-19 pandemic exacerbated barriers to antenatal exercise and highlight the importance of direct psychosocial support and clear, trustworthy information. Findings also support the fundamental need for better education amongst healthcare professionals regarding antenatal exercise

The Effect of Water Immersion during Exercise on Cerebral Blood Flow

Introduction: Regular exercise induces recurrent increases in cerebrovascular perfusion. In peripheral arteries, such episodic increases in perfusion are responsible for improvement in arterial function and health. We examined the hypothesis that exercise during immersion augments cerebral blood flow velocity compared with intensity-matched land-based exercise. Methods: Fifteen normotensive participants were recruited (26 ± 4 yr, 24.3 ± 1.9 kg·m−2). We continuously assessed mean arterial blood pressure, HR, stroke volume, oxygen consumption, and blood flow velocities through the middle and posterior cerebral arteries before, during, and after 20-min bouts of water- and land-based stepping exercise of matched intensity. The order in which the exercise conditions were performed was randomized between subjects. Water-based exercise was performed in 30°C water to the level of the right atrium. Results: The water- and land-based exercise bouts were closely matched for oxygen consumption (13.3 mL·kg−1·min−1 (95% confidence interval (CI), 12.2–14.6) vs 13.5 mL·kg−1·min−1 (95% CI, 12.1–14.8), P = 0.89) and HR (95 bpm (95% CI, 90–101) vs 96 bpm (95% CI, 91–102), P = 0.65). Compared with land-based exercise, water-based exercise induced an increase in middle cerebral artery blood flow velocity (74 cm·s−1 (95% CI, 66–81) vs 67 cm·s−1 (95% CI, 60–74) P < 0.001), posterior cerebral artery blood flow velocity (47 cm·s−1 (95% CI, 40–53) vs 43 cm·s−1 (95% CI, 37–49), P < 0.001), mean arterial blood pressure (106 mm Hg (95% CI, 100–111) vs 101 mm Hg (95% CI, 95–106), P < 0.001), and partial pressure of expired CO2 (P ≤ 0.001). Conclusions: Our findings suggest that water-based exercise augments cerebral blood flow, relative to land-based exercise of similar intensity, in healthy humans

No evidence of compensatory changes in energy balance, despite reductions in body weight and liver fat, during dapagliflozin treatment in type 2 diabetes mellitus: A randomized, double-blind, placebo-controlled, cross-over trial (ENERGIZE).

AimThis study assessed the impact of dapagliflozin on food intake, eating behaviour, energy expenditure, magnetic resonance imaging (MRI)-determined brain response to food cues and body composition in patients with type 2 diabetes mellitus (T2D).Materials and methodsPatients were given dapagliflozin 10 mg once daily in a randomized, double-blind, placebo-controlled trial with short-term (1 week) and long-term (12 weeks) cross-over periods. The primary outcome was the difference in test meal food intake between long-term dapagliflozin and placebo treatment. Secondary outcomes included short-term differences in test meal food intake, short- and long-term differences in appetite and eating rate, energy expenditure and functional MRI brain activity in relation to food images. We determined differences in glycated haemoglobin, weight, liver fat (by 1 H magnetic resonance spectroscopy) and subcutaneous/visceral adipose tissue volumes (by MRI).ResultsIn total, 52 patients (43% were women) were randomized; with the analysis of 49 patients: median age 58 years, weight 99.1 kg, body mass index 35 kg/m2 , glycated haemoglobin 49 mmol/mol. Dapagliflozin reduced glycated haemoglobin by 9.7 mmol/mol [95% confidence interval (CI) 3.91-16.27, p = .004], and body weight (-2.84 vs. -0.87 kg) versus placebo. There was no short- or long-term difference in test meal food intake between dapagliflozin and placebo [mean difference 5.7 g (95% CI -127.9 to 139.3, p = .933); 15.8 g (95% CI -147.7 to 116.1, p = .813), respectively] nor in the rate of eating, energy expenditure, appetite, or brain responses to food cues. Liver fat (median reduction -4.7 vs. 1.95%), but not subcutaneous/visceral adipose tissue, decreased significantly with 12 weeks of dapagliflozin.ConclusionsThe reduction in body weight and liver fat with dapagliflozin was not associated with compensatory adaptations in food intake or energy expenditure

Dissociation between exercise-induced reduction in liver fat and changes in hepatic and peripheral glucose homoeostasis in obese patients with non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is associated with multi-organ (hepatic, skeletal muscle, adipose tissue) insulin resistance (IR). Exercise is an effective treatment for lowering liver fat but its effect on IR in NAFLD is unknown. We aimed to determine whether supervised exercise in NAFLD would reduce liver fat and improve hepatic and peripheral (skeletal muscle and adipose tissue) insulin sensitivity. Sixty nine NAFLD patients were randomized to 16 weeks exercise supervision (n=38) or counselling (n=31) without dietary modification. All participants underwent MRI/spectroscopy to assess changes in body fat and in liver and skeletal muscle triglyceride, before and following exercise/counselling. To quantify changes in hepatic and peripheral insulin sensitivity, a pre-determined subset (n=12 per group) underwent a two-stage hyperinsulinaemic euglycaemic clamp pre- and post-intervention. Results are shown as mean [95% confidence interval (CI)]. Fifty participants (30 exercise, 20 counselling), 51 years (IQR 40, 56), body mass index (BMI) 31 kg/m(2) (IQR 29, 35) with baseline liver fat/water % of 18.8% (IQR 10.7, 34.6) completed the study (12/12 exercise and 7/12 counselling completed the clamp studies). Supervised exercise mediated a greater reduction in liver fat/water percentage than counselling [Δ mean change 4.7% (0.01, 9.4); P<0.05], which correlated with the change in cardiorespiratory fitness (r=-0.34, P=0.0173). With exercise, peripheral insulin sensitivity significantly increased (following high-dose insulin) despite no significant change in hepatic glucose production (HGP; following low-dose insulin); no changes were observed in the control group. Although supervised exercise effectively reduced liver fat, improving peripheral IR in NAFLD, the reduction in liver fat was insufficient to improve hepatic IR

Ectopic lipid storage in non-alcoholic fatty liver disease is not mediated by impaired mitochondrial oxidative capacity in skeletal muscle

Background and Aims. Simple clinical algorithms including the Fatty Liver Index (FLI) and Lipid Accumulation Product (LAP) have been developed as a surrogate marker for Non-Alcoholic Fatty Liver Disease (NAFLD). These algorithms have been constructed using ultrasonography, a semi-quantitative method. This study aimed to validate FLI and LAP as measures of hepatic steatosis, as measured quantitatively by proton magnetic resonance spectroscopy (1H-MRS). Methods. Data were collected from 168 patients with NAFLD and 168 controls who had undergone clinical, biochemical and anthropometric assessment in the course of research studies. Values of FLI and LAP were determined, and assessed both as predictors of the presence of hepatic steatosis (liver fat >5.5 %) and of actual liver fat content, as measured by 1H MRS. The discriminative ability of FLI and LAP was estimated using the area under the Receiver Operator Characteristic curve (AUROC). Since FLI can also be interpreted as a predictive probability of hepatic steatosis, we assessed how well calibrated it was in our cohort. Linear regression with prediction intervals was used to assess the ability of FLI and LAP to predict liver fat content. Results. FLI and LAP discriminated between patients with and without hepatic steatosis with an AUROC of 0.79 (IQR= 0.74, 0.84) and 0.78 (IQR= 0.72, 0.83), although quantitative prediction of liver fat content was unsuccessful. Additionally, the algorithms accurately matched the observed percentages of patients with hepatic steatosis in our cohort. Conclusions. FLI and LAP may be used clinically, and for metabolic and epidemiological research, to identify patients with hepatic steatosis, but not as surrogates for liver fat content

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P &lt; 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P &lt; 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

The impact of obesity and fitness on endothelial function in polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is a highly prevalent heterogeneous syndrome associated with abdominal obesity, insulin resistance and the metabolic syndrome. This clustering of risk factors could translate into an adverse cardiovascular disease (CVD) risk profile. Endothelial dysfunction, an early barometer of CVD, has been exhibited by women with PCOS; however, it remains unclear whether endothelial dysfunction is independent of CVD risk factors in this population. Exercise training has been found to enhance conduit artery and cutaneous microvessel endothelial function in various populations. Nevertheless, limited research exists regarding the cardiovascular effects of exercise in PCOS, and its impact on endothelial function in conduit arteries and cutaneous microvessels, has not been explored. The primary aim of this thesis was to examine nitric oxide (NO)-mediated endothelial function at different levels of the vascular tree in women with PCOS and to establish whether supervised exercise training induces a therapeutic effect on endothelial function. A systematic review of published studies comparing FMD in PCOS and control women was conducted. Twenty-one published studies were identified for inclusion (pCOS n=908; controls n=566). Differences in FMD between PCOS and controls were synthesised and meta-regressed against BMI and age. The pooled mean FMD was 3.5% lower (95% CI=3.4, 3.7%; P<O.OO1) in women with PCOS compared with controls; and the PCOS-mediated reduction in FMD was most evident in studies involving less obese women.EThOS - Electronic Theses Online ServiceGBUnited Kingdo