Mental health and quality of life during weight loss in females with clinically severe obesity : A randomized clinical trial

The purpose of this investigation was to explore the effects of dietary weight loss intervention, with and without the addition of exercise on health-related quality of life, depressive symptoms, and anxiety. As part of the EMPOWER study for women, sixty premenopausal women (BMI of 40.4 ± 6.7) were randomized to energy restriction only (ER) or to exercise plus energy restriction (EXER) for 12 months. Health-related quality of life was assessed using the SF-36, depressive symptoms were assessed using the Beck Depression Inventory II (BDI), and anxiety symptoms using the Spielberger state and trait anxiety questionnaire. All measures were completed at baseline, 3, 6 and 12 months. At 12 months, there were significant (p < 0.05) group-by-time interactions favouring the EXER group for five of the eight domains and the mental component summary score. At 12 months, a significant group-by-time interaction favouring the EXER group is reported for both state and trait anxiety (p = .005 and p = .001, respectively). At 12 months, there was a significant group-by-time interaction for depressive symptoms favouring EXER (p < 0.05). Within-group changes for BDI scores were improved at all follow-up time points in the EXER group. Exercise training confers an additional benefit to energy restriction in the absence of additional weight loss at 12 months for health-related quality of life, depressive symptoms, and state and trait anxiety scores when compared to energy restriction only. Exercise and an energy-restricted diet improve health-related quality of life and mental health. Exercise may protect mental health without further weight loss for women with severe obesity

Neck Circumference Is Associated with Muscle Sympathetic Nerve Activity in Overweight and Obese Men but Not Women

Background: Neck circumference (NC) is a predictor of cardiometabolic risk. The objective of this study was to explore the relationship of NC to muscle sympathetic nerve activity (MSNA) within an overweight and obese population. Methods: The study design was a retrospective cross-sectional analysis. Un-medicated persons (72 men, 53 postmenopausal women) aged 56 ± 1 years (mean ± SEM) with body mass index (BMI) 32.8 ± 0.4 kg/m(2), were studied. NC was measured together with traditional anthropometric measures, supine blood pressure, fasting blood lipids, insulin, and glucose. Insulin sensitivity was assessed by homeostasis model (HOMA-IR) and Matsuda Insulin Sensitivity Index (ISI) derived from 75-g oral glucose tolerance test. Resting multiunit MSNA was recorded by microneurography in the peroneal nerve and expressed as burst frequency and burst incidence. Results: Men within the highest tertile of NC had significantly higher fasting and post-glucose plasma insulin levels (insulin AUC(0−120)), HOMA-IR, non-esterified fatty acids, MSNA (45 ± 2 vs. 36 ± 2 bursts per min; 69 ± 3 vs. 58 ± 3 bursts per 100 hb) and heart rate, and lower Matsuda ISI compared to men in the lowest tertile (P all <0.05). In stepwise regression analyses, NC alone explained 12%, and together with insulin AUC(0−120) it accounted for 22%, of the variance in MSNA in men. In women, NC was associated with anthropometric measures but not with MSNA or metabolic indices. Conclusions: Among overweight and obese men, NC was independently associated with elevated MSNA and hyperinsulinemia, and thus may be relevant to cardiometabolic risk prediction. The biological basis of gender differences merits further elucidation

Baseline sympathetic nervous system activity predicts dietary weight loss in obese metabolic syndrome subjects

Context: The sympathetic nervous system is an important physiological modulator of basal and postprandial energy expenditure. Objective: Our objective was to investigate whether the variability of weight loss attained during hypocaloric dietary intervention is related to individual differences in baseline sympathetic drive and nutritional sympathetic nervous system responsiveness. Participants and Methods: Untreated obese subjects (n = 42; body mass index = 32.1 ± 0.5 kg/m), aged 57 ± 1 yr, who fulfilled Adult Treatment Panel III metabolic syndrome criteria participated in a 12-wk weight loss program using a modified Dietary Approaches to Treat Hypertension (DASH) diet. Muscle sympathetic nerve activity (MSNA) was measured by microneurography at rest and in a subset of subjects during a standard 75-g oral glucose tolerance test. Results: Weight loss (6.7 ± 0.5 kg) was independently predicted by baseline resting MSNA burst incidence (r = 0.38; P = 0.019), which accounted for 14.3% of the variance after adjustment for age and baseline body weight. Weight loss-resistant subjects in the lower tertile of weight loss (4.4 ± 0.3%) had significantly blunted MSNA responses to oral glucose at baseline compared with successful weight losers (9.6 ± 0.8%). Absolute Δ MSNA averaged -7 ± 2, -6 ± 5, and -3 ± 3 bursts per 100 heartbeats at 30, 60, and 90 min after glucose in the weight loss-resistant group. Corresponding values in the successful weight loss group were 9 ± 3, 12 ± 3, and 15 ± 4 bursts per 100 heartbeats (time X group interaction, P = 0.004). Conclusions: These findings indicate that baseline sympathetic drive and nutritional sympathetic responsiveness may be important prognostic biological markers for weight loss outcome

Reduction in peripheral vascular resistance predicts improvement in insulin clearance following weight loss

BACKGROUND: The hyperinsulinemia of obesity is a function of both increased pancreatic insulin secretion and decreased insulin clearance, and contributes to cardiovascular risk. Whilst weight loss is known to enhance insulin clearance, there is a paucity of data concerning the underlying mechanisms. This study was conducted to examine the inter-relationships between changes in sympathetic nervous system (SNS) activity, vascular function and insulin clearance during a weight loss program. METHODS: Seventeen non-smoking, un-medicated individuals aged 55 ± 1 years (mean ± SEM), body mass index (BMI) 33.9 ± 1.7 kg/m(2), underwent a 4-month hypocaloric diet (HCD), using a modified Dietary Approaches to Stop Hypertension diet, whilst seventeen age- and BMI-matched subjects acted as controls. Insulin sensitivity and insulin clearance were assessed via euglycemic hyperinsulinemic clamp (exogenous insulin clearance); hepatic insulin extraction was calculated as fasting C-peptide to insulin ratio (endogenous insulin clearance); SNS activity was quantified by microneurographic nerve recordings of muscle sympathetic nerve activity (MSNA) and whole-body norepinephrine kinetics; and vascular function by calf venous occlusion plethysmography and finger arterial tonometry. RESULTS: Weight loss averaged −8.3 ± 0.6 % of body weight in the HCD group and was accompanied by increased clamp-derived glucose utilization (by 20 ± 9 %, P = 0.04) and exogenous insulin clearance (by 12 ± 5 %, P = 0.02). Hepatic insulin extraction increased from 6.3 ± 0.8 to 7.1 ± 0.9 (P = 0.09). Arterial norepinephrine concentration decreased by −12 ± 5 %, whole-body norepinephrine spillover rate by −14 ± 8 %, and MSNA by −9 ± 5 bursts per 100 heartbeats in the HCD group (P all >0.05 versus control group). Step-wise regression analysis revealed a bidirectional relationship between enhanced exogenous insulin clearance post weight loss and reduction in calf vascular resistance (r = −0.63, P = 0.01) which explained 40 % of the variance. Increase in hepatic insulin extraction was predicted by enhanced finger reactive hyperaemic response (P = 0.006) and improvement in oral glucose tolerance (P = 0.002) which together explained 64 % of the variance. CONCLUSIONS: Insulin clearance is independently and reciprocally associated with changes in vascular function during weight loss intervention. Trial registration ClinicalTrials.gov: NCT01771042 and NCT0040885