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Intermittent versus continuous enteral nutrition attenuates increases in insulin and leptin during short-term bed rest.
Gonzalez, JT, Dirks, ML, Holwerda, AM, Kouw, IWK, van Loon, LJC
European journal of applied physiology. 2020;(9):2083-2094
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Abstract
PURPOSE To compare endocrine responses to intermittent vs continuous enteral nutrition provision during short-term bed rest. METHODS Twenty healthy men underwent 7 days of bed rest, during which they were randomized to receive enteral nutrition (47%E as carbohydrate, 34%E as fat, 16%E as protein and 3%E as fibre) in a continuous (CONTINUOUS; n = 10; 24 h day-1 at a constant rate) or intermittent (INTERMITTENT; n = 10; as 4 meals per day separated by 5 h) pattern. Daily plasma samples were taken every morning to assess metabolite/hormone concentrations. RESULTS During bed rest, plasma leptin concentrations were elevated to a lesser extent with INTERMITTENT vs CONTINUOUS (iAUC: 0.42 ± 0.38 vs 0.95 ± 0.48 nmol L-1, respectively; P = 0.014) as were insulin concentrations (interaction effect, P < 0.001) which reached a peak of 369 ± 225 pmol L-1 in CONTINUOUS, compared to 94 ± 38 pmol L-1 in INTERMITTENT (P = 0.001). Changes in glucose infusion rate were positively correlated with changes in fasting plasma GLP-1 concentrations (r = 0.44, P = 0.049). CONCLUSION Intermittent enteral nutrition attenuates the progressive rise in plasma leptin and insulinemia seen with continuous feeding during bed rest, suggesting that continuous feeding increases insulin requirements to maintain euglycemia. This raises the possibility that hepatic insulin sensitivity is impaired to a greater extent with continuous versus intermittent feeding during bed rest. To attenuate endocrine and metabolic changes with enteral feeding, an intermittent feeding strategy may, therefore, be preferable to continuous provision of nutrition. This trial was registered on clinicaltrials.gov as NCT02521025.
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Impact to short-term high intensity intermittent training on different storages of body fat, leptin and soluble leptin receptor levels in physically active non-obese men: A pilot investigation.
Caldeira, RS, Panissa, VLG, Inoue, DS, Campos, EZ, Monteiro, PA, Giglio, BM, Pimentel, GD, Hofmann, P, Lira, FS
Clinical nutrition ESPEN. 2018;:186-192
Abstract
BACKGROUND & AIMS Studies have postulated High Intensity Intermittent Training (HIIT) as a superior strategy to reduce body fat. The purpose of this study was to compare the effects HIIT and steady-state training (SST) on body composition, leptin, soluble leptin receptor (sOB-R) levels, and hunger perception in physically active non-obese men. METHODS Twenty men performed five weeks of HIIT (5 km - 1 min running at 100% speed correspondent to VȩO2peak - v VȩO2peak - interspersed with 1-min passive recovery; n = 10) or SST (5 km at 70% of vVȩO2peak continuously; n = 10) three times a week. Body composition, and hunger perception were assessed at pre- and post-training and were compared by a two-way analysis (group and training period) with repeated measures in the second factor. A fasting time-course (baseline, 24 h, and 48 h after an experimental session of exercise) of leptin and sOB-R levels were measured at pre- and post-five weeks of training and assessed by a three-way analysis (group, period and time of measurement) with repeated measures in the second and third factors. RESULTS There was no effect on body composition and hunger perception. Leptin was reduced in both groups, while sOB-R was increased post-five weeks of training in HIIT but not in the SST. CONCLUSIONS Although both training groups exerted alterations in leptin levels, only HIIT was able increased sOB-R levels, this suggest a superior impact on central responses in physically active non-obese men.
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Plasma leptin in postmenopausal women with coronary artery disease: effect of transdermal 17beta-estradiol and intermittent medroxyprogesterone acetate.
Os, I, Os, A, Abdelnoor, M, Larsen, A, Birkeland, K, Westheim, A
Climacteric : the journal of the International Menopause Society. 2003;(3):204-10
Abstract
OBJECTIVES In the present study, the relationship between plasma leptin and other cardiovascular risk factors in high-risk postmenopausal women was assessed, as well as the effect of transdermal 17beta-estradiol unopposed or in combination with intermittent medroxyprogesterone acetate (MPA) on plasma leptin. METHODS Postmenopausal women (n = 118) with coronary artery disease (CAD) were consecutively recruited from women admitted to hospital for coronary angiography. They were randomized to estradiol plus intermittent MPA or to a control group, and investigated at study inclusion, and after 3 and 12 months. RESULTS A strong relationship was found between leptin and body mass index (r = 0.69, p < 0.001). Leptin was related to lipid fractions (high-density lipoprotein cholesterol: r = -0.33, p < 0.001; apolipoprotein A: r = -0.28, p = 0.004; and triglycerides: r = 0.27, p = 0.003) and indices of glucose metabolism (C-peptide: r = 0.47, p < 0.001; fasting insulin: r = 0.42, p < 0.001; glucose: r = 0.25, p = 0.008; insulin resistance: r = 0.45, p < 0.001; and insulin secretion: r = 0.36, p < 0.001). In a multiple regression model, only body mass index (p < 0.001) and C-peptide (p = 0.002) remained as independent factors for leptin levels. Despite the association with sex hormone-binding globulin (r = 0.30, p = 0.001), no effect on leptin levels was observed with either unopposed transdermal estradiol or estradiol combined with MPA. CONCLUSION Plasma leptin is related to other cardiovascular risk factors in postmenopausal women with CAD, but seems to be unaffected by transdermal 17beta-estradiol administration.