OBJECTIVE: Ghrelin has been implicated in energy homeostasis, body weight regulation and glucose metabolism. Level of unacylated ghrelin (UAG), but not acylated ghrelin (AG), has been suggested to increase during long-term exercise. However, the association of the level of UAG with exercise-induced changes of insulin sensitivity and lipid metabolism has not been previously investigated. We hypothesized that an increase in UAG level in response to a long-term exercise programme improves insulin sensitivity and associated lipid profile, independently of weight loss. DESIGN, PATIENTS AND MEASUREMENTS: A prospective study of 552 young men (mean age 19·3 and range 19-28 years) undergoing military service with structured 6-month exercise training programme. Exercise performance, clinical and biochemical measurements were obtained at baseline and follow-up. Association between UAG level and fasting glucose, insulin, insulin sensitivity and lipid levels were evaluated. RESULTS: An overall increase in the level of UAG was observed during the 6-month follow-up (P < 0·001), which was largest among those with weight loss ≥ 2·5% or among those whose reduction in waist circumference was largest (P = 0·007 and P < 0·001, respectively). A change in UAG level correlated inversely with a change in fasting glucose and insulin levels, HOMA-IR, total cholesterol and total triglyceride levels (P < 0·001 for all). The association between change in the UAG level and the change in insulin sensitivity was independent of weight loss or reduction in waist circumference. CONCLUSIONS: Increase in UAG level was associated with improved insulin sensitivity via mechanisms independent of weight loss during an intensive, long-term exercise intervention in young healthy men.
OBJECTIVE:Ghrelin has been implicated in energy homeostasis, body weight regulation and glucose metabolism. Level of unacylated ghrelin (UAG), but not acylated ghrelin (AG), has been suggested to increase during long-term exercise. However, the association of the level of UAG with exercise-induced changes of insulin sensitivity and lipid metabolism has not been previously investigated. We hypothesized that an increase in UAG level in response to a long-term exercise programme improves insulin sensitivity and associated lipid profile, independently of weight loss. DESIGN, PATIENTS AND MEASUREMENTS: A prospective study of 552 young men (mean age 19·3 and range 19-28 years) undergoing military service with structured 6-month exercise training programme. Exercise performance, clinical and biochemical measurements were obtained at baseline and follow-up. Association between UAG level and fasting glucose, insulin, insulin sensitivity and lipid levels were evaluated. RESULTS: An overall increase in the level of UAG was observed during the 6-month follow-up (P < 0·001), which was largest among those with weight loss ≥ 2·5% or among those whose reduction in waist circumference was largest (P = 0·007 and P < 0·001, respectively). A change in UAG level correlated inversely with a change in fasting glucose and insulin levels, HOMA-IR, total cholesterol and total triglyceride levels (P < 0·001 for all). The association between change in the UAG level and the change in insulin sensitivity was independent of weight loss or reduction in waist circumference. CONCLUSIONS: Increase in UAG level was associated with improved insulin sensitivity via mechanisms independent of weight loss during an intensive, long-term exercise intervention in young healthy men.
Authors: T D Müller; R Nogueiras; M L Andermann; Z B Andrews; S D Anker; J Argente; R L Batterham; S C Benoit; C Y Bowers; F Broglio; F F Casanueva; D D'Alessio; I Depoortere; A Geliebter; E Ghigo; P A Cole; M Cowley; D E Cummings; A Dagher; S Diano; S L Dickson; C Diéguez; R Granata; H J Grill; K Grove; K M Habegger; K Heppner; M L Heiman; L Holsen; B Holst; A Inui; J O Jansson; H Kirchner; M Korbonits; B Laferrère; C W LeRoux; M Lopez; S Morin; M Nakazato; R Nass; D Perez-Tilve; P T Pfluger; T W Schwartz; R J Seeley; M Sleeman; Y Sun; L Sussel; J Tong; M O Thorner; A J van der Lely; L H T van der Ploeg; J M Zigman; M Kojima; K Kangawa; R G Smith; T Horvath; M H Tschöp Journal: Mol Metab Date: 2015-03-21 Impact factor: 7.422
Authors: Lee M Ashton; Melinda J Hutchesson; Megan E Rollo; Philip J Morgan; Clare E Collins Journal: BMC Public Health Date: 2014-09-16 Impact factor: 3.295