title: The effects of tesamorelin on phosphocreatine recovery in obese subjects with reduced GH.
abstract: BACKGROUND
  Few studies have assessed the relationship between GH and mitochondrial function.
  
  
  OBJECTIVE
  The objective of this study was to determine the effects of improving IGF-I using a GHRH analog, tesamorelin, on mitochondrial function assessed by phosphocreatine (PCr) recovery using (31)P magnetic resonance spectroscopy in obese adults with reduced GH.
  
  
  METHODS
  A total of 39 obese men and women with reduced GH secretion as determined by GHRH-arginine stimulation tests underwent magnetic resonance spectroscopy as part of a 12-month, double-blind, randomized, placebo-controlled trial comparing tesamorelin vs placebo. PCr recovery after submaximal exercise was assessed at baseline and at 12 months.
  
  
  RESULTS
  At baseline, there were no differences in age, sex, race/ethnicity, and GH or PCr parameters between tesamorelin and placebo. After 12 months, tesamorelin treatment led to a significantly greater increase in IGF-I than did placebo treatment (change, 102.9±31.8 μg/L vs 22.8±8.9 μg/L, tesamorelin vs placebo; P=.02). We demonstrated a significant positive relationship between increases in IGF-I and improvements in PCr recovery represented as ViPCr (R=0.56; P=.01). The association between IGF-I and PCr recovery was even stronger among subjects treated with tesamorelin only (ViPCr: R=0.71; P=.03). This association remained significant after controlling for age, sex, race, ethnicity, and parameters of body composition and insulin sensitivity (all P<.05).
  
  
  CONCLUSIONS
  Increases in IGF-I from 12 months of treatment with tesamorelin were significantly associated with improvements in PCr recovery parameters in obese men and women with reduced GH secretion, suggestive of improvements in mitochondrial function.
authors.affiliation: Program in Nutritional Metabolism and Neuroendocrine Unit (H.M., C.A.M., M.N.F., S.K.G.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114.
authors.forename: Hideo
authors.initials: H
authors.lastname: Makimura
authors.forename: Caitlin A
authors.initials: CA
authors.lastname: Murphy
authors.forename: Meghan N
authors.initials: MN
authors.lastname: Feldpausch
authors.forename: Steven K
authors.initials: SK
authors.lastname: Grinspoon
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D019382:Human Growth Hormone / Q000172:deficiency*; D006801:Humans; D007018:Hypopituitarism / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D010725:Phosphocreatine / Q000378:metabolism*; D010919:Placebos; D055815:Young Adult
chemical_list: D010919:Placebos; D010725:Phosphocreatine; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D013007:Growth Hormone-Releasing Hormone; C479538:tesamorelin