title: Osteocalcin increase after bariatric surgery predicts androgen recovery in hypogonadal obese males.
abstract: OBJECTIVE
  Bone modulates testis function through osteocalcin (OCN) production. This paper assesses the association between serum OCN and androgen production recovery in morbidly obese males at 9 months after bariatric surgery.
  
  
  METHODS
  A cohort of n=103 obese males with mean±s.d. body mass index (BMI) 47.7±8.2 kg m(-2), age 42±11 years, consisting of n=76 patients undergoing gastric bypass and n=27 in the waiting list for surgery.
  
  
  RESULTS
  At 9 months from surgery, a significant increase was observed in mean±s.d. total OCN (tOCN=10.4±10.3 ng ml(-1), P<0.001) and undercarboxylated OCN (ucOCN=5.4±3.7 ng ml(-1), P<0.001), total testosterone (TT, 5.6±6.5 nM, P<0.001) and calculated free testosterone (cFT, 0.035±0.133 nM, P<0.006), sex hormone binding globulin (SHBG, 21.2±16.7 nM, P<0.001) and decrease in estradiol (E2, -30.1±51.9 pM, P<0.001) levels only in operated patients, with a significant reduction in BMI (24%) and waist (20%). A positive correlation existed between tOCN and ucOCN (age-adjustment (age-adj.): β=0.692, P<0.001) and their variations (age-adj.: β=0.629, P<0.001) after surgery. Multivariate analysis in operated patients showed a significant positive association between variations in tOCN and TT (age-adj.: β=0.289, P=0.012), SHBG (age-adj.: β=0.326, P=0.005) but not with cFT variation. tOCN, but not luteinizing hormone (LH) variation was the only significant predictive factor of cFT recovery in the hypogonadal (TT<12 nM) operated subjects even after age- and BMI-adjustment (adj.: β=0.582, P<0.05). cFT improvement was significantly higher when considering operated patients with tOCN increase (0.045±0.123 vs -0.02±0.118 nM, P=0.015), hypogonadism (0.059±0.111 vs -0.059±0.138 nM, P=0.002) and younger than 35 years (0.102±0.108 vs -0.019±0.123 nM, P=0.009).
  
  
  CONCLUSIONS
  OCN recovery observed after bariatric surgery is significantly associated with cFT improvement independently of BMI variation and age in hypogonadal morbidly obese males.
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Endocrinology Unit, University of Florence, Florence, Italy.
authors.forename: J
authors.initials: J
authors.lastname: Samavat
authors.affiliation: Bariatric and Metabolic Surgery, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Facchiano
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Endocrinology Unit, University of Florence, Florence, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cantini
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Endocrinology Unit, University of Florence, Florence, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Di Franco
authors.affiliation: Servizio di Dietologia, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Alpigiano
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Endocrinology Unit, University of Florence, Florence, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Poli
authors.affiliation: Servizio Dietetico, General Hospital, Pistoia, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Seghieri
authors.affiliation: Bariatric and Metabolic Surgery, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Lucchese
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Endocrinology Unit, University of Florence, Florence, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Forti
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, Endocrinology Unit, University of Florence, Florence, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Luconi
mesh_terms: D000328:Adult; D000728:Androgens / Q000378:metabolism*; D015992:Body Mass Index; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D015390:Gastric Bypass; D006801:Humans; D007006:Hypogonadism / Q000209:etiology / Q000378:metabolism / Q000601:surgery*; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D009767:Obesity, Morbid / Q000150:complications / Q000378:metabolism / Q000601:surgery*; D015675:Osteocalcin / Q000378:metabolism*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012074:Remission Induction; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013739:Testosterone / Q000378:metabolism*; D016896:Treatment Outcome
chemical_list: D000728:Androgens; D012738:Sex Hormone-Binding Globulin; D015675:Osteocalcin; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone