title: Serum leptin as a determinant of bone resorption in healthy postmenopausal women.
abstract: To examine the relationships between serum leptin and bone metabolism, we measured bone mineral density (BMD) at the spine and the hip, fasting serum leptin, and osteocalcin and urinary excretion of C-terminal crosslinking telopeptide of type I collagen (CTX), as markers of bone formation and resorption, respectively, in 121 postmenopausal women aged 54 +/- 5 years. These parameters were also assessed at 6 months and 2 years of treatment with either 2.5 mg tibolone (n = 34), 1.25 mg tibolone (n = 45), or 2 mg estradiol plus 1 mg norethindrone acetate (n = 42). At baseline, serum leptin correlated positively with spine (r = 0.21, P = 0.02) and total hip (r = 0.26, P = 0.0044) BMD and negatively with CTX (r = -0.38, P < 0.0001) and osteocalcin (r = 0.21, P = 0.025). After adjustment for BMI and for fat mass, the association between serum leptin and CTX persisted with a partial correlation coefficient of -0.18 (P = 0.046) and of -0.22 (P = 0.03), respectively. Women in the highest quartile of leptin levels had 11% higher total hip (P = 0.0039) and lumbar spine BMD (P = 0.016), 21% lower osteocalcin (P = 0.01), and 38% lower CTX (P = 0.0005) than women in the lowest quartile (P < 0.05). During treatment, serum leptin levels increased (+14.7 +/- 47.3%, P = 0.019), without significant difference between the groups. This increase correlated with the increase in body weight (r = 0.46, P < 10(-4)). No correlation was found between the changes in leptin and the changes in bone parameters. In conclusion, leptin may play a role as a determinant of bone resorption in healthy, untreated postmenopausal women, but the effect of estradiol or tibolone on bone are not mediated by leptin.
authors: Centre d'Evaluation des Maladies Osseuses, Département de Rhumatologie, Hôpital Cochin (AP-HP), Université René Descartes, Paris, France. christian.roux@cch.ap-hop-paris.fr
authors: Christian
authors: C
authors: Roux
authors: Asma
authors: A
authors: Arabi
authors: Raphaël
authors: R
authors: Porcher
authors: Patrick
authors: P
authors: Garnero
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000187:drug effects / Q000502:physiology*; D001862:Bone Resorption / Q000097:blood* / Q000188:drug therapy; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D008875:Middle Aged; D009652:Norpregnenes / Q000494:pharmacology / Q000627:therapeutic use; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000188:drug therapy; D017698:Postmenopause / Q000097:blood* / Q000187:drug effects; D011446:Prospective Studies; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D020738:Leptin; D009652:Norpregnenes; C027385:tibolone