title: Impact of marked weight loss induced by bariatric surgery on bone mineral density and remodeling.
abstract: Data about the impact of bariatric surgery (BS) and subsequent weight loss on bone are limited. The objective of the present study was to determine bone mineral density (BMD), bone remodeling metabolites and hormones that influence bone trophism in premenopausal women submitted to BS 9.8 months, on average, before the study (OGg, N = 16). The data were compared to those obtained for women of normal weight (CG, N = 11) and for obese women (OG, N = 12). Eight patients in each group were monitored for one year, with the determination of BMD, of serum calcium, phosphorus, magnesium, parathyroid hormone, 25-hydroxyvitamin D, insulin-like growth factor-I (IGF-I) and osteocalcin, and of urinary calcium and deoxypyridinoline. The biochemical determinations were repeated every three months in the longitudinal study and BMD was measured at the end of the study. Parathyroid hormone levels were similar in the three groups. IGF-I levels (CG = 332 +/- 62 vs OG = 230 +/- 37 vs OGg = 128 +/- 19 ng/mL) were significantly lower in the operated patients compared to the non-operated obese women. Only OGg patients presented a significant fall in BMD of 6.2% at L1-L4, of 10.2% in the femoral neck, and of 5.1% in the forearm. These results suggest that the weight loss induced by BS is associated with a significant loss of bone mass even at sites that are not influenced by weight overload, with hormonal factors such as IGF-I being associated with this process.
authors.affiliation: Divisão de Endocrinologia e Metabolismo, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: F A
authors.initials: FA
authors.lastname: Pereira
authors.forename: J A S
authors.initials: JA
authors.lastname: de Castro
authors.forename: J E
authors.initials: JE
authors.lastname: dos Santos
authors.forename: M C
authors.initials: MC
authors.lastname: Foss
authors.forename: F J A
authors.initials: FJ
authors.lastname: Paula
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D015415:Biomarkers; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology*; D016723:Bone Remodeling / Q000502:physiology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D009765:Obesity / Q000097:blood / Q000601:surgery*; D011446:Prospective Studies; D015431:Weight Loss / Q000502:physiology*
chemical_list: D015415:Biomarkers