Bone metabolism and risk of secondary hyperparathyroidism 12 months after gastric banding in obese pre-menopausal women.
OBJECTIVE
To evaluate, during the first postoperative year in obese pre-menopausal women, the effects of laparoscopic gastric banding on calcium and vitamin D metabolism, the potential modifications of bone mineral content and bone mineral density, and the risk of development of secondary hyperparathyroidism.


METHODS
Thirty-one obese pre-menopausal women aged between 25 and 52 y with a mean body mass index (BMI) of 43.6 kg/m(2), scheduled for gastric banding were included. Patients with renal, hepatic, metabolic and bone disease were excluded.


METHODS
Body composition and bone mineral density (BMD) were measured at baseline, 6 and 12 months after gastric banding using dual-energy X-ray absorptiometry. Serum calcium, phosphate, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, bilirubin, urea, creatinine, uric acid, proteins, parathormone, vitamin D(3), IGF-1, IGF-BP3 and telopeptide, as well as urinary telopeptide, were measured at baseline and 1, 3, 6, 9 and 12 months after surgery.


RESULTS
After 1 y vitamin D3 remained stable and PTH decreased by 12%, but the difference was not significant. Serum telopeptide C increased significantly by 100% (P<0.001). There was an initial drop of the IGF-BP3 during the first 6 months (P<0.05), but the reduction was no longer significant after 1 y. The BMD of cortical bone (femoral neck) decreased significantly and showed a trend of a positive correlation with the increase of telopeptides (P<0.06). The BMD of trabecular bone, at the lumbar spine, increased proportionally to the reduction of hip circumference and of body fat.


CONCLUSIONS
There is no evidence of secondary hyperparathyroidism 1 y after gastric banding. Nevertheless biochemical bone markers show a negative remodelling balance, characterized by an increase of bone resorption. The serum telopeptide seems to be a reliable parameter, not affected by weight loss, to follow up bone turnover after gastroplasty.
Pugnale
N
N
Division of Endocrinology, Diabetology and Metabolism, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
Giusti
V
V
Suter
M
M
Zysset
E
E
Héraïef
E
E
Gaillard
R C
RC
Burckhardt
P
P
D000328:Adult; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology*; D016723:Bone Remodeling; D002118:Calcium / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass / Q000009:adverse effects*; D005773:Gastroscopy / Q000379:methods; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000209:etiology* / Q000378:metabolism; D008875:Middle Aged; D009767:Obesity, Morbid / Q000378:metabolism* / Q000601:surgery; D017697:Premenopause / Q000378:metabolism; D012307:Risk Factors; D014807:Vitamin D / Q000378:metabolism
D014807:Vitamin D; D002118:Calcium