Gastric banding induces negative bone remodelling in the absence of secondary hyperparathyroidism: potential role of serum C telopeptides for follow-up

doi:doi:10.1038/sj.ijo.0803040

International Journal of Obesity homepage

International Journal of Obesity (2005) 29, 1429–1435. doi:10.1038/sj.ijo.0803040; published online 2 August 2005

Gastric banding induces negative bone remodelling in the absence of secondary hyperparathyroidism: potential role of serum C telopeptides for follow-up

V Giusti¹, C Gasteyger¹, M Suter¹, E Heraief¹, R C Gaillard¹ and P Burckhardt¹

¹Department of internal Medicine, Division of endocrinology, Diabetes and Metabolism, University Hospital CHUV, 1011 Lausanne, Switzerland

Correspondence: Dr V Giusti, Division of Endocrinology, Diabetes and Metabolism, University Hospital CHUV, Lausanne 1011, Switzerland. E-mail: vittorio.giusti@chuv.hospvd.ch

Received 18 January 2005; Revised 24 April 2005; Accepted 29 May 2005; Published online 2 August 2005.

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Abstract

OBJECTIVE:

Data about the consequences of laparoscopic adjustable gastric banding (LAGB) on phospho-calcic and bone metabolism remain scarce.

SUBJECTS:

We studied a group of 37 obese premenopausal women (age: 24–52 y; mean BMI=43.7 kg/m²) who underwent LAGB.

METHODS:

Serum calcium, phosphate, alkaline phosphatase, parathormone (PTH), vitamin D₃, serum C-telopeptides, IGFBP-3 and IGF-1 were measured at baseline, 6, 12, 18 and 24 months after surgery. Body composition, bone mineral content (BMC) and density (BMD) were measured using dual-X-ray absorptiometry (DXA) at baseline, 6, 12 and 24 months after surgery.

RESULTS:

There was no clinically significant decrease of calcemia; PTH remained stable. Serum telopeptides increased by 100% (P<0.001) and serum IGFBP-3 decreased by 16% (P<0.001) during the first 6 months, and then stabilized, whereas IGF-1 remained stable over the 2 y. BMC and BMD decreased, especially at the femoral neck; this decrease was significantly correlated with the decrease of waist and hip circumference.

CONCLUSIONS:

We concluded that there was no evidence of secondary hyperparathyroidism 24 months after LAGB. The observed bone resorption could be linked to the decrease of IGFBP-3, although this decrease could be attributable to other confounding factors. Serum telopeptides seem to be a reliable marker of bone metabolism after gastric banding. DXA must be interpreted cautiously during major weight loss, because of the artefacts caused by the important variation of fat tissue after LAGB.