Modification of bone architecture following sleeve gastrectomy: a five-year follow-up

Bariatric surgery induces a decrease in areal BMD (aBMD), but the long-term effect on trabecular and cortical volumetric BMD (vBMD) has not been well assessed. The main aim of this 5-yr longitudinal study was to investigate the changes following sleeve gastrectomy (SG) in aBMD, bone turnover markers, and trabecular and cortical vBMD. Forty-five patients with obesity were assessed before and 1, 2, and 5 yr after SG. Trabecular and cortical vBMD, cortical thickness, and structural parameters were assessed by 3D-Shaper software at the hip. Values of bone turnover markers peaked after 1 yr and decreased after 2 and 5 yr, but without returning to baseline values. aBMD decreased mostly at the femoral neck (-9.7%) and total hip (-10.7%) over the 5 yr, with the greatest loss occurring at 1 yr (-5.9% and -6.3%, respectively). A similar profile of decrease was observed for integral hip vBMD with significant decreases of 6.6%, 7.7%, and 10.7% after 1, 2, and 5 yr, mainly due to a reduction in the trabecular (10.5%, 12.0%, and 17.2%, respectively) rather than cortical (1.4%, 1.9%, and 2.9%, respectively) component. A modest decrease in mean cortical thickness (2.5%, 2.8%, and 3.9%, respectively) and an alteration in the structural parameters were concomitantly observed. Older age and greater body weight loss were the factors most associated with an increased loss of aBMD and vBMD. In conclusion, the study demonstrates that SG induces not only an alteration in bone turnover and aBMD, but also a reduction in vBMD at the hip, predominantly due to trabecular component deterioration as determined by 3D-Shaper software. The maintenance of bone deterioration for at least 5 yr-ie, after 4 yr of relative body weight stabilization or minimal weight regain-suggests the need for a therapeutic approach to preserve bone health in patients who undergo SG.

Effect of Nutritional Deprivation after Sleeve Gastrectomy on Bone Mass, Periostin, Sclerostin and Semaphorin 4D: A Two-Year Longitudinal Study

Bariatric surgery induces bone loss, but the exact mechanisms by which this process occurs are not fully known. The aims of this 2-year longitudinal study were to (i) investigate the changes in areal bone mineral density (aBMD) and bone turnover markers following sleeve gastrectomy (SG) and (ii) determine the parameters associated with the aBMD variations. Bone turnover markers, sclerostin, periostin and semaphorin 4D were assessed before and 1, 12 and 24 months after SG, and aBMD was determined by DXA at baseline and after 12 and 24 months in 83 patients with obesity. Bone turnover increased from 1 month, peaked at 12 months and remained elevated at 24 months. Periostin and sclerostin presented only modest increases at 1 month, whereas semaphorin 4D showed increases only at 12 and 24 months. A significant aBMD decrease was observed only at total hip regions at 12 and 24 months. This demineralisation was mainly related to body weight loss. In summary, reduced aBMD was observed after SG in the hip region (mechanical-loading bone sites) due to an increase in bone turnover in favour of bone resorption. Periostin, sclerostin and semaphorin 4D levels varied after SG, showing different time lags, but contrary to weight loss, these biological parameters did not seem to be directly implicated in the skeletal deterioration.