Effects of bariatric surgery on bone

Pre-Operative Bariatric Surgery Imparts An Increased Risk of Infection, Re-Admission and Operative Intervention Following Elective Instrumented Lumbar Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To evaluate the impact of bariatric surgery on patient outcomes following elective instrumented lumbar fusion.

METHODS

A retrospective review of a prospectively collected database was performed. Patients who underwent a bariatric procedure prior to an elective instrumented lumbar fusion were evaluated. Lumbar procedures were performed at a large academic medical center from 1/1/2012 to 1/1/2018. The primary outcome was surgical site infection (SSI) requiring surgical debridement. Secondary outcomes were prolonged wound drainage requiring treatment, implant failure requiring revision, revision secondary to adjacent segment disease (ASD), and chronic pain states. A randomly selected, surgeon and comorbidity-matched group of 59 patients that underwent an elective lumbar fusion during that period was used as a control. Statistical analysis was performed using Student's two-way t-tests for continuous data, with significance defined as P < .05.

RESULTS

Twenty-five patients were identified who underwent bariatric surgery prior to elective lumbar fusion. Mean follow-up was 2.4 ± 1.9 years in the bariatric group vs. 1.5 ± 1.3 years in the control group. Patients with a history of bariatric surgery had an increased incidence of SSI that required operative debridement, revision surgery due to ASD, and a higher incidence of chronic pain. Prolonged wound drainage and implant failure were equivalent between groups.

CONCLUSION

In the present study, bariatric surgery prior to elective instrumented lumbar fusion was associated increased risk of surgical site infection, adjacent segment disease and chronic pain when compared to non-bariatric patients.

Follow-up after bariatric surgery: A review

Bariatric surgery is becoming increasingly popular in the treatment of severely obese patients who failed to lose weight with the help of non-surgical interventions. Such patients are at increased risk for premature death, type 2 diabetes, high blood pressure, gallstones, coronary heart disease, dyslipidemia, some cancers, anxiety, depression, and degenerative joint disorders. Although bariatric surgery appears to be the most effective and durable treatment option for obesity, it is associated with a number of surgical and medical complications. These include a range of conditions, of which dumping syndrome and malnutrition due to malabsorption of vitamins and minerals are the most common. To achieve better surgery outcomes, a number of postsurgical strategies must be considered. The aim of this review was to describe possible complications, ailments, and important moments in the follow-up after bariatric surgery. Adequate lifelong monitoring is crucial for the achievement of long-lasting goals and reduction of post-bariatric complications.

Alterations in Fat Mass and Bone Mineral Density Are Associated with Decreased Lipocalin-2 After Laparoscopic Sleeve Gastrectomy in Obese Chinese Women

OBJECTIVE

Lipocalin-2 (LCN2) plays an important role in the regulation of the obesity and obesity-related dysmetabolic state. This study aimed to analyze serum LCN2 level in Chinese women with obesity before and after laparoscopic sleeve gastrectomy (LSG) and determine the association between alteration in fat mass and bone mineral density (BMD) and LCN2 level.

METHODS

Fifty-two women (38 patients with obesity and 14 with normal body mass index (BMI)) were enrolled in this study. All patients with obesity underwent LSG. BMDs of the arm, leg, thoracic and lumbar spine, and pelvis were measured by dual-energy X-ray absorptiometry. Body fat mass and distribution were measured by dual-energy X-ray absorptiometry, and routine anthropometric/laboratory biochemical parameters at baseline and 3 and 12 months after LSG were recorded. Serum LCN2 levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

Serum LCN2 level was significantly higher in women with obesity than in the controls with normal BMI (102.70 ± 27.19 vs. 80.66 ± 19.55 ng/mL, P = 0.009). LCN2 level was decreased at 3 and 12 months after LSG (86.73 ± 26.79 ng/mL, P = 0.171, and 64.79 ± 28.39 ng/mL, P < 0.001, respectively). LSG led to marked body fat mass and slight BMD decrease. Decreased LCN2 level was significantly correlated with alterations in left and right leg BMDs and trunk fat mass at 12 months after LSG.

CONCLUSIONS

Obesity was associated with up-regulated serum LCN2 level. Decreased LCN2 level was positively correlated with changes in BMD and fat mass at 12 months after LSG in Chinese women.

A meta-analysis of the effects of bariatric surgery on fracture risk

Bariatric surgery effectively treats morbid obesity. However, the negative effect of this surgery on the bone is concerning. The aim of this meta-analysis was to investigate the fracture risk associated with bariatric surgery in morbidly obese subjects. Relevant studies published from database inception to September 2017 were identified in PubMed, Embase and the Cochrane Library. The Newcastle-Ottawa Scale was used to evaluate the quality of the observational studies, and the Jadad score evaluated randomized controlled trials. Among the 1003 studies initially identified, five observational trials and one randomized controlled trial were eligible for inclusion. All studies included in the meta-analysis were considered high quality. Risk for any type of fracture was higher in the surgical group than in the non-surgical group (risk ratio [RR] 1.29, 95% confidence interval [CI] 1.18-1.42). After surgery, the fracture risk in non-vertebral sites was significantly increased, especially in the upper limbs (RR 1.42, 95% CI 1.08-1.87; and RR 1.68, 95% CI 1.15-2.45). Compared with those with restrictive procedures, subjects who underwent mixed restrictive and malabsorptive procedures tended to have an increased fracture risk (RR 1.54, 95% CI 0.96-2.46). To conclude, bariatric surgery is associated with an increased risk of total and non-vertebral fractures, especially in the upper limbs.