Determining changes in bone metabolism after bariatric surgery in postmenopausal women

Bariatric surgery and secondary hyperparathyroidism: a meta-analysis

BACKGROUND

Obesity increases the risk of obesity-related medical problems. Weight loss after metabolic and bariatric surgery (MBS) has been well studied. However, the effects of MBS on parathyroid function remain unclear.

OBJECTIVE

The objective of this study was to perform a meta-analysis to examine the impact of MBS on the risk of secondary hyperparathyroidism (SHPT).

SETTING

The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.

METHODS

The PubMed, Embase, Web of Science, and the Cochrane Library databases were systematically reviewed from inception to May 2022 to identify studies reporting quantitative measurements of SHPT risk pre-MBS and post-MBS. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were estimated and compared. Effects were pooled using a random-effects or fixed-effects model. Subgroup analyses were performed according to the follow-up time and surgical procedure.

RESULTS

The final meta-analysis included 9 studies with a total of 5585 patients. The mean follow-up time was 3.5 years (range 0.25-5). Overall, MBS appears to does not affect SHPT risk (OR = 1.34, 95% CI 0.81-2.20, I² = 95%). Follow-up data showed no evidence of SHPT within 2 years following gastric bypass (GB) and sleeve gastrectomy procedures (OR = 1.42, 95% CI 0.66-3.07 for GB, OR = 0.39, 95% CI 0.09-1.62 for sleeve gastrectomy ). At the 2-year and long-term follow-up intervals, a marked increase in SHPT was detected for GB (OR = 6.06, 95% CI 3.39-10.85 for GB). In addition, the surgical procedure for GB decreased the likelihood of SHPT compared with the surgical procedure for biliopancreatic diversion with duodenal switch (OR = 0.29, 95% CI 0.17-0.49).

CONCLUSIONS

Our meta-analysis indicated that GB appears to increase SHPT risk. Patients undergoing MBS should be aware of the risk of SHPT. Larger studies are needed to evaluate the outcomes and side effects and may eventually provide a better and more comprehensive understanding of the risks.

BONE HEALTH ASSESSMENT OF ELDERLY PATIENTS UNDERGOING BARIATRIC SURGERY

BACKGROUND

Bariatric surgery promotes changes in body composition, that can include the loss of bone mineral density (BMD). There is a lack of studies on the evolution of bone health of elderly people who underwent bariatric surgery, in general, and when comparing the gastric bypass (GB) and sleeve gastrectomy (SG) techniques.

OBJECTIVE

To evaluate the bone health of elderly patients with obesity undergoing bariatric surgery.

METHODS

This is a prospective randomized clinical study, that was carried out with individuals of both sexes, ≥65 years, undergoing GB or SG and who met the inclusion criteria. Age, gender and comorbidities (type 2 diabetes mellitus, arterial hypertension, dyslipidemia and osteoarthrosis) were collected and analyzed at baseline. Anthropometric data (weight, body mass index, percentage of weight loss, percentage of excess weight loss), laboratory tests related to bone health and bone mineral density were analyzed before and 24 months after surgery.

RESULTS

A total of 36 patients (GB, n=18; SG, n=18) were evaluated. At baseline, except for sex and preoperative body mass index, which was higher in GB, groups were similar. After 24 months, GB was superior for weight loss (%WL) and excess weight loss (%EWL). Regarding bone health, a significant decrease of BMD was observed in the spine, total proximal femur and femoral neck in all groups, with an average decrease of 5.1%, 10.5% and 15.1%, respectively. In addition, the observed decrease in BMD was up to 25% in the total femur after 24 months, six patients went from normal BMD to osteopenia and one from osteopenia to osteoporosis. There was no difference in parathormone values. However, there was an association between the increase in parathormone and the decrease in BMD in the spine, mainly in the GB group. There was no association between %WL and %EWL with the reduction in BMD.

CONCLUSION

Bariatric surgery was related to the reduction of BMD in elderly patients, but there was no statistical difference between the two surgical techniques.

The role of obesity and bariatric surgery-induced weight loss in breast cancer

Obesity is a complex metabolic condition considered a worldwide public health crisis, and a deeper mechanistic understanding of obesity-associated diseases is urgently needed. Obesity comorbidities include many associated cancers and are estimated to account for 20% of female cancer deaths in the USA. Breast cancer, in particular, is associated with obesity and is the focus of this review. The exact causal links between obesity and breast cancer remain unclear. Still, interactions have emerged between body mass index, tumor molecular subtype, genetic background, and environmental factors that strongly suggest obesity influences the risk and progression of certain breast cancers. Supportive preclinical research uses various diet-induced obesity models to demonstrate that weight loss, via dietary interventions or changes in energy expenditure, reduces the onset or progression of breast cancers. Ongoing and future studies are now aimed at elucidating the underpinning mechanisms behind weight-loss-driven observations to improve therapy and outcomes in patients with breast cancer and reduce risk. This review aims to summarize the rapidly emerging literature on obesity and weight loss strategies with a focused discussion of bariatric surgery in both clinical and preclinical studies detailing the complex interactions between metabolism, immune response, and immunotherapy in the setting of obesity and breast cancer.

The Impact of Bariatric Surgery on Bone Health: State of the Art and New Recognized Links

Bariatric surgery (BS) is the most effective therapy for severe obesity, which improves several comorbidities (such as diabetes, hypertension, dyslipidemia, among others) and results in marked weight loss. Despite these consensual beneficial effects, sleeve gastrectomy and Roux-en-Y gastric bypass (the two main bariatric techniques) have also been associated with changes in bone metabolism and progressive bone loss. The objective of this literature review is to examine the impact of bariatric surgery on bone and its main metabolic links, and to analyze the latest findings regarding the risk of fracture among patients submitted to bariatric surgery.

Effects of Gastric Bypass and Sleeve Gastrectomy on Bone Mineral Density and Bone Turnover Markers: A Systematic Review and Meta-Analysis

BACKGROUND

There is a growing interest in the post-operative bone-related effects of bariatric surgery. However, little is known about the comparative effects of the most commonly performed bariatric procedures, namely Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).

OBJECTIVES

To systematically assess the differences in areal bone mineral density (aBMD) and biochemical and hormonal markers of bone metabolism among patients undergoing RYGB and SG.

METHODS

We conducted a systematic review and meta-analysis of studies aBMD at different sites, as well as bone-specific alkaline phosphatase (BALP), 25-OH-vitamin D, calcium and parathyroid hormone (PTH) after RYGB and SG.

RESULTS

Fourteen studies were included (717 patients, 50.63% in the RYGB arm). Based on data collected at 1 year, 2 years and > 2 years, there were no significant differences in aBMD measurements at the total hip, lumbar spine, femoral neck, and the whole body with no statistical heterogeneity among different comparisons. Patients in the RYGB group showed significantly higher concentrations of BALP at 1 year (SMD = 0.52, 95%CI, 0.23-0.81, p = 0.0004) and PTH at > 2 years of follow-up (SMD = 0.68, 95%CI, 0.31-1.05, p = 0.0003) compared to the SG group.

CONCLUSION

There were no significant differences in aBMD measurements at the hip, lumbar spine, femoral neck, and the total body following RYGB and SG procedures. However, BALP and PTH concentrations were significantly higher after RYGB surgeries compared to SG. Attention should be paid to patients undergoing RYGB to prevent the expected skeletal fragility over time.

Intersection of smoking, e-cigarette use, obesity, and metabolic and bariatric surgery: a systematic review of the current state of evidence

BACKGROUND

Millions of Americans qualify for metabolic and bariatric surgery (MBS) based on the proportion of the population with severe obesity. Simultaneously, the use of electronic nicotine/non-nicotine delivery systems (ENDS) has become epidemic.

OBJECTIVE

We conducted a timely systematic review to examine the impact of tobacco and ENDS use on post-operative health outcomes among MBS patients.

METHODS

PRISMA guidelines were used as the search framework. Keyword combinations of either "smoking," "tobacco," "e-cigarette," "vaping," or "ENDS" and "bariatric surgery," "RYGB," or "sleeve gastrectomy" were used as search terms in PUBMED, Science Direct, and EMBASE. Studies published in English between January 1990 and June 2020 were screened.

RESULTS

From the 3251 articles found, a total of 48 articles were included in the review. No articles described a relationship between ENDS and post-operative health outcomes in MBS patients. Seven studies reported smokers had greater post-MBS weight loss, six studies suggested no relationship between smoking and post-MBS weight loss, and one study reported smoking cessation pre-MBS was related to post-MBS weight gain. Perioperative use of tobacco is positively associated with several post-surgery complications and mortality in MBS patients.

CONCLUSIONS

Combustible tobacco use among MBS patients is significantly related to higher mortality risk and complication rates, but not weight loss. No data currently is available on the impact of ENDS use in these patients. With ENDS use at epidemic levels, it is imperative to determine any potential health effects among patients with severe obesity, and who complete MBS.

Changes in Bone Mineral Density After Weight Loss Due to Metabolic Surgery or Lifestyle Intervention in Obese Patients

PURPOSE

Metabolic surgery and lifestyle intervention are two common methods used to treat obesity, but the effects of weight loss on bone mineral density (BMD) remain controversial. Our aim was to evaluate changes in BMD of the total hip, femoral neck, and lumbar spine after weight loss caused by metabolic surgery or lifestyle intervention.

MATERIALS AND METHODS

We searched PubMed, Web of Science, and the Cochrane Library to identify relevant studies published before 5 August 2020. The primary outcomes, including the BMD of the total hip, femoral neck, and lumbar spine before and 12 months after metabolic surgery or lifestyle intervention, were extracted.

RESULTS

A total of 19 studies with 1095 participants with obesity were included. Among them, 603 participants with obesity accepted metabolic surgery, while 492 accepted lifestyle intervention. At 12 months after weight loss, the BMD of the total hip decreased significantly in obese patients (mean difference [MD] = 0.06 g/cm²; 95% confidence interval [CI] 0.03 to 0.08; I² = 67%; P < 0.001), while the BMD of the lumbar spine did not significantly change (P > 0.05). In the subgroup analysis, the BMD of the femoral neck decreased significantly at 12 months in obese patients who underwent metabolic surgery (MD = 0.08 g/cm²; 95% CI 0.04 to 0.13; I² = 84%; P < 0.001), while it did not significantly change in obese patients who underwent lifestyle treatment (P > 0.05).

CONCLUSION

Regardless of whether the patients underwent metabolic surgery or lifestyle treatment, the BMD of the total hip significantly decreased in obese patients after weight loss. Different methods used to lose weight may have different effects on the BMD of the femoral neck. Prospective studies, preferably randomized controlled trials (RCTs), are still required to investigate whether the effects of the two treatments on bone metabolism are truly different.

Bone mineral density changes after bariatric surgery

INTRODUCTION

Although bariatric surgery is associated with multiple health benefits, decreased bone mass is a known complication of the procedure. Roux-en-Y gastric bypass (RYGB) is associated with significant bone loss and increased fracture risk. However, data on the effect of sleeve gastrectomy (SG) on bone mineral changes are sparse. The impact of vitamin D and calcium levels on bone mineral density (BMD) after SG is also unknown.

METHODS

A retrospective chart review was performed to include patients who underwent RYGB or SG from 2014 to 2016 at a single institution. Patients were included if bone densitometry was performed preoperatively and within 2 years postoperatively. Serum 25-hydroxy vitamin D and calcium levels were collected preoperatively and at time of bone densitometry scan. BMD and T-score changes at the femoral neck, femoral trochanter, total hip, and lumbar spine were compared between RYGB and SG patients.

RESULTS

A total of 40 patients were included. 24 (60%) of patients underwent RYGB and 16 (40%) patients underwent SG. No statistically significant difference in baseline characteristics was noted between RYGB and SG patients. All measurements, except for serum 25-hydroxy vitamin D, were significantly decreased in RYGB patients, postoperatively. All measurements, except for BMD and T-score at the lumbar spine and serum 25-hydroxy vitamin D, were significantly decreased in SG patients, postoperatively. The extent of decrease in serum 25-hydroxyvitamin D was significantly associated with decreased BMD (p = 0.049) and T-score (p = 0.032) at the lumbar spine. The extent of decrease in serum calcium was significantly associated with decreased BMD (p = 0.046) at the femoral neck.

CONCLUSION

All patients were found to have decreased BMD after RYGB and SG. Surgery type was not a significant risk factor in BMD change. Despite vitamin D and calcium supplementation in all patients, a decrease in vitamin D and calcium levels were associated with a decrease in BMD. Close follow-up and treatment of vitamin D and calcium levels are warranted in all bariatric patients.

Roux-en-Y gastric bypass and gastric sleeve surgery result in long term bone loss

OBJECTIVES

Little is known about the long-term skeletal impact of bariatric procedures, particularly the increasingly commonly performed gastric sleeve surgery (GS). We examined bone density (BMD) change following three types of bariatric surgery Roux-en-Y gastric bypass (RYGB), GS and laparoscopic adjustable gastric banding (LAGB), compared with diet, over 36 months.

METHODS

Non-randomized, prospective study of participants with severe obesity (n = 52), undergoing weight-loss interventions: RYGB (n = 7), GS (n = 21), LAGB (n = 11) and diet (n = 13). Measurements of calciotropic indices, gut hormones (fasting and post prandial) peptide YY (PYY), glucagon-like peptide 1 (GLP1) and adiponectin together with dual-X-ray absorptiometry and quantitative computed tomography scans were performed thorough the study.

RESULTS

All groups lost weight during the first 12 months. Despite weight stability from 12 to 36 months and supplementation of calcium and vitamin D, there was progressive bone loss at the total hip (TH) over 36 months in RYGB -14% (95% CI: -12, -17) and GS -9% (95% CI: -7, -10). In RYGB forearm BMD also declined over 36 months -9% (95% CI: -6, -12) and LS BMD declined over the first 12 months -7% (95% CI: -3, -12). RYGB and GS groups experienced significantly greater bone loss until 36 months than LAGB and diet groups, which experienced no significant BMD loss. These bone losses remained significant after adjustment for weight loss and age. RYGB and GS procedures resulted in elevated postprandial PYY, adiponectin and bone turnover markers up to 36 months without such changes among LAGB and diet participants.

CONCLUSIONS

RYGB and GS but not LAGB resulted in ongoing TH bone loss for three postoperative years. For RYGB, bone loss was also observed at LS and non-weight-bearing forearms. These BMD changes were independent of weight and age differences. We, therefore, recommend close monitoring of bone health following RYGB and GS surgeries.

Review: Sex-Specific Aspects in the Bariatric Treatment of Severely Obese Women

This systematic literature review aims to point out sex-specific special features that are important in the bariatric treatment of women suffering from severe obesity. A systematic literature search was carried out according to Cochrane and Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) guidelines. After the literature selection, the following categories were determined: sexuality and sexual function; contraception; fertility; sex hormones and polycystic ovary syndrome; menopause and osteoporosis; pregnancy and breastfeeding; pelvic floor disorders and urinary incontinence; female-specific cancer; and metabolism, outcome, and quality of life. For each category, the current status of research is illuminated and implications for bariatric treatment are determined. A summary that includes key messages is given for each subsection. An overall result of this paper is an understanding that sex-specific risks that follow or result from bariatric surgery should be considered more in aftercare. In order to increase the evidence, further research focusing on sex-specific differences in the outcome of bariatric surgery and promising treatment approaches to female-specific diseases is needed. Nevertheless, bariatric surgery shows good potential in the treatment of sex-specific aspects for severely obese women that goes far beyond mere weight loss and reduction of metabolic risks.

The change of bone mineral density and bone metabolism after gastrectomy for gastric cancer: a meta-analysis

Bone mineral density (BMD) is significantly decreased after gastrectomy in patients with gastric cancer. Calcium malabsorption, secondary hyperparathyroidism, and dominant bone resorption appear to contribute to bone loss in these patients. Patients should undergo early surveillance and nutritional or pharmacologic intensive interventions for bone health.

PURPOSE

Survivorship care, including bone health, has become an important issue in gastric cancer. We performed a meta-analysis of the available observational studies to determine whether and how osteoporosis risk is increased after gastrectomy in patients with gastric cancer.

METHODS

A total of 1204 patients (802 men) from 19 cohort studies were included. We evaluated the prevalence of osteoporosis in postgastrectomy patients, comparing the incidence according to the type of gastrectomy and sex. Additionally, we evaluated changes in bone mineral density (BMD) and bone metabolism-related markers pre- to postoperatively and between patients who underwent gastrectomy and matched controls. Proportion meta-analysis was performed and pooled odds ratios (ORs) were calculated.

RESULTS

The pooled incidence estimate was 36% [95% confidence interval (CI), 32-40]. The incidence of osteoporosis was significantly higher in women than in men (OR = 1.90, p < 0.001) but was similar between partial and total gastrectomy groups (OR = 0.983, p = 0.939). BMD was significantly decreased, and calcium, phosphorous, and parathyroid hormone levels were significantly increased in patients after gastrectomy compared to those before gastrectomy. BMD and calcium and 25OH-vitamin D levels were significantly decreased, and parathyroid hormone and 1,25OH-vitamin D levels were significantly increased in the gastrectomy group compared to that in the control group.

CONCLUSION

We found that BMD is significantly decreased after gastrectomy in patients with gastric cancer. Vitamin D deficiency and secondary hyperparathyroidism are suggested to be common mechanism underlying BMD impairment. After resection, patients should undergo long-term nutritional and bone health surveillance, in addition to their oncological follow-up.

Effects of Laparoscopic Sleeve Gastrectomy on Bone Mineral Density and Bone Metabolism in Chinese Patients with Obesity

OBJECTIVE

Laparoscopic sleeve gastrectomy (LSG) is one of the most effective therapies to treat obesity. Due to a lack of longitudinal research, we explored the changes in BMD and bone metabolism in Chinese patients with obesity before and after LSG.

MATERIALS AND METHODS

A total of 49 obese Chinese patients with obesity were recruited from the Second Xiangya Hospital of Central South University. All patients underwent LSG, and the metabolic indicators were evaluated, including the serum osteocalcin (OC), total-terminal propeptide of type I procollagen (TPINP) and carboxy terminal telopeptide of collagen type I (CTX) levels at baseline and 2, 6 and 12 months postoperatively. Dual energy X-ray absorptiometry (DEXA) was used to measure body composition and BMD before and 12 months after LSG.

RESULTS

The body mass index (BMI) significantly decreased at 12 months postoperatively, and no patients developed osteoporosis. The BMD of femoral neck and total hip significantly decreased from the baseline to 12 months postoperatively, while the BMD of lumbar spine did not change significantly. The OC, TPINP and CTX levels significantly increased at 12 months postoperatively. The excess BMI loss (EBMIL) was positively related while the reduction in visceral adipose tissue (VAT) mass was negatively related to the decreases in BMD of the femoral neck and total hip at 12 months postoperatively. The increase in OC was negatively correlated with the decrease in BMD of the femoral neck, while the increase in TPINP was positively correlated with the decrease in BMD of total hip.

CONCLUSION

Based on the 12-month follow-up results, the BMD of the femoral neck and total hip was decreased in Chinese patients with obesity after LSG, while bone remodelling was active. This finding suggested that weight loss, a decrease in the VAT mass and an increase in bone remodelling may be correlated with a reduction in BMD.