Effects of Roux-en-Y Gastric Bypass on Osteoclast Activity and Bone Density in Morbidly Obese Patients with Type 2 Diabetes.

Obesity surgery. 2020;30(1):290-295

Plain language summary

Gastric surgery and the resultant weight loss can improve an individual’s outcomes in a number of diseases, such as heart disease and type 2 diabetes, however an unfortunate side effect is bone loss. Roux-en-Y gastric bypass is a process whereby the size of your stomach is significantly reduced, and it is unclear as to the effect this type of surgery has on bone density. This cohort study of sixty-one individuals who underwent Roux-en-Y gastric bypass aimed to determine the effect on bone density one year post surgery. The results showed that following surgery, bone resorption was increased compared to control and although bone density was similar between the two groups, bone mineral content and bone surface area were decreased. Women who were post-menopausal demonstrated diminished bone health, although this was not significant. It was concluded that Roux-en-Y gastric bypass surgery results in a negative impact on bone health. This study could be used by healthcare professionals to understand the importance of considering bone health when recommending surgery, especially in those at high-risk of bone loss such as post-menopausal women.

Abstract

INTRODUCTION Roux-en-Y gastric bypass (RYGB) is a well-established treatment for morbid obesity and type 2 diabetes. The effects of RYGB on bone metabolism and bone health are largely unknown. OBJECTIVE Determine the changes in osteoclast function and bone density 1 year after RYGB as compared with a control group undergoing a diabetes support and education program (DSE). DESIGN A prospective cohort study with patients matched for weight and age assigned to RYGB or DSE. SETTING Large academic institution. PATIENTS OR OTHER PARTICIPANTS Patients with type 2 diabetes mellitus and morbid obesity (body mass index greater than 35 kg/m2). INTERVENTION Subjects either received laparoscopic RYBG or DSE, which consisted of nutritional, exercise, and dietary counseling performed by a certified diabetic educator and a nutritionist three times over a year. MAIN OUTCOME MEASURE Osteoclast activity, bone mineral density. RESULTS One year after, intervention subjects undergoing RYGB have a 280% increase in osteoclast activity as compared with a 7.6% increase in the DSE control group (P < 0.001). Furthermore, there was a statistically significant increase in sclerostin levels in subjects undergoing RYGB compared with an increase in the control group. The total bone mineral density was statistically unchanged within 1 year of intervention in both groups. A statistically significant decrease in bone mineral density in the left ribs (decrease of 6.8%, P < 0.05) and lumbar spine (decrease of 4.0%, P < 0.05) was seen 1 year after RYGB. CONCLUSIONS There is a significant increase in osteoclast activity observed 1 year after RYGB; the long-term clinical implications of this increased bone metabolism are unknown.

Lifestyle medicine

Patient Centred Factors : Mediators/Obesity
Environmental Inputs : Diet ; Nutrients
Personal Lifestyle Factors : Not applicable
Functional Laboratory Testing : Tissue biopsy

Methodological quality

Jadad score : Not applicable
Allocation concealment : Not applicable

Metadata

Nutrition Evidence keywords : Weight loss ; Obesity ; Calcium ; Vitamin D