Bone Loss After Laparoscopic Roux-en-Y Gastric Bypass
Bone Loss After Laparoscopic Roux-en-Y Gastric Bypass
The objective of this study is to assess changes bone mineral density and bone metabolism
 after laparoscopic Roux-en-Y gastric bypass surgery. The investigators hypothesize that
 weight loss after laparoscopic Roux-en-Y gastric bypass surgery will be associated with
 increased bone turnover, changes in bone metabolism, and loss of bone mass.
Obesity is an increasing problem within the United States. Fifteen million people in the
 United States are considered morbidly obese, with a body mass index (BMI) greater than 40
 kg/m2. A wealth of literature has shown laparoscopic Roux-en Y gastric bypass surgery to be
 an effective procedure to reduce excess body weight. But a paucity of research examines the
 effects of laparoscopic Roux-en Y surgery on the skeleton.

 Bone remodeling is a complex process involving bone resorption and formation-a process
 dependent upon local and systemic influences. Obesity is one of these influences that is
 poorly understood. Obesity is associated with a reduced risk of osteoporosis. Obesity may be
 protective due to increased weight bearing, increased production of estrogen by adipose
 tissue, or increased bone formation due to higher levels of insulin.

 It is known that weight loss in healthy individuals is associated with bone loss. Several
 small studies have reported bone loss in patients undergoing vertical band gastroplasty or
 jejunoileal bypass weight loss surgeries. Other reported metabolic disease disarrangements
 following weight loss surgery are decreased serum calcium, decreased serum 25-hydroxy vitamin
 D, and hyperparathyroidism.

 In the bariatric literature, weight loss has been associated with an increased risk of bone
 mineral loss and fracture. Osteoporosis has been described in patients who lost weight after
 jejunoileal bypass surgery. Premenopausal women appeared to be spared from bone mineral loss,
 thus indicating a protective effect from the premenopausal state. Bone mineral loss is seen
 both in premenopausal women and in men after weight loss surgery.

 Roux-en Y gastric bypass has been shown to be more effective at weight loss than has the
 adjustable silicone gastric band. It has also been linked with increased loss of bone mineral
 density. Another study found an increase in bone turnover as well as a decrease in total bone
 mass and trochanteric bone density in laparoscopic Roux-en Y gastric bypass patients.

 Previous research at our institution has shown a statistically significant increase in the
 prevalence of hyperparathyroidism in post-gastric bypass patients. However, our previous
 research did not examine the impact that these hormonal changes impart upon bone density. We
 have found a statistically significant incidence of vitamin D deficiency in our patients
 following this surgery. We intend to expand upon our own research as well as that of others
 by exploring the associations between the development of hyperparathyroidism, bone metabolic
 derangements, weight loss, and bone density.
Inclusion Criteria:

 -  Morbidly obese female patients undergoing elective laparoscopic Roux-en-Y gastric
 bypass at a single institution

 Exclusion Criteria:

 -  Male patients

 -  Patients unable to fulfill the study protocol requirements