Factors associated with secondary hyperparathyroidism in premenopausal women undergoing Roux-en-Y gastric bypass for the treatment of obesity

Abstract

OBJECTIVE: To evaluate bone metabolism, bone density (BMD) and vertebral fractures in morbidly obese individuals. SUBJECTS AND METHODS: Case series of 29 premenopausal obese patients, 15 of whom had been submitted to bariatric surgery. Serum calcium, albumin, PTH and 25-hydroxy vitamin D (25OHD) were measured as well as bone densitometry of the lumbar spine and proximal femur, and lateral spine x-rays. RESULTS: High parathyroid hormone (PTH) levels were recorded in 46.6% of the surgical patients and in 21.4% of the non-surgical patients (p = 0.245); 26.7% of the former and 28.6% of the latter revealed levels 25OHD < 30 ng/mL (p = 1.000). Calcium intake was higher in the surgical group (p = 0.004) along with lower serum calcium concentrations (p = 0.019). There were no significant differences in bone mineral density (BMD) or in the prevalence of vertebral fractures between groups. CONCLUSION: In premenopausal women undergoing Roux-en-Y gastric bypass there is important intestinal calcium mal absorption which seems to be the main factor causing secondary hyperparathyroidism.

Bariatric Roux-En-Y Gastric Bypass Surgery: Adipocyte Proteins Involved in Increased Bone Remodeling in Humans

“…The negative influence of weight loss and the hormonal and biochemical changes induced by bariatric surgery on bone health has been reported [7,11,20,[31][32][33][34][35], in addition to the association between excess body weight loss and bone mineral density (BMD) 1 to 2 years after RYGB [20,34,36]. Bone turnover increased in the study sample, evidence by higher CTX and BSAP after RYGB.…”

Obesity and bone metabolism

“…However, in malabsorptive procedures, nutrient deficiency and secondary hyperparathyroidism probably play a significant role. Low serum 25OHD levels and poor absorption of calcium seem to be related to secondary hyperparathyroidism observed in women who had undergone RYGB [122], and there is association between changes in the cortical bone parameters and changes in PTH post-surgery [112]. A 6-month prospective clinical trial in obese patients who underwent RYGB showed a decrease in Ca absorption without alteration of the Ca-PTH axis, suggesting the implication of other regulating hormones [123].…”

Impact of Vitamin D and Calcium Deficiency in the Bones of Patients Undergoing Bariatric Surgery: A Systematic Review

“… Avgerinos et al, 2007 2 in his important prospective cohort in individuals of both genders for two years have shown the importance of vitamin D supplementation to prevent the decrease of calcium in the bones. Other authors also showed high deficiency of vitamin D in patients after this surgery 2 , 9 , 10 , 19 , 25 , 27 .…”

“…Researchers analyzed women in pre- and postmenopausal stage showing that there was no significant difference in calcium absorption deficiency and even differences in relationship to the type of surgery 20 , 25 ,29 .…”