Risk of secondary hyperparathyroidism after laparoscopic gastric bypass surgery in obese women

Y. Youssef, W. O. Richards, N. Sekhar, J. Kaiser, A. Spagnoli, N. Abumrad, A. Torquati

Research output: Contribution to journalArticlepeer-review

71 Scopus citations


Background: Metabolic bone disease is a potential complication of bariatric surgery. The aims of our study were to evaluate the effects of laparoscopic gastric bypass on calcium and vitamin D metabolism, and to identify patients at high risk to develop secondary hyperparathyroidism (HPT). Methods: Serum calcium, alkaline phosphatase, intact parathyroid hormone (PTH), and 25-hydroxy (OH) vitamin D were measured at 3, 6, 12, and 24 months after laparoscopic gastric bypass in a cohort of morbidly obese women. Logistic regression was used in both univariate and multivariate models to identify independent preoperative variables associated with secondary HPT. Results: The study enrolled 193 morbidly obese women. During the 2-year follow-up period, the incidence of elevated PTH levels (>65 pg/ml) was 53.3%. The mean time elapsed between surgery and detection of secondary HPT was 9.1 months (range, 3-24 months). Vitamin D deficiency was observed in 39 patients (20.2%). On univariate analysis, the preoperative factors associated with secondary HPT were race (high PTH levels were detected in 70% of African Americans versus 50% of Caucasians; p < 0.05), preoperative body mass index (BMI; high PTH: 52.5 ± 10.8 versus normal PTH: 48.9 ± 7.5 kg/m2; p < 0.01), and age (high PTH: 44.9 ± 9.2 versus normal PTH: 42.3 ± 9 years, p < 0.05). Race and age remained independent risk factors for secondary HPT in the multivariate logistic regression model after adjusting for the covariate Roux-limb length. African Americans were at more than 2.5 times greater risk to develop secondary HPT as Caucasian (RR 2.5; 95% CI: 1.03-6.17, p < 0.05). Patients older than 45 years were at 1.8 times higher risk of developing secondary HPT as their younger counterparts (RR 1.8; 95% CI: 1.01-3.32, p < 0.05). Conclusions: Morbidly obese women have a high incidence of elevated PTH levels after gastric bypass surgery. Low vitamin D levels did not constitute the only reason behind this finding. African-American women and women older than 45 years of age were at significantly higher risk of developing secondary HPT. In these populations, aggressive supplementation with calcium citrate and vitamin D should be implemented.

Original languageEnglish (US)
Pages (from-to)1393-1396
Number of pages4
JournalSurgical Endoscopy and Other Interventional Techniques
Issue number8
StatePublished - Aug 2007
Externally publishedYes


  • Bariatric surgery
  • Calcium metabolism
  • Gastric bypass
  • Secondary hyperparathyroidism
  • Vitamin D

ASJC Scopus subject areas

  • Surgery


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