Obesity Surgery

, Volume 23, Issue 3, pp 384–390

Secondary Hyperparathyroidism, Vitamin D Sufficiency, and Serum Calcium 5 Years After Gastric Bypass and Duodenal Switch

  • Stephen Hewitt
  • Torgeir T. Søvik
  • Erlend T. Aasheim
  • Jon Kristinsson
  • Jørgen Jahnsen
  • Grethe S. Birketvedt
  • Thomas Bøhmer
  • Erik F. Eriksen
  • Tom Mala
Clinical Research

DOI: 10.1007/s11695-012-0772-3

Cite this article as:
Hewitt, S., Søvik, T.T., Aasheim, E.T. et al. OBES SURG (2013) 23: 384. doi:10.1007/s11695-012-0772-3

Abstract

Background

The prevalence of secondary hyperparathyroidism (SHPT) is high after bariatric surgery. Vitamin D is supplied to counteract SHPT and bone disease, and we studied vitamin D associations with SHPT.

Methods

We measured serum levels of 25-OH vitamin D and parathyroid hormone (PTH) 5 years after gastric bypass and duodenal switch. One hundred twenty-five patients were included, of whom 114 (91 %) had undergone gastric bypass and 11 (9 %) had undergone duodenal switch. SHPT was defined as PTH > 7.0 pmol/l in the absence of hypercalcemia. 25-OH vitamin D levels were divided into three categories: <50, 50–74, and ≥75 nmol/l. Serum ionized calcium, magnesium, phosphate, and creatinine were divided into tertiles.

Results

Mean age ± SD was 44 ± 9 years at 5 years follow-up. Ninety out of 125 (72 %) patients were women. SHPT was present in 45 out of 114 (40 %) gastric bypass patients and in 11 out of 11 (100 %) duodenal switch patients. The prevalence was high in all vitamin D categories studied. An inverse association between ionized calcium and PTH was found. For the gastric bypass patients, the odds ratio for SHPT in the upper two tertiles of ionized calcium was 0.35; 95 % CI, 0.15–0.79; p = 0.011, compared with the lowest tertile. Supplements of vitamin D and calcium were not associated with a lower prevalence of SHPT at 5 years follow-up.

Conclusions

The prevalence of SHPT was high 5 years after gastric bypass and duodenal switch. SHPT was inversely associated with serum ionized calcium, but not with vitamin D. The supplementation used was insufficient to compensate for the impaired calcium absorption after surgery.

Keywords

Secondary hyperparathyroidism Parathyroid hormone Vitamin D Calcium Hypocalcemia Bariatric surgery Gastric bypass Duodenal switch 

Copyright information

© Springer Science + Business Media, LLC 2012

Authors and Affiliations

  • Stephen Hewitt
    • 1
  • Torgeir T. Søvik
    • 2
    • 3
  • Erlend T. Aasheim
    • 4
  • Jon Kristinsson
    • 1
    • 2
  • Jørgen Jahnsen
    • 5
  • Grethe S. Birketvedt
    • 1
  • Thomas Bøhmer
    • 4
  • Erik F. Eriksen
    • 3
    • 4
  • Tom Mala
    • 1
    • 2
  1. 1.Department of Morbid Obesity and Bariatric Surgery, Department of MedicineOslo University Hospital AkerOsloNorway
  2. 2.Department of Gastrointestinal Surgery, Department of SurgeryOslo University Hospital AkerOsloNorway
  3. 3.Faculty of MedicineUniversity of OsloOsloNorway
  4. 4.Department of Endocrinology, Department of MedicineOslo University Hospital AkerOsloNorway
  5. 5.Department of Gastroenterology, Department of MedicineOslo University Hospital AkerOsloNorway

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