title: Role of calcium malabsorption in the development of secondary hyperparathyroidism after biliopancreatic diversion.
abstract: Secondary hyperparathyroidism (SH) is a frequent metabolic complication of bariatric surgery. Around 70%of patients who undergo biliopancreatic diversion (BPD) have this complication in the long term. The aim of this study was to evaluate the relative influence of vitamin D deficiency and calcium malabsorption in the development of SH in patients who underwent BPD. We reviewed the mean values of PTH throughout the post-operative follow-up and of related biochemical data (25-hydroxyvitamin D, calcium, magnesium) of 121 patients who underwent BPD at our institute from November 1996 to November 2004 (mean follow-up 66 months). Mean PTH correlated negatively with mean 25-hydroxyvitamin D (r=-0.27, p=0.003) and with urinary calcium(r=-0.19, p=0.047), and positively with age (r=0.22, p=0.018). However, a high mean PTH was found in 48.7% patients with mean 25-hydroxyvitamin D >or=30 ng/ml and in 80.0% patients with mean 25-hydroxyvitamin D between 20 and 30 ng/ml. The mean PTH was normal in 5 patients without calcium supplements at present, and progressively increased in parallel to the calcium dose in the rest of patients, although mean 25-hydroxyvitamin D levels were not related to the calcium dose. Our data suggest that individual differences in active and/or passive calcium absorption determine intractable SH after BPD in around half of the patients who have normal levels of 25-hydroxyvitamin D and in 80% of patients with 25-hydroxyvitamin D levels between 20 and 30 ng/ml after BPD, worsening with age.
authors.affiliation: Department of Endocrinology and Clinical Nutrition, Ramón y Cajal Hospital, Madrid, Spain. jbalsa.hrc@salud.madrid.org
authors.forename: J A
authors.initials: JA
authors.lastname: Balsa
authors.forename: J I
authors.initials: JI
authors.lastname: Botella-Carretero
authors.forename: R
authors.initials: R
authors.lastname: Peromingo
authors.forename: I
authors.initials: I
authors.lastname: Zamarrón
authors.forename: F
authors.initials: F
authors.lastname: Arrieta
authors.forename: T
authors.initials: T
authors.lastname: Muñoz-Malo
authors.forename: C
authors.initials: C
authors.lastname: Vázquez
mesh_terms: D000328:Adult; D000368:Aged; D050110:Bariatric Surgery / Q000009:adverse effects; D015904:Biliopancreatic Diversion / Q000009:adverse effects*; D002118:Calcium / Q000378:metabolism* / Q000652:urine; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000209:etiology*; D008274:Magnesium / Q000097:blood; D008286:Malabsorption Syndromes / Q000150:complications*; D008297:Male; D008593:Menopause; D008875:Middle Aged; D009767:Obesity, Morbid / Q000601:surgery; D010281:Parathyroid Hormone / Q000378:metabolism; D012737:Sex Factors; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D008274:Magnesium; D002118:Calcium