Role of calcium malabsorption in the development of secondary hyperparathyroidism after biliopancreatic diversion

• Published in: Journal of endocrinological investigation Vol. 31; no. 10; pp. 845 - 850
• Main Authors: Balsa, J. A., Botella-Carretero, J. I., Peromingo, R., Zamarrón, I., Arrieta, F., Muñoz-Malo, T., Vázquez, C.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-10-2008
• Subjects: Adult; Aged; Bariatric Surgery - adverse effects; Biliopancreatic Diversion - adverse effects; Calcium - metabolism; Calcium - urine; Endocrinology; Female; Humans; Hyperparathyroidism, Secondary - etiology; Magnesium - blood; Malabsorption Syndromes - complications; Male; Medicine; Medicine & Public Health; Menopause; Metabolic Diseases; Middle Aged; Obesity, Morbid - surgery; Original Article; Parathyroid Hormone - metabolism; Sex Factors; Vitamin D - analogs & derivatives; Vitamin D - blood; Vitamin D Deficiency - complications; calcium malabsorption; Biliopancreatic diversion; secondary hyperparathyroidism
• ISSN: 0391-4097; 1720-8386
• DOI: 10.1007/BF03346429

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). MeanPTH 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 ≥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.