title: Increased PTH and 1.25(OH)(2)D levels associated with increased markers of bone turnover following bariatric surgery.
abstract: The objective of this study was to characterize changes in metabolic bone parameters following bariatric surgery. Seventy-three obese adult patients who underwent either gastric banding (GB), Roux-en-Y gastric bypass (RYGB), or biliopancreatic diversion with duodenal switch (BPD/DS) were followed prospectively for 18 months postoperatively. Changes in the calcium-vitamin D axis (25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)(2)D), calcium, parathyroid hormone (PTH)), markers of bone formation (osteocalcin, bone-specific alkaline phosphatase) and resorption (urinary N-telopeptide (NTx)), as well as bone mineral density (BMD) were assessed at 3-month intervals during this time period. Bariatric surgery resulted in significant and progressive weight loss over 18 months. With supplementation, 25OHD levels increased 65.3% (P < 0.0001) by 3 months, but leveled off and decreased <30 ng/ml by 18 months. PTH initially decreased 21.4% (P = 0.01) at 3 months, but later approached presurgery levels. 1,25(OH)(2)D increased significantly starting at month 12 (50.3% increase from baseline, P = 0.008), and was positively associated with PTH (r = 0.82, P = 0.0001). When stratified by surgery type, median PTH and 1,25(OH)(2)D levels were higher following combined restrictive and malabsorptive operations (RYGB and BPD/DS) compared to GB. Bone formation/resorption markers were increased by 3 months (P < 0.05) and remained elevated through 18 months. Radial BMD decreased 3.5% by month 18, but this change was not significant (P = 0.23). Our findings show that after transient improvement, preoperative vitamin D insufficiency and secondary hyperparathyroidism persisted following surgery despite supplementation. Postoperative secondary hyperparathyroidism was associated with increased 1,25(OH)(2)D levels and increased bone turnover markers.
authors: Department of Medicine, Division of Medicine, New York Presbyterian Hospital/Weill Cornell Medical College, New York, New York, USA. sinhana@med.cornell.edu
authors: Naina
authors: N
authors: Sinha
authors: Albert
authors: A
authors: Shieh
authors: Emily M
authors: EM
authors: Stein
authors: Gladys
authors: G
authors: Strain
authors: Aaron
authors: A
authors: Schulman
authors: Alfons
authors: A
authors: Pomp
authors: Michel
authors: M
authors: Gagner
authors: Gregory
authors: G
authors: Dakin
authors: Paul
authors: P
authors: Christos
authors: Richard S
authors: RS
authors: Bockman
references: Ann Surg. 2004 Sep;240(3):416-23; discussion 423-4
references: 15319713
references: Obes Surg. 2009 Aug;19(8):1132-8
references: 19517199
references: JAMA. 2006 Apr 5;295(13):1549-55
references: 16595758
references: Obes Surg. 2008 Feb;18(2):197-203
references: 18188655
references: Obes Surg. 2004 Sep;14(8):1062-6
references: 15479594
references: J Gastrointest Surg. 2005 Nov;9(8):1106-10; discussion 1110-1
references: 16269381
references: JAMA. 2002 Dec 11;288(22):2793-6
references: 12472304
references: Obes Surg. 2009 Dec;19(12):1605-11
references: 19885707
references: JAMA. 2003 Jan 1;289(1):76-9
references: 12503980
references: Surg Obes Relat Dis. 2008 Sep-Oct;4(5 Suppl):S73-108
references: 18490202
references: J Clin Endocrinol Metab. 2008 Oct;93(10):3735-40
references: 18647809
references: Surg Endosc. 2007 Aug;21(8):1393-6
references: 17318692
references: Circulation. 1998 Jun 2;97(21):2099-100
references: 9626167
references: Surgery. 2007 Dec;142(6):914-20; discussion 914-20
references: 18063076
references: Int J Obes Relat Metab Disord. 2003 Jan;27(1):110-6
references: 12532162
references: Horm Metab Res. 2010 May;42(5):299-306
references: 20217631
references: Obes Surg. 2007 Mar;17(3):348-54
references: 17546843
references: Appl Nurs Res. 2009 Feb;22(1):35-41
references: 19171293
references: J Am Coll Surg. 2007 Aug;205(2):294-7
references: 17660076
references: Obesity (Silver Spring). 2006 Nov;14(11):1940-8
references: 17135609
references: Int J Obes (Lond). 2005 Dec;29(12):1429-35
references: 16077715
references: J Clin Endocrinol Metab. 2008 Jun;93(6):2181-7
references: 18364384
references: Obes Surg. 2005 Mar;15(3):330-5
references: 15826464
references: J Clin Endocrinol Metab. 2004 Mar;89(3):1061-5
references: 15001587
references: Am J Med Sci. 2005 Feb;329(2):57-61
references: 15711420
references: Metabolism. 2004 Jul;53(7):918-21
references: 15254887
references: J Clin Endocrinol Metab. 2010 Jan;95(1):159-66
references: 19858320