Secondary hyperparathyroidism following biliopancreatic diversion
B. L. Chapin, H. J. LeMar Jr, D. H. Knodel and P. L. Carter
Department of Medicine, Madigan Army Medical Center, Tacoma, Wash., USA.
OBJECTIVE: To investigate the cause of osteomalacia following
biliopancreatic diversion(BPD) surgery for obesity. DESIGN: A
retrospective, case-comparison study. SETTING: A tertiary care center.
PATIENTS: A case group of 12 subjects (including 9 women; mean age +/- SEM,
48.5 +/- 3.0 years; mean preoperative body mass index +/- SEM, 43.7 +/- 2.3
kg/m2, and mean weight loss +/- SEM, 75 +/- 14 kg) who have undergone BPD
(referred to as BPD group hereafter) and a comparison group of 10 subjects
(including 9 women; mean age +/- SEM, 49.6 +/- 3.3 years; mean preoperative
body mass index +/- SEM, 44.0 +/- 2.5 kg/m2; and mean weight loss +/- SEM,
55 +/- 15 kg) following vertical banded gastroplasty (VBG) (referred to as
VBG group hereafter). MAIN OUTCOME MEASURES: Serum and urine markers for
bone metabolism. RESULTS: Compared with the VBG group, the BPD group had
significantly lower concentrations of the following components: serum
calcium (2.14 +/- 0.05 mmol/L vs 2.37 +/- 0.05 mmol/L [8.6 +/- 0.2 mg/dL vs
9.5 +/- 0.2 mg/dL]), serum 25-hydroxyvitamin D (24 +/- 6 nmol/L vs 64 +/- 6
nmol/L), urine calcium excretion (1.7 +/- 0.7 mmol/d vs 4.5 +/- 0.7 mmol/d
[68 +/- 28 mg/d vs 180 +/- 28 mg/d]), and serum carotene (0.40 +/- 0.15
mmol/L vs 1.29 +/- 0.16 mmol/L). The BPD group had significantly higher
concentrations of the following components: serum parathyroid hormone (13.6
+/- 2.1 pmol/L vs 5.2 +/- 2.3 pmol/L), serum alkaline phosphatase (139 +/-
8 U/L vs 86 +/- 9 U/L), and urinary hydroxyproline/creatine (52 +/- 5
mumol/mmol vs 19 +/- 5 mumol/mmol). CONCLUSION: These data suggest that
following BPD, secondary hyperparathyroidism attributed to hypocalcemia
results from malabsorption of vitamin D. However, we cannot exclude the
possibility of concurrent calcium malabsorption with vitamin D
malabsorption.
