The significance of elevated levels of parathyroid hormone in patients with morbid obesity before and after bariatric surgery.
OBJECTIVE
The risk of hyperparathyroidism after the duodenal switch operation is related to the length of the common channel.


METHODS
A retrospective analysis of patients following the duodenal switch operation from October 2, 2000, through February 1, 2002.


METHODS
Academic tertiary referral hospital.


METHODS
One hundred sixty-five consecutive patients underwent the duodenal switch operation, performed for morbid obesity, with common channel lengths of 75 cm (n = 103 [group A]) and 100 cm (n = 62 [group B]).


METHODS
Weight loss and parathyroid hormone, corrected calcium, and 25-hydroxyvitamin D (25-OH D) levels were compared between groups A and B. Values were determined preoperatively, early postoperatively (3-6 months), and late postoperatively (9-18 months).


RESULTS
Both groups exhibited a slight reduction in serum calcium concentration, with one quarter decreasing below the normal range. Hyperparathyroidism was more common in group A than group B preoperatively (38.9% vs 14.9%), reflecting the higher body mass index of patients in group A. Hyperparathyroidism was also more frequent in the early (54.9% vs 30.9%) and late (49.4% vs 20.5%) postoperative periods in group A vs group B. New-onset hyperparathyroidism was also more common in group A than group B (42.0% vs 13.3%). After 1 year, subnormal 25-OH D levels were found in 17.0% of the patients in group A and in 10.0% of the patients in group B. Median 25-OH D levels increased in both groups, but tended to be higher in group B.


CONCLUSIONS
Patients with shorter common channels had a higher risk of developing hyperparathyroidism. This may be related to limited 25-OH D absorption.
Hamoui
Nahid
N
Department of Surgery, University of Southern California, Los Angeles, CA 90033, USA.
Kim
Kiwan
K
Anthone
Gary
G
Crookes
Peter F
PF
D000328:Adult; D002118:Calcium / Q000097:blood; D016022:Case-Control Studies; D004386:Duodenum / Q000601:surgery*; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D009767:Obesity, Morbid / Q000097:blood* / Q000601:surgery*; D010281:Parathyroid Hormone / Q000097:blood*; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D015431:Weight Loss
D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium