Effects of omega-loop gastric bypass on vitamin D and bone metabolism in morbidly obese bariatric patients.
BACKGROUND
Bariatric patients often suffer from nutrient deficiencies. Little is known about vitamin D levels and bone metabolism in patients undergoing omega-loop gastric bypass (OLGB). We, therefore, evaluated parameters of vitamin D metabolism preoperatively and during the first postoperative year.


METHODS
Within our cohort study, we retrospectively evaluated the respective parameters pre-, 3, 6, and 12 months postoperatively in patients with OLGB, between February 2011 and February 2013.


RESULTS
In patients [n = 50; age 46 (15) years, mean (SD); 12 male, 38 female] BMI was 45.4 (6.6) kg/m(2) preoperatively and decreased to 29.1 (3.8) kg/m(2) after 12 months, corresponding to a total body weight loss of 36 %. Preoperatively, the prevalence of vitamin D deficiency was 96 and 30 % demonstrated elevated parathyroid hormone yielding a prevalence of secondary hyperparathyroidism of 17 %. Postoperatively, subjects received individually adjusted vitamin D3 supplementation (95 % CI 200-3000 IU/day), according to the available guidelines at that time. Nevertheless, every third patient was vitamin D deficient at 12 months (80 %). In patients with preoperative BMI >45 vs. <45 kg/m(2), we observed a 3-fold higher risk for vitamin D deficiency over 12 months [OR = 3.10, 95 % CI (1.01-9.51), p = 0.048].


CONCLUSIONS
To avoid vitamin D deficiency, morbidly obese patients, particularly those with higher preoperative BMI, should be regularly screened pre- and postoperatively. Standard postsurgical supplementation has not been adequate to restore 25-OHD status and current guidelines are not very specific in terms of timing and dosing of vitamin D3 supplementation. Consequently, further trials to enhance the evidence on vitamin D supplementation are warranted.
Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria, maria.luger@meduniwien.ac.at.
Maria
M
Luger
Renate
R
Kruschitz
Felix
F
Langer
Gerhard
G
Prager
Melanie
M
Walker
Rodrig
R
Marculescu
Friedrich
F
Hoppichler
Karin
K
Schindler
Bernhard
B
Ludvik
D000328:Adult; D015331:Cohort Studies; D005260:Female; D015390:Gastric Bypass / Q000379:methods*; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood / Q000453:epidemiology / Q000601:surgery*; D011184:Postoperative Period; D015995:Prevalence; D012189:Retrospective Studies; D016896:Treatment Outcome; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
D014807:Vitamin D