Predictive Factors of Secondary Normocalcemic Hyperparathyroidism after Roux-en-Y Gastric Bypass
Table 1
Inclusion and exclusion criteria for eligibility of the study.
Inclusion criteria
Exclusion criteria
Age between 18 and 60 years
Currently using pharmacological (e.g., hormone replacement therapy) or supplementation treatment to influence VD metabolism
Caucasian ethnicity
Disease influencing calcium metabolism, polyendocrinopathy or autoimmune disease and other causes of secondary hyperparathyroidism
BMI >40 kg/m2 or 35–40 kg/m2 with obesity-associated comorbidity
History of cancer
Availability and willingness to comply with 18-month outpatient follow-up
Prior head or neck surgery
Availability and willingness to have blood samples tested for calcium, 25-hydroxy vitamin D, and PTH levels.
Prior abdominal or bariatric surgery
Availability to take oral supplements, if needed
Lack of calcium metabolism documentation
Normal preoperative renal function
Lost to follow-up
Causes of secondary hyperparathyroidism according to Fraser [22]: (i) steroid therapy; (ii) patients overclothing; (iii) bisphosphonate therapy; (iv) osteolytic lesions; (v) diuretic therapy; (vi) previous acute pancreatitis; (vii) state of sepsis; (viii) chronic kidney disease and hypercalciuria; (ix) intake of drugs that interact with vitamin D (e.g., phenobarbital and phenytoin); and (x) use of antacids containing aluminum that interfere with phosphate absorption.