Post-bariatric surgery patients Surgery
Conditions
Interventions
This is a single-center outpatient study with consecutive ongoing recruitment in the Obesity Clinic of the Cantonal hospital St. Gallen in routine consultations of patients after bariatric surgery. In
Sponsors
Klinik für Endokrinologie, Diabetologie, Osteologie und Stoffwechselerkrankungen Kantonsspital St. Gallen
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: 1. Age > 18 years 2. Previous bariatric surgery, i.e. Roux-Y-gastric bypass, gastric sleeve resection, biliopancreatic diversion 3. Planned parenteral intravenous iron therapy with ferric carboxymaltose according to local guidelines (serum ferritin < 15 mcg/l or < 30 mcg/l with a previous history of iron deficiency anemia or symptoms compatible with iron deficiency) 4. Written informed consent
Exclusion criteria
Exclusion criteria: 1. Known hypersensitivity to FCM 2. Treatment with intravenous iron within the previous 14 days 3. Glomerular filtration rate < 60 ml/min/1.73m2 (CKD-EPI formula) 4. Plasma phosphate < 0.8 mmol/l at screening 5. Severe Vitamin D deficiency (< 20 nmol/l) 6. 1st trimester of pregnancy
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Proportion of post-bariatric patients developing significant hypophosphatemia, defined as plasma phosphate levels < 0.8 mmol/l one week following the intravenous application of ferric carboxymaltose. Blood samples will be taken from an antecubital vein in a sitting position at Visit 0 (before administration of FCM) and at Visit 1 (one week after FCM). Blood tubes will be sent to central laboratory (ZLM, Cantonal Hospital St. Gallen) where plasma phosphate is measured by standard clinical methods. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Time to recovery from hypophosphatemia following parenteral therapy with FCM in post-bariatric patients, assessed by plasma phosphate levels from blood samples at V2-V5 2. Clinical symptoms associated with the development of hypophosphatemia following parenteral therapy with FCM in post-bariatric patients, assessed by a standardized interview and clinical exam at V0-V5 3. Risk factors leading to the development of hypophosphatemia following parenteral therapy with FCM in post-bariatric patients, assessed using baseline, demographic, clinical and laboratory parameters 4. Pathogenetic mechanisms associated with the development of hypophosphatemia, assessed using baseline demographic and clinical characteristics and parameters of phosphate homeostasis (serum intact and c-terminal FGF 23, PTH, 25 and 1,25 (OH)2 Vitamin D3) Blood and urine markers of phosphate homeostasis and a standardized interview and clinical exam will be assessed at Visits 0-5. There is a minimum of one follow up visit (V1) one week after the screening visit (V0) and a maximum of 5 follow up visits until 12 weeks after screening visit. If the patient develops hypophosphatemia, discovered at visit 1 (V1), there will be a further visit. Each further visit after V1 will only be held if hypophosphatemia occurs at the previous visit. Visit windows: visit 1 (V1, week 1) will occur within 7 ± 1 days after the screening visit, which is the visit when FCM is given intravenously. V2 will occur within 7 ± 2 days after V1. Visit 3 (V3, week 4) will occur within 14 ± 2 days after V2. From V3, visit 4 (V4, week 8) should occur within 4 weeks ± 3 days and from V4, visit 5 (V5, week 12) should again occur within 4 weeks ± 3 days. | — |
Countries
Switzerland
Outcome results
None listed