After discharge from the bariatric surgery service, the patient should have an annual review with their GP.

At their annual review, GPs should check:

  • Weight
  • Blood results
  • Compliance with micronutrient supplements
  • Maintenance of lifestyle changes

Blood tests

These blood tests are recommended to be done as a minimum set. If stores are depleted and a patient is on treatment, check more frequently.

  • Full blood count
  • Complete iron profile including serum iron, TIBC, transferrin, ferritin (ferritin level can be normal/high due to acute phase response, normal ferritin level does not exclude depleted iron stores)
  • Serum folate (not red cell folate)
  • Vitamin B12, holotranscobalamin (active vitamin B12), methyl malonic acid (a functional marker of cellular vitamin B12 deficiency). Holotranscobalamin and MMA are more sensitive and specific markers of vitamin B12 deficiency, as a severely deficient patient can have normal levels of serum vitamin B12. (In absence of availability of active vitamin B12 and MMA, please ensure to maintain the serum vitamin B12 in the upper-normal reference range. You can ask your clinical biochemistry lab to send the sample to the Homerton Hospital lab as a specialist send away test if clinically indicated).
  • Bone profile including calcium, phosphate and magnesium.
  • Vitamin D and parathyroid hormone (PTH). Elevated PTH suggests secondary hyperparathyroidism due to vitamin D deficiency on a cellular level.
  • U&Es
  • Liver function tests
  • Preoperative diabetes  - HbA1c and/or FBG
  • Preoperative  dyslipidaemia - Lipid profiles
  • Known thyroid disorders - Thyroid function test

It must not be assumed that abnormal bloods results are always directly related to the surgery itself. There could be potential contributions from physiological and pathological changes in the body, including comorbidities worsened by ageing. High-risk patients might require more frequent monitoring e.g. pregnancy, lactation, acute illness etc.