From the Guidelines
Annual laboratory tests for bariatric surgery patients should include a comprehensive metabolic panel, complete blood count, lipid panel, hemoglobin A1C, vitamin B12, folate, iron studies (including ferritin, iron, TIBC), vitamin D, parathyroid hormone, and calcium levels. These tests are essential to monitor for nutritional deficiencies that commonly occur after bariatric procedures due to reduced nutrient absorption and decreased food intake, as recommended by the British Obesity and Metabolic Surgery Society guidelines 1. Patients who have undergone malabsorptive procedures like gastric bypass or duodenal switch require more vigilant monitoring than those with restrictive procedures like sleeve gastrectomy.
Key Laboratory Tests
- Comprehensive metabolic panel
- Complete blood count
- Lipid panel
- Hemoglobin A1C
- Vitamin B12
- Folate
- Iron studies (including ferritin, iron, TIBC)
- Vitamin D
- Parathyroid hormone
- Calcium levels According to the guidelines, checking full blood count including haemoglobin, ferritin, folate and vitamin B12 levels is recommended with a Grade B EL 2 (1+ to 4) evidence level 1. Additionally, checking serum 25-hydroxyvitamin D levels and serum/plasma parathyroid hormone levels is also recommended with a Grade B EL 2 (2++ to 3) evidence level 1.
Monitoring Frequency
The frequency of laboratory monitoring may decrease after the first few years if nutritional status remains stable, but lifelong monitoring is recommended 1. The postoperative follow-up should include a multidisciplinary medical team, and the follow-ups should include a surgeon, bariatric dietitian, psychologist or social worker, and family physician or endocrinologist 1. Vitamin and mineral status should be assessed every 3 mo in the first postoperative year, every 6 mo in the second year, and then annually 1.
From the Research
Bariatric Annual Labs
To check for various health conditions after bariatric surgery, the following annual labs are recommended:
- Complete Blood Count (CBC) to assess cardiovascular and metabolic diseases, including:
- White blood cell (WBC) count
- Neutrophil-to-lymphocyte ratio (NLR)
- Hemoglobin (Hb) level
- Mean corpuscular volume (MCV)
- Red cell distribution width (RDW)
- Platelet count
- Mean platelet volume (MPV)
- Platelet-to-lymphocyte ratio (PLR) 2
- Other tests may be recommended based on individual patient needs and medical history
Limitations of Current Evidence
There is limited direct evidence on the specific annual labs required for bariatric patients. However, studies suggest that CBC components can be useful markers to predict cardiovascular disease and metabolic diseases 2. Other studies are not directly relevant to this question, focusing on topics such as enzyme isolation and cancer therapy 3, 4