What is a comprehensive metabolic workup?

Comprehensive Metabolic Workup

A comprehensive metabolic workup consists of laboratory tests, imaging studies, and specialized assessments to evaluate metabolic function, with essential components including a complete blood count, comprehensive metabolic panel, lipid profile, thyroid function tests, and appropriate imaging based on suspected conditions.

Core Laboratory Components

Essential Blood Tests

• Complete Blood Count (CBC) - Evaluates blood cell counts and identifies potential anemias or infections 1
• Comprehensive Metabolic Panel (CMP) - Includes:
  • Glucose levels (fasting and/or HbA1c)
  • Kidney function (creatinine, BUN, eGFR)
  • Electrolytes (sodium, potassium, chloride, calcium)
  • Liver function tests (ALT, AST, alkaline phosphatase, bilirubin)
  • Protein levels (albumin, total protein) 2
• Lipid Profile - Total cholesterol, LDL, HDL, and triglycerides 2
• Thyroid Function Tests - TSH, particularly in patients with type 1 diabetes 2

Additional Laboratory Tests

• Urinalysis with albumin-to-creatinine ratio - To assess kidney function and protein excretion 2
• Serum uric acid - Often elevated in metabolic disorders 2
• Vitamin B12 levels - Especially for patients on metformin 2
• Hepatitis B and C testing - For high-risk patients and those with suspected liver disease 2
• Fasting insulin levels - To calculate HOMA-IR (insulin resistance) when indicated 2

Specialized Testing Based on Clinical Presentation

For Suspected Diabetes/Prediabetes

• Oral Glucose Tolerance Test (OGTT) - 75g standardized test for patients with increased diabetes risk 2
• HbA1c - For diagnosis and monitoring of diabetes 2

For Suspected Liver Disease

• Extended liver function tests - Including GGT and coagulation profile 1
• Viral hepatitis panel - Including HBsAg, hepatitis B surface antibody, hepatitis B core antibody 1
• Ferritin and transferrin saturation - To assess for hemochromatosis 2
• Tests for autoimmune liver disease - When clinically indicated 2

For Suspected Metabolic Bone Disease

• Calcium, vitamin D, and phosphorous levels - For appropriate patients 2
• Bone density testing - For patients with risk factors 2

Imaging Studies

First-Line Imaging

• Abdominal Ultrasound - Non-invasive assessment of:
  • Liver size, texture, and potential fatty infiltration
  • Gallbladder and biliary tract evaluation
  • Pancreatic assessment
  • Spleen size measurement 2, 1

Advanced Imaging (When Indicated)

• CT scan or MRI - For further evaluation of abnormalities detected on ultrasound 2
• Transient elastography (FibroScan) - To assess liver stiffness/fibrosis 2

Specialized Assessments

Cardiovascular Assessment

• Blood pressure measurement - Essential for all patients 2
• ECG or echocardiogram - For patients with cardiovascular risk factors 2

Sleep Evaluation

• Screening for obstructive sleep apnea - Using validated tools like the STOP-BANG questionnaire 2

Clinical Evaluation Components

Anthropometric Measurements

• Height, weight, and BMI calculation 2
• Waist circumference - To assess central obesity 2
• Waist-to-hip ratio - For additional assessment of fat distribution 2

Physical Examination Focus

• Skin examination - Look for acanthosis nigricans (insulin resistance), xanthomas (lipid disorders) 2
• Thyroid palpation 2
• Comprehensive foot examination - For patients with diabetes 2
• Blood pressure assessment - Including orthostatic measurements when indicated 2

Common Pitfalls to Avoid

1. Overlooking non-alcoholic fatty liver disease (NAFLD) - A common metabolic comorbidity that requires specific evaluation 2
2. Missing diabetes in patients with NAFLD - Screening for diabetes is mandatory in these patients 2
3. Failing to assess cardiovascular risk - Metabolic disorders significantly increase cardiovascular risk 2
4. Incomplete hepatitis screening - Particularly important before starting certain medications 2
5. Not considering rare metabolic disorders - When clinical presentation suggests possibility 2

Follow-Up Recommendations

• Regular monitoring of blood counts every 6-12 months 1
• Repeat imaging studies based on initial findings and clinical course 1
• Adjust frequency of follow-up based on severity of metabolic abnormalities 2

A comprehensive metabolic workup should be tailored to the specific clinical scenario but always include these core components to ensure thorough evaluation of metabolic health and identification of potential complications.