What metabolic panel workup should be ordered for an adult patient to assess overall metabolic status?

Metabolic Panel Workup for Adults

For a comprehensive assessment of metabolic status in adults, order a comprehensive metabolic panel (CMP) that includes electrolytes (sodium, potassium, chloride, bicarbonate), kidney function markers (creatinine with eGFR, blood urea nitrogen), liver enzymes (ALT, AST, alkaline phosphatase, total bilirubin), glucose, calcium, total protein, and albumin, along with a complete blood count, fasting lipid profile, hemoglobin A1c, TSH, and urinalysis. 1, 2, 3

Core Laboratory Components

Comprehensive Metabolic Panel (CMP)

The CMP provides essential information about multiple organ systems simultaneously and should include:

• Electrolytes: Sodium, potassium, chloride, and bicarbonate to assess fluid balance, acid-base status, and renal function 1, 3
• Kidney function: Serum creatinine with calculated eGFR and blood urea nitrogen (BUN) are essential for detecting chronic kidney disease and assessing renal function 1, 2, 3
• Liver function: ALT, AST, alkaline phosphatase, total bilirubin, total protein, and albumin to screen for hepatic disease and assess synthetic function 2, 3
• Glucose: Fasting plasma glucose to screen for diabetes and prediabetes 4, 2, 3
• Calcium: Serum calcium for metabolic and parathyroid assessment 1

Additional Essential Tests

• Complete Blood Count (CBC): Provides baseline hematologic assessment and screens for anemia, infection, and hematologic disorders 4, 1, 3
• Hemoglobin A1c: Superior to fasting glucose alone for diabetes screening; values ≥6.5% define diabetes, 5.7-6.4% define prediabetes 4, 2, 3
• Fasting Lipid Profile: Must include total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and calculated non-HDL-cholesterol for cardiovascular risk assessment 4, 1, 2, 3
• Thyroid-Stimulating Hormone (TSH): Universal screening is recommended due to high prevalence of thyroid dysfunction, particularly in patients with obesity or metabolic concerns 2, 3
• Urinalysis: Essential for detecting proteinuria/microalbuminuria (critical marker of kidney damage), hematuria, and other renal abnormalities 1, 3

Risk-Stratified Screening Approach

For Patients with Diabetes Risk Factors

Screen all adults aged 35 years and older every 3 years if initial results are normal 4, 3. Screen earlier and more frequently if the patient has:

• BMI ≥25 kg/m² (≥23 kg/m² in Asian Americans) with additional risk factors including first-degree relative with diabetes, high-risk ethnicity, hypertension (≥140/90 mmHg), HDL <35 mg/dL or triglycerides >250 mg/dL, physical inactivity, history of cardiovascular disease, polycystic ovary syndrome, or conditions associated with insulin resistance 4
• Prediabetes (A1C 5.7-6.4%, fasting glucose 100-125 mg/dL, or 2-hour glucose 140-199 mg/dL): Requires annual testing 4
• History of gestational diabetes: Lifelong testing at least every 3 years 4

For Patients with Metabolic Syndrome Features

When three or more of the following are present, diagnose metabolic syndrome and intensify monitoring 4, 2:

• Waist circumference ≥88 cm (women) or ≥102 cm (men)
• Triglycerides ≥150 mg/dL
• HDL-cholesterol <40 mg/dL (men) or <50 mg/dL (women)
• Blood pressure ≥130/85 mmHg
• Fasting glucose ≥100 mg/dL

For Patients with Liver Disease Risk

Add liver-specific assessment when risk factors are present:

• Liver function tests are essential for screening non-alcoholic fatty liver disease (NAFLD), which is strongly associated with metabolic syndrome 1, 2
• Fibrosis-4 (FIB-4) index should be calculated when liver enzymes are abnormal to estimate hepatic fibrosis risk 2
• Consider abdominal ultrasound as the primary screening modality for NAFLD when clinical suspicion is high 1

Critical Interpretation Points

"Know Your Numbers" Targets

Communicate these goals to patients in plain language 4:

• Blood pressure: Target <120/80 mmHg (normal); >140/90 mmHg is risky 4
• Fasting glucose: 70-100 mg/dL is normal; <70 or >140 mg/dL requires intervention 4
• A1c: <5.7% is normal; >6.5% defines diabetes 4
• LDL-cholesterol: <100 mg/dL for most patients; lower targets (<70 or <55 mg/dL) for high cardiovascular risk 4
• eGFR: >90 mL/min is normal; <60 mL/min indicates chronic kidney disease 4, 1
• Urine albumin-creatinine ratio (UACR): <30 mg/g is normal; >300 mg/g indicates significant kidney damage 4, 1

Common Pitfalls to Avoid

• Do not order non-fasting lipid panels when accurate cardiovascular risk assessment is needed; fasting values are required for proper interpretation 3
• Do not use point-of-care A1c devices for diagnosis without quality assurance participation; only laboratory-based NGSP-certified methods should be used 3
• Do not measure blood pressure incorrectly; improper technique leads to over-diagnosis and over-treatment of hypertension 3
• Do not overlook corrected sodium in hyperglycemic patients; add 1.6 mEq/L to measured sodium for each 100 mg/dL glucose elevation 4
• Do not rely solely on nitroprusside ketone testing in diabetic ketoacidosis; it does not measure β-hydroxybutyrate, the predominant ketone body 4

Frequency of Monitoring

• Normal results: Repeat screening every 3 years minimum, with more frequent testing based on risk factors 4, 3
• Prediabetes or metabolic syndrome: Annual comprehensive reassessment 4
• Established diabetes or chronic kidney disease: Every 3-6 months or as clinically indicated 4
• Lipid abnormalities with treatment: Repeat every 6-12 months 3