Laboratory Testing for Obese 17-Year-Old in Primary Care
For an obese 17-year-old presenting to primary care, obtain a comprehensive metabolic panel, fasting lipid profile, thyroid function tests (TSH), and hemoglobin A1C as the core laboratory evaluation. 1, 2
Core Laboratory Panel
The basic laboratory workup should include:
Comprehensive metabolic panel (CMP): Screens for glucose abnormalities, liver dysfunction (particularly non-alcoholic fatty liver disease), kidney function, and electrolyte disturbances associated with obesity 1, 2
Fasting lipid profile: Evaluates for dyslipidemia including elevated triglycerides, low HDL cholesterol, and elevated LDL cholesterol, which are common obesity-related complications 1, 2
Thyroid-stimulating hormone (TSH): Screens for hypothyroidism as a secondary cause of obesity and rules out thyroid dysfunction contributing to weight gain 1, 2
Hemoglobin A1C: Particularly important for screening abnormal glucose metabolism and prediabetes/type 2 diabetes, which are increasingly common in obese adolescents 1, 2
Rationale for This Approach
This laboratory panel directly targets the most clinically significant obesity-related comorbidities that affect morbidity and mortality in adolescents 1. The comprehensive metabolic panel identifies metabolic syndrome components, while the lipid profile and A1C specifically screen for cardiovascular risk factors and diabetes—the two leading causes of obesity-related mortality 1.
The physical examination should specifically assess for acanthosis nigricans (insulin resistance marker), hirsutism (polycystic ovarian syndrome), large neck circumference (obstructive sleep apnea risk), and measure waist circumference in addition to BMI. 1
Additional Considerations
While the above represents the essential screening panel, consider additional testing based on clinical findings:
Liver function tests (ALT/AST): If there are clinical signs suggesting non-alcoholic fatty liver disease, though these are already included in the CMP 1, 2
Complete blood count: Only if specific clinical indicators suggest anemia or other hematologic abnormalities 2
Common Pitfall to Avoid
Do not rely solely on BMI for risk stratification—waist circumference provides critical additional information about central adiposity and cardiovascular risk that BMI alone cannot capture 1. Central obesity is an independent mortality risk factor even when BMI appears only moderately elevated 1.