What is the recommended initial workup for a patient with diabetes?

Initial Diabetic Workup

All patients with newly diagnosed diabetes require immediate assessment of renal function (serum creatinine with eGFR), urinary albumin-to-creatinine ratio, lipid panel, A1C (if not already done for diagnosis), and comprehensive eye examination, with the timing of eye screening differing critically by diabetes type. 1

Essential Laboratory Testing at Initial Visit

Immediate Blood Work Required:

• A1C (if not obtained within past 3 months for diagnosis)
• Serum creatinine with eGFR calculation - establishes baseline kidney function and stages any chronic kidney disease 2
• Lipid profile (total cholesterol, LDL, HDL, triglycerides) - assesses cardiovascular risk 1
• Liver function tests - baseline assessment, particularly important before initiating certain medications 1
• Thyroid-stimulating hormone (TSH) - mandatory in type 1 diabetes due to increased autoimmune comorbidity risk; consider in type 2 diabetes 1
• Complete blood count with platelets 1
• Serum potassium - especially if hypertension present or anticipating ACE inhibitor/ARB therapy 1

Immediate Urine Testing Required:

• Spot urinary albumin-to-creatinine ratio - screens for diabetic nephropathy. This is the preferred method over 24-hour collections, which are more burdensome and add little accuracy 3

Critical caveat: Two of three specimens collected within 3-6 months should be abnormal before diagnosing microalbuminuria (30-299 μg/mg creatinine) or macroalbuminuria (≥300 μg/mg creatinine), as results can be affected by exercise within 24 hours, infection, fever, heart failure, marked hyperglycemia, or marked hypertension 3

Ophthalmologic Screening - Type-Specific Timing

Type 1 Diabetes:

• Initial dilated comprehensive eye examination within 5 years after diabetes onset by ophthalmologist or optometrist 4
• Generally not necessary before age 10 years, though prepubertal diabetes duration may be important for microvascular complications - use clinical judgment 5

Type 2 Diabetes:

• Initial dilated comprehensive eye examination immediately at diagnosis by ophthalmologist or optometrist 4
• This difference reflects that type 2 diabetes often exists undiagnosed for years before clinical recognition, meaning retinopathy may already be present

Subsequent screening: Annual examinations for both types. If no retinopathy for one or more exams and glycemia well-controlled, extend to every 1-2 years 4. More frequent if retinopathy progressing or sight-threatening.

Physical Examination Components

Cardiovascular Assessment:

• Blood pressure measurement (both arms initially)
• Orthostatic blood pressure if symptoms suggest autonomic neuropathy 1
• Height, weight, BMI calculation 1

Comprehensive Foot Examination:

Perform annually, but establish baseline at diagnosis 1:

• Visual inspection: skin integrity, callus formation, foot deformities, ulcers, toenail abnormalities
• Vascular assessment: palpate pedal pulses; if diminished, refer for ankle-brachial index
• Neurologic testing:
  • 10-gram monofilament examination (loss of protective sensation)
  • Vibration sensation (128-Hz tuning fork)
  • Temperature or pinprick sensation

Other Physical Findings:

• Thyroid palpation 1
• Skin examination: acanthosis nigricans (insulin resistance marker), insulin injection sites for lipodystrophy 1
• Fundoscopic examination (though formal dilated exam by specialist is required) 1

Additional Screening Considerations

Psychosocial Assessment:

• Screen for depression, anxiety, and disordered eating at initial visit 1
• These significantly impact diabetes self-management and outcomes

Cardiovascular Risk Stratification:

• Lipid panel interpretation: Guides statin therapy decisions independent of baseline values in many patients 6
• Blood pressure control: Target <140/90 mmHg generally, though individualize based on cardiovascular risk 2

Monitoring Schedule Based on eGFR:

The initial creatinine/eGFR determines subsequent monitoring frequency 2:

• eGFR ≥60: Yearly creatinine, urinary albumin, potassium
• eGFR 45-60: Monitor eGFR every 6 months; check electrolytes, bicarbonate, hemoglobin, calcium, phosphorus, PTH at least yearly; consider nephrology referral if nondiabetic kidney disease suspected
• eGFR 30-44: Monitor eGFR every 3 months; check electrolytes, bicarbonate, calcium, phosphorus, PTH, hemoglobin, albumin, weight every 3-6 months
• eGFR <30: Immediate nephrology referral

Common Pitfalls to Avoid

1. Delaying eye examination in type 2 diabetes - unlike type 1, these patients need immediate screening as they may have had undiagnosed diabetes for years
2. Using single urine albumin measurement - requires 2 of 3 abnormal specimens over 3-6 months to confirm albuminuria
3. Forgetting to check TSH in type 1 diabetes - autoimmune thyroid disease is common
4. Inadequate foot examination - must include monofilament testing, not just visual inspection
5. Measuring spot urine albumin without creatinine - albumin-to-creatinine ratio is the preferred method to account for urine concentration variability 3