What basic laboratory tests should be ordered annually for an elderly patient (≥65 years) to screen for common age‑related metabolic and organ‑function abnormalities?

Annual Laboratory Screening for Elderly Patients (≥65 Years)

For elderly patients aged 65 and older, annual screening should include: fasting glucose or A1C for diabetes, lipid profile, serum creatinine with eGFR calculation, urinalysis with albumin-to-creatinine ratio, complete blood count, and thyroid-stimulating hormone (TSH), with blood pressure measured at every visit. 1, 2

Core Metabolic Screening

Diabetes Screening

• Screen all adults aged 35 and older annually with fasting plasma glucose, 2-hour oral glucose tolerance test, or A1C, regardless of risk factors 1
• For patients with diagnosed diabetes, measure A1C at least twice yearly if meeting treatment goals, or quarterly if therapy has changed or goals are not met 1, 3
• Postprandial glucose values may be elevated up to 10 mg/dL per decade of age in healthy elderly individuals, which should be considered when interpreting results 4

Lipid Profile

• Obtain a fasting or non-fasting lipid profile annually in elderly patients, or every 1-2 years if lipid values are normal and no cardiovascular risk factors are present 2
• The lipid panel should include total cholesterol, HDL cholesterol, triglycerides, and calculated or measured LDL cholesterol 2
• More frequent testing (every 1-2 years) is warranted when lipid levels are near treatment thresholds or when two or more cardiac risk factors are present 2

Renal Function Assessment

Kidney Disease Screening

• Measure serum creatinine with eGFR calculation annually in all elderly patients 1, 3
• Obtain urine albumin-to-creatinine ratio annually, particularly in patients with diabetes or hypertension 1, 3
• Critical caveat: Serum creatinine may remain normal despite markedly decreased creatinine clearance in elderly patients due to reduced muscle mass 4, 5
• BUN values up to 28-35 mg/dL may be acceptable in healthy elderly individuals 4

Hematologic Screening

Complete Blood Count

• Screen for anemia with hemoglobin measurement, as anemia is not a normal part of aging 4, 5, 6
• The lowest acceptable hemoglobin level is 11.0 g/dL in women and 11.5 g/dL in men 4
• Erythrocyte sedimentation rate (ESR) up to 40 mm/hr may be acceptable in healthy elderly individuals 4

Additional Organ-Specific Screening

Thyroid Function

• Measure TSH at baseline and consider repeat testing every 1-2 years, particularly in patients with symptoms or risk factors 7

Liver Function

• Serum alkaline phosphatase may be elevated up to 2.5 times normal in healthy elderly individuals 4, 5
• Decreased serum albumin typically indicates chronic malnutrition rather than normal aging and warrants further evaluation 5

Electrolytes and Minerals

• Serum calcium and phosphorus should be measured, as small percentages of elderly patients show abnormalities 5
• Serum phosphorus may decrease with aging 5

Blood Pressure Monitoring

• Measure blood pressure at every clinical visit 1, 3
• Target blood pressure is <120/80 mmHg for adults aged 13 and older, or <90th percentile for age, sex, and height 7

Age-Related Considerations for Geriatric Patients

Cognitive Screening

• The American Geriatrics Society recommends annual screening for cognitive impairment in adults aged 65 and older 1

Individualized Glycemic Targets

• For geriatric patients with diabetes, A1C targets should be individualized: <7.5% for healthy older adults, and 8.0-8.5% for those with multiple chronic illnesses or functional dependence 1

Common Pitfalls to Avoid

• Do not assume abnormal laboratory values are due to aging alone—most laboratory values in healthy elderly individuals fall within normal ranges, and significantly abnormal results should raise suspicion of underlying disease 4, 5
• Do not overlook pre-analytical factors such as medication effects, multiple comorbidities, and specimen collection issues, which are particularly problematic in elderly patients 8
• Do not rely solely on serum creatinine to assess renal function, as it may be falsely reassuring due to decreased muscle mass in the elderly 4, 5
• Do not dismiss anemia as normal aging—it warrants investigation for underlying causes 5, 6
• Confirm abnormal results with repeat testing on a separate occasion before making treatment decisions 2