Aging Effect on Laboratory Values |
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Organ function declines with age and is correlated with changes in laboratory values. Understanding the effect of age on laboratory values can increase diagnostic accuracy. If age related changes are not recognized, clinically significant changes in lab results may be incorrectly attributed to age alone and changes that are normal with aging may be misinterpreted as signs of disease. The following bullet points and table summarize age related changes.
- Alkaline phosphatase increases by 20% between the third & eighth decade.
- ANA & rheumatoid factor are present in 20 - 30% of seniors in low titers & shouldn't be overinterpreted.
- Cholesterol increases by 30-40 mg/dL by age 60.
- Creatinine clearance decreases by 10 mL/min/1.73 m2 per decade. Serum creatinine may not change noticeably due to decreasing muscle mass.
- Gastrin levels increase secondary to hypochlorhydria.
- HDL cholesterol decreases by 30% in postmenopausal women.
- Hemoglobin & hematocrit decrease slightly if at all, so low levels should not be attributed to aging.
- Magnesium decreases by 15%
- PSA levels up to 6.5 ng/mL may be normal in men over the age of 70.
- PaO2 decreases by 25% between the third & eighth decade.
- Postprandial glucose increases 30-40 mg/dL per decade after age 40. Fasting glucose changes minimally.
- Sed Rate up to 40 may be normal in seniors.
- Free testosterone decreases in men with age, but total testosterone may be normal.
Increased |
Decreased |
Alkaline p'tase |
Aldosterone |
ANA |
Calcium, total |
Cholesterol |
Cholesterol, HDL |
Copper |
Creatine kinase |
Ferritin |
Creatinine clearance |
Fibrinogen |
Dihydroepiandrosterone |
Gastrin |
1,25-dihydroxyvitamin D |
Glucose, 2 h pp |
Estradiol |
Interleukin 6 |
Growth hormone |
PTH |
IGF-1 |
PSA |
Interleukin 1 |
Rheumatoid factor |
Magnesium |
Sed rate |
PaO2 |
Triglycerides |
Phosphorus |
Uric acid |
Testosterone, free |
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