Organ Function Markers

Alanine aminotransferase: enzyme that leaks out of damaged liver cells. Elevated with fatty liver (NAFLD), hepatitis, alcohol use or medication use. Often the first signal of liver damage.

Aspartate aminotransferase: also present in muscle and heart. Together with ALAT more specific for liver damage. Elevated ASAT/ALAT ratio (> 2) is characteristic of alcoholic liver disease.

Gamma-glutamyltransferase: sensitive indicator for alcohol use, biliary abnormalities and medication use. Isolated elevated GGT with otherwise normal liver tests often indicates alcohol or medication.

Estimated glomerular filtration rate: measures how well the kidneys filter waste products. Calculated from creatinine, age and sex. Decreased eGFR is the earliest sign of kidney insufficiency.

Breakdown product of muscle metabolism, filtered by the kidneys. Elevated creatinine indicates reduced kidney function. Influenced by muscle mass — that is why eGFR (corrected for this) is the better marker.

Protein produced by the prostate. Elevated PSA may indicate prostate cancer, benign enlargement (BPH) or prostatitis. Screening from age 45–50 in men with elevated risk.