HBDH (α‑hydroxybutyrate dehydrogenase) is a blood enzyme test that mainly reflects LDH‑1 and LDH‑2 activity. It’s concentrated in heart muscle and red blood cells, so raised levels can indicate myocardial injury, hemolysis, liver or muscle disease. HBDH is interpreted alongside clinical findings and other tests (troponins, total LDH) to determine the cause of elevation.

Hydroxybutyrate dehydrogenase catalyzes the reversible conversion between beta-hydroxybutyrate and acetoacetate using NAD+/NADH as cofactor. It facilitates ketone-body interconversion for energy production during fasting, prolonged exercise, or low-carbohydrate states, and helps maintain cellular redox balance in liver and peripheral tissues (heart, brain, muscle). The enzyme is central to ketone utilization and metabolic flexibility.

Alpha-hydroxybutyrate dehydrogenase (α-HBDH) is an enzyme activity that catalyzes conversion of α-hydroxybutyrate to α-ketobutyrate; its measurement largely reflects LDH isoenzymes abundant in heart and red blood cells. Serum α-HBDH rises with myocardial injury, hemolysis, liver or muscle damage, and some cancers. It’s used as a biomarker of tissue injury but interpreted alongside clinical findings and other lab tests.

Yes. The liver contains mitochondrial D-β-hydroxybutyrate dehydrogenase (BDH1), which catalyzes the reversible conversion between acetoacetate and D-β-hydroxybutyrate. It’s predominantly localized to hepatocyte mitochondria and plays a key role in ketone body metabolism during fasting, starvation, or low-carbohydrate states. BDH1 is also expressed in heart, kidney and brain for ketone utilization.

Lactate dehydrogenase (LDH) is an enzyme found in many tissues; its blood level reflects cell damage or breakdown. Elevated LDH can indicate heart attack, liver disease, hemolysis, muscle injury, severe infection, or certain cancers. It’s a non‑specific marker used alongside other tests to help diagnose, gauge severity, and monitor disease progression or response to treatment.

Creatine kinase (CK) test measures levels of the CK enzyme released into blood when muscle cells are damaged. It helps detect and monitor muscle injury from heart attack, myocarditis, rhabdomyolysis, myositis, muscular dystrophy, intense exercise or medication-related muscle damage. Isoenzyme patterns (CK-MB, CK-MM, CK-BB) can indicate whether damage is primarily cardiac, skeletal or brain-related, aiding diagnosis and treatment decisions.