Alpha-hydroxybutyrate dehydrogenase (α-HBDH) is a blood enzyme activity reflecting certain lactate dehydrogenase (LDH) isoenzymes, especially those abundant in heart and red blood cells. Elevated α-HBDH levels can indicate myocardial injury, hemolysis, liver disease, or muscle damage. It was historically used in diagnosing heart attacks but has largely been supplanted by more specific markers such as troponin.

Hydroxybutyrate dehydrogenase catalyzes the reversible conversion between β-hydroxybutyrate and acetoacetate, using NAD+/NADH as a cofactor. It is central to ketone body metabolism—supporting ketogenesis in the liver and ketone use in peripheral tissues—providing energy during fasting or exercise and helping maintain cellular redox balance. Altered activity reflects shifts in energy metabolism.

HBDH (alpha‑hydroxybutyrate dehydrogenase) is a lab test measuring activity of LDH isoenzymes, mainly LDH‑1 and LDH‑2. It helps detect tissue injury—especially heart muscle damage—but can also rise with hemolysis, liver disease, muscle disorders, or other causes of cell breakdown. Results must be interpreted in clinical context and alongside other cardiac tests.

Yes. D-β-hydroxybutyrate dehydrogenase (BDH1) is highly expressed in liver mitochondria and catalyzes the reversible conversion between β-hydroxybutyrate and acetoacetate during ketone-body metabolism. It’s essential for hepatic ketone production and utilization. A related cytosolic isoform (BDH2) exists, but BDH1 is the primary mitochondrial enzyme in hepatocytes.

Alpha‑keto acid dehydrogenase catalyzes oxidative decarboxylation of alpha‑keto acids, converting them into acyl‑CoA derivatives (for example pyruvate to acetyl‑CoA). This reaction produces NADH and CO2, linking glycolysis and amino‑acid catabolism to the citric acid cycle for ATP production. The multienzyme complex requires cofactors such as thiamine pyrophosphate, lipoamide, FAD, NAD+ and CoA.

The common abbreviation for beta‑hydroxybutyrate dehydrogenase is BDH (often BDH1 for the human mitochondrial enzyme). It is also referred to as D‑beta‑hydroxybutyrate dehydrogenase or β‑HBDH in some texts. BDH catalyzes the reversible conversion of beta‑hydroxybutyrate to acetoacetate in ketone‑body metabolism (EC 1.1.1.30).