Mitochondrial fatty acid beta-oxidation enzyme that catalyzes the third step of the beta-oxidation cycle for medium and short-chain 3-hydroxy fatty acyl-CoAs (C4 to C10) (PubMed:10231530, PubMed:11489939, PubMed:16725361). Plays a role in the control of insulin secretion by inhibiting the activation of glutamate dehydrogenase 1 (GLUD1), an enzyme that has an important role in regulating amino acid-induced insulin secretion (By similarity). a (3S)-3-hydroxyacyl-CoA + NAD(+) = a 3-oxoacyl-CoA + H(+) + NADH (3S)-3-hydroxybutanoyl-CoA + NAD(+) = acetoacetyl-CoA + H(+) + NADH (3S)-hydroxydecanoyl-CoA + NAD(+) = 3-oxodecanoyl-CoA + H(+) + NADH (3S)-hydroxyhexadecanoyl-CoA + NAD(+) = 3-oxohexadecanoyl-CoA + H(+) + NADH Optimum at neutral pH. Lipid metabolism; fatty acid beta-oxidation. Homodimer (PubMed:10231530, PubMed:10840044, PubMed:16725361). Interacts with GLUD1; this interaction inhibits the activation of glutamate dehydrogenase 1 (GLUD1) (By similarity). Expressed in liver, kidney, pancreas, heart and skeletal muscle. Succinylation at Lys-81, adjacent to a coenzyme A binding site. Desuccinylated by SIRT5. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the 3-hydroxyacyl-CoA dehydrogenase family.