Common Abnormalities of Cerebral Glucose Utilizations in Patients with Bipolar disorders and Their Unaffected Siblings

Objectives Cerebral glucose utilizations (GU) are critical for brain function, Brain glucose-utilizing abnormalities are implicated in the pathophysiology of bipolar disorder (BD). BD is highly heritable and mitochondrial abnormalities are involved in the development of BD. Since BD and unaffected siblings share identical mitochondrial genes, we hypothesized that certain brain GU abnormalities might present both in BD and their unaffected siblings and such abnormalities might serve as an endophenotype.

Methods Twenty-seven pairs of BD and their matching BDs (BD pairs), and 30 healthy control (HC) were recruited for GU by FDG PET.

Results BD pairs demonstrated abnormally lower dorso-prefrontal-GU and higher cerebellar-GU, but only BD had lower medio-prefrontal-GU. BD pairs presented abnormally negative correlations between insulin and prefrontal-GU, but only BD demonstrated a loss of normally positive correlations between insulin and cerebellar-GU.

Conclusions Decreased dorso-prefrontal GU and increased cerebellar GU were commonly found in BD families and might serve as an endophenotype for BD. Insufficient mitochondria-related energy utilizations with compensatory glucose up-regulation may underlie the abnormalities.