Elevation of cerebrospinal fluid lactate with aging in subjects with normal blood oxygen saturations

It has been hypothesized that cerebral oxidative glucose metabolism may become impaired with age and lead to deterioration of neuronal function. One marker of impaired cerebral oxidative glucose metabolism is increased cerebrospinal fluid (CSF) lactate. Prior studies have found an increase in CSF lactate in aged normals, but these studies have not controlled for the possibility that decreased respiratory function with age may lead to hypoxemia and increased CSF lactate. The current study measured peripheral blood oxygen saturations in 11 subjects during collection of CSF and documented that the increase in CSF lactate observed was not due to peripheral hypoxemia. Thus, increased CSF lactate with age appears to be of central origin.