Elevation of the renal enzyme N-acetyl-beta-glucosaminidase in affectively disordered patients

A minority of patients with affective disorders experience mild elevations of the renal enzyme N-acetyl-beta-glucosaminidase (NAG). Some affectively disordered patients also have reduced concentrating ability and reduced creatinine clearance. Thirty-one affectively disordered patients were compared to 17 healthy controls, to evaluate whether these various renal abnormalities are associated with one another and to further examine the proportion of affectively disordered patients experiencing NAG elevations. Twenty-nine percent of patients had an elevated NAG, whereas none of the controls did (P less than .005). There was a trend for an association between elevated NAGs and reduced creatinine clearance (P less than .08), but no association was found between concentrating ability and either elevated NAG or reduced creatinine clearance.