Serum Schiff bases are elevated in patients with dementia

Hypothesis: Increased oxidative stress may accompany diseases of the centra l nervous system either as a perpetrator or merely as the result of tissue damage in the course of neurodegeneration. The brain is especially suscepti ble to damage mediated by reactive oxygen species because it has a high rat e of oxygen consumption and contains large amounts of readily oxidizable su bstrates, such as polyunsaturated fatty acids. Indices of systemic oxidativ e stress, including serum lipid-peroxidation products, may be greater in de mentia than in normal aging. Methods: Study groups consisted of 30 patients with dementia and 18 healthy age-matched controls. All patients underwent neuropsychological testing an d qualified for the study on the basis of history, physical examination, co mplementary laboratory tests, and brain computed tomography scan. Serum lev els were assessed for the following lipid-peroxidation products: conjugated dienes, lipid peroxides, thiobarbituric acid reactive substances, and Schi ff bases. Results: There were two statistically significant differences in serum leve ls of lipid-peroxidation products between the study groups. Lipid peroxides were significantly lower (0.34 Angstrom 0.96 U532/mL versus 1.12 Angstrom 0.96 U532/mL, p = 0.000055), while Schiff bases were statistically higher ( 589.4 Angstrom 267.3 AU/mL versus 329.0 Angstrom 107.5 AU/mL, p = 0.000282) in the subject with dementia. There were statistically significant correla tions between all measured products of lipid peroxidation in the controls a nd between all products of lipid peroxidation except for Schiff bases in th e subjects with dementia. Cognitive impairment did not correlate with level s of lipid-peroxidation products. Age correlated negatively with Mini-Menta l State Examination score and lipid peroxides in healthy controls. Conclusion: More final fluorescent products of lipid peroxidation (Schiff b ases) were found in subjects with dementia than in healthy controls, implyi ng that oxidative stress is increased in dementia. Our data suggests a decr ease in lipid peroxides during normal aging.