Paraoxonase 1 activity: a new vascular marker of dementia?
Paraoxonase 1 (PON1), an A-esterase with peroxidase-like activity present on the surface of HDL, decreases the peroxidation of LDL. Serum PON1 activity (PON1a) decreases with aging and in disorders associated with a high risk of adverse cardiovascular events (acute myocardial infarction, diabetes mellitus, and chronic renal failure). The implication of vascular factors in Alzheimer-type dementia (ATD) is strongly suspected. We measured PON1a by spectrophotometry using the paraoxon substrate in 180 healthy subjects (controls; mean age: 75.3 +/- 8.9 years; 98 women) and 154 patients admitted for cognitive testing. According to criteria, 45 patients had mild cognitive impairments (MCI; mean age: 75.6 +/- 9.3 years; 28 women), 60 had ATD (mean age: 75.6 +/- 8.3 years; 47 women), and 49 had vascular dementia (VaD; mean age: 77.5 +/- 7.2 years; 33 women). Mean PON1a was lower in VaD (0.25 +/- 0.1 U/mL) than in controls or ATD (both 0.41 +/- 0.2 U/mL, p < 0.01). Mean PON1a values in MCI (0.34 +/- 0.2 U/mL) and ATD (0.41 +/- 0.2 U/mL) were not significantly different. In multiple linear regression, PON1a was negatively correlated with male sex, age, and VaD, and positively correlated with ATD (each correlation p < 0.001). As shown in other high-risk cardiovascular disorders, PON1a seems to be a reliable marker of VaD. Its modification in Alzheimer's disease supports the implication of vascular risk factors in this type of dementia.
Dantoine
Thierry F
TF
Département de Gérontologie Clinique, Centre Hospitalier Universitaire, 2 Avenue Martin Luther King, 87042 Limoges Cedex, France. tdantoine@wanadoo.fr
Debord
Jean
J
Merle
Louis
L
Lacroix-Ramiandrisoa
Hanta
H
Bourzeix
Laurence
L
Charmes
Jean-Pierre
JP
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis*; D043303:Aryldialkylphosphatase; D015415:Biomarkers / Q000032:analysis; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis*; D015140:Dementia, Vascular / Q000175:diagnosis*; D003937:Diagnosis, Differential; D004950:Esterases / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values
D015415:Biomarkers; D004950:Esterases; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human