性别因素对老年期神经系统变性过程的影响

目的：研究探讨正常人进入老年期后，性别和年龄对事件相关电位的交互作用影响是否仍然持续。方法：应用神经心理学测试和MRI检查筛选日本冲绳县年龄在60岁以上的正常老年人40名。其中男性17名，平均年龄是72．2±8．6岁；女性23名，平均年龄是75．7±8．2岁。应用听觉“oddball”范式诱发事件相关电位P300。分析Fz和Pz部位记录到的事件相关电位内源性成分P300和N2b。结果：P300潜伏期、P300波幅和N2b潜伏期的组间差异不显著。于Fz部位，男性组的N2b波幅低于女性组（F=4．59，P=0．039）。P300潜伏期和P300波幅与年龄的相关性，仅见于男性组（Fz-P300潜伏期：r=0．584，P=0．014；Fz-P300波幅：r=-0．782，P〈0．001；Pz—P300潜伏期：r=0．587，P=0．013；Pz—P300波幅：r=-0．657，P=0．004）。P300潜伏期和P300波幅对年龄的线性回归坡度，在两组闾均有显著性差异，在男性组更为陡峭（Fz—P300潜伏期：t=2．11，P=0．042；Fz-P300波幅：t=2．55，P=0．015；Pz-P300潜伏期：t：2．70，P=0．011：Pz-P300波幅：t=3．00，P=0．005）。结论：性别因素对老年期神经系统变性过程有显著影响。

THE INFLUENCE OF SEXUAL FACTOR IN THE NEURODEGENERATIVE PROCESS OF AGED POPULATION

Objective： The P300 component of event-related potentials （ERPs） is an electro- physiological index reflecting the neurodegenerative process Previous studies revealed sex effects on the relationship P300 and age among normal population. However, whether these effects exist in the aged population remains unclear, which was investigated in the present study. Methods： Fronty aged subjects were recruited in Okinawa, Japan, using both neuropsychological tests and MRI routine examination. The mean age of 17 males was 72.2 ± 8.6 years, and the mean age of 23 females was 75.7 ±8.2 years. Auditory ERPs were elicited using an oddball paradigm. Both P300 and N2b components of ERPs were analyzed using data from Fz and Pz. Results： No group difference was found for P300 latency, P300 amplitude and N2b latency. N2b amplitude at Fz was lower in the aged males than in the aged females （ F = 4. 59, P = 0. 039） . P300 latency and P300 amplitude correlated with age only in the aged males （ Fz-P300 latency ： r =0. 584, P=0. 014 ： Fz -P300 amplitude ： r = - 0. 782, P 〈0. 001 ; Pz-P300 latency ： r = 0. 587, P = 0. 013 ; Pz-P300 amplitude： r = - 0. 657, P = 0. 004） but not in the aged females. The linear regression slopes for P300 latency with age and for P300 amplitude with age were significantly steeper in the aged males than in the aged females （Fz-P300latency： t=2.11, P=0.042; Fz-P300amplitude： t=2.55, P=0.015; Pz-P300latency： t=2.70, P =0. 011 ; Pz-P300 amplitude： t =3.00, P =0. 005） . Conclusions： It was suggested that the sexual factor has a significant influence in the neurodegenerative process between aged males and aged females.