ABSTRACT
Objective To study changes in serum homocysteine(Hcy) and its correlation with serum levels of folic acid and high sensitivity C-reactive protein(hs-CRP)in Tibetan patients with mildto-moderate Alzheimer's disease at various high altitude areas,so as to direct the clinical diagnosis and treatment of AD in plateau hypoxia environment Method 108 cases were divided into four groups:23 AD Tibetan patients at middle altitude(AD/middle altitude group)and 23 healthy Tibetan subjects (healthy/middle altitude group) in Qinghai-Tibet Plateau Xining region,altitude at 2,260 m,31 AD Tibetan patients (AD/high altitude group)and 31 healthy Tibetan elderly subjects (healthy/high altitude group)in Yushu region at altitude of 3,800 m.Among the total study subjects,half are males,aged from 60 to 85 years.The levels of serum Hcy,Vitamin B12 and folic acid(FA)were measured by the Fluorescence Polarization Immunoassay(FPIA).Serum hs-CRP,triglyceride(TG)and low density lipoprotein cholesterol(LDL-C)were measured by automatic biochemistry analyzer.Correlation of Hcy with FA and hs-CRP was analyzed.Result Both high altitude and middle altitude group showed the levels of Hcy and hs-CRP were significantly higher in AD Tibetan patients than in healthy control at the same altitude(allP＜0.05).The levels of Hcy,LDL-C and hs-CRP of subjects were higherat high altitude than at middle altitude(P＜0.05).In contrast,folic acid levels in AD and control groups were lower at the high altitude than at middle altitude(P＜0.05).The levels of vitamin B12 and TG were not significantly different among all four groups.Multiple logistic regression analysis showed that altitude,folacin and hs-CRP were the risk factors for Hcy in patients with AD at plateau(OR =0.351,2.794,3.021,P=0.045,0.037,0.016).Conclusion Along with increased altitude,serum level of Hcy is significantly increased in AD Tibetan patients living in high altitude area.High altitude,high hs-CRP and lower folacin may be the risk factors for hyper-homocysteine in AD Tibetan patients with high altitude,and their combined effects are involved in the occurrence and development of AD.