低密度脂蛋白胆固醇随访变异性对老年人脑血流速度的影响

Effect of visit to visit LDL-C variability on cerebral blood flow in the elderly

目的探讨LDL-C随访变异性对老年人脑血流速度的影响。方法选择2012年6月~2013年7月济南地区的老年人489例,每6个月随访1次,并检测血浆LDL-C水平,完成36个月随访,纳入分析的老年人共456例。依据随访期间LDL-C标准差的三分位分为低变异性组152例(LDL-C<0.66 mmol/L)、中变异性组152例(LDL-C 0.66~0.79 mmol/L)和高变异性组152例(LDL-C>0.79 mmol/L)。所有老年人于基线及随访结束时采用经颅多普勒超声检测大脑中动脉(MCA)、大脑前动脉(ACA)和大脑后动脉(PCA)血流速度。结果与低变异性组比较,中变异性组、高变异性组MCA、ACA及PCA血流速度下降幅度明显升高,差异有统计学意义(P<0.05)。与中变异性组比较,高变异性组PCA血流速度下降幅度明显升高,差异有统计学意义(P<0.05)。Spearman相关分析结果显示,随访期间MCA、ACA及PCA血流速度下降与LDL-C变异性呈正相关(r=0.339,r=0.273,r=0.407,P<0.01)。校正混杂因素后,多因素逐步线性回归分析显示,LDL-C变异性是MCA、ACA及PCA血流速度下降的独立危险因素(β=2.196,95%CI:0.966~3.426,P=0.000;β=2.478,95%CI:6.152~13.889,P=0.033;β=3.113,95%CI:1.569~4.652,P=0.000)。结论高LDL-C随访变异性是老年人脑血流速度下降的独立危险因素。

Objective To study the effect of visit to visit LDL-C variability on cerebral blood flow in the elderly.Methods Of the 489 elderly people selected from Jinan area in June 2012-July 2013 who were followed up once every 6 months,during which their serum LDL-C level was measured,456 who completed the 36-month follow-up period were enrolled for analysis and divided into low visit to visit LDL-C variability group or LDL-C<0.66 mmol/L group(n=152),median visit to visit LDL-C variability group or LDL-C=0.66-0.79 mmol/L group(n=152),and high visit to visit LDL-C variability group or LDL-C >0.79 mmol/L group(n=152) depending on the tertiles of standard LDL-C deviation during the follow-up period.The patients underwent transcrainial Dopplar ultrasonography for the measurement of blood flow velocity in middle cerebral artery(MCA),anterior cerebral artery(ACA) and posterior cerebral artery(PCA) at baseline and the last follow-up.Results The falling amplitude of blood flow velocity in MCA,ACA and PCA was significantly greater in median and high visit to visit LDL-C variability groups than in low visit to visit LDL-C variability group(P<0.05).The falling amplitude of blood flow velocity in PCA was significantly greater in high visit to visit LDL-C variability group than in median visit to visit LDL-C group(P<0.05).Spearman correlation analysis showed that the falling amplitude of blood flow velocity in MCA,ACA and PCA was positively related with the visit to visit LDL-C variability(r=0.339,r=0.273,r=0.407,P<0.01).Multivariate stepwise linear regression analysis showed that the visit to visit LDL-C variability was an independent risk factor for the falling blood flow velocity in MCA,ACA and PCA after adjustment for confounding factors(β=2.196,95%CI:0.966-3.426,P=0.000;β=2.478,95%CI:6.152-13.889,P=0.033;β=3.113,95%CI:1.569-4.652,P=0.000).Conclusion Excessive visit to visit LDL-C variability is an independent risk factor for the falling cerebral blood flow velocity in the elderly.