北京美兆体检人群的衰弱状态变化及衰弱恶化的影响因素分析

目的分析中老年人群衰弱状态随时间的变化以及衰弱恶化的影响因素。方法利用美兆健康体检中心的人群体检数据,纳入2008-2019年至少参加过2次体检且间隔>3年者,共13689人。采用28个变量(包括疾病、症状、体格测量指标等)构建衰弱指数,衰弱指数≥0.25定义为衰弱,衰弱指数>0.10且<0.25为衰弱前期。按照首次体检时的衰弱状态进行分层分析,采用logistic回归模型探究社会人口学因素和生活方式特征对衰弱状态恶化的影响。结果研究对象首次和末次体检时的年龄分别为(42.3±9.2)岁和(47.9±9.3)岁,首末次体检间隔时间为(5.7±1.9)年。首次体检时人群衰弱率和衰弱前期率分别为2.5%和50.3%,末次体检时分别上升至3.9%和55.4%。67.3%的研究对象在首末次体检时的衰弱状态保持不变,21.2%恶化,12.5%改善。在首次体检衰弱状态为健康的人群中,年龄大、女性、低文化程度、戒烟和每天吸烟、BMI定义的肥胖、以及腰臀比定义的中心性肥胖是衰弱状态恶化的危险因素。在首次体检为衰弱前期的人群中,年龄大、女性、BMI定义的肥胖、以及腰臀比定义的中心性肥胖是衰弱状态恶化的危险因素。结论低文化程度、吸烟和肥胖等会增加个体衰弱恶化的风险。

LIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATALIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATA

The author considers the life-span of classical solutions to Cauchy problem for general first order quasilinear strictly hyperbolic systems in two independent variables with "slow" decay initial data. By constructing an example, first it is illustrated that the classical solution to this kind of Cauchy problem may blow up in a finite time, even if the system is weakly linearly degenerate. Then some lower bounds of the life-span of classical solutions are given in the case that the system is weakly linearly degenerate. These estimates imply that, when the system is weakly linearly degenerate, the classical solution exists almost globally in time. Finally, it is proved that Theorems 1.1-1.3 in [2] are still valid for this kind of initial data.