研究目的:探讨低体重指数(body mass index, BMI)与老年共病患者发生不良预后结局的关系。研究方法:纳入2018年7月至2019年6月就诊于青岛大学附属医院保健科的60岁以上的老年住院患者350例。研究对象依据BMI < 18.50 kg/m2与18.50 ≤ BMI < 24.00 kg/m2分为2组。同时收集所有研究对象的一般资料及相关的实验室检查结果,并进行相关的医学评分,每位研究对象在出院后进行为期1年的随访,记录其发生终点事件的时间。生存时间即发生终点事件日期与先前所记录BMI日期的时间差。组间比较采用Pearson卡方(χ2)检验或fisher精确检验,采用Kaplan-Meier法进行单因素生存分析,其后采用Cox回归模型多因素分析影响患者的生存率的危险因素,自变量为已用单因素分析评估过的有意义的因素。以P < 0.05为差异有统计学意义。研究结果:两组患者PA、Alb、共病指数、共病指数、NRS2002、ADL评分、衰弱量表、是否发生终点事件间差异具有统计学意义(P < 0.05)。BMI、共病指数、NRS2002、ADL评分指标均是影响患者发生不良结局的独立危险因素(P < 0.05),且BMI越小,NRS2002越高,ADL评分越小,共病指数越高,患者发生不良结局的风险越高,而其余指标均不是影响患者发生不良结局的独立危险因素(P > 0.05)。研究结果:在BMI < 24 kg/m2的老年共病患者中,低BMI、高共病指数、高NRS2002、低ADL评分均是影响患者发生MACE、AECOPD、脑卒中及TIA、严重感染及其他可引起老年人急诊入院或死亡等不良结局的独立危险因素。 Objective: To investigate the relationship between low body mass index (BMI) and poor prognosis in elderly patients with comorbidities. Methods: A total of 350 elderly inpatients over 60 years old who were admitted to the Health Care Department of the Affiliated Hospital of Qingdao University from July 2018 to June 2019 were included. Subjects were divided into two groups according to BMI < 18.50 kg/m2 or 18.50 ≤ BMI < 24.00 kg/m2. At the same time, the general data and relevant laboratory examination results of all subjects were collected, and the relevant medical scores were made. Each subject was followed up for 1 year after discharge, and the time of occurrence of the end event was recorded. Survival time is the time difference between the date of the end event and the previously recorded BMI date. Comparison between groups was performed by Pearson chi-square (χ2) test or Fisher's exact test. Univariate survival analysis was performed by Kaplan-Meier method, followed by multivariate analysis of risk factors affecting survival by Cox regression model. The independent variables were significant factors that had been evaluated by univariate analysis. P < 0.05 was considered statistically significant. Results: There were statistically significant differences in PA, ALB, comorbidity index, comorbidity index, NRS2002, ADL score, frailty scale and endpoint event between 2 groups (P < 0.05). BMI, comorbidity index, NRS2002, and ADL score were all independent risk factors for adverse outcomes in patients (P < 0.05), and the smaller the BMI, the higher the NRS2002, the smaller the ADL score, the higher the comorbidity index, and the higher the risk of adverse outcomes in patients. The other indicators were not independent risk factors for adverse outcomes (P > 0.05). Conclusion: In the elderly comorbidities with BMI < 24 kg/m2, low BMI, high comorbidities, high NRS2002, and low ADL score were all independent risk factors for MACE, AECOPD, stroke, TIA, severe infection, and other adverse outcomes that could lead to emergency admission or death in the elderly.
研究目的:探讨低体重指数(body mass index, BMI)与老年共病患者发生不良预后结局的关系。研究方法:纳入2018年7月至2019年6月就诊于青岛大学附属医院保健科的60岁以上的老年住院患者350例。研究对象依据BMI < 18.50 kg/m2与18.50 ≤ BMI < 24.00 kg/m2分为2组。同时收集所有研究对象的一般资料及相关的实验室检查结果,并进行相关的医学评分,每位研究对象在出院后进行为期1年的随访,记录其发生终点事件的时间。生存时间即发生终点事件日期与先前所记录BMI日期的时间差。组间比较采用Pearson卡方(χ2)检验或fisher精确检验,采用Kaplan-Meier法进行单因素生存分析,其后采用Cox回归模型多因素分析影响患者的生存率的危险因素,自变量为已用单因素分析评估过的有意义的因素。以P < 0.05为差异有统计学意义。研究结果:两组患者PA、Alb、共病指数、共病指数、NRS2002、ADL评分、衰弱量表、是否发生终点事件间差异具有统计学意义(P < 0.05)。BMI、共病指数、NRS2002、ADL评分指标均是影响患者发生不良结局的独立危险因素(P < 0.05),且BMI越小,NRS2002越高,ADL评分越小,共病指数越高,患者发生不良结局的风险越高,而其余指标均不是影响患者发生不良结局的独立危险因素(P > 0.05)。研究结果:在BMI < 24 kg/m2的老年共病患者中,低BMI、高共病指数、高NRS2002、低ADL评分均是影响患者发生MACE、AECOPD、脑卒中及TIA、严重感染及其他可引起老年人急诊入院或死亡等不良结局的独立危险因素。
低体重指数,老年人,共病,预后,营养不良
Yinghua Han, Jia Liu, Song Hu, Yongjun Mao
Department of Geriatrics, The Affiliated Hospital of Qingdao University, Qingdao Shandong
Received: May 17th, 2021; accepted: Jun. 3rd, 2021; published: Jun. 21st, 2021
Objective: To investigate the relationship between low body mass index (BMI) and poor prognosis in elderly patients with comorbidities. Methods: A total of 350 elderly inpatients over 60 years old who were admitted to the Health Care Department of the Affiliated Hospital of Qingdao University from July 2018 to June 2019 were included. Subjects were divided into two groups according to BMI < 18.50 kg/m2 or 18.50 ≤ BMI < 24.00 kg/m2. At the same time, the general data and relevant laboratory examination results of all subjects were collected, and the relevant medical scores were made. Each subject was followed up for 1 year after discharge, and the time of occurrence of the end event was recorded. Survival time is the time difference between the date of the end event and the previously recorded BMI date. Comparison between groups was performed by Pearson chi-square (χ2) test or Fisher's exact test. Univariate survival analysis was performed by Kaplan-Meier method, followed by multivariate analysis of risk factors affecting survival by Cox regression model. The independent variables were significant factors that had been evaluated by univariate analysis. P < 0.05 was considered statistically significant. Results: There were statistically significant differences in PA, ALB, comorbidity index, comorbidity index, NRS2002, ADL score, frailty scale and endpoint event between 2 groups (P < 0.05). BMI, comorbidity index, NRS2002, and ADL score were all independent risk factors for adverse outcomes in patients (P < 0.05), and the smaller the BMI, the higher the NRS2002, the smaller the ADL score, the higher the comorbidity index, and the higher the risk of adverse outcomes in patients. The other indicators were not independent risk factors for adverse outcomes (P > 0.05). Conclusion: In the elderly comorbidities with BMI < 24 kg/m2, low BMI, high comorbidities, high NRS2002, and low ADL score were all independent risk factors for MACE, AECOPD, stroke, TIA, severe infection, and other adverse outcomes that could lead to emergency admission or death in the elderly.
Keywords:Low Body Mass Index, The Elderly, Comorbidities, Prognosis, Malnutrition
Copyright © 2021 by author(s) and Hans Publishers Inc.
This work is licensed under the Creative Commons Attribution International License (CC BY 4.0).
http://creativecommons.org/licenses/by/4.0/
当今社会,我国人均预期寿命在不断延长,老年人口占比也在逐年增加,老龄化形势日趋严峻,老年人的健康问题亟待处理,但其中许多问题是可以通过保持健康的生活方式来预防、推迟或改善的。BMI作为一项实用的筛查营养状况的指标 [
低BMI其实是一种体质量过轻的状态,国内的许多研究 [
本研究为前瞻性研究,最终收集到2018年7月至2019年6月就诊于青岛大学附属医院保健科350例老年住院患者的基本信息。1) 纳入标准:年龄在60~95岁的老年人;BMI < 24 kg/m2;能够大致正常交流且可以简单配合进行本研究的相关评估。2) 排除标准:患者处于疾病终末期预期寿命 < 1年;基本资料或者实验室检查结果缺失,或者在12个月的观察期内失访;拒绝参与本研究者。
根据我国制定的BMI分类标准,将研究对象依据BMI < 18.50 kg/m2与18.50 ≤ BMI < 24.00 kg/m2分为A组(低体重指数组)和B组(正常体重指数组),其中A组52例,B组298例。
收集研究对象住院期间的一般临床基线资料包括性别、年龄、身高、体重、BMI、收缩压、空腹血糖(FPG)、低密度脂蛋白(LDL)、总胆固醇(TC)、前白蛋白(PA)、白蛋白(Alb)等。
对研究对象进行如下评分:1) Charlson共病指数:用以初步评估老年患者共病状态,根据研究对象的年龄、疾病状态、各系统器官功能等进行赋分,分值越高往往提示预后不佳;2) NRS2002:对住院患者进行营养情况筛查,得出的数值用以简单量化住院时的营养状态,评分 ≥ 3分提示需要营养干预;3) FRAIL衰弱量表 [
患者出院时记录出院当天的日期。其后对每位出院患者进行为期1年(12月)的随访,随访过程中记录患者出现的各种终点事件发生的日期,终点事件包括:主要心血管事件(MACE),慢性阻塞性肺疾病急性加重(AECOPD),脑卒中及短暂性脑缺血发作,严重感染,以及其他再入院及死亡事件。
生存时间的计算:即发生终点事件日期与先前所记录BMI日期的时间差。
将收集的临床资料结果录入Excel表格中,采用SPSS 23.0软件进行数据统计分析。根据临床常用截点或相关文献提供的截点,将连续变量转化为分类变量,分类资料用频数和百分数表示,组间比较采用Pearson卡方(χ2)检验或fisher精确检验。采用Kaplan-Meier法进行单因素生存分析,计算出中位生存时间及生存率,其差异性应用Log-rank test进行检验。采用Cox回归模型多因素分析影响患者的生存率的危险因素,自变量为已用单因素分析评估过的有意义的因素,结果用校正后的优势比(HR)和与之相应的95%可信区间表示。生存曲线用Graphpad Prism7.0软件绘制。以P < 0.05为差异有统计学意义。
共计350例老年共病患者被纳入,低体重指数组(A组) 52例,正常体重指数组(B组) 298例。其中A组发生终点事件的有24例(46.2%),B组发终点事件的有80例(26.8%)。两组患者PA、Alb、共病指数、共病指数、NRS2002、ADL评分、衰弱量表、是否发生终点事件间差异具有统计学意义(P < 0.05)。详见表1。
低BMI组(n = 52) | 正常BMI组(n = 298) | χ2 | P | ||
---|---|---|---|---|---|
年龄(岁) | 60~69 | 11 (3.1%) | 100 (28.6%) | 3.623 | 0.163 |
70~79 | 18 (5.1%) | 98 (28.0%) | |||
≥80 | 23 (6.6%) | 100 (28.6%) | |||
性别 | 女 | 22 (6.3%) | 143 (40.9%) | 0.573 | 0.449 |
男 | 30 (8.6%) | 155 (44.3%) | |||
收缩压(mmHg) | <140 | 36 (10.3%) | 198 (56.5%) | 0.155 | 0.694 |
≥140 | 16 (4.6%) | 100 (28.6%) | |||
FPG(mmol/L) | <6.1 | 39 (11.1%) | 231 (66.0%) | 0.159 | 0.690 |
≥6.1 | 13 (3.7%) | 67 (19.1%) | |||
LDL(mmol/L) | <3.4 | 47 (13.4%) | 248 (70.9%) | 1.715 | 0.190 |
≥3.4 | 5 (1.4%) | 50 (14.3%) | |||
TC(mmol/L) | <5.2 | 39 (11.1%) | 213 (60.9%) | 0.082 | 0.774 |
≥5.2 | 13 (3.7%) | 85 (24.3%) | |||
PA(mg/L) | <280 | 48 (13.7%) | 232 (66.3%) | 5.782 | 0.016* |
≥280 | 4 (1.1%) | 66 (18.9%) | |||
Alb(g/L) | <40 | 47 (13.4%) | 200 (57.1%) | 11.544 | 0.000* |
≥40 | 5 (1.4%) | 98 (28.0%) | |||
共病指数 | <6 | 15 (42.9%) | 137 (39.1%) | 5.286 | 0.021* |
≥6 | 37 (10.6%) | 161 (46.0%) | |||
NRS2002 | <3 | 8 (2.3%) | 219 (62.6%) | 65.583 | 0.000* |
≥3 | 44 (12.6%) | 79 (22.6%) | |||
ADL评分 | <80 | 39 (11.1%) | 88 (25.1%) | 39.594 | 0.000* |
≥80 | 13 (3.7%) | 210 (60.0%) | |||
衰弱量表 | <2 | 3 (0.9%) | 116 (33.1%) | 21.691 | 0.000* |
≥2 | 49 (14.0%) | 182 (52.0%) | |||
发生终点事件 | 有 | 24 (6.9%) | 80 (22.9%) | 7.903 | 0.005* |
无 | 28 (8.0%) | 218 (62.3%) |
表1. 低BMI组和正常BMI组的一般资料比较
*为P < 0.05,差异有统计学意义。
根据Kaplan-Meier法单因素分析结果可得,整体未发生不良结局的时间均数为10.40月,3月内未发生不良结局率为96.3%,6月内未发生不良结局率为88.0%,1年内未发生不良结局率为68.0%。
年龄、BMI、TC、PA、Alb、共病指数、NRS2002、ADL评分、衰弱量表共9个观察指标对患者发生不良结局率具有显著影响(P < 0.05)。且年龄越大、BMI < 18.50 kg/m2、TC < 5.2 mmol/L、PA < 280 mg/L、Alb < 40g/L、共病指数 ≥ 6、NRS2002 ≥ 3、ADL评分 < 80、衰弱量表 ≥ 2的观察对象的发生不良结局率较高。其余指标对患者发生不良结局率、发生不良结局时间均无显著影响(P > 0.05)。具体结果详见表2。
临床指标 | 例数 | 3月率a(%) | 6月率a(%) | 12月率a(%) | c2 | P值 | 时间均数 | ||||
---|---|---|---|---|---|---|---|---|---|---|---|
估计值 | 标准误 | 95% CI | |||||||||
下限 | 上限 | ||||||||||
整体 | 350 | 96.3 | 88.0 | 68.0 | 10.402 | 0.152 | 10.104 | 10.700 | |||
性别 | 女 | 162 | 98.2 | 91.3 | 71.4 | 2.171 | 0.141 | 10.708 | 0.197 | 10.322 | 11.094 |
男 | 185 | 94.6 | 85.1 | 65.0 | 10.129 | 0.228 | 9.682 | 10.576 | |||
年龄(岁) | 60~69 | 111 | 99.1 | 95.4 | 81.6 | 15.562 | 0.000* | 11.241 | 0.181 | 10.885 | 11.596 |
70~79 | 116 | 94.8 | 87.8 | 66.3 | 10.174 | 0.277 | 9.632 | 10.716 | |||
≥80 | 123 | 95.1 | 81.5 | 57.0 | 9.854 | 0.291 | 9.283 | 10.424 | |||
BMI (kg/m2) | <18.50 | 52 | 84.2 | 59.3 | 34.4 | 51.181 | 0.000* | 7.433 | 0.605 | 6.247 | 8.620 |
18.50~23.99 | 298 | 98.3 | 92.3 | 72.2 | 10.795 | 0.137 | 10.525 | 11.064 | |||
收缩压(mmHg) | <140 | 234 | 96.1 | 89.4 | 66.6 | 0.156 | 0.693 | 10.435 | 0.184 | 10.074 | 10.796 |
≥140 | 116 | 96.6 | 85.3 | 70.3 | 10.334 | 0.272 | 9.800 | 10.867 | |||
FPG (mmol/L) | <6.1 | 270 | 95.9 | 87.2 | 67.1 | 0.308 | 0.579 | 10.371 | 0.177 | 10.025 | 10.718 |
≥6.1 | 80 | 97.5 | 91.0 | 70.8 | 10.509 | 0.294 | 9.933 | 11.085 | |||
LDL (mmol/L) | <3.4 | 295 | 95.9 | 87.1 | 66.5 | 2.096 | 0.148 | 10.280 | 0.171 | 9.944 | 10.616 |
≥3.4 | 55 | 98.2 | 92.7 | 75.6 | 11.036 | 0.309 | 10.431 | 11.641 | |||
TC (mmol/L) | <5.2 | 252 | 95.2 | 87.5 | 64.3 | 4.883 | 0.027* | 10.211 | 0.188 | 9.842 | 10.579 |
≥5.2 | 98 | 99.0 | 89.4 | 77.2 | 10.885 | 0.243 | 10.409 | 11.360 | |||
PA (mg/L) | <280 | 280 | 95.7 | 86.1 | 63.7 | 9.931 | 0.002* | 10.169 | 0.180 | 9.815 | 10.523 |
≥280 | 70 | 98.6 | 95.7 | 84.1 | 11.296 | 0.216 | 10.872 | 11.719 | |||
Alb (g/L) | <40 | 247 | 95.5 | 86.2 | 63.4 | 6.945 | 0.008* | 10.160 | 0.193 | 9.781 | 10.539 |
≥40 | 103 | 98.1 | 92.2 | 78.3 | 10.956 | 0.223 | 10.518 | 11.394 | |||
共病指数 | <6 | 152 | 98.7 | 96.6 | 87.3 | 41.499 | 0.000* | 11.366 | 0.152 | 11.069 | 11.664 |
≥6 | 198 | 94.4 | 81.5 | 53.1 | 9.663 | 0.228 | 9.216 | 10.110 | |||
NRS2002 | <3 | 227 | 98.2 | 94.7 | 78.7 | 47.554 | 0.000* | 11.100 | 0.141 | 10.824 | 11.376 |
≥3 | 123 | 92.6 | 74.8 | 44.7 | 8.961 | 0.323 | 8.329 | 9.594 | |||
ADL评分 | <80 | 127 | 92.1 | 74.9 | 41.9 | 61.076 | 0.000* | 8.933 | 0.310 | 8.325 | 9.541 |
≥80 | 223 | 98.6 | 95.0 | 81.2 | 11.169 | 0.140 | 10.895 | 11.444 | |||
衰弱量表 | <2 | 119 | 98.3 | 95.0 | 82.1 | 16.630 | 0.000* | 11.180 | 0.185 | 10.818 | 11.542 |
≥2 | 231 | 95.2 | 84.3 | 60.0 | 9.978 | 0.206 | 9.573 | 10.382 |
表2. 各指标的K-M分析结果
注:CI:可信区间;a为不同时间内未发生不良结局率;*为P < 0.05,差异有统计学意义。
为了进一步检验Kaplan-Meier单因素分析P < 0.05的9个指标与患者发生不良结局风险之间的相关性,寻求它们的关系,我们将年龄、BMI、TC、PA、Alb、共病指数、NRS2002、ADL评分、衰弱量表共9个观察指标作为自变量,进行Cox多因素回归分析。结果见表3。
变量 | b | SE | Wald | P值 | HR | 95% CI | |
---|---|---|---|---|---|---|---|
下限 | 上限 | ||||||
年龄 | -0.017 | 0.018 | 0.908 | 0.341 | 0.983 | 0.948 | 1.019 |
BMI | −0.293 | 0.058 | 25.503 | 0.000* | 0.746 | 0.666 | 0.836 |
TC | 0.038 | 0.092 | 0.170 | 0.680 | 1.039 | 0.867 | 1.244 |
PA | −0.001 | 0.002 | 0.172 | 0.678 | 0.999 | 0.995 | 1.003 |
Alb | 0.000 | 0.031 | 0.000 | 0.994 | 1.000 | 0.941 | 1.062 |
共病指数 | 0.166 | 0.065 | 6.601 | 0.010* | 1.181 | 1.040 | 1.341 |
NRS2002 | 0.273 | 0.134 | 4.175 | 0.041* | 1.314 | 1.011 | 1.708 |
ADL评分 | −0.026 | 0.006 | 16.350 | 0.000* | 0.974 | 0.962 | 0.987 |
衰弱量表 | −0.087 | 0.152 | 0.324 | 0.569 | 0.917 | 0.680 | 1.236 |
表3. 影响老年共病患者发生终点事件的Cox多因素分析
注:b:系数估计;Wald:卡方值;HR:优势比,表示实验变量增加的单位量;CI:可信区间;*为P < 0.05,差异有统计学意义。
Cox多因素回归分析结果显示,BMI、NRS2002、ADL评分、共病指数指标均是影响患者发生结局的独立影响因素(P < 0.05),且BMI越小(HR = 0.746; 95% CI 0.666~0.836, P < 0.05),NRS2002越高(HR = 1.314; 95% CI 1.011~1.708, P < 0.05),ADL评分越小(HR = 0.974; 95% CI 0.962~0.987, P < 0.05),共病指数越高(HR = 1.181; 95% CI 1.040~1.341, P < 0.05),患者发生不良结局的风险越高,而其余指标均不是影响患者发生不良结局的独立影响因素(P > 0.05)。图1为2组不同BMI分组时的K-M生存曲线。
图1. 不同BMI分组所对应的K-M生存曲线
本研究所得出的结果提示,在BMI < 24 kg/m2的老年共病患者群体中,BMI值越小,其在1年内发生MACE、AECOPD、脑卒中或TIA、严重感染、急诊入院等不良结局的风险会显著升高。既往对于BMI与终点事件的关系研究中,研究观察期较长,最长观察时间可长达20年,样本量可高达上万例,终点事件常常以死亡为结局,在最终的BMI与死亡率的关系曲线可得出“U”型曲线 [
低BMI在老年人群中并不少见,只是在一般情况下很少给予关注,其往往反映着营养不良的状态,而在此情境下,会潜移默化地影响老年共病患者的健康。低BMI水平对多病共存的老年患者的影响是多方面的。在神经系统疾病中,认知功能障碍对老年人的日常生活能力产生了极大的影响。有研究发现,在BMI较高的老年人群中,他们会有着更好的认知能力 [
本研究仍存在诸多的局限性。研究对象的选择上仅选取自我院保健科病房的老年住院患者,以此来代表老年人群确实会存在一定的偏差。受人力、物力限制的影响未能动态观察研究对象的各变量,不能体现患者在接受营养支持治疗后的预后及各种危险因素的变化情况。且观察期仅为1年时间,相较于既往研究时间较短,对于终点事件的定义较为宽泛,均会对最终结果造成偏差,但为临床研究提供了一种可行思路。故应在后续研究中延长观察时间,增加样本量,在观察期内重新评估各变量情况,以做出更为合理的研究结果。
在BMI < 24 kg/m2的老年共病患者中,低BMI、高共病指数、高NRS2002、低ADL评分均是影响患者发生MACE、AECOPD、脑卒中及TIA、严重感染及其他可引起老年人急诊入院或死亡等不良结局的独立危险因素。
韩英华,刘 佳,胡 松,毛拥军. 低体重指数对老年共病患者预后价值的研究Prognostic Value of Low Body Mass Index in Elderly Patients with Comorbidities[J]. 临床医学进展, 2021, 11(06): 2716-2723. https://doi.org/10.12677/ACM.2021.116393