老年糖尿病患者社区获得性肺炎病原分布及空腹血糖、糖化血红蛋白的预测价值

Pathogen distribution of community acquired pneumonia in elderly patients with diabetes and the predictive value of fasting blood glucose and glycosylated hemoglobin

目的分析老年糖尿病患者社区获得性肺炎(CAP)病原分布特点,并探讨空腹血糖(FBG)联合糖化血红蛋白(HbA1c)对其预测价值。方法系统抽样法选取2020年1月至2021年11月南充市第五人民医院收治的192例老年糖尿病出院患者开展队列研究,均接受随访。统计出院后3个月内患者CAP的发生率,分析病原分布特点。根据是否发生CAP将入组患者分为感染组(43例)和未感染组(149例),比较两组患者FBG和HbA1c水平;采用多因素Logistic回归分析探讨CAP危险因素,绘制受试者工作特征(ROC)曲线分析FBG变化率和HbA1c变化率对并发CAP的预测价值,并以曲线下面积(AUC)评价预测效能。结果老年糖尿病患者CAP发生率为22.40%(43/192);并发CAP患者中细菌感染占比最高(79.07%、34/43),其次为肺炎支原体感染(4.76%、2/43)、病毒感染(4.65%、2/43)、真菌感染(4.65%、2/43)、细菌与真菌混合感染(4.65%、2/43),肺炎衣原体感染占比最低(2.33%、1/43)。痰标本培养后共分离55株病原菌,其中革兰阴性菌、革兰阳性菌、真菌占比分别为63.64%(35/43)、27.27%(15/43)和9.09%(5/43)。感染组患者出院后1个月、2个月、3个月FBG和HbA1c水平均显著高于出院时(FBG:t=17.943、14.535、16.546,P均<0.001;HbA1c:t=16.976、16.735、16.734,P均<0.001),且感染组患者出院后以上3个时间点FBG和HbA1c水平均显著高于未感染组(FBG:t=15.435、46.522、17.865,P均<0.001;HbA1c:t=16.765、17.057、16.846,P均<0.001)。感染组患者FBG变化率[(48.93±7.61)%]和HbA1c变化率[(65.84±7.97)%]均显著高于未感染组[FBG变化率:(20.04±4.35)%,HbA1c变化率:(34.05±5.11)%],差异均有统计学意义(t=11.026、15.884,P均<0.001)。多因素Logistic回归分析显示,脑卒中后吞咽障碍(OR=4.246、95%CI:1.486~4.264、P<0.001)、并发胃食管反流(OR=3.888、95%CI:1.175~3.946、P=0.003)、出院3个月FBG变化率(≥47.58%)(OR=4.246、95%CI:2.937~5.555、P=0.015)和出院3个月HbA1c变化率(≥28.65%)(OR=3.888、95%CI:2.689~5.088、P=0.012)均为发生CAP的危险因素。ROC曲线分析显示,FBG变化率和HbA1c变化率预测老年糖尿病患者并发CAP的Cut-off值分别为47.58%和28.65%,灵敏度、特异度和AUC分别为51.16%、89.26%和0.779,60.47%、87.92%和0.741;二者联合预测老年糖尿病患者并发CAP的灵敏度、特异度和AUC分别为81.39%、88.59%和0.909,二者联合预测CAP的AUC显著高于FBG变化率或HbA1c变化率单指标预测,差异有统计学意义(Z=2.201、P=0.028,Z=2.579、P=0.010)。结论老年糖尿病患者CAP发生率高,常见革兰阴性菌感染,感染者FBG变化率和HbA1c变化率均较高,且二者联合对CAP发生预测价值较高。

Objective To investigate the characteristics of pathogen distribution of community acquired pneumonia(CAP)in elderly patients with diabetes,and to analyze the predictive value of fasting blood glucose(FBG)combined with glycosylated hemoglobin(HbA1c).Methods Total of 192 elderly patients with diabetes who were discharged from the Fifth People's Hospital of Nanchong from January 2020 to November 2021 were selected by systematic sampling method for cohort study,all of whom were followed up.The incidence of CAP of patients within 3 months after discharge and the distribution characteristics of pathogens were analyzed.All patients were divided into infected group(43 cases)and uninfected group(149 cases)based on whether complicated with CAP,and the levels of FBG and HbA1c between the two groups were compared,respectively.The risk factors of CAP were conducted by multivariate Logistic regression analysis.The predictive values of FBG change rate and HbA1c change rate for concurrent CAP were analyzed by the receiver operating characteristic(ROC)curve,and the predictive performances were evaluated by the area under the curve(AUC).Results The incidence rate of CAP was 22.40%(43/192).Among patients with CAP,bacterial infection accounted for the highest proportion(79.07%,34/43),followed by Mycoplasma pneumoniae infection(4.76%,2/43),viral infection(4.65%,2/43),fungal infection(4.65%,2/43)and bacterial and fungal mixed infection(4.65%,2/43);Chlamydia pneumoniae infection accounted for the lowest proportion(2.33%,1/43).After sputum culture,a total of 55 pathogenic bacteria were isolated,among which Gram-negative bacteria,Gram-positive bacteria and fungi accounted for 63.64%(35/43),27.27%(15/43)and 9.09%(5/43),respectively.The levels of FBG and HbA1c at discharge of patients in infected group were significantly higher than those of 1 month,2 months and 3 months after discharge(FBG:t=17.943,14.535,16.546;all P<0.001.HbA1c:t=16.976,16.735,16.734;all P<0.001).And the levels of FBG and HbA1c of Infected patients were significantly higher at above three time points after discharge than those of uninfected patients(FBG:t=15.435,46.522,17.865;all P<0.001.HbA1c:t=16.765,17.057,16.846;all P<0.001).The FBG change rate[(48.93±7.61)%]and HbA1c change rate[(65.84±7.97)%]of patients in infected group were significantly higher than those of uninfected group[FBG:(20.04±4.35)%,HbA1c:(34.05±5.11)%],with significant differences(t=11.026,15.884;both P<0.001).Multivariate Logistic regression analysis showed that post stroke dysphagia(OR=4.246,95%CI:1.486-4.264,P<0.001),concurrent gastroesophageal reflux(OR=3.888,95%CI:1.175-3.946,P=0.003),FBG change rate at 3 months after discharge(≥47.58%)(OR=4.246,95%CI:2.937-5.555,P=0.015)and HbA1c change rate at 3 months after discharge(≥28.65%)(OR=3.888,95%CI:2.689-5.088,P=0.012)were all influencing factors for CAP.ROC analysis showed that the cut-off values predicted by the change rates of FBG and HbA1c in elderly patients with diabetes complicated with CAP were 47.58%and 28.65%,respectively;and the sensitivity,specificity and AUC were 51.16%,89.26%and 0.779,60.47%,87.92%and 0.741,respectively.The sensitivity,specificity and AUC predicted by the combination of the two indicators were 81.39%,88.59%and 0.909,respectively,the AUC predicted by the combination of the two indicators were significantly higher than predicted by the change rates of FBG or HbA1c alone,with significant differences(Z=2.201,P=0.028;Z=2.579,P=0.010).Conclusions The incidence of CAP was high in elderly patients with diabetes mellitus,and the Gram-negative bacteria infection was common,the change rate of FBG and HbA1c in infected patients were high,and the combination of the two indicators had a high predictive value for CAP.