FEV1/FVC≥0.7的吸烟者肺功能指标变化特点及其临床意义

张彩云; 韩志海; 孟激光; 刘方; 赖莉芬; 李泳群

doi:10.3969/j.issn.2095-5227.2022.07.003

摘要:

背景慢性阻塞性肺疾病(chronic obstructive pulmonary disease，COPD)患者在达到流速指标第1秒用力呼气容积(forced expiratory volume in one second，FEV1)/用力肺活量(forced vital capacity，FVC)＜0.7之前已经存在肺功能指标的受损，但具体受损特点尚不明确，目前相关研究较少。

目的本研究通过比较FEV1/FVC≥0.7的吸烟者和不吸烟者肺功能指标的差异，探讨FEV1/FVC≥0.7的吸烟者肺功能受损特点及其影响因素，以期为早期识别COPD提供依据。

方法回顾性研究2017年3月- 2020年4月在我中心接受肺功能检查的FEV1/FVC≥0.7且无慢性气道疾病的吸烟者(吸烟指数＞50)和不吸烟者共388例，其中男性223例，女性165例。依据年龄分为＜50岁组(86例)、50 ~ 70岁组(197例)和＞70岁组(105例)，对各组吸烟者与不吸烟者肺功能指标进行比较。对这一人群各肺功能指标影响因素进行统计分析。

结果＜50岁组中吸烟者肺功能容量指标FVCpred%、ICpred%较不吸烟者明显降低(P均＜0.05)。50 ~ 70岁组中吸烟者流速指标FEV1pred%、FEV1/FVC和容量指标FVC、FVCpred%、ICpred%均较不吸烟者降低(P均＜0.05)。＞70岁组吸烟者FVCpred%、FEV1pred%、ICpred%低于不吸烟者(P均＜0.05)。以各肺功能指标为因变量，以性别、年龄、吸烟指数为自变量，分别对纳入的人群进行九次线性回归分析，结果发现FVC与性别(B=-0.756，95% CI：-1.079 ~ -0.432)、年龄(B=-0.032，95% CI：-0.040 ~ -0.025)、吸烟指数(B=-0.001，95% CI：-0.001 ~ 0.000)独立关联；FEV1与性别(B=-0.586，95% CI：-0.840 ~ -0.333)、年龄(B=-0.028，95% CI：-0.034 ~ -0.022)、吸烟指数(B=-0.001，95% CI：-0.001 ~ 0.000)独立关联；IC与性别(B=-0.530，95% CI：-0.814 ~ -0.247)、年龄(B=-0.018，95% CI：-0.025 ~ -0.011)、吸烟指数(B=-0.001，95% CI：-0.001 ~ 0.000)独立关联。在肺功能指标中，仅与吸烟指数独立关联的指标包括FVCpred%(B=-0.027，95% CI：-0.034 ~ -0.020)、FEV1pred%(B=-0.028，95% CI：-0.034 ~ -0.022)、ICpred%(B=-0.033，95% CI：-0.041 ~ -0.025)，RV仅与年龄独立关联(B=0.013，95% CI：0.003 ~ 0.024)，而FEV1/FVC、RVpred%几乎不受性别、年龄和吸烟指数的影响。

结论在FEV1/FVC≥0.7吸烟人群中，吸烟对肺功能的损伤在各年龄组均可发现。但在＜50岁组的年轻人群中，肺功能容量指标FVCpred%、ICpred%下降更明显。肺功能容量指标下降在吸烟导致的肺功能早期损害中需引起重视。

Abstract:

Background Patients with chronic obstructive pulmonary disease (COPD) may have impaired pulmonary function before reaching FEV1/FVC<0.7, and the characteristics of impaired pulmonary function are still unclear. There are few relevant studies at present.

Objective To compare the differences of lung function indexes between smokers and non-smokers with FEV1/FVC≥0.7, and explore the characteristics and influencing factors of lung function impairment in smokers with FEV1/FVC≥0.7, so as to provide evidence for early identification of COPD.

Methods Totally 388 smokers (smoking index: more than 50) and non-smokers who underwent pulmonary function examination in our hospital from March 2017 to April 2020 were studied retrospectively (including 223 males and 165 females). These included patients did not have chronic airway disease and their lung function showed FEV1/FVC ≥ 0.7. According to age, they were divided into younger than 50 years old group (n=86), 50-70 years old group (n=197) and more than 70 years old group (n=105). The pulmonary function indexes of smokers and non-smokers in each group were compared and analyzed. Statistical analysis was carried out on the influencing factors of each pulmonary function index in this population.

Results In the younger than 50 years old group, the lung function volume indexes FVCpred% and ICpred% of smokers were significantly lower than those of non-smokers (P=0.041, P=0.043). In the 50-70 years old group, the flow rate indexes FEV1pred%, FEV1 / FVC, the volume indexes FVC, FVCpred% and ICpred% of smokers were lower than those of non-smokers (P<0.05). In the older than 70 years old group, the FVCpred%, FEV1pred% and IC pred% of smokers were lower than those of non-smokers (P<0.05). Nine linear regression analyses were performed on the smokers population with lung function indexes as dependent variables and gender, age and smoking index as independent variables. The results showed that the influencing factors of FVC included gender (B=-0.756, 95% CI:-1.079 to -0.432), age (B=-0.032, 95% CI: -0.040 to -0.025) and smoking index (B=-0.001, 95% CI: -0.001 to 0.000); the influencing factors of FEV1 included gender (B=-0.586, 95% CI: -0.840 to -0.333), age (B=-0.028, 95% CI: -0.034 to -0.022) and smoking index (B=-0.001, 95% CI: -0.001 to 0.000); The influencing factors of IC included gender (B=-0.530, 95% CI: -0.814 to -0.247), age (B=-0.018, 95% CI: -0.025 to -0.011) and smoking index (B=-0.001, 95% CI: -0.001 to 0.000). Among the lung function indexes, FVC pred% (B=-0.027, 95% CI:-0.034 to -0.020), FEV1 pred% (B=-0.028, 95% CI: -0.034 to -0.022) and IC pred% (B=-0.033, 95%CI: -0.041 to -0.025) were affected only by smoking index. RV was only affected by age (B=0.013, 95%CI: 0.003 to 0.024), while FEV1/FVC and RV pred% was almost not affected by gender, age or smoking index.

Conclusion Among smokers with FEV1/FVC ≥ 0.7, the impairment of smoking to lung function can be found in all age groups. However, in the young population of < 50 years old group, the decline of FVC pred% and IC pred% were more obvious. The decline of volume indexes in the early impairment of lung function induced by smoking need to be paid more attention.

FEV1/FVC≥0.7的吸烟者肺功能指标变化特点及其临床意义

Characteristics of lung function indexes in smokers with FEV1/FVC≥0.7 and its clinical significance