Analysis Of Pulmonary Function In 15 Patients With Glycogen Storage Disease Type Ⅱ

Background:Glycogen accumulation type Ⅱ(glycogen storage disease type Ⅱ,GSD II,OMIM 232300)is a rare autosomal recessive genetic disease caused by GAA gene defect,so it is also known as Pompe disease.For the patients belonging to late onset Pompe disease,when respiratory muscle involvement shows respiratory muscle weakness,they can be diagnosed in respiratory department for the first time because of chest tightness or shortness of breath after exercise,and pulmonary ventilation function test is usually performed routinely.At the same time,some studies have shown that compared with patients in Europe and the United States and other countries,Chinese patients with LOPD have the characteristics of earlier age of onset,faster disease progression and earlier respiratory muscle involvement.Therefore,we need to summarize the characteristics of pulmonary function test results of patients with Pompeii disease,which is helpful for early detection,early diagnosis and early treatment of Pompeii disease patients,and improve their life cycle and quality of life.Existing studies have shown that the lung function of patients with Pompeii disease often shows restrictive ventilatory dysfunction due to respiratory muscle weakness,and this restrictive ventilatory disorder is significantly different from the most common interstitial lung disease-related restrictive ventilatory disorder in the expiratory descending branch of the flow-volume(F-V)curve.Most of the studies only focus on several important parameters and indicators of pulmonary ventilation function in patients with Pompeii disease,but there is no analysis of geometric characteristics related to the figure of the F-V curve itself.at the same time,due to the low incidence of Pompeii disease,there is a relative lack of clinical evidence related to pulmonary function,so we collected the results of pulmonary ventilation function tests in 15 patients with Pompeii disease,and made a descriptive and correlation analysis.And creatively derive the first and second derivatives of the F-V curve.Objective:To collect the clinical data related to pulmonary ventilation function of patients with Pompe disease,analyze the performance characteristics of related indexes,and summarize the morphological changes and geometric characteristics of F-V and V-T curves.These characteristics will be helpful to clinical practice to screen out neuromuscular diseases such as Pompe disease from patients with restrictive ventilatory disorders.To further improve the respiratory physicians’ awareness of differential diagnosis of Pompe disease patients who were first diagnosed in the respiratory department because of chest tightness and other respiratory myasthenia related symptoms after exercise,so as to realize the early detection and diagnosis of Pompe disease patients.Materials and methods:Fifteen patients with LOPD were diagnosed in the Department of Respiratory and critical Care Medicine and Department of Neurology,Qilu Hospital of Shandong University from 2001 to 2020.All patients were diagnosed by muscle biopsy,histochemical staining,GAA enzyme activity and gene detection in the Department of Neurology and Neuromuscular Pathology,Qilu Hospital of Shandong University.The data of important indexes related to lung function recorded in excel were converted into csv format,and then imported into statistical software Jamovi(Version 1.2.27.0)for statistical analysis.The graphic curve of the original pulmonary ventilation function report of the subjects was derived from the pulmonary function room,and the curve was obtained by get data software,and then the coordinate positions of a series of discrete points were obtained according to the extracted curve point position by origin2017 software.The fitting curve was obtained by non-linear fitting,and then the first and second derivatives of the fitting curve were obtained.Results:1.Descriptive analysis:the age of 15 patients ranged from 13 to 53 years old,with a relatively large age span,which was consistent with the characteristics of Pompeii disease.The ratio of male to female was 8:7,and there was no significant gender difference.The overall BMI index of the patients is not high,ranging from 12.98 to 26.19kg/m2,indicating that the nutritional status of the patients is relatively poor.The one-second rate of all patients,that is,FEV1/FVC is greater than 70%,fluctuating between 80%to 100%,suggesting that there is no obstructive ventilatory dysfunction.The ratio of FVC to predicted value was less than 80%in 14 cases except 1 patients,suggesting restrictive ventilatory dysfunction,which is consistent with the characteristic that ventilatory disorder caused by cumulative respiratory system of Pompeii disease is restrictive ventilatory disorder.The percentage of PEF%was lower than the predicted value.It is suggested that there is a decrease in peak velocity during respiratory exercise caused by the decrease of respiratory muscle strength in patients with Pompe disease.2.Correlation analysis:the percentage of FEV1 in the predicted value and the p value of the patient’s age were 0.046<0.5.There was statistical difference.It is suggested that the older the patient is,the better the pulmonary function is.The predicted value of PEF%and the p value of BMI were 0.041<0.05.It was suggested that the higher the BMI of the patients,the higher the percentage of the predicted PEF%,that is,the respiratory muscle strength was maintained better.The p value of PEF%predicted value and FEV1%predicted value is less than 0.001,suggesting that the higher the percentage of PEF%predicted value,the better the lung function of the patients.3.The measured value and the predicted value curve of the subjects’ F-V curve basically coincided after the descending branch,that is,the volume 1L,suggesting that the slope of the curve formed by the expiratory descending branch of restrictive ventilatory disorder associated with Pompe disease was similar to that of the predicted value,that is,the two curves were almost parallel.4.The first derivative of V-T curve shows the curve that the absolute value increases at first and then decreases.The extreme value and shape of the second derivative curve are roughly symmetrical,indicating that the expiratory flow rate of patients with Pompeii disease is basically consistent and symmetrical in the increasing and decreasing stages.Conclusion:1.The main result of pulmonary ventilation function in patients with Pompe disease was restrictive ventilation disorder,accompanied by a decrease in peak expiratory flow.2.The older the patients with Pompe disease are,the longer the disease cycle is,and the general condition of the patients’ lung function may be relatively better.3.In patients with Pompeii disease,there may be a parallel slope between the measured value and the predicted value of the descending branch of the F-V curve of pulmonary function in patients with Pompe disease,which is different from that of other types of restrictive ventilatory dysfunction.4.The first derivative of the V-T curve of patients with Pompe disease is a curve in which the absolute value first increases and then decreases,and the extreme value and shape of the second derivative curve are roughly symmetrical,indicating that when Pompeii disease patients exhale,the velocities before and after the increase and attenuation of respiratory muscle strength are symmetrical.However,the time to maintain high muscle strength output became shorter and the instantaneous endurance became worse.