Pulmonary Function Tests and Their Associated Factors Among Type 2 Diabetic Patients At Jimma Medical Center, Jimma, Southwest Ethiopia, 2019: Comparative Cross Sectional Study

Abstract

Background: Impairments of lung function due to type 2 Diabetes Mellitus (DM) have been less addressed in our country even though they have a marked impact on life of people and may lead to morbidity and mortality. Objective: The aim of the present study was to assess pulmonary function tests (PFTs) and identify their associated factors among type 2 diabetic patients at Jimma Medical Center (JMC), Jimma, Southwest Ethiopia, 2019. Methods: A comparative cross-sectional study was conducted at JMC, Jimma, Southwest Ethiopia among 298 study participants from 01, April to 30, May, 2019. A face to face interview with semistructured questionnaire was conducted. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), ratio of FEV1/FVC, peak expiratory flow (PEF) and forced expiratory flow (FEF25 -75) were recorded by using digital Spirometer. The Collected data were analysed by using SPSS version 23. Independent samples t test, simple and multiple linear regression analysis were used. Results: Out of the total of 298 sample size, 145 type 2 diabetics and 145 non-diabetic subjects participated in this study with the overall response rate of 97.3%. The present study indicated that means of the PFTs among type 2 diabetics were significantly reduced when compared to their matched non-diabetics (FVC(%) (m =73.7 ± 13.8 vs m=93.8 ± 12.3), FEV1 (%) (m =76.4 ± 13.4 vs m=93.3±12.4 ), FEV1/FVC (%) (m =78.99 ± 11.4 vs m=96.6 ± 9.33), PEF (L/s) (m = 3.91±0.28 vs m=5.03 ± 0.35 ), and FEF25-75 (L/s) (m =2.89 ± 0.75 vs m=3.39 ± 0.82 )). This study also indicated that body mass index (BMI) (β = -1.93, p<0.001) and fasting blood sugar (FBS) (β = -0.22, p<0.001) were negative predictors of FVC%. BMI (β = -1.93, p<0.001) and FBS (β = -0.29, p<0.001) were negative predictors of FEV1%. BMI were (β = -1.403, p<0.001) was negative predictor of mean FEV1/FVC. BMI (β = -1.39 p<0.001) and FBS (β =-0.15, p<0.001) were negative predictors of mean of PEF(L/s). BMI (β = -0.075, p<0.001) and FBS (β = -0.075, p<0.001) were negative predictors of FEF25-75 (L/s) Conclusion: Compared to the non-diabetic participants, type 2 diabetics had signicantly reduced the PFTs. BMI and FBS were independent risk factors of the PFTs among the diabetic patients.