Correlation of Lung Volumes with HbA1c and Duration of Diabetes, in Type 2 Diabetics, at a Tertiary Care Hospital, Karachi, Pakistan.

Abstract

Introduction: Various studies have detected a link between lung abnormalities and
Diabetes Mellitus (DM) but this relationship isn't that well established.
Objectives: To document the correlation between pulmonary function tests (PFTs)
and glycated hemoglobin (HbA1c) and the duration of DM.
Methodology: This single-center study recruited 100 individuals with Diabetes
Mellitus, who presented to the medicine Outpatient department (OPD) or admitted
in Medical Unit-1/C1 of “Dr. Ruth KM Pfau Civil Hospital Karachi” from 1st November 2019 till 10th October 2020. Data was analyzed using SPSS version 23.0.
Results: Of the 100 participants, the majority of them were men (n=57), had DM for
the past ≤8 years (n=54), and had moderately controlled DM with an HbA1c in the
range 6.5-7.9 (n=37). The spirometry results of over half of the patients (n=57) were
normal however, approximately in one third of them (n=35) restrictive lung pattern
was detected. Significant inverse correlations were found between HbA1c and FEV1
(r= -0.281, p-value=0.005), HbA1c and FEV1/FVC (r= -0.386, p-value=0.000), duration of DM and FEV1 (r= -0.259, p-value=0.009) and duration of DM and FEV1/FVC
(r= -0.381, p-value=0.000).
Conclusion: A significant relationship was found between lung function tests (FEV1
and FEV1/FVC ratio) and poor glycemic control and increased duration of DM;
therefore, periodic assessment of PFTs and HbA1c is crucial in early screening and
management of lung abnormalities in type2 diabetics.

Keywords: Type 2 DM, HbA1c, “Forced Vital Capacity (FVC)”, “Forced Expiratory
Volume in 1second (FEV1)”, “Pulmonary Function test (PFT)”.