Pulmonary function tests in type 2 diabetes: a meta-analysis

Abstract

ObjectivesTo determine the association between type 2 diabetes (T2D) and pulmonary function tests.MethodsAfter conducting an exhaustive literature search, we performed a meta-analysis. We employed the inverse variance method with a random effects model to calculate the effect estimate as the mean difference (MD) and 95% confidence interval (CI). We calculated the heterogeneity with the I2 statistic and performed a meta-regression analysis by sex, body mass index (BMI), smoking and geographical region. We also conducted a sensitivity analysis according to the studies’ publication date, size of the T2D group and the study quality, excluding the study with the greatest weight in the effect.ResultsThe meta-analysis included 66 studies, one longitudinal, 2 case-control and 63 cross-sectional ones, with 11 134 patients with T2D and 48 377 control participants. The pooled MD (95%CI) for the predicted percentage of FEV1, FVC, FEF25–75%, PEF and DLCO were −7.15 (95%CI −8.27, −6.03; p<0.001), −9.21 (95%CI −11.15, −7.26; p<0.001), −9.89 (95%CI −14.42, −5.36; p<0.001), −9.79 (95%CI −13.42, −6.15; p<0.001) and −7.13 (95%CI −10.62, −3.64; p<0.001), respectively. There was no difference in the ratio of FEV1/FVC (95%CI −0.27; −1.63, 1.08; p=0.69). In all cases, there was considerable heterogeneity. The meta-regression analysis showed that between studies heterogeneity was not explained by patient sex, BMI, smoking or geographical region. The findings were consistent in the sensitivity analysis.ConclusionsT2D is associated with impaired pulmonary function, independently of sex, smoking, BMI, and geographical region. Longitudinal studies are needed to investigate outcomes for patients with T2D and impaired pulmonary function.

Association of Pulmonary Function Decline over Time with Longitudinal Change of Glycated Hemoglobin in Participants without Diabetes Mellitus

“…From the Korea National Health and Nutrition Survey database, compared with non-DM participants, type 2 DM had a significantly lower FEV1 (2.7 vs. 2.8 L) and FEV1/FVC (75.9 vs. 77.9%) [25]. The difference between DM and non-DM patients for the FEV1/FVC ratio was insignificant in a pooled meta-analysis [26]. The baseline FEV1 (3.05 L for men; 2.09 L for women) and FVC (3.64 L for men; 2.49 L for women) in our participants were similar to those in nondiabetic and healthy Asian adults [25,27].…”

Effect of Glycated Hemoglobin (HbA1c) and Duration of Disease on Lung Functions in Type 2 Diabetic Patients

“…Díez-Manglano et al 2021 [ 21 ] conducted a meta-analysis to hypothesize that the lung is a target organ of T2D. The authors identified a relationship between T2DM and impaired lung function, including FVC, FEV1, PEF, and FEF 25–75%, independent of gender, smoking habits, BMI, and geographical region.…”

Diabetic endothelial microangiopathy and pulmonary dysfunction

“…In clinical practice, abnormal pulmonary function is observed in some diabetic patients; the most consistent abnormalities are reduced lung volume, pulmonary elastic recoil, and pulmonary diffusion impairment in both young and adult diabetic subjects, which are caused by decreased capillary blood volume in the adult group ( 16 , 17 ). The existence of pulmonary microangiopathy is suggested by the histological data, which also shows thickening of the basal lamina of the pulmonary capillaries ( 18 ).…”