The Association of Normal Range Glycated Hemoglobin with Restrictive Lung Pattern in the General Population

Abstract

Glycated hemoglobin (HbA1c) is an important diagnostic indicator of diabetes mellitus, and some authors have argued that it is related to impaired lung function in the diabetic population. However, there was rare study for association between lung function and HbA1c in the non-diabetic population. We investigated whether HbA1c below the diagnostic threshold is related to deficits in lung function. We analyzed biochemical and spirometry data from a nation-wide, population-based, case-control study (the KNHANES IV and V). Eligible as cases were all native Koreans aged 40 years or more with no medical illness. A total of 3670 participants were divided into 4 groups according to HbA1c (%) as follows: Group I (n = 842), ≥ 4.0 and ≤ 5.3; Group II (n = 833), > 5.3 and ≤ 5.5; Group III (n = 898), > 5.5 and ≤ 5.7; and Group IV (n = 1097), > 5.7 and ≤ 6.4. Group I had the greatest forced vital capacity (FVC, 96.3 ± 0.5% pred, P < 0.0001), forced expiratory volume per second (FEV1, 93.8 ± 0.5% pred, P < 0.0001) and FEV1/FVC (0.792 ± 0.003, P < 0.0001) compared with the other groups. Linear regression showed that HbA1c was closely related to FVC (β = -6.972154, P < 0.0001) and FEV1 (β = -5.591589, P < 0.0001), but not to FEV1/FVC. Logistic regression analysis revealed a significant association between HbA1c and a restrictive spirometric pattern (FVC < 80% pred., FEV1/FVC ≥ 0.70; OR = 3.772, 95% CI = 1.234-11.53), indicating that elevated HbA1c is closely associated with lung impairment in the non-diabetic population. In the healthy population, relatively high HbA1c level is associated with decrements of FVC and FEV1 and may be a reliable predictor of poor lung function, especially the restrictive pattern.

Breathlessness and Restrictive Lung Disease: An Important Diabetes-Related Feature in Patients with Type 2 Diabetes

“…Previous studies in patients with and without diabetes have described associations between a restrictive lung pattern and glucose metabolism [32-34, 39]. These findings are supported by the results shown in this study (Table 3).…”

Metabolic Determinants of Impaired Pulmonary Function in Patients with Newly Diagnosed Type 2 Diabetes Mellitus

“…However, progression of lung diseases, such as COPD, may predispose to impairment of glycemic control, though not reported by all studies [28]. Likewise, in a metabolically healthy population, an increase in HbA 1c within the normal range was associated with a decline in pulmonary function [29]. Although the underlying mechanisms are currently unknown, advanced glycation end-products (AGEs) may play a role in this context.…”

“…Although the underlying mechanisms are currently unknown, advanced glycation end-products (AGEs) may play a role in this context. AGEs may initiate adaptive immune reactions and reactive oxygen species (ROS) production, leading to microvascular damages and structural changes (e. g. thickening of alveolar epithelial basal laminae) and, consequently, to impaired lung function [29]. Indeed, some experimental human data support the concept of an association between AGEs and lung function or increased severity of lung pathologies [29].…”

Tipo de tratamiento farmacológico y deterioro de la función pulmonar en pacientes con diabetes tipo 2: un estudio de corte transversal

“…En algunos estudios longitudinales se ha encontrado que mucho antes del diagnóstico de la enfermedad los pacientes ya acusaban cambios en la función pulmonar (3,25,26). Los valores elevados de los biomarcadores pueden estar relacionados con la fisiopatología de las enfermedades cardiovasculares, renales y pulmonares, e incluso del cáncer, en los pacientes diabéticos (27,28).…”