Diabetic Pneumopathy: Myth or Emerging Clinical Reality?

Abstract

Diabetes mellitus has long been recognized as a systemic disease with vascular, renal, and neurological complications. In recent years, increasing evidence suggests that the lungs may also be a target organ for diabetic injury, a condition tentatively termed 'diabetic pneumopathy.' or diabetic lung. Diabetic pneumopathy is a progressive lung disease resulting from diabetes, often involving DNA damage, cellular senescence, and the release of inflammatory factors that lead to fibrosis. This diabetes-related lung complication is linked to poor blood sugar control and can manifest as accelerated loss of respiratory function, making patients more susceptible to other lung issues like pneumonia. Diabetes-induced pulmonary fibrosis (DiPF) refers to lung scarring and dysfunction caused by diabetes, a chronic metabolic disease where excessive fibrosis, or extracellular matrix deposition, occurs in the lungs, leading to impaired organ function. While not a single defined disease, it's a known complication where the lungs are a targeted organ for damage, and patients with advanced diabetes show signs of fibrosis.

This review consolidates recent findings (2023–2025) on the epidemiology, pathophysiology, clinical manifestations, diagnostic methods, and therapeutic considerations of diabetic pneumopathy, and discusses its implications for long-term diabetes care.

Introduction

Chronic hyperglycemia and metabolic dysregulation in diabetes mellitus have well-established complications involving microvascular and macrovascular systems. However, the lung, with its vast microvascular network and connective tissue matrix, is increasingly being identified as a potential site of diabetes-related injury. The concept of 'diabetic pneumopathy' (DP) has emerged to describe structural, functional, and immunological lung changes in diabetes. Recent studies demonstrate associations between diabetes, impaired pulmonary function, increased risk of pulmonary fibrosis, and adverse respiratory outcomes. Despite this, diabetic lung disease remains under-recognized in clinical practice and absent from standard complication screening protocols.

Epidemiology

Epidemiological data from large cohort studies suggest that patients with diabetes exhibit a faster decline in pulmonary function compared to non-diabetic controls. A 16-year prospective Korean study demonstrated an accelerated decline in FEV₁ and FVC among diabetic adults. The Fremantle Diabetes Study (Australia) confirmed significantly lower spirometric indices in type 2 diabetes, independent of smoking and obesity. Recent meta-analyses highlight diabetes as a risk factor for post-COVID-19 pulmonary fibrosis. Prevalence estimates vary, but restrictive patterns predominate, with reported impairment rates between 20–45% of diabetic patients.

Pathophysiology

Several mechanisms are implicated:

1. Microangiopathy: Pulmonary capillary basement membrane thickening mirrors diabetic nephropathy and retinopathy.

2. Connective tissue glycation: Advanced glycation end-products (AGEs) stiffen lung parenchyma, impairing compliance.

3. Oxidative stress and inflammation: Chronic hyperglycemia promotes oxidative injury, cytokine release, and alveolar-capillary dysfunction.

4. Altered surfactant metabolism: Insulin resistance may disrupt surfactant homeostasis, impairing gas exchange.

5. Fibrogenesis: Diabetes increases susceptibility to pulmonary fibrosis, possibly via TGF-β and RAGE signaling pathways.

Clinical Manifestations

Most patients are asymptomatic early, but progressive lung involvement can manifest as:

- Mild exertional dyspnea

- Restrictive spirometric pattern (↓ FVC, preserved FEV₁/FVC ratio)

- Reduced diffusing capacity (DLCO)

- Increased risk of pulmonary infections and delayed recovery

- Higher incidence of interstitial lung disease and pulmonary fibrosis

Importantly, diabetic pneumopathy may contribute to increased cardiovascular and all-cause mortality, independent of other risk factors.

Diagnostic Considerations

Diagnosis involves a comprehensive medical evaluation, including history, physical examination, pulmonary function tests, imaging, and laboratory tests.

Specific lung function tests may show restrictive impairment especially reduced forced vital capacity (FVC) and diffusion capacity (DLCO).

Imaging: High-resolution CT scans show interstitial changes in subsets of diabetic patients.

Biomarkers: Elevated AGEs, inflammatory cytokines, and circulating fibrosis markers are being investigated.

Therapeutic Implications

• Strict blood sugar management and ongoing medical evaluation are crucial for early detection and to prevent the progression of this debilitating condition.

• Glycemic control: Better glucose regulation correlates with preserved lung function.

• Lifestyle interventions: Weight loss and exercise improve pulmonary mechanics.

• Pharmacotherapy: Some antidiabetic drugs like metformin, (GLP-1 receptor agonists, SGLT2 inhibitors) may have protective pulmonary effects via anti-inflammatory pathways. Pioglitazone shows antifibrotic effects in experimental studies.

• Screening: Routine PFTs in long-standing diabetes may allow earlier identification of at-risk patients.

• Vaccination: Recommended vaccinations can help prevent infections like pneumonia, which can be more severe in people with diabetes.

  
  

Future Directions

Longitudinal studies are required to establish causality and define diagnostic criteria. Integration of lung function assessment into diabetes complication screening guidelines should be considered. Further exploration of therapeutic interventions targeting pulmonary microangiopathy and fibrosis is warranted.

Conclusion

Diabetic pneumopathy is emerging as a genuine diabetes-related complication with significant clinical implications. Though under-recognized, mounting evidence from 2023–2025 underscores its impact on lung function, susceptibility to pulmonary fibrosis, and overall prognosis. Clinicians should maintain a high index of suspicion and consider pulmonary evaluation in patients with long-standing diabetes. Strict blood sugar management and ongoing medical evaluation are crucial for early detection and to prevent the progression of this debilitating condition. Recognition of diabetic pneumopathy may pave the way for comprehensive complication management, bridging metabolic and respiratory medicine.

References

• Kopf S, Kumar V, Kender Z, Han Z, Fleming T, Herzig S, Nawroth PP. Diabetic Pneumopathy–A New Diabetes-Associated Complication: Mechanisms, Consequences and Treatment Considerations. Front Endocrinol (Lausanne). 2021;12:765201. doi:10.3389/fendo.2021.765201.

  
  

• Choi W, Lee J, Lee J, et al. Trajectory of lung function in diabetic adults: A 16-year community-based prospective study. Respirology. 2024;29(7):e14658. doi:10.1111/resp.14658.

  
  

• Hayfron-Benjamin CF, et al. Pulmonary Function in Adults With Type 2 Diabetes: The Fremantle Diabetes Study. Chest Pulmonary. 2023;207:978-995.

  
  

• Chen C, Huang Z, Liu L, Su B, Feng Y, Huang Y. Lung Function Impairment and Risks of Incident Cardiovascular Diseases and Mortality Among People With Type 2 Diabetes: A Prospective Cohort Study. Diabetes Care. 2025;48(5):728-736. doi:10.2337/dc24-2188.

  
  

• Sharma A, Sharma A, Chauhan R. Spirometric Lung Functions in Type 2 Diabetes Mellitus: A Hospital-Based Study. Cureus. 2023;15(5):e38919. doi:10.7759/cureus.38919.

  
  

• Rajput S, Parashar R, Sharma JP, Raghuwanshi P, Pakhare A, Joshi R, Hulke S. Assessment of Pulmonary Functions and Dysfunctions in Type II Diabetes Mellitus: A Comparative Cross-Sectional Study. Cureus. 2023;15(2):e35081. doi:10.7759/cureus.35081.

  
  

• Mehrabi S, Alishapour E, Soveid M. Pulmonary function in type 2 diabetes mellitus patients: a case-control study in southern Iran. Egypt J Intern Med. 2025;37:81. doi:10.1186/s43162-025-00472-3.

  
  

• Alanazia AH, Norwood C, et al. The impact of diabetes mellitus on blood-tissue barrier regulation and vascular complications: Is the lung different from other organs? Clin Exp Ther. 2024;doi:10.1080/21688370.2024.2386183.

  
  

• Mzimela N, Dimba N, Sosibo A, Khathi A. Evaluating the impact of type 2 diabetes mellitus on pulmonary vascular function and the development of pulmonary fibrosis. Front Endocrinol (Lausanne). 2024;15:1431405. doi:10.3389/fendo.2024.1431405.

  
  

• Wang L, et al. The discrepant effect of blood glucose on the risk of early and late restrictive lung disease: a cohort and cross-sectional study. BMC Pulm Med. 2024;24:3376. doi:10.1186/s12890-024-03376-0.

  
  

• Tan F, Li C, Jingyi J, et al. Diabetes mellitus increases the risk of post-COVID-19 pulmonary fibrosis: a meta-analysis of observational studies. [Journal]. 2025;[in press].

  
  

• Bai L, Zhang L, Pan T, Wu X, Wang G, Chen Z, et al. Idiopathic pulmonary fibrosis and diabetes mellitus: a meta-analysis and systematic review. Respir Res. 2021;22(1):175. doi:10.1186/s12931-021-01760-6.

  
  

• Molina-Luque R, et al. The Impact of Metabolic Syndrome Risk Factors on Lung Function: A Population-Based Study. JMIR Public Health Surveill. 2023;9:e43737. doi:10.2196/43737.

  
  

• Molina-Luque R, et al. Exploring the Relationship Between Insulin Resistance, Liver Health and Lung Function in Type 2 Diabetes. J Pers Med. 2024;15(8):340. doi:10.3390/jpm15080340.

  
  

• Kolahian S, Fernandez IE, Eickelberg O, Hartl D. Diabetic lung disease: fact or fiction? Respir Res. 2019;20:259. doi:10.1186/s12931-019-1234-y.