For patients with type 1 and type 2 diabetes, the lung is often overlooked as a target organ, but there are many respiratory function abnormalities associated with diabetes, according to commentary published in Diabetes Metabolism Research and Review.
Currently, the lung is not considered a potential target organ for diabetes. However, increasing evidence has linked diabetes with respiratory abnormalities including lung volumes, pulmonary diffusing capacity, control of ventilation, bronchomotor tone, and neuroadrenergic bronchial innervation. New evidence has also pointed toward a link between diabetes and pulmonary hypertension (PH).
The researchers noted that patients with diabetes often have decreased lung volumes. Studies have shown that patients with diabetes have a 1.6-fold higher risk for restrictive lung function impairment compared with those who do not have diabetes. Lung function impairment erodes the pulmonary reserve and can lead to repeated respiratory infections, chronic hypoxia, and volume overload.
Other studies have shown that PH is more common among those with diabetes compared with those without. Additionally, patients with diabetes and chronic obstructive pulmonary disease have significantly higher mean pulmonary arterial pressure compared with patients who have chronic obstructive pulmonary disease alone.
Patients with diabetes have related abnormalities that the researchers believe can contribute to PH. Patients with diabetes have significantly thicker epithelial and capillary basal laminas of the alveoli as well as thicker basal laminas in renal tubules and muscle capillaries. Autonomic neuropathy may worsen the inflammatory status of the lung. Additionally, hyperglycemia among patients with diabetes upregulates profibrotic mediators.
“By the moment, there is matter to conclude that fighting [metabolic syndrome] and diabetes would not only prevent major and well recognized complications such as visual loss or renal failure, but also might improve the lung function reserve and smooth the increase in pulmonary artery pressure, whichever is its primary cause,” the researchers wrote.
Fuso L, Pitocco D, Incalzi RA. Diabetic lung, an underrated complication from restrictive functional pattern to pulmonary hypertension [published online March 25, 2019]. Diabetes Metab Res Rev. doi: 10.1002/dmrr.3159