Pulmonary complications in diabetes mellitus

Diabetes mellitus is a chronic debilitating and devastating disease, which affects various organs including lungs. The incidence and prevalence of diabetes mellitus and its complications is increasing day by day. Many studies have reported different pulmonary complications in diabetic patients. Chronic hyperglycemia causes non-enzymatic glycation of the chest wall and bronchial tree collagen protein that leads to fibrous tissue formation. Due to increased protein catabolism, there is decreased respiratory muscle strength. Neuropathy of phrenic nerve may cause diaphragmatic paralysis. So, the diabetes mellitus causes reduced ventilatory function. The disease also causes thickening of the basal lamina by glycation and reduces the gas diffusing capacity. It also causes glycation of immunoglobulin and increases the chance of acute and chronic pulmonary infections that causes fibrosis of lung parenchyma and consequently reduces the lung mechanics. Hyperglycemia causes local biochemical changes in the lungs and reduces the antioxidant defense of the lungs. The consequence of the local oxidative stress reduces the lung volumes, elastic recoil of the lungs and also causes reduced bronchodilatation. So, diabetes mellitus plays a significant role in development of pulmonary complication and like other organs lungs are the target organ in diabetes mellitus.