Lung Function Changes Related to Diabetes Mellitus

Abstract

Diabetic microangiopathy targets the lung as it does other organs. Even though respiratory dysfunction in most patients with diabetes is subclinical and rarely the presenting complaint, there are several reasons why pulmonary assessment is important: (1) Pulmonary function testing noninvasively quantifies physiological reserves in a large microvascular bed that is not clinically devastated by diabetes. (2) Subclinical loss of pulmonary reserves becomes overtly debilitating under conditions of stress, such as with aging, chronic hypoxia due to lung disease or high altitude exposure, or volume overload secondary to cardiac and renal failure. (3) Unlike myocardial or skeletal muscle function, pulmonary indices are largely independent of physical fitness. (4) Interpretation of pulmonary function indices is not complicated by secondary sequelae of diabetic end-organ failure or prior therapy. Lung function could provide useful measures of the progression of systemic microangiopathy. (5) Chronic use of inhaled insulin may affect long-term pulmonary function, while preexisting pulmonary dysfunction may alter the absorption and bioavailability of inhaled insulin. This review will discuss the changes in lung function observed in diabetes, their underlying mechanisms, and their physiological and clinical implications.

The Diabetic Lung - A New Target Organ?

“…This is mainly because the alveolar-capillary system is characterized by a great microvascular reserve, and pulmonary abnormalities are commonly subclinical in diabetic patient [4]. However, the loss of microvascular reserve in the lung may become clinically important, with increased risk of hypoxia, in case of acute or chronic pathological lung conditions, including pneumonia, chronic obstructive pulmonary disease, and asthma, or fluid overload secondary to heart failure [5].…”

“…Also, insulin resistance could alter lung volume and mechanical function via mediators such as leptin. Indeed, animal studies have provided evidence for leptin as a stimulant of ventilation, whereas researchers have also proposed an important role for leptin in lung maturation and development [5]. Studies further suggest a significant impact of leptin on specific respiratory diseases, including obstructive sleep apnoeahypopnoea syndrome, asthma, chronic obstructive pulmonary disease (COPD), and lung cancer [5].…”

Comparative Study of Pulmonary Function Tests With Microvascular Complications, Retinopathy and Nephropathy in Type 2 Diabetes Mellitus and Correlation With Duration of Diabetes

“…But this loss of microvascular reserve in the lung may become clinically important in case of acute or chronic pathological lung conditions like pneumonia, chronic obstructive pulmonary disease, asthma and heart failure and hence should not be disregarded. [37] …”

FVC, FEV1 And FEV1/FVC% In Type-1 Diabetic Male And Their Relationships With HbA1c

“…enzymatic glycosylation and thus eventually causes reduction in lung compliance and subsequent chronic airflow obstruction 5,6 .…”

“…Chronic hyperglycemia causes microvascular changes such as thickening of basal laminae in the smaller vessels of the lungs and ultimately causes reduction of vascular diffusing capacity 5 . It was also observed that hyperglycemia affects the lung by nonenzymatic glycosylation of chest wall and bronchial tree proteins which prevents lung expansion 6 .…”