Spirometry and Diffusion Studies in Patients with Type-2 Diabetes Mellitus and Their Association with Microvascular Complications

Abstract

Background. Diabetes is a systemic disease with-well known complications involving eyes, kidneys and nerves. The presence of an extensive pulmonary microvascular circulation and abundant connective tissue raises the possibility that lung may also be a target organ in diabetes. Methods.A total of 45 subjects were included in the study. All patients were evaluated for diabetic microangiopathies: nephropathy (by 24-hour protein excretion), retinopathy (by direct ophthalmoscopy) and neuropathy (by clinical examination). The patients were divided into following three groups: Group A: patients with type-2 diabetes mellitus (DM) with evidence of microangiopathy (n=15); Group B: patients with type-2 DM without any evidence of microangiopathy (n=15); Group C: non-diabetic subjects (n=15) as controls. Glycosylated haemoglobin (HbA1C) was measured as an indicator of glycemic control. Spirometry and single-breath diffusion capacity for carbon-monoxide (DLCO) were performed on all patients using Elite Series Body Plethysmograph machine.Results. A significant reduction of diffusion capacity corrected for alveolar volume (%DL/VA) was observed in group A (p<0.001), as compared to the other groups. There were no differences among the three groups for other pulmonary functions. There was a significant correlation between DL/VA percent predicted and albuminuria (r= -0.975, p<0.001), and DL/VA percent predicted and the retinopathy (r = -0.550, p< 0.05). Conclusion.This study shows a mild reduction in diffusing capacity in patients with type-2 DM with microangiopathy.

A Step Toward the Exploration of Better Spirometric Parameters for Early Diagnosis of Pulmonary Dysfunction in Persons With Type 2 Diabetes Mellitus

“…Hence, in the case of diabetic patients with high BMI, FEV1/SVC had a greater diagnostic value than FEV1/FVC. Similar results were observed in a population-based study in Southern Australia, where BMI, coronary artery disease, and age were found to be significant determinants of ventilatory function [ 7 ]. The effect of BMI on reducing lung function has been well documented [ 20 - 24 ].…”

“…The effect of VC of diabetic patients on pulmonary function has been reported by many authors [ 6 , 7 ]. The VC decreases with increasing BMI.…”

“…Forced vital capacity (FVC) and slow vital capacity (SVC) maneuvers are the parameters to determine VC. Obese and diabetic individuals have reduced pulmonary function parameters like FVC, forced expiratory volume in one second (FEV1), predicted FVC%, and predicted FEV1% [ 7 ]. SVC parameters have not been explored properly in diabetic obese patients.…”