Alteration of pulmonary function in diabetic nephropathy

BACKGROUND: Type 2 diabetes mellitus is increasing worldwide with an alarming rate. It is associated with the development of various chronic complications. The aim of this study was to explore the alteration of pulmonary function, and its association with renal complications in people with type 2 diabetes mellitus. METHODS: This cross-sectional study was conducted on three groups; 40 diabetic subjects without nephropathy (urinary albumin<30 mg/day), 40 subjects with nephropathy (urinary albumin≥30 mg/day), and 40 healthy subjects as the control group. The subjects with nephropathy were divided into those with microalbuminuria (urinary albumin=30-300 mg/day) and those with macroalbuminuria (urinary albumin>300 mg/day) .Diabetic subjects were matched to the control group in terms of age, sex, and BMI. Pulmonary function tests were performed and the results were compared between groups. RESULTS: Forced vital capacity (FVC; % predicted), forced expiratory volume in 1 second (FEV1; % predicted), and peak expiratory flow (PEF; % predicted) were significantly lower in subjects with diabetic nephropathy compared to the healthy controls (P<0.05). Meanwhile, in diabetic subjects, FVC and FEV1 were lower in those with diabetic nephropathy compared to those with normal albumin excretion (P<0.05). On the other hand, FEV1/FVC was significantly higher in diabetic people with nephropathy. Furthermore, a significant difference was observed between FVC and FEV1 in diabetic people with microalbuminuria compared to those with macroalbuminuria. CONCLUSIONS: This study showed that the pulmonary function was impaired in people with Diabetes. The progression of diabetic nephropathy to more advanced stages was also associated with more impairment of pulmonary function.