COMPARATIVE STUDY OF PULMONARY FUNCTION TESTS WITH MICROVASCULAR COMPLICATIONS, RETINOPATHY AND NEPHROPATHY IN TYPE 2 DIABETES MELLITUS AND CORRELATION WITH DURATION OF DIABETES

Background: The major morbidity in type 2 diabetes mellitus is due to microangiopathic and macroangiopathic complications. Though lung has been widely acknowledged to be a target organ in diabetes mellitus, its correlation and severity of involvement to other microvascular complications has not been studied. Aim: To study pulmonary function tests in type 2 diabetes mellitus and evaluate association of PFTs with microvascular complications, retinopathy and nephropathy and further assess the relationship of retinopathy, nephropathy and lungs with duration of diabetes. Methods: A cross sectional study was carried out in 100 male type 2 diabetic patients attending diabetic clinic in tertiary hospital. 100 non- diabetic subjects were selected as control from general population. PFTs tests were performed. Results were interpreted by one way ANOVA test. Association of PFT parameters FVC, FEV₁, FEV_1% in type 2 diabetic patients with nephropathy and retinopathy was analysed by Pearson's correlation coefficient. The patient population was subdivided according to the duration of diabetes into 2 groups; less than 10 years of illness and more than 10 years. Relationship of each microvascular complications, retinopathy, nephropathy and pulmonary function tests with duration of diabetes was assessed by one- way ANOVA test. Results: There was a significant decrease in PFT parameters as compared to non-diabetic controls. The PFTs in type 2 diabetic subjects with nephropathy showed decline in FVC, FEV_1, FEV_1%, however association of these parameters with GFR and microalbuminuria was not significant. Also, a similar decline of PFT parameters was observed with increasing grades of retinopathy, though not significant. There was a significant positive correlation of retinopathy with microalbuminuria and GFR (nephropathy) in type 2 diabetic subjects. Also, there was significant association of microalbuminuria, GFR and retinopathy with increase in duration of diabetes. On the contrary the decline in FVC, FEV₁, FEV_1% with duration of diabetes was not statistically significant. Conclusion: Type 2 diabetic patients with poor glycaemic control and longer duration of diabetes history had significant correlation with microvascular complications, nephropathy and retinopathy as compared to pulmonary complications (PFT parameters). It is highly suggestive that diabetic patients with retinopathy must be screened for nephropathy.