’Diabetic pulmonopathy’ has been described in type 2 diabetes patients though not well characterized. The present study was done to study the effect of type 2 diabetes on pulmonary function tests (PFTs), to find the influence of glycemic control and disease duration on PFTs and to see the effect of glycemic control and losartan therapy on PFTs.
Thirty type 2 diabetes patients with disease duration >10 years with microalbuminuria were selected. Group 1: 15 patients kept on strict glycemic control, group 2: 15 patients on losartan 50 mg/day along with strict glycemic control. Spirometry, blood sugar, HbA1C and microalbuminuria were measured at baseline and 12 weeks of treatment.
PFT parameters like FVC, FEV1, TLC, FEV1/FVC, FEF75, PEFR and DLCO were significantly decreased in diabetics compared to controls (p<0.001). A significant correlation was found between the duration of diabetes and these PFT parameters (p<0.001). HbA1C levels also correlated significantly with FEV1, FEF75, PEFR, FVC and TLC (p<0.01) and with DLCO (p<0.004). There was significant improvement in FEV1/FVC in group 1 diabetics after 12 weeks of strict glycemic control (p<0.04) but no improvement in other PFT parameters. In group 2 diabetics, there was significant improvement in FEV1 (p=0.04), TLC (p=0.02) but no improvement in other PFT parameters after losartan therapy.CONCLUSIONS: A mixed restrictive-obstructive pattern of pulmonary dysfunction is seen in patients with type 2 diabetes which is more severe in longer duration of disease and poor glycemic control. Strict glycemic control over 12 weeks is not sufficient to improve this pulmonary dysfunction. Losartan with strict glycemic control does not improve pulmonary function.
Pulmonary dysfunction should be regarded as a specific derangement induced by diabetes mellitus. Further studies may clarify whether this should be included as a long term complication of diabetes. The role of strict glycemic control and losartan therapy on pulmonary function in diabetics with incipient nephropathy is another interesting aspect and needs further studies.
B. Sharma, None.