Shilpa^1*, Rohit²

¹Assistant Professor, ²Post Graduate, Department of General Medicine Navodaya Medical College Hospital and Research centre

Raichur Karnataka, INDIA.

Email: shilpaanil14@gmail.com

Table 1: Association of FVC% and FEV1/FVC with Sex

Out of 60 subjects, total of 25 (41.6%) subjects had reduced FVC% with males comprising of 14 (56%) and females 11 (44%).A total of 5 (8.33%) subjects had FEV1/FVC% of <70% and 55 subjects had FEV1/FVC% of >70%.

Table 2: Association of FVC and FEV1/FVC with Age

There was reduction in FVC% as the age increases. As the age progresses, there was reduction in FEV1/FVC%.

Table 3: Association of FVC and FEV1/FVC with duration of Diabetes

As the duration of diabetes increases there is increasing trend in number of patients with reduced FVC% and FEV1/FVC%. Also as the duration of diabetes increases there was reduction in FVC% and FEV1/FVC%. Hence, there is correlation between duration of diabetes and FVC%. Also as the p-value is <0.05 it is statistically significant.

Table 4: Association of FVC and FEV1/FVC withHbA1c

Out of 10 patients of well controlled group 6 patients had reduction in FVC%. In moderately controlled group 11 out of 21 patients had reduced FVC%. In poorly controlled group 11 out of 33 patients had reduced FVC%. (p-value- 0.21). Out of 21 patients in moderately controlled group, 2 had reduction in FEV1/FVC%. In poorly controlled group 3 out of 33 patients had reduced FEV1/FVC%.

DISCUSSION

Present study was undertaken to assess pulmonary function abnormalities in patients with type 2 diabetes mellitus. Few studies have focused on the relationship between pulmonary function and diabetes. Most such studies have been conducted on subjects with type 1 diabetes. When duration of diseases was compared with all parameters the following was observed:

• There was a tendency of all parameters to fall with longer duration of diabetes.
• Poor glycemic control was associated with reducing pulmonary functions.
• Also patients with diabetic retinopathy had more pronounced reduction in pulmonary functions compared to diabetic patients with normal fundus study.

In the study of Guzzi et al,^6​ absolute values and percentage of predicted normal values of FEV1, MVV, vital capacity and total lung capacity were reduced in NIDDM group. In Lange et al study,⁷ the diabetic subjects had slightly smaller height adjusted FEV1 andFVC compare values of non-diabetic subjects, their regression analysis also, showed association between raised values of plasma glucose  and reduction of the lung function was highly significant. Ozmen et al⁸reported abnormal pulmonary function tests in their diabetic patients that were mild and unlikely to be of clinical significance. The most likely explanation is that single breath method may not be sensitive enough to detect pulmonary vascular microangiopathy. Low pulmonary vascular pressures determine only minor changes in pulmonary capillaries of diabetes mellitus subjects, and so the commonly used method of DLco might not discriminate between diabetics mellitus and normal subjects. In our study, we did not look at diffusing capacity. However, a similar explanation may account for our observation that the spirometric abnormalities though being consistently noted in diabetics, did not reach levels of statistical significance as expected. Diabetes mellitus may involve the lung apart from kidneys, eyes and nerves since the pulmonary microvascular circulation is extensive and has abundant connective tissue.​⁹The pulmonary complications of diabetes mellitus have been poorly characterized. Although some authors have reported normal pulmonary function, others found abnormalities in lung volumes, pulmonary mechanics, and diffusing capacity​.¹⁰ Uchida et al found that there was decreased pulmonary diffusing capacity in patients with diabetes with perfusion defect on ventilation perfusion scintigrams.¹¹Ehrlich et al showed that patients with type 2 DM were at increased risk of several pulmonary condition like - asthma, Chronic Obstructive Pulmonary Disease (COPD), fibrosis, and pneumonia.¹² Alveolar capillary membrane begins to thicken with longer diabetes duration, and this reflects itself both on ventilation functions and ventilation perfusion parameters.​^​The study of Weynand et al¹³ shows basal lamina thickening of capillaries and epithelia in lungs and kidneys in a couple of diabetic patients. However, whereas basal lamina thickening of renal capillaries correlated well with the duration of diabetes, the pulmonary lesions did not. Weynand et al did not discuss the discrepancy of their results in detail. The discrepancy can be explained by functional differences or by differences in vascular pressure between the kidney and the lung.¹³In a study by Walter et al there was a progressive decrease in mean FVC values by 109 ml/year.¹⁴In study done by Kanya Kumari et al¹⁵ there was a progressive decrease in mean FVC values in diabetic patients. In a study by Shah et al, the PFTs were significantly decreased in diabetic patients compared with the healthy controls except FEV₁/FVC. There was no correlation found between FVC and FEV₁ and duration of illness as well as HbA1c.In our study there is decrease in pulmonary functions as duration of diabetes increases.

CONCLUSION

The PFT should be essentially done in these patients for better management as pulmonary parameters are seem to be effected in patients of diabetes. The effect on the FVC was even more pronounced in diabetics who had duration of disease longer than 5 years, and the effect was not explained by the difference in age alone.

REFERENCES

1. World Health Organization. Fact sheet: Diabetes. Available from: http://www.who.int/news-room/fact-sheets/detail/diabetes
2. Mohan V, Madan Z, Jha R, Deepa R, Pradeepa R. Diabetes–social and economic perspectives in the new millenium. ​International Journal of Diabetes in DevelopingCountries ​200;​ 24:29-35.
3. Panner Selvam A. Gross hyperglycemia, domiciliary management in a rural set up. Manual of advanced Postgraduate course in Diabetology 1998; 18:170-175.
4. Hamlin CR, Kohn RR, Luschin JH. Apparent accelerated aging of human collagen in diabetes mellitus. Diabetes. 1975; 24: 902–4. 
5. Fogarty AW, Jones S, Britton JR, Lewis SA, McKeever TM. Systemic inflammation and decline in lung function in a general population: A prospective study. Thorax. 2007; 62: 515–20.
6. Guazzi et al. Improvement in alveolar-capillary membrane diffusing capacity with enalapril in CCF  and counteracting effect of aspirin: Circulation 1997; 95; 1930-36.
7. Lange P, Groth S, Kastrup J, Appleyard M, Jansen J, Schnohr P. Diabetes mellitus, plasma glucose  and lung function in a cross-sectional population study. Eur Resp J 1989; 2: 14-19.
8. Ozmen B, et al. Pulmonary function parameters in patients with DM. Diabetes Research  and Clinical Practice 2002; 57: 209–211.
9. Sandler M, Bunn AE, Stewart RI: Cross-section study of pulmonary function in patients with insulin dependent diabetes mellitus. Am Rev Resp Dis 1989; 137: 13-16.
10. Shah SH, Sonawane P, Nahar P, Vaidya S, Salvi S. Pulmonary function tests in type 2 diabetes mellitus and their association with glycemic control and duration of the disease. Lung India. 2013; 30(2):108-12.
11. Uchida K, Takahashi K, Aoki R, Ashitaka T. Ventilation-perfusion scintigram in diabetics. Ann Nucl Med. 1991; 5: 97–102.
12. Ehrlich SF, Quesenberry CP, Vanden Eeden SK, Shan J, Ferrara A. Patients diagnosed with diabetes are at increased risk for asthma, COPD, pulmonary fibrosis and pneumonia but not lung cancer. Diabetes Care. 2010; 33: 55–60.
13. Weynand B, Jonckheere A, Frans A, Rahier J. Diabetes mellitus induces a thickening of the pulmonary basal lamina. Respiration 1999; 66: 14-19.
14. Walter R, Beiser A, Rachel J, et al. Association between glycemic state and lung function. The Framingham Heart Study. Am J Respir Crit Care Med. 2003; 167: 911–16.
15. Kanya Kumari DH, Nataraj SM, Devaraj HS. Correlation of duration of diabetes and pulmonary function tests in type 2 diabetes mellitus patients. Int J Biol Med Res. 2011; 2(4):1168 -1170.