Plethysmography and its relationship with biochemical parameters in the Maltese population

Abstract

Plethysmography is an ever increasing test being performed at Mater Dei Hospital. The aim of the study was to obtain descriptive data regarding plethysmography in the Maltese population as well as to investigate the association of these lung function tests to various biochemical parameters.

282 patients who had plethysmography between June 2015 and March 2016 at Mater Dei Hospital were enrolled in the study. The indications for referral, demographic data, lung function parameters, white cell count (WCC), urea, potassium and fasting blood glucose were noted. The mean BMI of the population cohort was 29.06. BMI was found to be negatively correlated to serum potassium levels (r value: -0.14) and residual volume (r value: -0.2). DLCO, total lung capacity and forced expiratory flow in one second were negatively correlated to the WCC (r value: -0.2, -0.17 and -0.12 respectively) in the population. The current study confirms a significant association between lung function testing, diabetes, BMI and total serum white cell count after correcting for confounding factors. This highlights the need for clinicians to be more aware of the possibility of underlying lung disease in these patients. A good clinical evaluation using history and examination of such patients is essential so as to identify which patients should be referred for lung function testing. Such early referrals could potentially avoid progression of undiagnosed lung disease thus reducing the burden on the health care service with particular emphasis on acute hospital admissions and respiratory outpatient clinics.