The relation between insulin resistance and lung function: a cross sectional study.

BACKGROUND: Impaired lung function and insulin resistance have been associated and thereby have also been indicated to be powerful predictors of cardiovascular mortality. Therefore, the co-existence of insulin resistance and impaired lung function accompanied with cardiovascular risk factors should induce cardiovascular mortality even in patients without known respiratory disease in a cumulative pattern. It could be useful to determine the lung function of patients with insulin resistance in order to decrease cardiovascular mortality by means of taking measures that minimize the risk of decline in lung function. However, no prior studies have been done on association between insulin resistance and lung function in adults in Turkey. We aimed to determine if insulin resistance plays a detrimental role in lung function in outpatients admitted to internal medicine clinics in adults from Turkey. METHODS: A total of 171 outpatients (mean ± SD) age: 43.1 ± 11.9) years) admitted to internal medicine clinics were included in this single-center cross-sectional study, and were divided into patients with (n = 63, mean ± SD) age: 43.2 ± 12.5) years, 83.5 % female) or without (n = 108, mean ± SD) age: 43.0 ± 11.6) years, 93.5 % female) insulin resistance. All patients were non-smokers. Data on gender, age, anthropometrics, blood pressure, blood biochemistry, metabolic syndrome (MetS), and lung function tests were collected in each patient. Correlates of insulin resistance were determined via logistic regression analysis. RESULTS: Insulin resistance was present in 36.8 % of patients. Logistic regression analysis revealed an increase in the likelihood of having insulin resistance of 1.07 times with every 1-point increase in waist circumference, 1.01 times with every 1-point increase in triglycerides, 0.93 times with every 1-point decrease in HDL (high density lipoprotein) cholesterol, and 0.86 times with every 1-point decrease in percentage of FEV1/FVC pre (FEV1%pre: Forced expiratory volume in the first second of expiration for predicted values; FVC%pre.: Forced vital capacity for predicted values). CONCLUSIONS: Insulin resistance should also be considered amongst the contributing factors for decline in lung function.