L-arginine pathway metabolites can predict exacerbation independently from beta blocker treatment in patients with COPD: A follow-up study

Abstract

Acute exacerbation of COPD (ECOPD) remains a challenge. Recently, beta blocker (BB) pretreatment was found to be associated with a significant reduction in ECOPD. We compared serum levels of asymmetric and symmetric dimethylarginine (ADMA, SDMA, respectively) and hsCRP in COPD patients with and without BB treatment. Methods: Serum ADMA, SDMA and hsCRP were investigated in 44 consecutive COPD patients (10 pretreated with BB). Diagnosis of ECOPD was based on GOLD criteria. The number of exacerbation episodes was registered over the past 5 years. Results: Initial ADMA, but no other markers was significantly higher in BB pretreated COPD patients independently from exacerbation There was no correlation between BB pretreatment and number of exacerbations over the follow-up period. Interestingly, initial hsCRP obtained at enrollment was significantly lower in patients with ECOPD compared to COPD patients in the BB pretreated subgroup. As expected, hsCRP was significantly higher in ECOPD compared to COPD patients in the non-BB pretreated subgroup. Both, initial ADMA and SDMA obtained at enrollment were significantly higher in patients with exacerbation independently from treatment subgroup. Moreover, ADMA and SDMA positively correlated with the number of exacerbations over the follow-up period in the total population. In contrast, hsCRP showed a positive correlation with the number of exacerbations only in the non-BB pretreated subgroup. Conclusions: ADMA and SDMA can predict subsequent exacerbations. BB pretreatment may attenuate systemic inflammatory response, thus hsCRP is less informative for monitoring this special subgroup of COPD patients.