To the Editor:
With interest we have read the letter by Lau et al. [1] regarding circulating asymmetric dimethylarginine (ADMA) in a cohort of children with asthma from the Australian Childhood Asthma Prevention Study.
ADMA, a product of protein degradation, is an endogenous nitric oxide synthase inhibitor that has been shown to be increased in mouse models of allergic airway inflammation and to be associated with airways hyperresponsiveness in these animals [2]. ADMA has also been reported to be increased in sputum samples [2] and exhaled breath condensates [3] from paediatric patients with asthma. Increased ADMA in serum has recently been found to be associated with the severity of symptoms in late-onset asthma and obesity [4].
Lau et al. [1] found no difference in …
