1. Determine if L-citrulline supplementation improves asthma control and increases FeNO (co-primary outcomes). Secondary outcomes will include changes in plasma L-arginine/ADMA, lung function (FEV1) and bronchial hyperreactivity. Asthmatic subjects will receive either 15 g L-citrulline/day or matched placebo for 7 weeks followed by a 4 week washout and then 7 weeks of the opposite treatment. A parallel subset study of healthy obese controls will receive open label L-citrulline for 7 weeks.
This is a proof-of-concept, randomized, double blinded, placebo controlled study to determine if adding on L-citrulline to controller therapy in obese late onset asthmatics: a) improves asthma control, and b) increases FeNO levels. Secondary research questions are to determine if L-citrulline supplementation can: a) increase plasma L-Arginine/ADMA ratio, b) improve lung function (FEV1), and c) reduce bronchial hyperresponsiveness (methacholine PC20).
1. Asthma 2. BMI >/= 30 3. Not currently smoking 4. Prescribed asthma medication NA
Principal Investigator