Plasma L-arginine levels distinguish pulmonary arterial hypertension from left ventricular systolic dysfunction.
Pulmonary arterial hypertension (PAH) is a life-threatening condition, characterized by an imbalance of vasoactive substances and remodeling of pulmonary vasculature. Nitric oxide, formed from L-arginine, is essential for homeostasis and smooth muscle cell relaxation in PAH. Our aim was to compare plasma concentrations of L-arginine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) in PAH compared to left ventricular systolic dysfunction (LVSD) and healthy subjects. This was an observational, multicenter study comparing 21 patients with PAH to 14 patients with LVSD and 27 healthy subjects. Physical examinations were obtained and blood samples were collected. Plasma levels of ADMA, SDMA, L-arginine, L-ornithine, and L-citrulline were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Plasma levels of ADMA and SDMA were higher, whereas L-arginine and L-arginine/ADMA ratio were lower in PAH patients compared to healthy subjects (p < 0.001). Patients with PAH also had lower levels of L-arginine than patients with LVSD (p < 0.05). L-Arginine correlated to 6 min walking distance (6MWD) (r s = 0.58, p = 0.006) and L-arginine/ADMA correlated to WHO functional class (r s = -0.46, p = 0.043) in PAH. In conclusion, L-arginine levels were significantly lower in treatment naïve PAH patients compared to patients with LVSD. Furthermore, L-arginine correlated with 6MWD in PAH. L-arginine may provide useful information in differentiating PAH from LVSD.
['Sandqvist|Anna|A|http://orcid.org/0000-0003-4980-8230', 'Schneede|Jörn|J|', 'Kylhammar|David|D|', 'Henrohn|Dan|D|', 'Lundgren|Jakob|J|', 'Hedeland|Mikael|M|', 'Bondesson|Ulf|U|', 'Rådegran|Göran|G|', 'Wikström|Gerhard|G|']
D000368:Aged D000369:Aged, 80 and over D001120:Arginine D015415:Biomarkers D002853:Chromatography, Liquid D003937:Diagnosis, Differential D005260:Female D006801:Humans D006976:Hypertension, Pulmonary D008297:Male D008875:Middle Aged D053719:Tandem Mass Spectrometry D018487:Ventricular Dysfunction, Left D016277:Ventricular Function, Left
L-Arginine Pulmonary arterial hypertension Systolic dysfunction Dimethylarginines Left heart failure