Chandrasekharan UM, et al. - Given that L-arginine is the sole precursor of nitric oxide (NO), authors tested the premise that levels of L-arginine metabolic products reflecting NO metabolism are altered in patients with rheumatoid arthritis (RA). Findings suggested diminished bioavailability of global L-arginine, while levels of plasma arginase activity, asymmetric dimethylarginine, and symmetric dimethylarginine (SDMA) were elevated in patients with RA vs healthy control subjects. Experts noted an link between plasma SDMA and both hypertension and hyperlipidemia in patients with RA. In these patients, this dysregulated L-arginine metabolism could function as a potential indicator of CVD risk.