Nitric oxide, oxidant status and antioxidant response in morbidly obese patients: the impact of 1-year surgical weight loss.

BACKGROUND The aims of this study were to evaluate nitric oxide (NO) metabolites (nitrite/nitrate NO x ) as proinflammatory parameter and total oxidant status (TOS) as well as total antioxidant response (TAR) as oxidative stress (OS) markers in morbidly obese (MO) patients in comparison with normal-weight healthy (NWH) subjects and to determine the post-bariatric surgery changes of NO x and OS indicators in relation with weight loss. METHODS We examined serum NO x , TOS, and TAR in a bariatric group of MO patients and a NWH control group (n = 23 each group). In the NWH group, serum was examined once, while in the MO group, serum was examined before and at 3, 6, and 12 months after silastic ring vertical gastroplasty (SRVG). RESULTS Serum NO x and TOS values were higher (p < 0.001), while TAR level was lower (p < 0.001) in MO patients as compared to the NWH group. No significant changes occurred at 12 months after surgery in the MO group as far as the NO x (p = 0.93), TOS (p = 0.11), and TAR (p = 0.15) levels were concerned as compared to baseline values. However, NO x increased at 6 months after surgery (p < 0.008) and then decreased by the 12th month after SRVG (p < 0.008), reaching almost baseline values. CONCLUSIONS At baseline, there was a high production of proinflammatory and OS markers in MO patients. SRVG surgical weight loss was not accompanied by significant changes of these parameters at 1 year after surgery.