Background: N-acetylcysteine (NAC), the acetylated variant of amino acid l-cysteine, acts as a free radical scavenger and plays multifunctional roles by suppressing endogenous level of oxidative stress and inflammation and by enhancing nitric oxide bioavailability. Thus, present study aimed to evaluate the efficacy of NAC on various inherent components of metabolic syndrome (MetS). Methods: An open-label pilot study was conducted at diabetes outpatient clinic. Thirty-five patients (aged ≥18 years) fulfilling the NCEP-ATP III diagnostic criteria for MetS were recruited and allocated to NAC tablets as 600 mg (twice a day) along with their ongoing therapeutic regimen. Blood pressure (BP), body mass index, lipid profile, fasting plasma glucose and insulin, insulin resistance estimated by homeostatic model assessment (HOMA-IR), high-sensitivity C-reactive proteins (hsCRP), nitrite, and thiobarbituric acid reactive substances (TBARS) were measured after 6 weeks treatment. Results: HOMA-IR, hsCRP and systolic BP were decreased significantly from 4.74 ± 0.30% to 3.86 ± 0.21%; 5.66 ± 0.27 to 4.92 ± 0.18 mg/L; and 133.2 ± 1.84 to 128.3 ± 1.52 mmHg, respectively. Among dyslipidemic variables, there was decrease in triglycerides from 194.20 ± 5.03 to 188.04 ± 4.93 mg/dL, but increase in HDL from 33.32 ± 0.19 to 36.29 ± 1.16 mg/dL. Nitrite levels were significantly increased from 6.25 ± 0.20 to 7.92 ± 0.18 μmol/L (P = 0.04), while TBARS levels were decreased from 14.65 ± 0.32 to 13.68 ± 0.33 nmol/L (P = 0.05). It was found from correlation analysis that hsCRP was the main culprit, that is, inflammation was perpetuator of endothelial dysfunction, IR, oxidative stress, hypertension, and vice-versa. Conclusion: This study has provided a new approach of management of MetS with NAC beyond controlling the disease with various drug therapies. NAC may reduce the risk burden via multiple antioxidant, anti-inflammatory, and vasodilatory effect.
Keywords: endothelial dysfunction; insulin resistance; low-grade systemic inflammation; metabolic syndrome; multiple pharmacological properties; oxidative stress.