Oxidative stress and reduced anti-oxidative status, along with endothelial dysfunction in acromegaly
P. Anagnostis1, Z. Efstathiadou1, S. Gougoura2, S. Polyzos1, E. Karathanasi1, P. Dritsa2, M. Kita1 & G. Koukoulis2
Introduction: Acromegaly is characterized by high cardiovascular morbidity and mortality. Oxidative stress and endothelial dysfunction are underlying mechanisms of atherosclerosis. The aim of this study was to evaluate the blood redox status and endothelial function by means of nitric oxide (NO) levels in patients with acromegaly.
Description of methods/design: Total antioxidant capacity (TAC), catalase activity and glutathione concentration (GSH), as measures of anti-oxidative capacity, total oxidized glutathione (GSSG) and thiobarbituric acid reactive substances (TBARS), as indices of oxidative stress, and NO levels were assessed in 15 patients with acromegaly (age 55.4±2.7 years; six males) and 15 age- and sex-matched controls (age 58.4±2.1 years; seven males).
Results: Active disease was present in 12 patients: 11 on current pharmacotherapy and one newly diagnosed. Three acromegalics were in remission after successful treatment.
Compared to controls, acromegalics had significantly lower levels of catalase activity (8.2±1.5 vs 51.3±7.5 μmol/ml per min, P<0.001), GSH (0.97±0.14 vs 1.41±0.09 mmol/l, P=0.006), GSSG (0.27±0.05 vs 2.04±0.34 mmol/l, P=0.002) and NO levels (6.0±0.8 vs 43.0±7.7 μmol/l, P<0.001), but higher TBARS (16.3±2.3 vs 10.1±2.8 nmol/ml, P=0.019). After adjustment for confounders, differences in catalase activity, NO levels and TBARS remained significant (P=0.004, P<0.001 and P=0.025, respectively).
No association between IGF1/GH and oxidative stress markers was noticed, except for a positive correlation between nadir GH and GSSG (r2=0.563, P=0.036).
Conclusion: Acromegaly is associated with increased levels of oxidative stress coupled by diminished antioxidant capacity that may be implicated.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.