Plasma asymmetric dimethylarginine, symmetric dimethylarginine, homoarginine and arginine levels in patients with active acromegaly
Sibel Guldiken1, Bengur Taskiran1, C Hakan Karadag2, Ozgur Gunduz2, Betul Ekiz Bilir1, Betul Ugur Altun1 & Armagan Tugrul1
Aim: Acromegaly is associated with accelerated atherosclerosis and cardiovascular disease. Nitric oxide (NO) is enzimatically formed from L-arginine by endothelial nitric oxide synthase (eNOS). Several studies have shown that reduction in NO synthesis causes endothelial dysfunction and impaired endothelium-dependent vasodilation. Asymmetric dimethylarginine (ADMA), the endogenous inhibitor of NOS, accumulation plays a prominent role in the pathogenesis and in progression of atherosclerosis. The aim of present study was to evaluate the plasma ADMA, symmetric dimethylarginine (SDMA), homoarginine and arginine levels as biochemical markers of endothelial functions in patients with active acromegaly.
Materials and methods: Twenty-one patients with active acromegaly and twenty controls were enrolled in the study. Plasma ADMA, SDMA, homoarginine and arginine levels were determined by HPLC. The patients and controls were matched for age, gender, lipid levels, diabetes mellitus and hypertension.
Results: Plasma homoarginine and arginine levels were reduced in active acromegalic patients compared to controls (P<0.001, P<0.05, respectively). There was no significant difference in plasma ADMA and SDMA levels between groups (P>0.05).
Conclusion: In conclusion, our study demonstrated that reduced arginine levels rather than ADMA levels play an important role for the development of endothelial dysfunction in active acromegaly.