The relationship of asymmetric dimethylarginine levels with uncontrolled arterial hypertension and hypertension disease stage

Background: Patients with treatment-resistant hypertension have a worse cardiovascular prognosis compared to those who achieve their target levels of blood pressure (BP). One of biochemical and clinical markers of a decreased response to antihypertensive therapy can be asymmetric dimethylarginine (ADMA), a molecule that reduces formation of nitric oxide and promotes endothelial dysfunction and vasoconstriction. Aim: To assess the status of the nitrogen oxide synthesis system and clinical and laboratory profile in patients, depending on the hypertensive disease stage, who achieved or not achieved their target BP levels during hospitalization. Materials and methods: We performed аn observational retrospective uncontrolled study in a consecutive sample of 192 patients aged 45–65 years who were admitted to the City Clinical Hospital No. 25 (city of Novosibirsk) with a diagnosis of uncomplicated hypertensive crisis. On the day of discharge, the patients were retrospectively divided into 2 groups. Group 1 included patients who achieved their target BP during hospitalization (target BP group, n = 116). Group 2 included patients with uncontrolled hypertension, in whom the administration of three antihypertensive drugs including a diuretic in optimal or maximal tolerated doses did not result in the achievement of the target BP below 140 and/or 90 mm Hg during hospitalization (non-target BP group, n = 76). The following parameters were measured: ADMA, symmetrical dimethylarginine (SDMA), N-monomethyl-L-arginine (NMMA), and total nitric oxide. Results: Serum ADMA concentrations (Me [Q25%; Q75%] were increasing with the stage of hypertension: stage I, 0.75 µmol/L [0.66; 0.78], stage II, 1.14 µmol/L [0.87; 1.39], stage III, 1.38 µmol/L [1.22; 1.49] (p 0.0001, Kruskal-Wallis test). In the pairwise comparison, the difference between all these subgroups was significant at p 0.01. In the patients with uncontrolled arterial hypertension ADMA levels were increased compared to those in the target BP group: 1.2 µmol/L [0.99; 1.47] vs 1.07 [0.79; 1.34] µmol/L (p = 0.002). The proportion of patients with type 2 diabetes mellitus among those with uncontrolled arterial hypertension was 31.2% (24/76), while in the target BP group there were only 3.5% of such patients (4/116) (odds ratio 12.57, 95% confidence interval 4.15–38.05; p = 0.00001). Conclusion: ADMA measurement may help identify patients with a potential poor response to antihypertensive therapy. This should be taken into account when choosing a treatment regimen and BP monitoring. In addition, ADMA seems to be a promising target for the development of new drug classes.