Objective: To investigate levels of the stable nitric oxide metabolites (NOx) in relation to components of the metabolic syndrome (MS) in essential hypertension (EH)
Methods: We examined 124 untreated patients with EH (mean age 51.4 ± 6.5 years, mean hypertension duration 8,5±7,6 years) and 25 healthy volunteers with comparable age (47.2 ± 7.8 years, p>0,05). Plasma leptin levels were measured by radioimmunoassay, plasma NOx - by spectrophotometry. Results were processed with Statistica 6.0 software.
Results: Visceral obesity had 64% of hypertensive patients, dyslipidemia - 80.6%, hyperglycemia - 41,6%, MS - 24%. In 32% the MS diagnosis was based on the presence of two additional criteria, in 68% - on three. NOx levels were significantly higher in hypertensives (43,18±21, μmol/l) than in controls (28.3 ± 9.6 μmol/l) (p = 0.01). In patients with hyperglycemia NOx concentration was higher (46,5 ± 23,9 μmol/l) than in those without it (38,6±18, μmol/l)(p<0,05). NOx levels correlated with blood glucose levels (r=0,32, p<0,05). NOx concentration did not differ between hypertensives with or without dyslipidemia (43,2±22,2 and 42,05±21,1 μmol/l, accordingly p>0,05). Nonobese hypertensives had lower NOx concentration than obese hypertensives (38,8±17,9 and 48,5±24,7 μmol/l, p<0,05). NOx levels correlated with the presence (r=-0,44, p<0,05) and degree of obesity (r=-0,3, p<0,05). NOx levels were lower in patients with MS (31,6±11,3 and 47,05±20,7 μmol/l, p<0,05). NOx levels decreased with the increase of additional MS criterias: 37,99 ± 12,6 μmol/l in the presence of 2 and 28,3 ± 9,6 μmol/l in the presence of 3 criteria (p<0,05). NOx levels correlated with the amount MS components (r=-0,38, p<0,05). Hypertensives with high leptin levels had lower NOx concentration (29 ± 12,2 μmol/l), compared to hypertensives with normal leptin levels (34,7±10,5 μmol/l) (p<0,05).
Conclusion: In essential hypertension NOx metabolism differs in relation to metabolic status. Hypertension per se and hyperglycemia increase NOx levels, whereas MS and its essential signsas visceral obesity and high plasma leptin level decrease NOx levels.