Relationship between obesity, smoking, and the endogenous nitric oxide synthase inhibitor, asymmetric dimethylarginine.
ABSTRACT We investigated the levels of asymmetric dimethylarginine (ADMA), an important endogenous inhibitor of nitric oxide (NO), as related to metabolic risk factors known to contribute to atherosclerotic disease. Dimethylarginines were analysed in a cross-sectional study of 563 elderly high-risk men (70 +/- 6 years). ADMA and the l-arginine/ADMA (l-arg/ADMA) ratio were highly significantly correlated with several metabolic risk factors. However, only the association with body mass index (BMI) remained significant after adjustment for inter-related variables. When analyzing the results according to being overweight or not, ADMA levels were independently significantly higher (P = .05) and the L-arg/ADMA ratios were significantly lower (P < .008) in individuals with high BMI (> or =26 kg/m(2), median value) as compared with subjects with low BMI. ADMA levels were furthermore significantly lower (P = .037) and L-arginine and the l-arg/ADMA ratios were significantly higher (P = .004 and P = .001, respectively) in smokers compared with nonsmokers, the latter being independent of other risk factors. The strong relationship found between BMI and plasma levels of ADMA and the l-arg/ADMA ratio indicate a link to endothelial dysfunction in overweight subjects. The beneficial dimethylarginine profile observed in smokers in this elderly population is not easily explainable and should be further investigated.
- Atherosclerosis 01/2000; 151(1):145-145. · 3.71 Impact Factor
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ABSTRACT: Reduced availability of nitric oxide (NO) is thought to contribute to the age-associated increase of renovascular tone and blood pressure. We assessed blood concentrations of the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA) as well as renal hemodynamics, comparing young (n=24, 13 men, 25+/-1 years) and elderly (n=24, 13 men, 69+/-2 years) healthy subjects and elderly subjects with essential hypertension (n=24, 13 men, 70+/-2 years). Plasma ADMA concentration and renovascular resistance (RVR) were significantly higher (P<0.05) and effective renal plasma flow (ERPF) significantly lower (P<0.05) in elderly (2.77+/-0.20 micromol/L, 125+/-10 mm Hg/mL per minute, 487+/-26 mL/min per 1.73 m2) than in young healthy subjects (1.30+/-0.11, 77+/-3, 654+/-18). Both ADMA levels and RVR were higher and ERPF lower in the hypertensive elderly subjects (3.53+/-0.23, 163+/-11, 427+/-19; P<0.05 versus both groups). In contrast, plasma concentrations of the biologically inactive stereoisomer symmetric dimethylarginine, l-arginine, and homocysteine were similar in the 3 groups studied. In the logistic regression analysis only ADMA was an independent determinant of both ERPF (P<0.001; r2=0.80) and RVR (P<0.002; r2=0.86). In addition, ADMA (P<0.002) and serum glucose (P<0.036) were independently related (r2=0.67) to the level of blood pressure. These results are compatible with the notion that accumulation of the endogenous NO synthase inhibitor ADMA in senescent individuals is involved in the decrease of renal perfusion and increase of blood pressure.Circulation 04/2003; 107(14):1891-5. · 15.20 Impact Factor
- The American Journal of Cardiology 12/2001; 88(10):1201-3. · 3.21 Impact Factor