Objectives: We investigated serum asymmetric dimethylarginine (ADMA) levels and their association with smoking, metabolic syndrome (MS), and coronary heart disease (CHD) among Turkish adults.
Study design: Serum ADMA concentrations were measured in a cross-sectional study by a validated ELISA kit in a random sample of 464 Turkish adults (222 men, 242 women; mean age 55+/-11 years; range 34-89). Metabolic syndrome was identified by the criteria of the Adult Treatment Panel-III modified for male abdominal obesity.
Results: The median serum ADMA concentration was 0.80 micromol/l, with the interquartile range of 0.57 to 1.13 micromol/l. Compared to nonsmokers, age-adjusted ADMA level was 20% lower in smoking men (p=0.057), and 6% lower in smoking women (p=0.6). Serum ADMA levels showed significant and positive correlations with age, testosterone, and fibrinogen concentrations in men, and a borderline significance with triglyceride, C-reactive protein, and sex hormone-binding globulin in women. No significant association was found with MS, hypertension, or CHD likelihood among men; but, after adjustment for age, smoking status, and systolic blood pressure, the odds ratio of doubling of ADMA for the likelihood of MS reached significance in women (OR 1.25; 95% CI 1.01; 1.53). Age- and smoking-adjusted ADMA in women tended to be associated also with hypertension (OR 2.55, p=0.07).
Conclusion: Serum ADMA levels are significantly associated with MS likelihood in women alone, but not with the likelihood for CHD in either gender. Serum ADMA in middle-aged and elderly Turks is inversely associated with cigarette smoking, and thus possibly contributes to the smoking-related protection of Turkish women from MS.