Predictive value of asymmetric dimethylarginine and C-reactive protein for the risk of developing metabolic syndrome in middle-aged men

•We assessed whether ADMA, an endogenous NO synthase inhibitor, and CRP predicted the risk of metabolic syndrome.•ADMA did not predict the risk of metabolic syndrome, but CRP did.•The combination of CRP and ADMA could predict the risk of metabolic syndrome more reliably than CRP alone.

BackgroundWe aimed to examine whether serum levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, and C-reactive protein (CRP) are associated with the risk of developing metabolic syndrome in middle-aged men.MethodsIn this longitudinal study, serum ADMA and CRP levels were measured in Japanese men without metabolic syndrome, which was diagnosed according to the currently accepted unified criteria. The subjects were followed-up for a maximum of four years to determine new-onset metabolic syndrome. A Cox proportional hazards model with adjusting for potential confounders was applied to determine the hazard ratio (HR) for developing metabolic syndrome according to serum levels of ADMA and CRP, considered either alone or in combination.ResultsOf the 848 subjects (mean age, 43 ± 6 years), 100 subjects developed metabolic syndrome. High ADMA levels (≥ 0.45 μmol/L) alone did not show a significant HR for developing metabolic syndrome, while high CRP levels (≥ 0.3 mg/L) did (HR 1.75, 95% CI 1.12–2.74). The combination of high levels of both CRP and ADMA had a high HR (2.09, 95% CI 1.12–3.76) as compared to low levels of both markers. In contrast, the HR was not significant in the combination of high CRP and low ADMA levels, as well as low CRP and high ADMA levels.ConclusionsSerum CRP, but not ADMA, levels were associated with the risk of metabolic syndrome. Nevertheless, the risk of metabolic syndrome could be predicted more reliably by considering these two markers together rather than CRP alone.