Objective: Alarming increases in hypertension and type 2 diabetes among Africans accentuate the need to identify factors that could serve as targets for prevention or treatment. In Caucasian populations asymmetric dimethylarginine (ADMA), the predominant endogenous nitric oxide synthase inhibitor, is associated with cardiovascular disease and insulin resistance. ADMA's counterpart, symmetric dimethylarginine (SDMA), originally thought to be inert, was recently also linked with cardiovascular risk. Since little information regarding ADMA or SDMA is available for Africans, our aim was to explore the relationships of ADMA and SDMA with measures of arterial stiffness and insulin resistance in Africans and Caucasians from South Africa. Methods: The study consisted of 235 non-smoking, non-diabetic, non-obese, HIV uninfected Africans (N=64) and Caucasians (N=171), aged 20-70 years. We measured blood pressure, pulse wave velocity (PWV), ADMA, SDMA, and insulin resistance (HOMA). Results: African and Caucasian men had similar ADMA and SDMA, whereas Caucasian women had higher ADMA and SDMA than African women (p
