Although this is the first study of its kind we recognise a number of limitations. Our study size increases the chances of our results being subject to a type II error. Larger similar studies are needed to confirm our findings. Furthermore, some of the medications taken by our patients, such as ACE inhibitors, angiotensin receptor blockers, and ß blockers may have affected arterial stiffness. However, all patients were stabilised on their therapies and the CKD groups were on similar treatments in this respect. We also saw a high prevalence of diabetes in our cohort and so our findings may not be generalizable to population outside Sri Lanka. Finally, we were unable to assess the influence of proteinuria or other more novel CVD risk factors such as circulating C-reactive protein, asymmetric dimethylarginine or endothelin-1, all of which may contribute to arterial stiffening23 and so may, in part, explain the differences we are seeing. This was not possible in the current study but should be the focus for future work.