Cohort profile: The Rugao Longevity and Ageing Study (RuLAS)

The Rugao Longevity and Ageing Study (RuLAS) is a two-arm cohort. The longevity arm was initiated by Fudan University and the government of Rugao between December 2007 and February 2008 in Rugao, a well-known ‘longevity town’ in China, with the aim of examining genetic factors of longevity. In addition, the arm was expanded to enable us to understand what specific biological, psychological and sociological characteristics these long-lived individuals possess that would allow them to survive longer, namely, their unique adaptational characteristics.1 However, in the majority of studies the longevity phenotype measures overall lifespan without consideration of physical/cognitive function and diseases, and hence an intuitive question was raised regarding long-lived individuals' representativeness of healthy ageing.2 In the era of rapid population ageing, ageing-related phenotypes have been studied such as disease-free survival,3,4 avoidance of bone loss,5 successful ageing6,7 and frailty8,9 in cohort studies. These alternatives provide us with a great opportunity for elucidating determinates of healthy ageing.