Dr. Chhetri holds both a master's (2013) and a doctorate (2018) from CCKRMU and now serves as an associate researcher at the National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital. Recognized as a Beijing-imported talent, he leads a Beijing Natural Science Foundation project for international scholars and spent part of his doctoral training at Johns Hopkins University. He has published 46 SCI-indexed papers — 23 as first or corresponding author — in journals including The Lancet Public Health , Age and Ageing , and JAMDA . He sits on the council of the International Association of Gerontology and Geriatrics (IAGG), serves as an expert member for the WHO's Department of Ageing and Life Course, and is Editor-in-Chief of the Journal of Frailty, Sarcopenia and Falls  and Deputy Editor of Age and Ageing .