Paper on ‘The reference values of bone turnover marker PINP and the effect of circadian rhythm on its value in healthy elderly population: A systematic review and meta-analysis’, presented by Dr Noushin Fahimfar from the Endocrinology and Metabolism Research Institute (EMRI) of the Tehran University of Medical Sciences (TUMS) during the World Congress on Osteoporosis, Osteoarthritis and Musculoskeletal diseases 2019 in Paris, France on 5-7.4.2019.