This is worth noting: > Our study has several potential limitations. First, participants were not randomly selected, possibly leading to selection bias. Howev

This is worth noting: > Our study has several potential limitations. First, participants were not randomly selected, possibly leading to selection bias. However, the parameters of BMI and estimated glomerular filtration rate were similar to corresponding national data in Japan and the follow-up rate was sufficiently high. > Second, bedroom light intensity was measured without eye-level light meters, and sleep/awake status was measured only over 2 days.