This study has several strengths. It is one of the largest studies of the association of TL with kidney impairment. Kidney impairment was assessed by both eGFR and proteinuria. The selection of participants was based on random sampling of the general population and therefore the results can be extrapolated to the general population. As the data collection was performed on all days of the week throughout the year in NHANES, the potential for selection bias is very low [25, 26]. The findings from our study should be considered in the context of some limitations. The cross-sectional nature does not allow inference about causality. We did not have available any repeated measure of TL with quantitative polymerase chain reaction in the same subjects after several follow-up years to elucidate temporality of these findings.