The joint and interactive effects of the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and body mass index on the risk of depression, as well as the mediating role of NHHR: results from NHANES 2005–2023

Depression risk is linked to both NHHR and BMI, and NHHR has a significant mediating impact on the association between BMI and depression. Notably, there is a non-negligible mediated interaction effect between BMI and NHHR in male participants. Compared to considering NHHR or BMI individually, participants had a higher risk of depression when the combined terms of the two were in the higher quartiles. These findings suggest that the combined assessment of these two indicators may help deepen the understanding and evaluation of depression, enhance the accuracy of risk stratification, and is worthy of further research.