Sensitivity to thyroid hormones is associated with sleep duration in the euthyroid population with depression degree lower than moderate

We collected thyroid-related hormone index levels, sleep duration, and other basic characteristics of the population with depression from the NHANES 2009-2012 cycles and evaluated the association of Thyroid-Stimulating Hormone Index (TSHI) with sleep duration in the euthyroid population with depression via different analysis methods. We found that the association between TSHI and sleep duration was only found in patients with depression degree < Moderate (score: 1-14) rather than > Moderate group. Among the populations with degree < Moderate (N = 1918), only 4 indexes (parametric Thyroid Feedback Quantile Index, PTFQI, Thyrotroph Thyroxine Resistance Index, TT4RI, Thyroid-Stimulating Hormone TSH, and TSHI) reflecting the sensitivity to thyroid hormones were related to the sleep duration, with a significant non-linear relationship after adjusting for potential confounders (all P < 0.05). Trend analysis indicated that with the level increase of these 4 indexes, the sleep duration increased (all P for trend < 0.001). Further, we found that TSHI was relatively more important among the 4 indexes. Sum up, sensitivity to thyroid hormones is associated with sleep duration in the euthyroid population with depression degree lower than Moderate. Poor sensitivity referred to a longer sleep duration.