Lipid metabolism characteristics have a causal relationship with nightmare risk, with higher triglyceride levels in HDL and LDL being protective and higher free cholesterol to total lipids ratio in medium LDL associated with increased nightmare risk.
Higher triglyceride levels in HDL were associated with reduced risk of nightmares.
Higher triglyceride levels in LDL were associated with reduced risk of nightmares.
A higher triglycerides to total lipids ratio in medium HDL was protective against nightmare occurrence.
A higher free cholesterol to total lipids ratio in medium LDL was associated with an increased risk of nightmares.
A two-sample Mendelian randomization design using GWAS data was employed to investigate causal relationships between lipid metabolism and nightmares.
This research suggests that certain characteristics of blood fat (lipid) metabolism are causally linked to the likelihood of experiencing nightmares. Using a technique called Mendelian randomization — which uses people's genetic makeup to infer cause-and-effect relationships rather than just correlations — the researchers found that higher levels of triglycerides (a type of fat) within HDL and LDL cholesterol particles were associated with a lower chance of having nightmares. Similarly, a higher ratio of triglycerides to total fats in a specific size of HDL particle also appeared protective. In contrast, a higher proportion of free cholesterol relative to total fats in medium-sized LDL particles was associated with more than triple the risk of nightmares. This research suggests that the composition of lipid particles in the blood — not just simple cholesterol or triglyceride levels — may play a role in sleep quality, specifically in nightmare occurrence. The use of Mendelian randomization strengthens the case for a causal link rather than a coincidental association, because genetic variants that influence lipid traits are randomly assigned at birth and are less susceptible to lifestyle confounders. The practical implication is that lipid metabolism management could potentially be relevant to nightmare prevalence, particularly for vulnerable groups such as those with PTSD or anxiety disorders who commonly experience nightmares. However, the authors note that further studies are needed to confirm these findings and to understand the biological mechanisms connecting lipid metabolism to dream disturbances during sleep.
Tang N, He G, Zeng Y, Chen S. (2026). The association between serum lipid metabolism and nightmares: insights from Mendelian randomization analysis of two samples.. Nutricion hospitalaria. https://doi.org/10.20960/nh.05678