Chronotype and sleep duration in relation to leukaemia subtypes: a two-sample Mendelian randomization analysis

Area of Science:

• Genetics
• Epidemiology
• Sleep Science

Background:

• Observational studies suggest a link between sleep patterns and leukaemia risk.
• Causal inference is needed to confirm these associations.

Purpose of the Study:

• To determine the causal association between sleep traits and leukaemia using two-sample Mendelian Randomization (MR).
• To investigate potential confounding factors and reverse causation.

Main Methods:

• Utilized summary statistics from genome-wide association studies (GWAS) for sleep traits (UK BioBank) and leukaemia (FinnGen).
• Employed Inverse Variance Weighted (IVW) method for primary MR analysis, with sensitivity analyses and reverse MR.
• Steiger directionality test used to ascertain causality direction.

Main Results:

• Nominal associations found between chronotype and acute lymphoblastic leukaemia, chronotype and chronic myeloid leukaemia, and short sleep duration and lymphoid leukaemia.
• These associations were not significant after FDR correction.
• Multivariable MR adjusting for smoking and BMI abolished all associations; reverse MR indicated a significant effect from acute lymphoblastic leukaemia to chronotype.

Conclusions:

• The MR study identified nominal associations between sleep traits and leukaemia subtypes.
• These associations were attenuated by confounding factors (smoking, BMI) and potentially influenced by pleiotropy or reverse causation.
• No robust causal link was established between sleep traits and leukaemia.