Assessing the causal role of sleep characteristics on glycated hemoglobin: a Mendelian randomized study. 

Diabetes Care 2022;45(4):772-781

https://doi.org/10.2337/dc21-0089

Commentary

This study was designed to investigate the effect of sleep characteristics on glycated hemoglobin (HbA 1c ).

The study design included sensitivity analyses of the effects of five self-reported sleep characteristics and was described as multivariate regression (MVR) and triangulation of evidence across one sample (1 SMR) and two samples Mendelian randomization (2 SMR). Samples were HbA 1c (SD units) sleep duration, daytime insomnia, napping, and diurnal variation in adults of European descent in the UK Biobank (n =336,999; mean [SD] age 57[8] years; 54% female) to the Glucose and Insulin Related Traits Consortium (MAGIC) meta Genome-wide association analysis from analysis (n = 46,368; 53[11] years; 52% female).

Results showed that a higher frequency of insomnia symptoms was associated with higher HbA 1c. After excluding participants with diabetes, the point estimates were somewhat weakened, but there was little consistency across methods for other sleep characteristics, with some providing evidence of an effect.