Association of sleep traits and heel bone mineral density: Observational and Mendelian randomization studies

This study aimed to 1) replicate the findings by examining observational association of sleep traits with low eBMD; 2) examine whether these associations were causal by using mendelian randomization (MR) analyses, and 3) investigate potential modulation effects of sex and menopause. 398,137 White British subjects (aged 39-73y) with valid BMD estimated by quantitative ultrasound of the heel (eBMD) at baseline were included. Linear regression analyses and inverse-variance weighted method were used as main methods for observational and one-sample MR analyses respectively, to investigate the associations between self-reported sleep traits (sleep duration, chronotype, daytime sleepiness and insomnia) and low eBMD. Furthermore, sensitivity analyses were performed in subgroups based on sex and menopause in both observational and MR analyses. In observational analyses, short/long sleep, insomnia and definite eveningness were associated with low eBMD (short sleep: β = −0.045, effect in standard deviation change of rank-based inverse normally transformed eBMD; long sleep: β = −0.028; sometimes insomnia: β = −0.012; usually insomnia: β = −0.021; definite eveningness: β = −0.047), while definite morningness was associated with decreased risk of low eBMD (β = 0.011). Subgroup analyses suggested associations of short/long sleep and definite eveningness with low eBMD among men, short sleep with low eBMD among premenopausal women, and short sleep, eveningness and ...
Source: Journal of Bone and Mineral Research - Category: Orthopaedics Authors: Tags: Original Article Source Type: research