How often someone takes a late-afternoon snooze could be partly genetic, a new study has found.
A Harvard Medical School-led team of researchers conducted a genome-wide association study of daytime napping using the UK Biobank and 23andMe datasets. The participants were asked if they never, sometimes, or often take naps during the day. As they report in Nature Communications, the researchers uncovered 61 loci linked to napping, including ones in regions tied to sleep disorders, arousal, and increased body-mass index. Some of these regions are already sleep disorder targets, they note.
The researchers add that clustering of these loci pointed to three scenarios that could underlie the need for a nap: a general requirement for more sleep, the result of poor or disrupted sleep, and, if combined with getting up early, a need to "catch up" on sleep.
"This tells us that daytime napping is biologically driven and not just an environmental or behavioral choice," co-first author Hassan Saeed Dashti from the Massachusetts General Hospital's Center for Genomic Medicine says in a statement.