Genetic link between frequent naps and high blood pressure

Napping on a regular basis is associated with higher risks for high blood pressure and stroke, according to new research published today in Hypertension, an American Heart Association journal.

Researchers in China examined whether frequent naps could be a potential causal risk factor for high blood pressure and/or stroke. This is the first study to use both observational analysis of participants over a long period of time and Mendelian randomization – a genetic risk validation to investigate whether frequent napping was associated with high blood pressure and ischemic stroke.

Researchers used information from UK Biobank, UK Biobank recruited more than 500,000 participants between the ages of 40 and 69 who lived in the United Kingdom between 2006 and 2010. They regularly provided blood, urine and saliva samples, as well as detailed information about their lifestyle. The daytime napping frequency survey occurred 4 times from 2006 – 2019 in a small proportion of UK Biobank participants.

Study found that a higher percentage of usual-nappers were men, had lower education and income levels, and reported cigarette smoking, daily drinking, insomnia, snoring and being an evening person compared to never- or sometimes-nappers. When compared to people who reported never taking a nap, people who usually nap had a 12% higher likelihood of developing high blood pressure and 24% higher likelihood of having a stroke;

Participants younger than age 60 who usually napped had a 20% higher risk of developing high blood pressure compared to people the same age who never napped. After age 60, usual napping was associated with 10% higher risk of high blood pressure compared to those who reported never napping;

The Mendelian randomization result showed that If napping frequency increased by one category (from never to sometimes or sometimes to usually) high blood pressure risk increased 40%. Higher napping frequency was related to the genetic propensity for high blood pressure risk.

Reseatchers said these results may be because, although taking a nap itself is not harmful, many people who take naps may do so because of poor sleep at night. Poor sleep at night is associated with poorer health, and naps are not enough to make up for that.

Reference: "Study shows link between frequent naps and high blood pressure"; AMERICAN HEART ASSOCIATION, JOURNAL- Hypertension; DOI:10.1161/HYPERTENSIONAHA.122.19120.