Tom Nolan’s research reviews—21 September 2023

Bad news for night owls

Will chronotype be weaved into risk calculators of the future? Chronotype is another way of saying whether someone is an early bird or a night owl, and the bad news for night owls is that a prospective cohort study of nurses aged between 45 and 62 years has found that people with “definitely evening” chronotypes were more likely to have unhealthy lifestyles and were at higher risk of diabetes (hazard ratio for diabetes 1.72 (95% CI 1.50 to 1.98) compared with “definitely morning” people). As always, further research is needed, but maybe in decades time, when we’re completing a QRISK14 score for a patient, we’ll be ticking a box for “Are they a morning person?” and perhaps it will also include other watercooler classics such as “Do they like Marmite?” and “Do they put milk in their tea before or after the water?”

Ann Intern Med doi:10.7326/M23-0728

CT scanning at Oktoberfest

Six million people attend Oktoberfest each year, during which around 15 million pints—or 7.5 million steins—of beer are drunk. All this creates plenty of work for the local healthcare services, so much so that in 2022 they decided to have an on-site mobile computed tomography (CT) scanner to help work out whether people with presumed head injuries had an intracranial bleed or just needed a few more hours to sober up.

Perhaps the most startling finding of the report in the New England Journal of Medicine is that, over the 17 day festival, 205 patients with presumed or observed mild brain injury underwent 317 scans. Eleven had intracranial bleeding, and 23 had mid-face fractures. There was a small reduction in local hospital admissions for surgically treated injuries compared with previous years, but whether this was due to the roving scanning unit isn’t clear.

N Engl J Med doi:10.1056/NEJMc2306490

Psychological benefits of ablation

Several patients I’ve seen with symptomatic paroxysmal atrial fibrillation (AF) have been very distressed by it and frustrated that the impact of their symptoms on their everyday life has not been fully recognised when treatment—catheter ablation or medical therapy—is being considered.

A randomised controlled trial enrolled 100 people with AF or paroxysmal AF and allocated them to receive either catheter ablation or medical therapy. The primary outcome wasn’t whether they were in AF or having palpitations at the end of the study, but their Hospital Anxiety and Depression Scale (HADS) score at 12 months. The combined HADS score in the ablation group reduced from 12.3 at baseline to 7.6 at 12 months, whereas it declined only slightly, from 12.4 to 11.8, in the medical therapy group.

JAMA doi:10.1001/jama.2023.14685

Amyloid transfusion transmission risk

The second most common cause of spontaneous intracerebral haemorrhage is cerebral amyloid angiopathy (CAA)—accounting for 20% of cases according to one study in Finland. Previous research has suggested that CAA may be transmissible in a “prion-like” way. National databases in Denmark and Sweden were examined to see if there is any association between spontaneous intracranial haemorrhages in blood donors and their recipients. The study is limited in that it used intracranial haemorrhage not due to trauma or venous malformation as a proxy for CAA, but it did find that people who had received transfusions from donors who later developed multiple spontaneous intracranial haemorrhages were at increased risk of developing intracranial haemorrhage themselves (3.16 v 1.12 per 1000 person-years, hazard ratio 2.73 (95% CI 1.72 to 4.35)).

JAMA doi:10.1001/jama.2023.14445

Happy hobbies

Every few months I—and those around me—decide that I need a new hobby: cartoon drawing, printmaking, tennis, chess. I’ve tried so many, but they never last. A meta-analysis of longitudinal studies from around the globe found that in people over 65 years old having a hobby was associated “with fewer depressive symptoms, better self-reported health, more happiness and higher life satisfaction.” There was little variation between countries in this association, although there was a wide variation in hobbying: only 51% of respondents in Spain reported having hobbies compared with 96% of those in Denmark. People will say that this points to hobbies making you happier; but I’d argue from bitter experience that it's not so much that hobbies make you happy, but that not being able to find one that you like is a hugely dissatisfying experience.

Nat Med doi:10.1038/s41591-023-02506-1