[lunarcave]

> including physical activity, smoking, alcohol, diet, sleep duration, socioeconomic status, and polygenic risk

Wondering how much of this is due to geography and air quality. City centers have relatively bad air quality and a high amount of ambient lighting at night, compared to non urbanized areas.

The cardiovascular effects of poor air quality is arguably well understood.

[trollbridge]

Most studies pull from urban populations and usually contrasting with a rural population is done for a demographic comparison. (Most people also live in cities.) The study was careful to use personal light monitoring, so urban residents who nonetheless find ways to live/sleep in the dark would be included in the study.

[danielschreber]

My bet is that cardiovascular problems cause light exposure at night.

[renmillar]

Almost believable. You'd probably instinctively want fresh air when your heart's acting up.

[ethan_smith]

The study measured personal light exposure via wrist-worn trackers for a week rather than using geographic light pollution data, which would better control for the urban air quality confounding you've identified.

[lo0dot0]

No, measuring light doesn't remove the air quality confounder. Measuring air quality would allow to remove the air quality confounder. What are you smoking?

[trollbridge]

It turns out they took both rural and urban samples too and there was no meaningful difference between the two populations. Exposure to indoor overhead light is probably far more significant than what streams in your window with the drapes shut.

[lowwave]

>> including physical activity, smoking, alcohol, diet, sleep duration, socioeconomic status, and polygenic risk And also light at night inhibits melatonin production. That along should already be able to lead to all kinds of healthy issues.