How To Double Your Heart Attack Risk With This One Easy Sleep Habit

A lot of heart attack risk factors are quite big things to change. Stop smoking, stop drinking, stop eating red meat, exercise a certain amount, and so forth.

This one, in contrast, is quite easy to change:

The one easy habit is…

If you would like to double your heart attack risk, then what you want to do is simply get in the habit of sliding your sleep schedule around each day, so that its lacks regularity.

We wrote about this a bit before, here: How Regularity Of Sleep Can Be Even More Important Than Duration

…however, today’s article is not just a rehash of that one, because with the evidence when we wrote that one, we could “only” point to a 26% increased risk of cardiovascular disease (in general, not heart attack risk specifically).

Now, however, new evidence has come to light, that makes this several times more important!

Researchers (Dr. Laura Nauha et al.) followed 3,231 people from the Northern Finland Birth Cohort 1966, measuring sleep timing at age 46 with wearable activity monitors over 7 days, then tracking cardiovascular outcomes for more than 10 years through to 2023—and yes, it’s just been published now in 2026, because science is like that; we cannot accuse them of not being rigorous in their conscientiousness of checking and double-checking things and doing things right! In fact, for more on that, see the peer review notes at the end of this section, because it’s interesting too.

Notably, people with the most irregular bedtimes had more than double the risk of major adverse cardiac events (HR* 2.01) compared with those with regular bedtimes, while irregular sleep midpoints also doubled risk (HR 2.00).

*^{HR = “Hazard Ratio”, a way of measuring risk. 1.0 means the risk is the same, 0.5 means the risk is halved, 2.0 means the risk is doubled, and so on.}

You may be wondering what counted as “major” events: for the purposes of this study, serious cardiovascular problems included heart attack, unstable angina, stroke, heart failure hospitalization, and/or cardiovascular death.

One important thing to take note of: inconsistent bedtimes—but not irregular wake-up times—showed the strongest independent association with later heart risk, suggesting when you go to bed may matter more than when you get up. That said, controlling when you get up (bearing in mind you can control when you wake up more strongly than you can control when you fall asleep) is a good way of influencing being able to fall asleep at the appointed hour in the evening.

You can learn more about that, here: Calculate (And Enjoy) The Perfect Night’s Sleep

And as for the study we’ve been talking about, you can read the paper in full here: Sleep timing irregularity in midlife: association with incident major adverse cardiac events and cardiovascular disease mortality over a 10-year follow-up

Incidentally, if you’re at all curious about what peer review actually looks like in real terms, this paper has a great and very accessible example, in the short back-and-forth that can be seen between Dr. Nauha and her team (the researchers) and the reviewers (the peer reviewers, that is to say, similar researchers in the same industry, double-checking the team’s work and asking salient questions about it, providing challenges where appropriate, and allowing the authors to make stuff clearer where necessary).

Click here to see this back-and-forth exchange between the scientists who wrote the paper and the scientists who did the peer review!

Want to learn more?

For a much more in-depth treatment of the topic, you might like this book that we reviewed a while back:

Why We Sleep – by Dr Matthew Walker

Basically, if you will read only one book on sleep, that’s the book.

Sweet dreams!