Digestery
Lifestyle practices › Sleep Length and Health › Studies

Systematic review

Review of 69 pooled analyses: short and long sleep linked to higher death risk

Li and colleagues · Sleep & breathing = Schlaf & Atmung · 2022

Original title: Sleep duration and health outcomes: an umbrella review.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Mixed

A 1-h reduction per 24 hours among short sleepers was linked to 3-11% higher risk of all-cause death, heart disease, stroke and type 2 diabetes. A 1-h increase in long sleepers was linked to 7-17% higher risk of stroke death, heart disease, stroke and diabetes.

The study at a glance

Type of study
Systematic review
Who or what was studied
69 studies · adults in 69 meta-analyses of sleep duration and health
What was tested
Short and long sleep compared with normal sleep; per 1-hour change in sleep per 24 hours
What it measured
The question itself: death, heart disease and other health outcomes
Who has a stake
No disclosure in PubMed
No disclosure in PubMed.
Journal
Sleep & breathing = Schlaf & Atmung, 2022
Source
PubMed record 34435311. This page is based on the abstract only.

How much this study counts

  • •Sums up 69 studies found with a set search method, without pooling the numbers.
  • ✓Measured the question itself: death, heart disease and other health outcomes.
  • •The PubMed record has no conflict-of-interest statement.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

This paper is not on the ladder. It is a systematic review, and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: death and chronic disease

    0

    Not done yet. This is the step that would answer the question.

  2. Trials in people: other measures

    1

    1 benefit

  3. Trials in people: lab tests or safety

    0

    None among the papers we read.

  4. Population studies

    11

    5 benefit, 4 mixed, 2 no difference

  5. Blood levels and genes

    1

    1 benefit

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “How much sleep do adults need for good health?”

Lowest risk at about 7 hours.

Confidence: low. Based on 22 on-topic papers.

Read the full answer
  • Summed up in “What reviews found”: Gathered 69 meta-analyses. Each hour less among short sleepers was linked to 3-11% higher risk of death, heart disease, stroke and diabetes; each hour more among long sleepers to 7-17% higher risk of similar conditions.
  • Open item for a person: Itani 2017 and Jike 2018 are companion meta-analyses; they and umbrella review Li 2022 likely share cohorts. Check overlap.

Other reviews on this question

See all 22 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads agreed on every checked field. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
Not yet. Required before search engines may list this page.

Spot an error? Email a flag with a link to your source, or use the form on the question page.