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Pooled review (meta-analysis)

Pooled review of 15 studies: heat therapy lowered blood pressure, not heart rate

Pizzey and colleagues · Experimental physiology · 2021

Original title: The effect of heat therapy on blood pressure and peripheral vascular function: A systematic review and meta-analysis.

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

Points to benefit

Heat therapy lowered systolic blood pressure (MD: -3.94 mmHg, 95% CI: -7.22, -0.67) and diastolic (MD: -3.88 mmHg, 95% CI: -6.13, -1.63). Resting heart rate did not change (MD: -1.25 beats/min).

The study at a glance

Type of study
Pooled review (meta-analysis)
Who or what was studied
15 studies · healthy people and people with health conditions
What was tested
Heat therapy for 30-90 minutes, over 10-36 sessions, vs control
What it measured
The question itself: heart disease, blood pressure and death
Who has a stake
No disclosure in PubMed
No disclosure in PubMed.
Journal
Experimental physiology, 2021
Source
PubMed record 33866630. This page is based on the abstract only.

How much this study counts

  • ✓Pools the results of 15 studies.
  • •A pooled review is only as strong as the studies it pools.
  • ✓Measured the question itself: heart disease, blood pressure and death.
  • •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 pooled review (meta-analysis), and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: heart disease, blood pressure and death

    3

    3 benefit

  2. Trials in people: other measures

    2

    1 benefit, 1 no difference

  3. Trials in people: lab tests or safety

    5

    2 benefit, 1 mixed, 2 no difference

  4. Population studies

    4

    4 benefit

  5. Blood levels and genes

    0

    None among the papers we read.

↓ Weaker evidence

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

How it fits with the other research

The short answer to “Does sauna use lower heart disease risk?”

Possibly, but not proven in trials.

Confidence: low. Based on 21 on-topic papers.

Read the full answer
  • Part of the finding “Blood pressure: reviews and trials disagree”.
  • Summed up in “What reviews found”: Pooled 15 heat therapy studies (type not named) in healthy and sick people. Heat lowered systolic pressure by 3.94 mmHg and diastolic by 3.88 mmHg; resting heart rate did not change. Certainty was rated moderate.
  • Open item for a person: Pizzey 2021 and Ye 2020 pool heat therapy generally; abstracts do not say how many studies used sauna.

Other reviews on this question

See all 21 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 reviewer corrected 2 fields after reading the abstract. 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
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