Research Summary
Analyzed using Evidence Intelligence™

Light therapy improves sleep quality in older adults with diabetes

Last updated July 11, 2026

Key finding

PSQI scores decreased significantly from baseline.

This study evaluated the impact of light therapy on sleep quality and circadian rhythm in older adults with type 2 diabetes, finding significant improvements in sleep quality.

Quick read

Study at a glance

The essential study design details in one scan.

EvidenceScore™

Moderate

Study type

RCTs

Follow-up

Short-Term (≤3 mo)

Risk of bias

Some Concerns

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Plain-language summary

What this paper says

A plain-language read of the study's main message and where it applies.

Study focus

This study evaluated the impact of light therapy on sleep quality and circadian rhythm in older adults with type 2 diabetes, finding significant improvements in sleep quality.

Clinical relevance

Improving sleep quality is crucial for older adults, particularly those with type 2 diabetes, as it can enhance overall health and well-being. This study suggests that light therapy could be a viable non-pharmacological intervention to address sleep disturbances in this population.

Keep in mind

The study's sample size may limit generalizability. The control group showed no significant changes, raising questions about the intervention's effectiveness. The study did not account for potential confounding factors affecting sleep quality.

Published in

Journal Reference

Publication details and source links for this paper.

Qin W, Shuang W, Zhenhua L, et al. Light Therapy Improves Sleep Quality and Circadian Rhythm in Older Adults with Type 2 Diabetes. Frontiers in Endocrinology. 2024;15:1307537. doi:10.3389/fendo.2024.1307537

Main Effects

PSQI scores decreased significantly by 4.5 points in the light therapy group (p=0.001).

MEQ scores decreased significantly by 4.85 points in the light therapy group (p=0.001).

No significant difference in GSP values between groups at T1 and T2.

Evidence network

How this study fits

Understand where this research contributes within the broader evidence network.

Evidence Context

This study contributes evidence to Control Group - Blinded Nutrition Therapy, Photobiomodulation therapy and Glycated serum protein (GSP) levels, Morningness-Eveningness Questionnaire (MEQ) score, Sleep quality.

Primary intervention

Control Group - Blinded Nutrition Therapy

Primary outcomes

  • Glycated serum protein (GSP) levels
  • Morningness-Eveningness Questionnaire (MEQ) score
  • Sleep quality

Evidence relationships

Intervention and outcome relationships this study adds to the evidence network.

6
Evidence pairs
6
Relationships
0
Evidence topics
contributes_evidence

Editorial context

Why this study matters

See why this paper is useful beyond its individual results.

Evidence network role

This section describes how the study fits into the current evidence network. It does not determine whether an intervention works on its own.

Moderate contributionModerate confidenceNetwork score: 50

0

Related topics

6

Evidence pairs

0

Related studies

Why it is useful

  • Contributes to 6 evidence relationships
  • Includes primary outcome data
  • Linked to 0 direct semantic evidence topics

Core evidence

Study findings

The primary outcomes reported in this study.

Glycated serum protein (GSP) levels

Control Group - Blinded Nutrition Therapy → Glycated serum protein (GSP) levels

Control Group - Blinded Nutrition Therapy → Glycated serum protein (GSP) levels

Evidence Intelligence™
ImpactScore™
50
Neutral
EvidenceScore™
Emerging
Score 59 · Based on 1 study
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Unlock full evidence details

Morningness-Eveningness Questionnaire (MEQ) score

Control Group - Blinded Nutrition Therapy → Morningness-Eveningness Questionnaire (MEQ) score

Control Group - Blinded Nutrition Therapy → Morningness-Eveningness Questionnaire (MEQ) score

Evidence Intelligence™
ImpactScore™
50
Neutral
EvidenceScore™
Emerging
Score 59 · Based on 1 study
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Unlock full evidence details

Sleep quality

Control Group - Blinded Nutrition Therapy → Sleep quality

Control Group - Blinded Nutrition Therapy → Sleep quality

Evidence Intelligence™
ImpactScore™
50
Neutral
EvidenceScore™
Emerging
Score 59 · Based on 1 study
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Unlock full evidence details

Glycated serum protein (GSP) levels

Photobiomodulation therapy → Glycated serum protein (GSP) levels

Photobiomodulation therapy → Glycated serum protein (GSP) levels

Evidence Intelligence™
ImpactScore™
50
Neutral
EvidenceScore™
Emerging
Score 59 · Based on 1 study
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Unlock full evidence details

Morningness-Eveningness Questionnaire (MEQ) score

Photobiomodulation therapy → Morningness-Eveningness Questionnaire (MEQ) score

Photobiomodulation therapy → Morningness-Eveningness Questionnaire (MEQ) score

Evidence Intelligence™
ImpactScore™
100
Very Positive
EvidenceScore™
Emerging
Score 59 · Based on 1 study
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Unlock full evidence details

Sleep quality

Photobiomodulation therapy → Sleep quality

Photobiomodulation therapy → Sleep quality

Evidence Intelligence™
ImpactScore™
100
Very Positive
EvidenceScore™
Emerging
Score 59 · Based on 1 study
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Unlock full evidence details

Unlock full evidence analysis

Create a free account to access effectiveness ratings, evidence strength and depth scores, consistency analysis, and direct links to all supporting studies.

evidence suggest

Evidence Suggest

  • Light therapy improved sleep quality as indicated by a 4.5 point decrease in PSQI scores.
  • MEQ scores also improved significantly, decreasing by 4.85 points.
  • No significant changes in GSP levels were observed between groups.
who this applies

Who this applies to

  • Older adults aged 65 and above.
  • Individuals diagnosed with type 2 diabetes.
keep in mind

Keep in Mind

  • Results may not apply to younger populations or those without diabetes.
  • The study's findings are based on self-reported measures, which can be subjective.
  • Further research is needed to explore long-term effects of light therapy.
between the lines

Between the Lines

  • The study's sample size may limit generalizability.
  • The control group showed no significant changes, raising questions about the intervention's effectiveness.
  • The study did not account for potential confounding factors affecting sleep quality.

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Connected Evidence

Explore related studies, evidence collections, and research questions.

Relationships organized using the Dediabetes Evidence Intelligence™ framework.

This study contributes to evidence on Control Group - Blinded Nutrition Therapy and Glycated serum protein (GSP) levels, Control Group - Blinded Nutrition Therapy and Morningness-Eveningness Questionnaire (MEQ) score.

Related evidence relationships

Explore in Evidence Archive

This study contributes to the evidence on the following intervention-outcome relationships.

Included in these evidence collections

Curated evidence collections and hubs this study is part of.

Explore more in the evidence archive

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Questions answered by this study

Generated from the study's connected evidence using Evidence Intelligence™.

Does Photobiomodulation therapy improve morningness-eveningness questionnaire (meq) score?

Emerging Evidence

Photobiomodulation therapy appears to improve Morningness-Eveningness Questionnaire (MEQ) score.

ConsistencyScore™: Consistency cannot yet be determined from the available evidence.

Ranked evidence signals

  1. 1

    Morningness-Eveningness Questionnaire (MEQ) score

    EvidenceScore™ Emerging | EvidenceScore™ 59.0 | strong positive | ConsistencyScore™ Unclear | 1 study

Why this answer: This answer is based on a single supporting study.

Limitations

  • Only one supporting study is available.
  • Consistency cannot yet be determined.
  • Population details are unavailable.
1 supporting studyUpdated: Jul 2026

Does Photobiomodulation therapy improve sleep quality?

Emerging Evidence

Photobiomodulation therapy appears to improve Sleep quality.

ConsistencyScore™: Consistency cannot yet be determined from the available evidence.

Ranked evidence signals

  1. 1

    Sleep quality

    EvidenceScore™ Emerging | EvidenceScore™ 59.0 | strong positive | ConsistencyScore™ Unclear | 1 study

Why this answer: This answer is based on a single supporting study.

Limitations

  • Only one supporting study is available.
  • Consistency cannot yet be determined.
  • Population details are unavailable.
1 supporting studyUpdated: Jul 2026

Does Control Group - Blinded Nutrition Therapy improve glycated serum protein (gsp) levels?

Emerging Evidence

Current evidence does not show a clear benefit of Control Group - Blinded Nutrition Therapy for Glycated serum protein (GSP) levels.

ConsistencyScore™: Consistency cannot yet be determined from the available evidence.

Ranked evidence signals

  1. 1

    Glycated serum protein (GSP) levels

    EvidenceScore™ Emerging | EvidenceScore™ 59.0 | neutral | ConsistencyScore™ Unclear | 1 study

Why this answer: This answer is based on a single supporting study.

Limitations

  • Only one supporting study is available.
  • Consistency cannot yet be determined.
  • Population details are unavailable.
1 supporting studyUpdated: Jul 2026

Does Control Group - Blinded Nutrition Therapy improve morningness-eveningness questionnaire (meq) score?

Emerging Evidence

Current evidence does not show a clear benefit of Control Group - Blinded Nutrition Therapy for Morningness-Eveningness Questionnaire (MEQ) score.

ConsistencyScore™: Consistency cannot yet be determined from the available evidence.

Ranked evidence signals

  1. 1

    Morningness-Eveningness Questionnaire (MEQ) score

    EvidenceScore™ Emerging | EvidenceScore™ 59.0 | neutral | ConsistencyScore™ Unclear | 1 study

Why this answer: This answer is based on a single supporting study.

Limitations

  • Only one supporting study is available.
  • Consistency cannot yet be determined.
  • Population details are unavailable.
1 supporting studyUpdated: Jul 2026
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