Last updated August 16, 2026
Key finding
Melatonin supplementation for 8 weeks significantly decreased the mean levels of SBP post-intervention (p < 0.05).
This study examined the impact of melatonin supplementation on cardiovascular disease risk factors in patients with type 2 diabetes. It found significant reductions in various cardiovascular and anthropometric measures.
Quick read
The essential study design details in one scan.
EvidenceScore™
Moderate
Study type
RCTs
Follow-up
Medium-Term (3–12 mo)
Risk of bias
Some Concerns
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Plain-language summary
A plain-language read of the study’s main message and where it applies.
Study focus
This study examined the impact of melatonin supplementation on cardiovascular disease risk factors in patients with type 2 diabetes. It found significant reductions in various cardiovascular and anthropometric measures.
The findings are clinically significant as they suggest that melatonin supplementation could be a simple and effective strategy for reducing cardiovascular risk factors in patients with type 2 diabetes. Given the high prevalence of cardiovascular disease in this population, these results may inform treatment approaches and improve patient outcomes.
The study may have limited generalizability due to the specific population studied. Sample size and duration may not fully capture long-term effects. Potential confounding factors were not extensively controlled.
Published in
Publication details and source links for this paper.
Hadi B, Ahmad ZJ, Hossein BB, Fardin M, Bahman MP, Parichehr A. Effects of melatonin supplementation on cardiovascular disease risk factors and anthropometric indices in patients with type 2 diabetes mellitus: a double-blind, randomized, placebo-controlled trial. Trials. 2021;22:231. doi:10.1186/s13063-021-05174-z
Melatonin supplementation reduced systolic blood pressure by 4.4 mmHg (p < 0.05).
Body weight decreased by 3.6 kg following melatonin supplementation (p < 0.05).
Waist circumference was significantly reduced post-intervention (p < 0.05).
Evidence network
Understand where this research contributes within the broader evidence network.
This study contributes evidence to Melatonin and Atherogenic Index of Plasma Increase, BMI, Body adiposity index, and 9 more.
This study contributes evidence to
Primary intervention
Melatonin
Primary outcomes
Evidence topics
Primary intervention
Primary outcomes
Intervention and outcome relationships this study adds to the evidence network.
Editorial context
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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.
1
Related topics
12
Evidence pairs
184
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Evidence topic
Contributes evidence
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Primary evidence
Evidence topic
matched_outcome
Core evidence
The primary outcomes reported in this study.
Melatonin → Atherogenic Index of Plasma Increase
Melatonin → Atherogenic Index of Plasma Increase
Melatonin → Decrease in Abdominal Volume Index
Melatonin → Decrease in Abdominal Volume Index
Melatonin → Mean arterial pressure reduction
Melatonin → Mean arterial pressure reduction
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Relationships organized using the Dediabetes Evidence Intelligence™ framework.
This study contributes to evidence on Melatonin and Body Mass Index, Melatonin and Body Weight.
This study contributes to the evidence on the following intervention-outcome relationships.
Supplements
Supplements
Supplements
Curated evidence collections and hubs this study is part of.
All studies measuring Blood Pressure
Measures Blood Pressure as a key outcome.
All studies measuring Body Mass Index
Measures Body Mass Index as a key outcome.
All studies measuring Body Weight
Measures Body Weight as a key outcome.
All studies on Melatonin
Contributes to Melatonin evidence base.
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2 results
2 results
2 results
2 results
2 results
Generated from the study's connected evidence using Evidence Intelligence™.
Melatonin appears to improve BMI.
ConsistencyScore™: Results are consistent across studies.
Ranked evidence signals
BMI
EvidenceScore™ Moderate | EvidenceScore™ 69.0 | strong positive | ConsistencyScore™ Consistent | 1 study
Why this answer: This answer is based on a single supporting study.
Limitations
Melatonin appears to improve Body weight.
ConsistencyScore™: Results are consistent across studies.
Ranked evidence signals
Body weight
EvidenceScore™ Moderate | EvidenceScore™ 69.0 | strong positive | ConsistencyScore™ Consistent | 1 study
Why this answer: This answer is based on a single supporting study.
Limitations
Melatonin appears to improve Hip circumference.
ConsistencyScore™: Results are consistent across studies.
Ranked evidence signals
Hip circumference
EvidenceScore™ Moderate | EvidenceScore™ 69.0 | strong positive | ConsistencyScore™ Consistent | 1 study
Why this answer: This answer is based on a single supporting study.
Limitations
Melatonin appears to improve Systolic blood pressure.
ConsistencyScore™: Results are consistent across studies.
Ranked evidence signals
Systolic blood pressure
EvidenceScore™ Moderate | EvidenceScore™ 69.0 | strong positive | ConsistencyScore™ Consistent | 1 study
Why this answer: This answer is based on a single supporting study.
Limitations
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