In new research published in JAMA Ophthalmology, investigators evaluated the relationship between melatonin supplementation and risk of progression or development of age-related macular degeneration (AMD).
Give me some background first.
AMD is the leading cause of irreversible vision loss in adults aged 60+, affecting an estimated 20 million Americans.
Its two primary forms include:
- Dry AMD
- Prevalent in an estimated 80% of AMD patients
- Wet AMD
- Less common form
- Typically leads to more severe vision loss
Currently, there is no cure; however, treatment options are available to slow disease progression.
Why investigate melatonin?
Previous research found that melatonin may demonstrate opposition to processes known to mediate AMD.
However: There is no clear answer as to whether melatonin can provide benefits for the retinal disease.
Now, talk about the study.
Researchers accessed data from TriNetX—a national database of de-identified electronic medical records—between December 4, 2023, and March 19, 2024, from inpatient and outpatient healthcare organizations in the United States.
Note: These organizations were not identified.
Go on …
Participants with no history of AMD (AMD-naive group) and a history of nonexudative (dry) AMD (nonexudative AMD group) were queried for instances of melatonin medication codes from November 14, 2008, to November 14, 2023.
Give me some participant details.
A total of 121,523 electronic health records (EHR) were assessed, comprising of:
- 4,848 patients in the melatonin group
- 4,580 after propensity score matching (PSM)
- Mean (SD) age: 68.24
- 2,588 females (56.5%
- 116,675 controls
- 4,580 after PSM
- Mean (SD) age: 68.17
- 2,681 females (58.5%)
- Aged 50+
How was the study conducted?
Participants were classified into either the melatonin or control group based on the presence of medication codes for melatonin.
The researchers then used PSM to match cohorts based on:
- Demographic variables
- Comorbidities
- Non-melatonin hypnotic medication use
Note: Exposure was defined as the presence of a minimum of four instances of melatonin records that occurred at least 3 months apart.
And what were the main outcomes and measures?
Researchers compared the melatonin and control cohorts to assess:
- Risk ratios (RRs)
- 95% confidence intervals (CIs) (of having an outcome)
Outcomes were defined as:
- New diagnosis of any AMD (AMD-naïve group)
- Progression to exudative (wet) AMD (Nonexudative AMD group)
Now on to the findings.
When the melatonin naïve group (aged 50+) and the control group were compared, it was found that:
- Melatonin use was associated with a reduced risk of developing AMD
- RR, 0.42; 95% CI, 0.28-0.62
In 66,253 participants in the nonexudative AMD group aged (50+):
- Melatonin was associated with a reduced risk of AMD progression to exudative AMD
- RR, 0.44; 95% CI, 0.34-0.56
Tell me more.
These results remained consistent among subsets of participants aged:
- 60+
- AMD-naive cohort:
- RR, 0.36; 95% CI, 0.25-0.54
- Nonexudative AMD cohort
- RR, 0.38; 95% CI, 0.30-0.49
- AMD-naive cohort:
- 70+
- AMD-naive cohort
- RR, 0.35; 95% CI, 0.23-0.53
- Nonexudative AMD cohort
- RR, 0.40; 95% CI, 0.31-0.51
- AMD-naive cohort
Limitations?
Smoking and supplements that may increase the risk of developing or progressing AMD were not accounted for.
What this means: The melatonin group may have been healthier than the control group, which provided positive results in the study.
The study authors also noted that melatonin use was not monitored during the observational period of the study. Additionally, miscoding on participants’ EHRs may have occurred.
Expert opinion?
Per the authors’ statement, while lifestyle factors may have influenced the association, the data indicates a need for further research on the potential benefits of melatonin for preventing or mediating the progression of AMD.
Take home.
The findings of this study show that melatonin use may be associated with decreased risk of development and progression of AMD.