A comprehensive systematic review published in Diabetes Metabolic Syndrome has revealed significant associations between disrupted melatonin production and diabetic retinopathy (DR), offering new insights into the role of circadian rhythms in this sight-threatening condition.

The research, which analysed 12 studies measuring melatonin concentrations across various body fluids, found strong evidence that patients with DR experience reduced nocturnal melatonin production compared to those without the condition.1

While studies examining salivary melatonin levels showed no significant differences between type 2 diabetes patients with and without DR, research measuring serum melatonin levels produced inconsistent results across different stages of the disease.

Most concerning was the finding that only 33% to 57% of DR patients had detectable dim light melatonin onset (DLMO) in saliva and serum respectively. DLMO serves as a highly accurate biomarker for circadian regulation, suggesting significant disruption to normal sleep-wake cycles in affected patients.

All studies evaluating overnight melatonin production through urinary aMT6s (6-sulfaoxymelatonin) levels demonstrated a clear association between DR and lower nocturnal melatonin production, providing the most consistent evidence across the research. The researchers concluded that while DR patients show evidence of reduced nocturnal melatonin production, there were no significant changes in melatonin circadian timing. These findings may inform future therapeutic approaches and shed light on the importance of circadian health in diabetes management.

The study adds to growing evidence of the complex interplay between metabolic disorders and circadian rhythm disruption in ocular complications.

Reference available at mivision.com.au.