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Melatonin may play role in diabetes risk in men

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September 19, 2018

A higher endogenous melatonin level in older Japanese men may be associated with decreased risk for developing type 2 diabetes, according to findings published in Clinical Endocrinology.

Kenji Obayashi 

Melatonin could play a role in preventing diabetes mellitus, possibly through the multiple pathways involved in beta-cell function and insulin resistance,” Kenji Obayashi, MD, PhD, of the department of epidemiology at Nara Medical University School of Medicine, Japan, told Endocrine Today. “Prospective studies further investigating the association between melatonin secretion and diabetes mellitus in males and females are needed.”

In a cross-sectional study, researchers analyzed data from 1,096 older Japanese adults (577 women; mean age, 72 years) who participated in a community-based cohort study between 2010 and 2014. Researchers measured levels of endogenous melatonin, glycemic measurements to determine diabetes status and urinary 6-sulfatoxymelatonin.

Urinary 6-sulfatoxymelatonin levels were grouped into quartiles and log-transformed for analyses. Researchers used logistic regression models to determine trends for the relationship between urinary 6-sulfatoxymelatonin quartiles and diabetes prevalence.

Results were adjusted for age, smoking status, alcohol intake, household income, caloric intake, physical activity, beta-blocker use, chronic kidney disease, bedtime, and length of time in bed.

Within the cohort, diabetes prevalence was 17.5% for men and 10.7% for women.

The median urinary 6-sulfatoxymelatonin level for the cohort was 6.7 g. Men had a median urinary 6-sulfatoxymelatonin of 3.2 g in the lowest quartile group, 6.3 µg in the second quartile, 9.5 µg in the third quartile and 15.6 µg in the fourth quartile. In women, the median urinary 6-sulfatoxymelatonin was 2.6 g, 4.6 g, 7.1 g and 12.3 g across quartiles, according to researchers.

Researchers observed a decrease in diabetes prevalence with increases in urinary 6-sulfatoxymelatonin levels, ranging from 24.6% in quartile 1 to 12.3% in quartile 4 (P for trend = .009). The same trend was not observed in women; however, with diabetes prevalence ranging from 13.2% in the first quartile to 11.8% in the fourth quartile (P for trend = .96).

In multivariable logistic regression analyses adjusted for confounders, researchers found that the highest urinary 6-sulfatoxymelatonin quartile in men was associated with reduced risk for diabetes (OR = 0.35; 95% CI, 0.17-0.7), whereas no such association was observed in women (OR = 0.94; 95% CI, 0.45-1.95).

“In the present cohort, higher melatonin secretion was significantly associated with lower diabetes prevalence in males, but not in females,” the researchers wrote. “Prospective studies further investigating the association between melatonin secretion and diabetes mellitus in males and females are needed.” – by Jennifer Byrne


For more information:

Kenji Obayashi, MD, PhD, can be reached at 840 Shijocho, Kashiharashi, Nara, 634-8521, Japan, Department of Community Health and Epidemiology, Nara Medical University School of Medicine, Nara, Japan; email:

Disclosures: Obayashi reports he received research grants from EnviroLife Research Institute Co., Sekisui Chemical Co., Tokyo Electric Power Company, Ushio Inc., and YKK AP Inc. Please see the study for all other authors’ relevant financial disclosures.

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