No impact of 12-week melatonin administration on diabetes risk markers and fat intake in overweight women night workers

The study no impact of melatonin administration on DM risk markers according to dietary lipids profile (pro-inflammatory or anti-inflammatory potential) in excessive weight night workers. Concerning fat consumption, melatonin administration promoted no change in consumption profile throughout the intervention for total fats, dichotomized into anti-inflammatory or pro-inflammatory types, or for isolated fats (saturated fat, trans fat, cholesterol, monounsaturated fat and EPA + DHA).

In the study, the total consumption of anti-inflammatory fats was greater than pro-inflammatory fats, although a high consumption of saturated and trans-fat was evident and, in parallel, a low intake of monounsaturated and EPA + DHA.

Engaging in night shift work can affect biological rhythms and is often associated with alteration in sleep patterns, reduced recovery, and poor quality of life. Circadian misalignment at eating times, as well as activity during the night among night workers, has been tied to an increased risk of developing hypertension, diabetes, obesity and cardiovascular disease.

Previous studies have shown the importance of interactions between circadian clocks and key mediators of chronic low-grade inflammation associated with fat consumption in maintaining metabolic homeostasis and may pose a risk for the development of obesity-associated comorbidities, particularly type 2 diabetes (T2D).

Melatonin administration can represent a therapeutic and/or preventive alternative for metabolic alterations associated with night work, given its action on mechanisms of inflammation, glycemic homeostasis, and energy metabolism.

Against the above background, Carlos Alberto Rodrigues de Sousa, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, and colleagues aimed to evaluate the effects of melatonin administration on diabetes risk markers according to dietary lipid profile in excessive weight night workers. They also determined the effect of administration on fat consumption profile.

For this purpose, they conducted a randomized, controlled, double-blind, crossover clinical trial comprising g 27 nursing professionals working permanent night shifts under a 12×36-hour system. The melatonin group (12 weeks) used 3 mg synthetic melatonin only on days off and between shifts, while the placebo group (12 weeks) was instructed to take a placebo, also on days off and between shifts.

Regarding inflammatory characteristics, participants were divided into pro-inflammatory (trans fats, saturated fats, and cholesterol) and anti-inflammatory (polyunsaturated, monounsaturated fats and EPA + DHA) groups according to fatty acid determinations.

At baseline and the end of each phase, insulin, blood glucose, and glycosylated haemoglobin plasma concentrations were collected, and HOMA-IR was calculated.

"Melatonin administration for 12 weeks did not affect type 2 diabetes risk markers according to dietary lipid profile in excessive weight night workers," the researchers wrote.

Limitations of the study include using low-dose melatonin, which may have influenced the results expected in the hypothesis, and individual adaptations to night work were not evaluated.

The authors stated the importance of the insights discussed for future research investigating the influence of melatonin and fats considered anti- or pro-inflammatory on glucose and insulin homeostasis related to night work.

"Given the originality of the topic addressed in the present study, future studies should involve a longer administration time, individualized doses, and possibly concomitant dietary prescription, should be encouraged," the study authors concluded.

Reference:

De Sousa, C. A., Nogueira, L. F., Moreno, C. R., & Marqueze, E. C. (2024). 12-week melatonin administration had no effect on diabetes risk markers and fat intake in overweight women night workers. Frontiers in Nutrition, 11, 1285398. https://doi.org/10.3389/fnut.2024.1285398