Metabolism

It has long been known that melatonin is a key regulator of glucose metabolism and energy balance. More recent studies have also demonstrated that an impairment of the interaction between melatonin and the receptor can contribute to the pathogenesis of type 2 diabetes, although the mechanisms behind this are not yet understood.

Lifestyle affects insulin resistance

There may be many reasons for the development of insulin resistance, resulting in dysfunction of the body’s sugar metabolism, but one of the main factors is the disruption of the 24-hour circadian rhythm – researchers agree on this. Sleep problems, shift work and social jet lag have been named as examples of how the likelihood of insulin resistance and the resultant diabetes can be increased. Melatonin seems to play a key role here, as the body’s own melatonin production is suppressed or delayed in cases of all the aforementioned disorders.

Timing of food consumption is critical

Studies have also discovered that the timing of food intake also plays a key role here. For example, people who engage in shift and night work are at much greater risk of obesity and metabolic syndrome, which presents a high risk of both cardiovascular diseases and type 2 diabetes. These people are forced to eat at times where the body’s internal melatonin production is often highest – a situation that is not especially helpful in relation to the physiological effect of insulin.

Circadian insulin

Insulin is cyclically released at the three main mealtimes – which should always be during the day, namely times when melatonin concentration is lowest. Insulin is also released when eating a quick snack, but the sugar is not used physiologically, which can result in obesity.