Making poor food choices is one thing. I'll wake up the next day feeling like death; my blood sugar levels are all over the place and regret sets in.
Melatonin, Sleep and Type 2 DiabetesA recent clinical study performed at Lund University in Sweden has confirmed what I already suspected: That there is a connection between sleep, melatonin, and type 2 diabetes. 
Researchers found that melatonin, a potent sleep hormone, has the ability to impair insulin secretion in people who carry a specific and common gene variant. Simply stated, individuals with this gene variant became more sensitive to melatonin (and melatonin supplementation) and their ability to secrete insulin was impaired.
Hindrik Mulder, a researcher involved with the study, went on to say:
"A third of all people carry this specific gene variant. Our results show that the effect of melatonin is stronger in them. We believe that this explains their increased risk of developing type 2 diabetes."A third of all people carry this gene variant. Folks with two copies of the risk variant MTNR1B gene have higher levels of the melatonin receptor compared to those that have zero or one copy.
A clinical study was performed on 45 non-diabetic subjects. 23 of these individuals carried the MTNR1B gene variant and 22 without. Each night before bed they self-administered 4 milligrams of melatonin. This protocol was followed for three months.
At the conclusion of the study, researchers found a direct correlation between the gene variant and insulin secretion. Individuals who did not carry the MTNR1B gene variant had an insulin secretion rate that was three times higher than those with the gene.
Melatonin is a vital hormone that helps the body keep track of time. Mulder added,
"We don't typically eat or are physically active at night, so our energy demands drop and we don't need maximum insulin secretion. A likely explanation is that, as melatonin levels rise, they tell our beta cells not to release as much insulin."
Late Shifts, Sleep Disruption, Melatonin and Type 2 Diabetes
For those carrying this gene variant, melatonin supplementation may not be the wisest choice. For those without the gene variant, proper sleep is an necessity in the battle against type 2 diabetes. In goes without saying that if you have a difficult time sleeping, supplementing with melatonin may actually assist with proper insulin secretion and works towards staving off type 2 diabetes.
In humans, melatonin levels rise throughout the day and lead to an increase in sleep propensity about two hours before our normal bedtime. This could be referred to as the opening of the "sleep gate." This rhythmic release of melatonin is regulated by the SCN, or suprachiasmatic nucleus.
Melatonin is also believed to be an "endogenous synchronizer that stabilizes and reinforces various circadian rhythms in the body." 
Disruptions of sleep may lead to a disruption of the body's circadian rhythms, and a disruption to how melatonin is released. Korean researchers found that if you struggle with chaotic sleep patterns, this can potentially disrupt your circadian rhythms and contribute to a number of health problems. 
"Circadian disruption, typically induced by shift work, may negatively impact health due to impaired glucose and lipid homeostasis, reversed melatonin and cortisol rhythms, and loss of clock gene rhythmicity."Bottom line: Sleep disruptions can contribute to crazy melatonin rhythms. With disrupted melatonin release we may also experience an impact how our body normally secretes insulin.
The result, as it appears based on the latest research, is that improper sleep and the disruption in proper melatonin release may be a contributing factor to the onset of type 2 diabetes.
Take Home AdviceFor the 30 percent of the population that carries gene variant MTNR1B, melatonin supplementation may actually negatively impact insulin secretion. But for the rest of us, proper sleep and melatonin supplementation may actually work to lower our risk for type 2 diabetes.
In the long run, roper sleep and melatonin release is essential for maintaining good health. Take your sleep patterns seriously and listen to your body. Consider a melatonin supplement if you struggle with stress, sleep disruptions, a crazy work schedule, or insomnia.
If you are concerned that you may have the gene variant MTNR1B, consult with your physician. Make him aware that you have concerns about nighttime insulin secretion, and that you wish to supplement with melatonin.