Melatonin, Diabetes & Sleep Disorders
Melatonin is considered by the majority of individuals as a sleeping aid, a supplement that can be taken on nights when lack of sleep or difficulty sleeping is keeping them awake. However, are you aware that melatonin also plays an important role in other functions in your body?It also affects the cardiovascular system, immune system and has been implicated in controlling several metabolic functions such as regulation of blood glucose.
Importance of Melatonin in Maintaining Circadian Rhythm
According to Ronald Goldberg, MD of the Diabetes Research Institute in Hollywood, melatonin is a hormone that is vital in regulating the body’s biological clock, also referred to as the circadian rhythm. It also helps to keep the pancreas working efficiently. It is an essential hormone that helps in controlling your body’s wake-sleep cycle. Melatonin is released from the pineal gland that is situated in the brain. It regulates both circadian and seasonal rhythms. The levels of melatonin become high during the night and they are low during the daytime. (Levels of insulin hormone also drop in the night and according to some experts, melatonin at least partially controls levels of insulin in the body).
Connection Between Type 2 Diabetes and Sleep Disorders
A large amount of research exists that indicates a strong connection between type 2 diabetes and sleep disorders. Evidence suggests that this link may be hereditary or genetic. According to a new study, researchers have found a link between a gene associated with melatonin and an increased risk of developing type 2 diabetes.
A team of researchers from the UK, France and Canada, have found a link between an increased risk of type 2 diabetes and several mutations in the melatonin receptor gene of the body, a gene referred to as MTNR1B. The researchers worked with a group of 7632 European females, out of which 3186 already had type 2 diabetes. They found:
- 40 rare and different mutations in the melatonin receptor gene that are associated with differing levels of increased risk of developing type 2 diabetes.
- Four of these rare and different mutations actually resulted in a total loss of function in the melatonin receptor gene.
- Researchers analyzed these four rare mutations in another group of 11,854 people and found that even the presence of a single gene increases the risk of type 2 diabetes significantly. The increase is at least six times higher than in an average individual.
A link between risk of diabetes and other common mutations has already been established by previous research. A wider range of mutations to the melatonin receptor gene that causes an increased risk of diabetes, along with increased risk of diabetes by the four rare mutations, have been revealed by the new study.
Melatonin plays a vital role in the synchronization of the biological body clock and regulating its wake-sleep cycle. The cycle of melatonin hormone release is critical for us to sleep at night. Disordered sleep will result if the body’s ability to secrete melatonin is disrupted.
Effect of Melatonin on Insulin Production
Evidence also suggests that disturbances in production of melatonin may affect the levels of insulin in the body. The major characteristic of type 2 diabetes is the body’s inability to utilize insulin effectively, a condition also referred to as insulin resistance. Under normal circumstances, the body secretes the right amount of insulin that is required for the cells to absorb glucose from the blood. Any disturbance to levels of insulin can disrupt this finely-tuned process.
This issue is complicated. The latest results of these studies raise questions, and also remind us that we still have much to learn about the biological sleep functions of the body and its relationship to type 2 diabetes.
What is known currently, is that there is growing and compelling evidence that sleep and its genetic and biological underpinnings play a vital role in determining the risk of type 2 diabetes. According to recent studies:
- Poor sleep is associated with both insulin resistance and weight gain in healthy adults.
- Sleeping for less than six hours per night raises your risk of developing type 2 diabetes. The risk increases with decreasing amounts of sleep. According to the same study, sleeping for less than five hours a night increases risk of diabetes even further.
- Just one night of sleeping four hours, instead of the recommended seven to eight hours, can result in insulin resistance.
According to a recent study, low levels of melatonin at night are associated with an increased risk of type 2 diabetes. For this particular study, 370 females were chosen who had diabetes, and 370 control females of the same age and race. On comparing the two groups, it was found that the participants who had low levels of melatonin at night, had around twice the risk of developing type 2 diabetes as those participants who had high levels of melatonin at night. The study also accounted for other risk factors for diabetes including a positive family history of diabetes, body mass index and various lifestyle factors such as exercise, diet, sleep duration and smoking. The study still demonstrated that secretion of melatonin remained an important risk factor.
Type 2 diabetes is often considered to be a disease related to unhealthy lifestyle factors such as exercise and diet. There’s no doubt that leading a sedentary lifestyle and eating a poor diet increases the risk of diabetes. However, sleep is often overlooked as one of the risk factors. While assessing risk factors for developing type 2 diabetes, disordered and disrupted sleep should be considered as serious a risk factor as poor diet or a lack of exercise. This is quite often not the case. Meanwhile, both patients and doctors should give more importance to sleep as a risk factor for diabetes, and also consider it as an indicator of overall general health.