Poor Sleep Quality Leads To Insulin Resistance

Researchers in Chicago found it is possible to induce a state of insulin resistance - with subsequent rises in blood glucose - in young, healthy, non-overweight subjects by simply disturbing their sleep.

When volunteers entered a stage of sleep called deep non-rapid eye movement (NREM), also known as slow-wave sleep (SWS), researchers made noise, but not enough to wake them. After three days, the participants' ability to regulate blood glucose declined by 25%.

This impaired glucose tolerance occurred even though the participants slept for 8.5 consecutive hours. It was the quality of their sleep, not the length, that determined their ability to manage blood glucose.

The research appeared in an online edition of the Proceedings of the National Academy of Sciences (PNAS) this month:

Slow-Wave Sleep And The Risk Of Type 2 Diabetes In Humans
________
Some news summaries:
Lack Of Deep Sleep May Increase Risk Of Type 2 Diabetes (Science Daily)
Sleep Disruptions May Up Diabetes Risk (Yahoo)

Are Your Blood Sugars High in the Morning?

Two common reasons for this are the Dawn Phenomenon and the Somogyi Effect:

Dawn Phenomenon

Every human being experiences the Dawn Phenomenon. While we sleep, usually around 3-8 AM, glucose is released in response to the stimulus of some hormones in order to repair and maintain our body. These hormones are growth hormone, cortisol, glucagon, and epinephrine (also called adrenalin), which are also known as counterregulatory hormones, since they have the opposite effect of insulin: they cause glucose levels to rise.
- About.com - The Dawn Phenomenon and the Somogyi Effect

Somogyi Effect

The Somogyi Effect happens when your blood glucose levels are high in the morning due to hypoglycemia (low blood glucose levels) overnight. [Low blood sugars can occur when there is extra insulin in the body.] This is also called rebound hyperglycemia, since your body reacts to low blood glucose levels by increasing the release of glucose from muscles, liver and fat, therefore causing hyperglycemia.
- About.com - The Dawn Phenomenon and the Somogyi Effect

How Can You Tell the Difference?

• If the blood sugar level is low at 2 a.m. to 3 a.m., suspect the Somogyi effect.
  
• If the blood sugar level is normal or high at 2 a.m. to 3 a.m., it's likely the dawn phenomenon.
  - A-Z Health Guide from WebMD: Dawn phenomenon and the Somogyi effect

What Can You Do?

Once you and your doctor determine the cause, there are a number of options. These include changing the time, the type, or the amount of insulin you take, making adjustments to your evening snack, or switching to an insulin pump.

________
Resources:
About.com - The Dawn Phenomenon and the Somogyi Effect

A-Z Health Guide from WebMD: Dawn phenomenon and the Somogyi effect

WebMD - Diabetes: Morning High Blood Sugar Levels

Sleep - Too Little or Too Much - Linked to Diabetes in Men

Researchers from New England found that men who slept either less than 6 hours, or greater than 8 hours, increased their risk for type 2 diabetes. That risk remained after adjustments were made for age, hypertension, smoking status, self-rated health status, education, and waist circumference.

These results suggest that even though you have a handle on your weight, blood pressure and smoking, you may still court a diagnosis of diabetes if your sleep is consistently short-changed, or over-indulged.

The study included 1564, primarily white men, aged 40 to 70, who were enrolled in the Massachusetts Male Aging Study (MMAS), and who did not have diabetes at baseline. The men were followed for up to 15 years. Similar, although less marked results were found in women who partook in the Nurses Health Study.

The study appears in the March 2006 issue of Diabetes Care.

________
For the MMAS study:
Sleep Duration as a Risk Factor for the Development of Type 2 Diabetes

For a summary of the MMAS study:
Diabetes Risk Raised By Too Much Or Too Little Sleep

For the Nurses Health Study:
A Prospective Study of Self-Reported Sleep Duration and Incident Diabetes in Women

Link Between Sleep and Diabetes

Researchers at Boston University find that too little sleep, less than 7 or 8 hours a night, could increase the risk for diabetes:
Too Little Sleep Could Cause Diabetes