Table of Contents
Getting enough sleep is important for more reasons than just how energetic you feel the next morning. Sleep affects your weight, your blood pressure, and even whether you will eventually get diabetes. The connection between sleep and the risk of future development of diabetes, however, is very different in men and women. Recent research has found that:
- Men who don't get enough sleep are at greater risk for developing type 2 diabetes.
- Men who get too much sleep are at greater risk for developing type 2 diabetes.
- Women who don't get enough sleep have a lower risk of developing diabetes than women who get normal amounts of sleep or even more.
In the European Relationship between Insulin Sensitivity and Cardiovascular Disease (EGIR-RISC) study, which involved 800 volunteers ranging in age for 30 to 60 in 14 countries at 19 testing centers in Europe, "normal" sleep was defined as seven hours per night.
What Is Insulin Resistance, and What Does It Have to Do with Diabetes?
Researchers measured sleep with a device called a single-axis accelerometer, designed to detect movement. They measured insulin resistance, which is predictive of future development of obesity, high triglycerides, high blood pressure, and type 2 diabetes, with a device called a hyperinsulinemic-euglycemic clamp. This "clamp" isn't a physical clamp but a strict control of blood sugar levels. The researchers carefully measured the amount of glucose that they had to give through an IV to raise a volunteer's blood sugar by 125 mg/dl over its normal levels through one vein, while measuring the effects of an insulin drip through another vein.
People who reached high blood sugar levels easily and whose blood sugar levels were slow to fall with the infusion on insulin were said to be insulin resistant. It's possible to be more insulin resistant or less insulin resistant. In people who are insulin resistant but not yet diabetic, the pancreas makes more and more insulin until blood sugars finally go down. This is an effect that the test measures by an actual drip of insulin into a vein. On a day to day basis, insulin "locks" fat in fat cells, so these people are prone to gain weight unless they diet carefully. Eventually the stress of having to produce large amounts of insulin all the time "burns out" the pancreas and diabetes sets in.
How Sleep and Insulin Resistance Differ in Men and Women
The EGIR-RISC researchers started with the observation that people report getting on average 90 minutes to two hours more sleep every night than they did 50 years ago, and that during that time the number of cases of diabetes has doubled. They theorized that excess sleep is either a cause or a result of insulin resistance, which is the driving force behind type 2 diabetes.
Over thirty sets of researchers had measured blood sugar levels and sleep, but the EGIR-RISC team was the first to measure insulin resistance. When actual insulin resistance was measured they found that in women, getting normal amounts of sleep (not too much and not too little) was associated with greater risk of diabetes, and in men, getting normal amounts of sleep (not too much and not too little) was associated with lower risk of diabetes.