Wellness Letter: Medical News

Sleep Deprivation Adds to Your Waistline
By Dr. Jannet Huang

Sleep curtailment is common in our society. The current average duration of sleep for Americans has fallen to 6.9-7.0 hours from 8.0-8.9 hours in 1960. Recent research has found significant adverse effects of sleep deprivation on our hormones and metabolism. In fact, some scientists feel that lack of sleep is one of the major contributing factors to the obesity and diabetes epidemic!

How does sleep loss add to your waistline?

Sleep deprivation raises the stress hormone cortisol. Normally cortisol concentration declines rapidly to the minimal levels shortly before habitual bedtime. After just several nights of sleep restriction, this rate of decline in cortisol becomes significantly slower. Elevations of evening cortisol levels in chronic sleep deprivation can induce insulin resistance which is a risk factor for obesity and is also the core problem that leads to diabetes.

Appetite-regulating hormones are profoundly influenced by the duration of sleep. Sleep loss is associated with an increase in appetite which is out of proportion to the caloric demands of staying awake. Leptin is a hormone secreted by fat cells to signal satiety to the brain and suppresses appetite. Leptin levels are decreased markedly after even short term sleep deprivation, resulting in excessive hunger, particularly during the nighttime. This reduction of leptin is accompanied by elevation of ghrelin, a hormone released by the stomach that stimulates appetite. Sleep loss therefore leads to increased hunger, especially for foods with high carbohydrate content.

A recent study showed that in young healthy subjects, just 6 days of sleep deprivation (4 hours in bed) led to higher blood sugar levels after breakfast. Inadequate sleep has been implicated in raising the risk of developing type 2 diabetes.

If you have been experiencing difficulty achieving a healthy weight loss, consider that your sleep deprivation may be sabotaging your efforts!!

Information excerpted from “The Impact of Sleep Deprivation on Hormones and Metabolism” Van Cauter et al. Medscape Neurology & Neurosurgery 2005; 7 (1).

—June 2005