A Downward Spiral
Appetite Hormones and ObesityPoor sleep and sleep deprivation can increase your appetite. Sleep apnea causes imbalances in the levels of two hormones that are associated with feelings of hunger and satiety: leptin and ghrelin.
- Leptin, which is produced by fat cells, is an appetite suppressant. When leptin is present at high levels, it normally produces a feeling of satiety—the feeling that you are full and have eaten enough.
- Ghrelin, which is produced by your stomach and pancreas, is leptin’s counterpart and has the reverse function: it’s an appetite stimulant. Levels of ghrelin increase before a meal and decrease afterwards.
Disrupted sleep causes your levels of ghrelin to rise, stimulating your appetite. It also causes levels of leptin, the appetite suppressant, to decrease, making you even hungrier. (However, some obese people have high levels of leptin because their bodies have become resistant to it, in much the same way the body can become resistant to insulin.) LESS
Sleep Deprivation and Glucose MetabolismOSA can raise your insulin and glucose (blood sugar) levels and damage your ability to process glucose—in some cases to the level of diabetics. In order to metabolize glucose, people who get 6-1/2 hours of sleep a night or less need to make 30% more insulin than people who get more sleep,
Insulin causes your body to store fat, and chronically high levels of insulin can pack the pounds on. Chronically high levels of insulin lead to insulin resistance.
Sleep Apnea and Insulin ResistanceSleep apnea appears to be a risk factor for insulin resistance, a precursor to diabetes, and people with moderate-to-severe sleep apnea may have twice the risk of developing insulin resistance. This risk is independent of age, BMI, and neck size.
Sleep apnea is linked to decreases in insulin sensitivity, glucose effectiveness, and pancreatic cell function. This is true whether or not the person with sleep apnea is overweight or obese.