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Indolence and Obesity
Inactivity or weight gain increase insulin resistance.
Insulin resistance -
- Increases blood pressure
- Lowers HDL (good) cholesterol
- Raises triglycerides
- Raises insulin levels
All these things poison the endothelium and cause premature atherosclerosis.
Atherosclerosis harms the brain and the heart: both are important to safe flight!
Notes:
Adult-type Diabetes is simply the tip of a very large iceberg. The large part below the water is insulin resistance and is almost as important as diabetes. Here's the deal on insulin resistance:
Glucose enters our cells through a gate that must first be unlocked. If glucose can't get in, it floats around in our blood, accumulates, and is excreted in the urine: diabetes mellitus.
The key that unlocks the glucose gate is insulin; the lock itself is the insulin receptor. As we gain adipose weight, our body reduces the number of locks ('down-regulates insulin receptors'). If we eat too much, the pancreas simply makes extra insulin to flood the receptors. Diabetes occurs only when this extra insulin isn't enough to keep the blood sugar normal.
The extra insulin has several adverse effects on our blood vessels. It directly promotes atherosclerosis, it increases blood pressure, and it alters the way our liver handles cholesterol and triglycerides. Production of good or HDL cholesterol, that acts like little sponges to mop up grease spots from our arteries, is decreased. Triglyceride production is increased, causing the bad or LDL to be converted to a more damaging form.
Insulin resistance is increased by weight gain and by hereditary factors. It is decreased by weight loss and through exercise, and with medication. Two types of medication that reduce insulin resistance are metformin and the 'glitazones,' costing $60 to $110 a month. But a half hour of aerobic exercise daily is more effective than either medication in reducing insulin resistance.