Oxygen Desaturation Index (ODI)

How are sleep disorders diagnosed?

The Oxygen Saturation Index (ODI) indicates how often per hour of sleep the oxygen content of the blood drops by a certain degree compared to the baseline.
The ODIis measured with an oximeter (oxygen saturation/ percentage of blood oxygen). This is a device that is normally attached to the finger and emits a red light on the skin and can estimate the amount of oxygen in the blood. Newer technologies can make it possible to measure this in different ways across the skin surface. As already described (how does the CIRCUL™ ring – link) this measurement is also possible with the CIRCUL™ ring. Each breathing event during sleep with a drop in blood oxygen content of 3 percent is detected. For example, a change from 95 percent to 92 percent would be an event that counted against the total of the index.
These oxygen drops are called desaturations. If breathing is disturbed during sleep, as can occur with obstructive sleep apnea, the oxygen content of the blood can decrease repeatedly. These wastes are typically associated with a collapse of the upper respiratory tract, which is called either apnea (respiratory arrest) or hypopnea (change in respiratory depth by 50) (hypopnea represents a partial collapse of the respiratory tract).

What causes a deteriorating ODI?

ODI may be worsening in people with underlying pulmonary disease,including chronic obstructive pulmonary disease (COPD) and heart failure. With reduced reserves, the collapse of the upper respiratory tract can cause the oxygen content of the blood to drop more quickly. This may also be associated with an increased carbon dioxide content, for example in severe overweight/obesity.

Health consequences

It is assumed that an increase in the ODI can lead to increased oxidative stress and free radicals in the body that can make people want long-term Cardiovascular risks such as high blood pressure (hypertension), heart attack, stroke, Arrhythmias such as atrial fibrillator and memory loss associated with dementia. Associated cortisol outbreaks can lead to insulin resistance and worsen the risk and severity of diabetes. These consequences are an active area of sleep research.


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