Is it common for the elderly to develop obstructive sleep apnea?

Yes, sort of: It is more common in the elderly due to loss of muscle tone, and often due to weight gain as well. However, it is not a foregone conclusion. Not everyone develops osa.

More likely: As we get older the risk of sleep apnea increases. Especially if we gain some weight and as we age our muscles that hold the throat open tend to relax.

Sleep apnea: As we get older unfortunately everything tends to be less elastic. If we gain weight there will be less airway. If the air way is less elastic it doesn't hold up well and will close when we lay down -so it can be very common to develop sleep apnea when we get older.

Depends: Sleep apnea, in varying degrees of severity, can affect people of all ages. Life style and body type may determine the onset of sleep apnea just as much as age.

All Age Groups: though most common in overweight men and over the age of 40.

Yes: Some of the risk factors (weight gain, flaccidity of tissues) increase with age.