Yes, it can, but not generally by itself. Carrie Fisher died after an episode of OSA, though a cocktail of drugs was also involved. What obstructive sleep apnea does is to weaken you so that you are less able to fight other conditions or poisons in your system. It can increase your blood pressure, and lead to sudden cardiac arrest. You are particularly vulnerable if you have a history of heart disease, diabetes, stroke, or one of many more chronic illnesses. OSA also disrupts your circadian rhythm and creates imbalances in your brain and body chemistry and increases your pulse rate.