Nicotine intake may lead to which of the following?

Nicotine intake is known to significantly influence sleep patterns, and insomnia is a common consequence associated with its use. Nicotine is a stimulant that can interfere with sleep by increasing arousal and reducing overall sleep time. This stimulant effect can lead to difficulties in falling asleep, staying asleep, or achieving restorative sleep, which characterizes insomnia.

In addition to altering sleep structure, nicotine withdrawal can also disrupt sleep patterns, further exacerbating insomnia in individuals who are trying to quit smoking. Thus, the relationship between nicotine use and insomnia is well-documented in literature, making insomnia the correct answer.

The other options relate to sleep disorders that are not directly caused by nicotine. Sleep apnea typically involves physical airway obstruction and is influenced more by structural factors and obesity than by stimulant use. Excessive dreaming can occur for various reasons, but it is not a well-established outcome of nicotine use. Narcolepsy is a neurological disorder characterized by excessive daytime sleepiness and sudden sleep attacks, which is not linked to nicotine consumption.