Excessive Daytime Sleepiness, Insomnia and Risk Factors in Elderly Population

Sleeping problems, especially insomnia, are frequently reported to increase with age. Excessive daytime sleepiness (EDS) is one of the most harmful daytime consequences of insomnia. The combination insomnia-EDS significantly contribute to deteriorate the quality of life (Ohayon et al., 2001).

Surprisingly, few studies explored these two symptoms in elderly population.

This study aims to assess the prevalence of insomnia and EDS and its associated factors in an elderly general population.

METHODS

Targeted population:
Individuals 60 years of age or older living in the community in the metropolitan area of Paris (France).

SUBJECTS

• 7,010 randomly selected households were called to find individuals ≥ 60 years,
• 1,269 of the 7,010 households had at least one household member ≥ 60 years.
• 1,026 individuals ≥ 60 years accepted to be interviewed (participation rate: 80.9%).

INSTRUMENT

The subjects were interviewed by telephone using the Sleep-EVAL expert System (Ohayon, 1994; CIPO #437699), an expert system designed to conduct interviews and to make sleep and mental disorders diagnoses in the general population.

Variables assessed:

• Sleep habits and sleep/wake schedule
• Excessive daytime sleepiness and insomnia symptomatology
• DSM-IV and ICSD diagnoses
• Psychological General Well-Being Schedule
• Cognitive Difficulties Scale (Mac Nair-R)
• Independent living scale
• Scale assessing the social network

EDS: Moderately to severely feel sleepy during the day OR to fall asleep easily during the daytime and almost everywhere (≥ 2 days/week)

The sample includes:

RESULTS

Excessive daytime sleepiness (EDS) was reported by 13.6% of the sample with no significant difference between age groups.

Insomnia symptoms (difficulty initiating or maintaining sleep, non-restorative sleep) occurring at least 3 nights per week significantly increased with age due mainly to a growing number of subjects who reported disrupted sleep with age.

PREVALENCE OF INSOMNIA SYMPTOMS

PREVALENCE OF INSOMNIA SYMPTOMS AND EDS

Insomnia symptoms (≥ 3 nights/week) without EDS was found in 46.6% of the sample. EDS without insomnia symptoms was found in 4.1% of the sample. The co-occurrence of EDS and insomnia symptoms was found in 9.6% of the sample.

ARE EDS AND INSOMNIA SYMPTOMS PREDICTIVE OF COGNITIVE DIFFICULTIES?

Cognitive difficulties were assessed on six dimensions:

• attention-concentration deficits,
• praxis, delay recall,
• difficulties in orientation for persons,
• difficulties in temporal orientation and
• prospective memory.

Logistic regressions were calculated.
The models were controlled for:

• age,
• gender,
• physical activity,
• occupation,
• organic diseases,
• use of sleep or anxiety medication,
• sleep duration and
• psychological well-being.

EDS with or without insomnia symptoms is one of the stronger predictive factors of cognitive difficulties. Insomnia symptoms without EDS were significantly associated with cognitive difficulties only on two dimensions:

• attention-concentration deficits and
• praxis.

CONCLUSIONS

Co-occurrence of EDS and insomnia symptoms are frequent: about 1 on 10 elderly people living in the community have both.

Insomnia symptoms without EDS have few impact on cognitive difficulties.

Elderly subjects with EDS (with or without insomnia symptoms) are 2 to 3 times more likely to have cognitive difficulties.