The Natural History of Insomnia in the Ibadan Study of Ageing

Abstract

There is a high incidence and chronicity of insomnia in this elderly population. Persons with chronic health conditions are particularly at risk of new onset as well as persistence of insomnia.

Risk factors for sleep disturbances in older adults: Evidence from prospective studies

“…Female gender 19, 23, 25-29 , depressed mood 19, 20, 24, 26-29 and poor physical health 21-24, 26-29 were most consistently reported as independent predictors of these sleep outcomes. Four studies examined physical activity with mixed findings (see discussion) 20, 21, 24, 30 .…”

“…Independent estimates of the effects of age were reported in the minority of these studies (5/13) 20, 21, 23, 27, 28 , in two cases presumably due to the fact that age was not associated with future sleep disturbance in univariate analyses 19, 25 . Of the studies examining the adjusted effect of age, one identified increased risk for older (75+ years) adults 18 , while another study found significantly increased risk for incident insomnia symptoms for white, but not black adults aged 75-84 27 .…”

“…One study also examined hypersomnia (sleeping too much) in addition to DIS/DMS complaints 23 . Only three studies required insomnia symptoms to be present for a certain duration (“often” in 21 ; at least 3 nights per week in 24 ; and lasting ≥2 weeks in 25 ), which is a key criteria required for an insomnia diagnosis.…”

“…Four studies examined physical activity with mixed findings (see discussion) 20, 21, 24, 30 . These studies also examined demographic and other psychosocial factors: African-American race (compared to white race) 27 , previous manual occupation 24, 31 , widowhood 19, 26 , and lower economic status 25 predicted incident insomnia symptoms; recent life events predicted hypersomnia but not insomnia in one study 23 .…”

The pathophysiology of insomnia

“…Recent studies include a population study assessing participants approximately 7 years after baseline in which, relative to good sleepers, persistently poor sleepers (with insomnia complaints, but not primary insomnia) were more likely to develop chronic insomnia and that this was associated with physical and mental health conditions, female sex, but not older age [35]. In a unique sample, community dwelling older adults in Africa, lower socioeconomic standing and chronic health conditions were significant factors for predicting the incidence of insomnia, whereas age and sex were not [36]. Compelling data from a 20-year longitudinal study of two different age cohorts (middle-aged and older adults) underscore the role of age and female sex, as well as manual rather than nonmanual occupations, in the development of chronic insomnia [37].…”