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SLEEP AND HEALTH 35
Leineweber et al., 2003) and diabetes type II (Nilsson et al., 2002). The mechanism
has not been identified but both lipid and glucose metabolisms are impaired
in relation to experimentally reduced sleep (Åkerstedt and Nilsson, 2003).
Burnout is another result of long-term stress and a growing health problem in
many industrialized countries (Weber and Jaekel-Reinhard, 2000). In Sweden,
burnout is thought to account for most of the doubling of long-term sickness
absence since the mid-1990s (RFV, 2003). The characteristic clinical symptoms of
the condition are excessive and persistent fatigue, emotional distress and cognitive
dysfunction (Kushnir and Melamed, 1992; Melamed, Kushnir and Sharom,
1992). Self-reports of disturbed sleep are pronounced in subjects scoring high on
burnout (Melamed et al., 1999; Grossi et al., 2003). Since shortened and fragmented
sleep is related to daytime sleepiness and impaired cognitive performance
(Bonnet, 1985, 1986a, 1986b; Dinges et al., 1997; Gillberg and Åkerstedt, 1998;
Åkerstedt, 1990), disturbed sleep might provide an important link between the
state of chronic stress and the complaints of fatigue and cognitive dysfunction
seen in burnout.
Partinen, Eskelinen and Tuomi (1984) investigated several occupational groups and
found disturbed sleep to be most common among manual workers and much less so
among physicians or managing directors. Geroldi et al. (1996) found in a retrospective
study of older individuals (above the age of 75) that former white-collar workers
reported better sleep than blue-collar workers. Kupperman et al. (1995) reported
fewer sleep problems in subjects satisfied with work.
In what seems to be the most detailed study so far, Ribet and Derriennic (1999) studied
more than 21 000 subjects in France, using a sleep disturbance index and logistic
regression analysis. They found that shift work, a long working week, exposure
to vibrations, and “having to hurry” appeared to be the main risk factors, controlling
for age and gender. Disturbed sleep was more frequent in women (Karacan et
al., 1976; Bixler, Kales and Soldatos, 1979; Ancoli-Israel and Roth, 1999) and in
higher age groups.
The particular stressor linked to disturbed sleep may be linked to pressure of work
(Urponen et al., 1988; Ancoli-Israel and Roth, 1999; Ribet and Derriennic, 1999; Åkerstedt
et al., 2002b). The demands of work are a classical work stress factor and, when
combined with low decision latitude, a relation has been shown to cardiovascular diseases
(Theorell et al., 1998) and absenteeism (North et al., 1996). Interestingly, when
“persistent thoughts about work” was added to the regression in the study by Åkerstedt
et al. (2002b) this variable took over part of the role of work demands as a predictor.
This suggests that it may not be work demands per se that are important, but rather their
effect on unwinding after work. In two studies it has been demonstrated that even moderate
worries about being woken during the night or having a negative feeling about the
next day will affect sleep negatively, mainly reducing SWS (Torsvall and Åkerstedt, 1988;
Kecklund and Åkerstedt, 1997). On the other hand, there is very little data to connect
real life stress with polysomnographical indicators of disturbed sleep. Most studies have
used rather innocuous and artificial stressors in a laboratory environment. Field studies
of stress are virtually lacking, with some exceptions (Hall et al., 2000).
A lack of social support at work is a risk indicator for disturbed sleep (Åkerstedt
et al., 2002b). Few previous data of this type have been found, but poor (general)
social support has been associated with sleep complaints in Vietnam veterans
(Fabsitz, Sholinsky and Goldberg, 1997). On the other hand, there are several
studies indicating a close connection with poor social support for, for example,
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