Introduction
An increase in the population of the elderly and its associated costs in
various societies are issues that has always been considered in recent
decades (1, 2). Accordingly, it is necessary to allocate a significant
portion of the health and medical resources of any community to the
elderly. The consequences of aging due to poor life style have been
proven in the form of destructive changes in the physiological,
cognitive and psychmotor functions in the elderly population. These
changes include changes in the central nervous system, and in particular
the brain, which affects most parts of the body and can make the elderly
vulnerable to diseases such as Alzheimer’s, Parkinson’s, Multiple
sclrosis and other diseases (1). As the human brain responds to the
environmental factors easily and creates structural and functional
changes that are called neurodegenerative shapes, intervening proper
strategies are highly recommended (3). Based on research evidences,
executive functions such as information processing, reaction time,
attention capacity are impaired in the elderly following aging process.
In this regard, sleeping as part of a daily life to recycle, rejuvenate
and restore the functioning of the nervous and physiological system of
the body is of utmost importance which contributes to the regulation of
biological rhythm and helps to improve mental and physiological
regeneration. Insomnia is the most common sleep disorder in aged
populations that has been extensively investiated . The patients with
sleeping disorders are characterized by inability to sleep and lack of
effective sleep. A previous study found that 30.7% of the elderly were
suffered from sleep disorders (4).
Recently, it has been hypothesized that vitamin D plays an important
role in controlling sleep in the brain stem, and it has been argued that
vitamin D deficiency is the epidemic reason of sleep disorder (5, 6). On
the other hand, the beneficial role of exercise in improving the quality
of sleep has always been of interest for scientists (1, 4). The
effectiveness of organized exercise protocols such as weight loss
exercises (7), strength training (8), aerobic exercises (1, 9) and
aquatic excercises on the quality of sleep have been proven. Spiegel et
al. (2005) concluded that sleep disorders for several consecutive days
increased the resistance of pripheral tissues to insulin, impaired
glucose tolerance, increased hunger, and food intake which were somewhat
different stimulants to disturb the hormonal balance in the body (12).
It has been shown that the lower the quality of sleep, the more
stressful hormones are produced in the body (13). The prevention of
sleep disorders, due to the importance in various functions of the body,
is one of the issues that has a high value of research and can affect
the fuctions of various organs in the body (13, 14). With respect to the
importance of lifestyle in the elderly, proper life style and physical
activity and having a suitable sleep pattern are among the factors that
can lead to successful aging. Considering the current prevalence of
sleep disturbances, the reduction in sleep time and the decrease of
physical activity in the elderly, the aim of the present study was to
investigate the effect of an aerobic training protocol along with
vitamin D supplementation on neurocognitive functions of elderly women
with sleep disorders.
In view of the above consideration, it was hypothesized that combined
aerobic training with vitamin D supplementation could improve the
neurocognitive functions of elderly women with sleep disorders.