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Clinical Investigation | August 16, 2000
Age-Related Changes in Slow Wave Sleep and REM Sleep and Relationship With Growth Hormone and Cortisol Levels in Healthy Men FREE
Eve Van Cauter, PhD; Rachel Leproult, MS; Laurence Plat, MD
[+-] Author Affiliations
Author Affiliations: Department of Medicine, University of Chicago, Chicago, Ill.
Context
In young adults, sleep affects the regulation of growth hormone (GH) and cortisol. The relationship between decreased sleep quality in older adults and age-related changes in the regulation of GH and cortisol is unknown.
Objective
To determine the chronology of age-related changes in sleep duration and quality (sleep stages) in healthy men and whether concomitant alterations occur in GH and cortisol levels.
Design and Setting
Data combined from a series of studies conducted between 1985 and 1999 at 4 laboratories.
Subjects
A total of 149 healthy men, aged 16 to 83 years, with a mean (SD) body mass index of 24.1 (2.3) kg/m[SUP]2[/SUP], without sleep complaints or histories of endocrine, psychiatric, or sleep disorders.
Main Outcome Measures
Twenty-four–hour profiles of plasma GH and cortisol levels and polygraphic sleep recordings.
Results
The mean (SEM) percentage of deep slow wave sleep decreased from 18.9% (1.3%) during early adulthood (age 16-25 years) to 3.4% (1.0%) during midlife (age 36-50 years) and was replaced by lighter sleep (stages 1 and 2) without significant increases in sleep fragmentation or decreases in rapid eye movement (REM) sleep. The transition from midlife to late life (age 71-83 years) involved no further significant decrease in slow wave sleep but an increase in time awake of 28 minutes per decade at the expense of decreases in both light non-REM sleep (−24 minutes per decade; P<.001) and REM sleep (−10 minutes per decade; P<.001). The decline in slow wave sleep from early adulthood to midlife was paralleled by a major decline in GH secretion (−372 µg per decade; P<.001). From midlife to late life, GH secretion further declined at a slower rate (−43 µg per decade; P<.02). Independently of age, the amount of GH secretion was significantly associated with slow wave sleep (P<.001). Increasing age was associated with an elevation of evening cortisol levels (+19.3 nmol/L per decade; P<.001) that became significant only after age 50 years, when sleep became more fragmented and REM sleep declined. A trend for an association between lower amounts of REM sleep and higher evening cortisol concentrations independent of age was detected (P<.10).
Conclusions
In men, age-related changes in slow wave sleep and REM sleep occur with markedly different chronologies and are each associated with specific hormonal alterations. Future studies should evaluate whether strategies to enhance sleep quality may have beneficial hormonal effects.
Figures in this Article
Decreased subjective sleep quality is one of the most common health complaints of older adults.[SUP]1[/SUP] The most consistent alterations associated with normal aging include increased number and duration of awakenings and decreased amounts of deep slow wave (SW) sleep (ie, stages 3 and 4 of non–rapid eye movement (non-REM) sleep).[SUP]2[/SUP][SUP]- 4[/SUP] REM sleep appears to be relatively better preserved during aging.[SUP]3[/SUP][SUP]- 7[/SUP] The age at which changes in amount and distribution of sleep stages appear is unclear because the majority of studies have been based on comparisons of young vs older adults. Several investigators have noticed that there are marked decreases in SW sleep in early adulthood in men but not in women.[SUP]8[/SUP][SUP]- 11[/SUP]
Sleep is a major modulator of endocrine function, particularly of pituitary-dependent hormonal release. Growth hormone (GH) secretion is stimulated during sleep and, in men, 60% to 70% of daily GH secretion occurs during early sleep, in association with SW sleep.[SUP]12[/SUP] Whether decrements in SW sleep contribute to the well-known decrease in GH secretion in normal aging is not known.[SUP]13[/SUP][SUP]- 15[/SUP]
In contrast to the enhanced activity of the GH axis during sleep, the hypothalamic-pituitary-adrenal (HPA) axis is acutely inhibited during early SW sleep.[SUP]16[/SUP][SUP]- 20[/SUP] Furthermore, even partial sleep deprivation results in an elevation of cortisol levels the following evening.[SUP]21[/SUP] Thus, both decreased SW sleep and sleep loss resulting from increased sleep fragmentation could contribute to elevating cortisol levels. An elevation of evening cortisol levels is a hallmark of aging[SUP]14[/SUP][SUP],15,22[/SUP] that is thought to reflect an impairment of the negative feedback control of the HPA axis and could underlie a constellation of metabolic and cognitive alterations.[SUP]23[/SUP][SUP]- 25[/SUP]
The present study defines the chronology of age-related changes in sleep duration and quality (ie, amounts of sleep stages), GH secretion, and cortisol levels in healthy men and examines whether decrements in sleep quality are associated with alterations of GH and cortisol levels.
Age-Related Changes in Slow Wave Sleep and REM Sleep and Relationship With Growth Hormone and Cortisol Levels in Healthy Men FREE
Eve Van Cauter, PhD; Rachel Leproult, MS; Laurence Plat, MD
[+-] Author Affiliations
Author Affiliations: Department of Medicine, University of Chicago, Chicago, Ill.
Context
In young adults, sleep affects the regulation of growth hormone (GH) and cortisol. The relationship between decreased sleep quality in older adults and age-related changes in the regulation of GH and cortisol is unknown.
Objective
To determine the chronology of age-related changes in sleep duration and quality (sleep stages) in healthy men and whether concomitant alterations occur in GH and cortisol levels.
Design and Setting
Data combined from a series of studies conducted between 1985 and 1999 at 4 laboratories.
Subjects
A total of 149 healthy men, aged 16 to 83 years, with a mean (SD) body mass index of 24.1 (2.3) kg/m[SUP]2[/SUP], without sleep complaints or histories of endocrine, psychiatric, or sleep disorders.
Main Outcome Measures
Twenty-four–hour profiles of plasma GH and cortisol levels and polygraphic sleep recordings.
Results
The mean (SEM) percentage of deep slow wave sleep decreased from 18.9% (1.3%) during early adulthood (age 16-25 years) to 3.4% (1.0%) during midlife (age 36-50 years) and was replaced by lighter sleep (stages 1 and 2) without significant increases in sleep fragmentation or decreases in rapid eye movement (REM) sleep. The transition from midlife to late life (age 71-83 years) involved no further significant decrease in slow wave sleep but an increase in time awake of 28 minutes per decade at the expense of decreases in both light non-REM sleep (−24 minutes per decade; P<.001) and REM sleep (−10 minutes per decade; P<.001). The decline in slow wave sleep from early adulthood to midlife was paralleled by a major decline in GH secretion (−372 µg per decade; P<.001). From midlife to late life, GH secretion further declined at a slower rate (−43 µg per decade; P<.02). Independently of age, the amount of GH secretion was significantly associated with slow wave sleep (P<.001). Increasing age was associated with an elevation of evening cortisol levels (+19.3 nmol/L per decade; P<.001) that became significant only after age 50 years, when sleep became more fragmented and REM sleep declined. A trend for an association between lower amounts of REM sleep and higher evening cortisol concentrations independent of age was detected (P<.10).
Conclusions
In men, age-related changes in slow wave sleep and REM sleep occur with markedly different chronologies and are each associated with specific hormonal alterations. Future studies should evaluate whether strategies to enhance sleep quality may have beneficial hormonal effects.
Figures in this Article
Decreased subjective sleep quality is one of the most common health complaints of older adults.[SUP]1[/SUP] The most consistent alterations associated with normal aging include increased number and duration of awakenings and decreased amounts of deep slow wave (SW) sleep (ie, stages 3 and 4 of non–rapid eye movement (non-REM) sleep).[SUP]2[/SUP][SUP]- 4[/SUP] REM sleep appears to be relatively better preserved during aging.[SUP]3[/SUP][SUP]- 7[/SUP] The age at which changes in amount and distribution of sleep stages appear is unclear because the majority of studies have been based on comparisons of young vs older adults. Several investigators have noticed that there are marked decreases in SW sleep in early adulthood in men but not in women.[SUP]8[/SUP][SUP]- 11[/SUP]
Sleep is a major modulator of endocrine function, particularly of pituitary-dependent hormonal release. Growth hormone (GH) secretion is stimulated during sleep and, in men, 60% to 70% of daily GH secretion occurs during early sleep, in association with SW sleep.[SUP]12[/SUP] Whether decrements in SW sleep contribute to the well-known decrease in GH secretion in normal aging is not known.[SUP]13[/SUP][SUP]- 15[/SUP]
In contrast to the enhanced activity of the GH axis during sleep, the hypothalamic-pituitary-adrenal (HPA) axis is acutely inhibited during early SW sleep.[SUP]16[/SUP][SUP]- 20[/SUP] Furthermore, even partial sleep deprivation results in an elevation of cortisol levels the following evening.[SUP]21[/SUP] Thus, both decreased SW sleep and sleep loss resulting from increased sleep fragmentation could contribute to elevating cortisol levels. An elevation of evening cortisol levels is a hallmark of aging[SUP]14[/SUP][SUP],15,22[/SUP] that is thought to reflect an impairment of the negative feedback control of the HPA axis and could underlie a constellation of metabolic and cognitive alterations.[SUP]23[/SUP][SUP]- 25[/SUP]
The present study defines the chronology of age-related changes in sleep duration and quality (ie, amounts of sleep stages), GH secretion, and cortisol levels in healthy men and examines whether decrements in sleep quality are associated with alterations of GH and cortisol levels.
