Letter: Circadian rhythm of cortisol secretion in elderly and blind subjects.

Protecting the Melatonin Rhythm through Circadian Healthy Light Exposure

“…In 1940, Remler studied the rhythms in rectal temperature, heart rate, blood pressure and urinary excretion in blind subjects, obtaining normal 24-h rhythms in some of them and inverted rhythms in others [ 322 ]. Other authors have found abnormalities in the secretion profiles of corticosteroids in the majority of blind subjects studied [ 323 , 324 , 325 , 326 ]. However, it has been demonstrated that some blind subjects with no conscious perception of light (NPL) present normal 17-hydroxycorticosteroid (17-OHCS) [ 323 ] and 11-hydroxycorticosteroid (11-OHCS) secretion patterns [ 324 ], although most of them presented abnormal rhythms for these hormones and cortisol [ 325 , 326 ].…”

“White Paper” on Sleep and Aging

“…The change in phase was thought to be a possible result of sleep disturbance in old age. In other studies, Montalbetti and colleagues found that the Cortisol rhythm was normal in the healthy elderly and in elderly patients with cerebrovascular hemiplegia, but abnormal in the elderly blind 53,60 . It seems probable that growth hormone secretion does not occur with a true circadian rhythm, but passively follows the appearance of Stage 3 and Stage 4 sleep (slow‐wave sleep); and both slow‐wave sleep and growth hormone secretion are minimal in the elderly 31,59,83 .…”

“…It is notable that the prevalence of “legal” blindness increases sharply with age, and that approximately half of all the blind people are 65 years of age or older 195 . This information appears most relevant to sleep disorders and biologic rhythm dysfunction, in view of evidence that sleep disorders are very common and significantly incapacitating in the blind community 186 and that blind people have abnormalities in their circadian rhythms 60,134,156,168,174,185,204,248 …”

Visual Impairment and Circadian Rhythm Sleep Disorders

“…In the 1940s, Remler recognized that some blind patients had normal 24-hour rhythms whereas some had Inverted rhythms In rectal temperature, heart rate, blood pressure, and urinary excretion (1948 31 cited In Hollwich and Dleckhues 32 ). Subsequently, Orth and Island, 33 Kreiger and Rizzo, 34 Bodenheimer et al, 35 and D'Allessandro et al 36 all found Irregularities In the plasma profiles of corticosteroid production In a majority of blind subjects. Orth and Island 33 studied three subjects with no conscious perception of light (NPL) and demonstrated a normal, an abnormal, and a free-running rhythm of 17-hydroxycorticosterold (17-OHCS) production In these subjects.…”

“…Similarly, Bodenheimer et al 35 reported that grouped data of 24-h Cortisol measurements from seven NPL subjects showed a phase difference compared with sighted controls. D'Allessandro et al 36 presented mean plasma Cortisol data from 11 NPL patients that did not show 24-h rhythmiclty. All the studies emphasized the Importance of light In modulating the secretion of corticosteroids and noted a split of these rhythms from the sleep-wake cycle.…”