Melatonin rhythms in renal transplant recipients with sleep-wake disturbances.
We assessed salivary melatonin levels in renal transplant (RTx) recipients who participated in a randomised, multicentre wait-list controlled trial on the effect of bright light therapy on their sleep and circadian rhythms. A large proportion of RTx recipients in our cohort had unexpectedly low melatonin values, which precluded calculation of the dim-light melatonin onset (DLMO) as a circadian marker. Thus, the aim of this post hoc analysis was to describe the melatonin profile of home-dwelling RTx recipients diagnosed with sleep-wake disturbances (SWDs). The participants were characterised by means of sleep questionnaires, validated psychometric instruments [Pittsburgh sleep quality Index (PSQI), Epworth sleepiness scale (ESS), Morningness-Eveningness Questionnaire (MEQ) and Depression, Anxiety and Stress Scale (DASS)] in addition to melatonin assay in saliva. Data were analysed with descriptive statistics and group comparisons made with appropriate post hoc tests. RTx recipients [n = 29 (aged 54.83 ± 13.73, transplanted 10.62 ± 6.84 years ago)] were retrospectively grouped into two groups: RTx recipients whose dim light melatonin onset (DLMO) could be calculated (n = 11) and those whose DLMO could not be calculated (n = 18). RTx recipients having a measurable DLMO had a number of differences from those without DLMO: they were younger [46.4 ± 14.9 compared to 60.0 ± 10.3 (p = .007)], had higher haemoglobin values [135.36 ± 12.01 versus 122.82 ± 11.56 (p = .01)], less anxiety [4 (0;8) versus 12 (6.5;14) (p = .021)] and a better overall sense of coherence [SOC Score: 71.09 ± 12.78 versus 56.28 ± 15.48 (p = 0.013)]. These results suggest that RTx recipients whose DLMO could be calculated have less health impairments, underlying the relevance of a stable circadian system.
a Centre for Sleep Medicine , Hirslanden Group , Zürich , Switzerland.|b Institute of Nursing Science, University of Basel , Basel , Switzerland.
Hanna
H
Burkhalter
b Institute of Nursing Science, University of Basel , Basel , Switzerland.|c Academic Center for Nursing and Midwifery , KU Leuven , Belgium.
Sabina
S
De Geest
d Centre for Chronobiology , Psychiatric Hospital of the University of Basel , Basel , Switzerland.
Anna
A
Wirz-Justice
d Centre for Chronobiology , Psychiatric Hospital of the University of Basel , Basel , Switzerland.
Christian
C
Cajochen
D000328:Adult; D000368:Aged; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008027:Light; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D008875:Middle Aged; D012463:Saliva / Q000378:metabolism; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000378:metabolism*; D011795:Surveys and Questionnaires
D008550:Melatonin
Adults; chronobiology; kidney transplantation; melatonin profile; rental transplant recipients; salivary melatonin; sleep-wake disturbances