Sleep quality varies as a function of 5-HTTLPR genotype and stress.
OBJECTIVE
To test the hypothesis that allelic variation in 5HTT gene-linked polymorphic region (5-HTTLPR) genotype was associated with sleep quality (Pittsburgh Sleep Quality Index, PSQI) as a main effect and as moderated by the chronic stress of caregiving. Serotonin (5HT) is involved in sleep regulation and the 5HT transporter (5HTT) regulates 5HT function. A common 44-base pair deletion (s allele) polymorphism in the 5-HTTLPR is associated with reduced 5HTT transcription efficiency and 5HT uptake in vitro.


METHODS
Subjects were 142 adult primary caregivers for a spouse or parent with dementia and 146 noncaregiver controls. Subjects underwent genotyping and completed the PSQI.


RESULTS
Variation in 5-HTTLPR genotype was not related to sleep quality as a main effect (p > .36). However, there was a caregiver X 5-HTTLPR interaction (p < .009), such that the s allele was associated with poorer sleep quality in caregivers as compared with controls.


CONCLUSIONS
Findings suggest that the s allele may moderate sleep disturbance in response to chronic stress.
Brummett
Beverly H
BH
Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA. brummett@duke.edu
Krystal
Andrew D
AD
Ashley-Koch
Allison
A
Kuhn
Cynthia M
CM
Züchner
Stephan
S
Siegler
Ilene C
IC
Barefoot
John C
JC
Ballard
Edna L
EL
Gwyther
Lisa P
LP
Williams
Redford B
RB
D000328:Adult; D000368:Aged; D000483:Alleles; D017028:Caregivers / Q000523:psychology; D016022:Case-Control Studies; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012701:Serotonin / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000235:genetics* / Q000523:psychology*; D013315:Stress, Psychological
D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin