Serotonin and serotonin transporter gene variant in rotating shift workers

• Published in: Sleep (New York, N.Y.) N.Y.), 2007-08, Vol.30 (8), p.1049-1053
• Main Authors: SOOKOIAN, Silvia, GEMMA, Carolina, FERNANDEZ GIANOTTI, Tomas, BURGUENO, Adriana, ALVAREZ, Azucena, GONZALEZ, Claudio Daniel, PIROLA, Carlos Jose
• Format: Article
• Language: English
• Subjects: Adult; Alleles; Behavioral psychophysiology; Biological and medical sciences; Blood Glucose - metabolism; Blood Platelets - metabolism; Cholesterol - blood; Cholesterol, HDL - blood; Cholesterol, LDL - blood; Chromosome Deletion; Circadian Rhythm - genetics; Circadian Rhythm - physiology; Fundamental and applied biological sciences. Psychology; Genotype; Humans; Hydroxyindoleacetic Acid - blood; Insulin - blood; Male; Mutagenesis, Insertional - genetics; Polymorphism, Genetic - genetics; Promoter Regions, Genetic - genetics; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Serotonin - blood; Serotonin Plasma Membrane Transport Proteins - genetics; Serotonin Transporter Gene in Shift Workers; Sleep Disorders, Circadian Rhythm - blood; Sleep Disorders, Circadian Rhythm - genetics; Triglycerides - blood; Work Schedule Tolerance
• ISSN: 0161-8105; 1550-9109
• DOI: 10.1093/sleep/30.8.1049

Because serotonin (5-HT) is a neurotransmitter associated with circadian rhythm regulation, we explored a possible relation among 5-HT, serotonin metabolite, 5-hydroxyindolacetic acid (5HIAA), and the functional polymorphism of the serotonin transporter gene (SLC6A4) promoter with rotating shift work. 683 men were included in this study: 437 day workers were compared with 246 rotating shift workers. Platelet 5-HT content differed significantly (P = 0.002) between day workers (41.28+/-1.99 pg/mg) and rotating shift workers (37.91+/-4.16 pg/mg); 5-HIAA content was also significantly (P = 0.00004) higher in day workers (11.40+/-0.82 pg/mg) than in rotating shift workers (9.33+/-1.02 pg/ mg). We looked for further differences in SLC6A4 promoter (5-HTTLPR, 44 bp insertion: long (L)/deletion: short (S) alleles). We found a significant (P = 0.016) difference in genotype distribution between day workers LL: 126 (28.8%), LS: 202 (46.2%), and SS: 109 (24.9%), and rotating shift workers LL: 47 (19.1%), LS: 124 (50.4%), and SS: 75 (30.5%). When we divided the subjects between workers with less and more than 60 month rotating shift-work exposure, the difference in SLC6A4 genotypes frequency was only significant in the group with > or =60 months (P = 0.011). In addition, there was a significantly lower content of platelet 5-HIAA in S allele carriers in comparison with the other genotypes (SS: 9.2+/-1.0 pg/mg vs. SL/LL: 11.0+/-0.8 pg/mg, P