medwireNews: Researchers have identified cytokine gene variations in women with breast cancer that may help to identify those at increased risk for sleep disturbance following surgery.
They found that variants of three cytokine genes – interleukin-1 receptor 2 (IL1R2), IL13, and nuclear factor kappa beta 2 (NFKB2) – differed significantly between women with high sustained sleep disturbance and those with low sustained sleep disturbance following surgery for breast cancer.
“If the genetic associations are replicated in an independent cohort, these findings may be used to identify patients who are at higher risk for the development of sleep disturbance,” say researchers Christine Miaskowski (University of California, San Francisco, USA) and team.
Among 377 women participating in the study, 219 were considered to have latent high sustained sleep disturbance based on General Sleep Disturbance Scale trajectories and total scores measured at baseline and over the 6 months following surgery.
These patients were more likely to be younger, report higher levels of comorbidity, and have poorer functional status than the 158 women with latent low sustained sleep disturbance.
These findings are in line with those of several previous studies, which together suggest that these factors “place individuals at higher risk for sleep disturbance,” the researchers write in the European Journal of Oncology Nursing.
In addition to these phenotypic features, the current study showed that the chance for having high sustained sleep disturbance was also increased 2.21-fold if women carried one or two versions of the rare T allele of the IL13 single nucleotide polymorphism (SNP) rs1800925, and 2.08-fold with each additional dose of a haplotype comprising the T allele of rs11674595 and A allele of IL1R2 HapA2 rs7570441.
The risk was lowered by 47%, however, if women carried one or two versions of the rare T allele of NFKB2 rs1056890.
While the functions of each of the individual SNPs are not known, the fact that they relate to cytokine genes suggests “a role for inflammation in the development and maintenance of sleep disturbance in patients prior to and following surgery for breast cancer,” the researchers conclude.
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