We have previously reported on the high prevalence and severity of insomnia amongst a large international cohort of MPN patients (Emanuel JCO 2012). We sought to further analyze the relationships between insomnia and the MPN disease features (in particular splenomegaly, status of blood counts), individual MPN symptom prevalence and severity, language, and overall quality of life.
Data was collected among an international cohort of patients with MPNs. Subjects completed the BFI, MPN-SAF, and EORTC QLQ-C30 instruments. Surveyed symptoms on the MPN-SAF included the patient’s perceptions of common MPN-related symptoms and overall quality of life (QOL) on a 0 (absent) to 10 (worst imaginable) scale. Specifically, the MPN-SAF insomnia item asked about “difficulty sleeping”. Total symptom score (TSS) was computed based on 10 symptom items using the published scoring algorithm on a 0 (all reported symptoms absent) to 100 (all reported symptoms worst imaginable) scale. Pairwise associations between the MPN-SAF insomnia item and continuous and categorical covariates were investigated using Pearson correlations and analysis of variance/t-tests, respectively. Multivariate regression models were used to investigate impact of groups of covariates on the insomnia item with the final multivariate model selected using forward regression.
A total of 1992 MPN patients (essential thrombocythemia=834, polycythemia vera=703, myelofibrosis=449, unknown=6) completed the insomnia item. Participants were of typical age (median=61, range-15-94) and gender (female=54%). Overall, 1307 subjects endorsed the MPN insomnia item (score >0) with an overall mean symptom score of 3.0 (median=2.0, SD=3.1. range=0-10); 603/1992 (30%) of patients had severe insomnia related complaints (score >4).
Among QLQ-C30 functioning scales, emotional functioning most highly correlated with the MPN-SAF insomnia item (r=-.47, p<0.001) with all other domains also having statistically significant but slightly weaker correlation (all p<0.001). Among QLQ-C30 symptom scales, insomnia (r=.79, p<0.001) and fatigue (r=.45, p<0.001) most highly correlated with the MPN-SAF insomnia item with all other QLQ-C30 symptoms having correlations between .13 and .37 (all p<.001). Among MPN-SAF items, the MPN-SAF insomnia item correlated with all MPN-SAF items (all p<0.001) including the TSS (r=0.55, p<0.001) and most highly with depression (r=.52, p<0.001), concentration problems (r=.43, p<0.001), overall QOL (r=.41, p<0.001), night sweats (r=.41, p<0.001), and extremity tingling (r=.40, p<0.001). MPN-SAF insomnia significantly differed by gender (means: M 2.4, F 3.4; p<0.001), language (means ranged from 2.6 [Italian] to 3.6 [German]; p=0.01), anemia (means: absent 2.8, present 3.5; p<0.001), prior hemorrhage (means: no 2.9, yes 3.7; p=0.01), and requiring red blood cell transfusion (means: no 2.9, yes 3.6; p=0.03), with a trend for a difference by MPN type (ET mean=2.7, PV mean=3.0, MF mean=3.2; p=0.06).
In a multivariate model of MPN-SAF insomnia containing all QLQ-C30 functioning scales, physical, emotional, and cognitive functioning along with global health status/QOL were all significant (all p<0.001). Numerous symptoms were also significant in a multivariate model of MPN-SAF insomnia containing all other MPN-SAF symptoms (all p<0.05: headaches, extremity tingling, depression, sexual problems, night sweats, pruritus, fever, and QOL). The final multivariate model based on forward regression starting with all demographics, clinical variables, and patient-reported QLQ-C30 scales and MPN-SAF items found age, gender, QLQ-C30 emotional functioning and MPN-SAF items to be significant.
Insomnia is highly prevalent and severe in MPN patients and closely correlates with most other MPN-related symptoms and functional domains bearing a multi-faceted impact on overall quality of life. Correlations between insomnia and emotional, cognitive, and physical complaints including depression/sad mood, concentration problems, night sweats, and numbness/tingling in the extremities suggest that the cause of MPN-related sleep complaints is likely complex. Future studies should evaluate the impact of interventions on MPN associated insomnia as well as its biological underpinnings.
Etienne:novartis: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Bristol Myers Squibb: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Pfizer: Membership on an entity’s Board of Directors or advisory committees; Ariad: Membership on an entity’s Board of Directors or advisory committees. Roy:Novartis, BMS: Honoraria. Harrison:Novartis: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; YM Bioscience: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Celgene: Honoraria; Shire: Speakers Bureau; S Bio: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity’s Board of Directors or advisory committees. Birgegard:Vifor Pharma: Honoraria.
Asterisk with author names denotes non-ASH members.