The role of sleep problems in the development of depression in those with persistent pain: a prospective cohort study

STUDY OBJECTIVES

One theoretical model suggests a pathway between pain and the development of depression through sleep problems. Here, we prospectively test the hypothesis that incident sleep problems, in those with persistent pain, increase risk of new onset probable depression, and investigate the role of "pain that interferes with daily life" (pain interference) on this pathway.

DESIGN

Prospective cohort study.

SETTING

Community based population study within UK.

PARTICIPANTS

Participants with persistent pain nested within a larger longitudinal community study.

MEASUREMENTS

Participants were mailed health questionnaires at baseline (time 1) with follow-up at 3 years (time 2) and 6 years from baseline (time 3). Questionnaires at baseline and at follow up contained measures of sleep problems (Jenkins Sleep Questionnaire), depressive symptoms (Hospital Anxiety and Depressive Scale), and pain interference.

RESULTS

In total, 2,622 participants returned health questionnaires at all time points and indicated the presence of pain at each time point. After adjustment for age, gender, marital status, employment status, alcohol intake, smoking status, and body mass index, having a new period of sleep problems at year 3 more than trebled the risk of a new period of probable depression at year 6 (relative risk 3.47, 95% CI 1.97 to 6.03). Mediation analysis showed that pain interference played a significant but relatively minor role in the pathway.

CONCLUSION

Clinicians treating patients with persistent pain may wish to consider options that involve addressing the prevention or treatment of sleep problems, in addition to their primary focus of pain management.

Total somatic symptom score as a predictor of health outcome in somatic symptom disorders

BACKGROUND

The diagnosis of somatisation disorder in DSM-IV was based on 'medically unexplained' symptoms, which is unsatisfactory.

AIMS

To determine the value of a total somatic symptom score as a predictor of health status and healthcare use after adjustment for anxiety, depression and general medical illness.

METHOD

Data from nine population-based studies (total n = 28 377) were analysed.

RESULTS

In all cross-sectional analyses total somatic symptom score was associated with health status and healthcare use after adjustment for confounders. In two prospective studies total somatic symptom score predicted subsequent health status. This association appeared stronger than that for medically unexplained symptoms.

CONCLUSIONS

Total somatic symptom score provides a predictor of health status and healthcare use over and above the effects of anxiety, depression and general medical illnesses.

Reasons why multimorbidity increases the risk of participation restriction in older adults with lower extremity osteoarthritis: a prospective cohort study in primary care

OBJECTIVE

To determine why multimorbidity causes participation restriction in adults ages ≥50 years who consult primary care with lower extremity osteoarthritis (OA).

METHODS

This was a population-based prospective cohort study of 1,053 consulters for lower extremity OA who were free of participation restriction at baseline. Path analysis was used to test proposed mechanisms by examining for mediation of the association between multimorbidity at baseline, defined by self-report and consultation data separately, and incident participation restriction at 3 years by lower extremity pain severity, obesity, locomotor disability, and depression.

RESULTS

Multimorbidity was associated with incident participation restriction (adjusted odds ratio [OR] 2.83, 95% confidence interval [95% CI] 2.03-3.94 for multimorbidity [self-report]; OR 1.59, 95% CI 1.15-2.21 for multimorbidity [consultation data]). The extent of mediation of the association of baseline multimorbidity, defined by self-report, and incident participation restriction was greater for severe lower extremity pain than obesity (standardized beta coefficients for indirect effect 0.032 [SE 0.015] and 0.020 [SE 0.019], respectively). The addition of depression and locomotor disability increased the amount of mediation (0.115 [SE 0.028]) and reduced the proportion explained by severe lower extremity pain (0.014 [SE 0.015]) and obesity (0.006 [SE 0.010]). Locomotor disability was the strongest mediator.

CONCLUSION

The additional impact on participation in social and domestic life that multimorbidity places on individuals with lower extremity OA appears to be mediated through further restriction of locomotor disability, as well as through depression. The results suggest that the effect of multimorbidity on the daily lives of people with lower extremity OA will be ameliorated by active management of depression and locomotor disability.

Musculoskeletal pain in older adults at the end-of-life: a systematic search and critical review of the literature with priorities for future research

Background

Pain is an important issue in end of life care. Although musculoskeletal pain is common in older adults, it is rarely associated with the cause of death and may be overlooked as death approaches. Hence a major target for improving quality of life may be being missed.

Methods

The aim of this study was to systematically search and critically review the literature on musculoskeletal pain at the end of life. Amed, Cinahl, Internurse, Medline, Psych Info, Web of Knowledge and Cochrane review databases were searched for relevant research up to September 2012. The search strategy combined key words expanding the terms ‘palliative’ for population, ‘musculoskeletal’ for exposure, and ‘pain’ for outcome. Predefined inclusion and exclusion criteria were applied.

Results

Five relevant papers and one letter to the editor were found, including case studies and epidemiological research. Current evidence suggests musculoskeletal pain is common in older adults at the end of life and that it can have a substantial impact on individual experience. No information about community based treatment of musculoskeletal pain at the end of life was found.

Conclusion

Priorities for future research include high quality epidemiological studies to establish the prevalence, natural history, impact, assessment, patient priorities and outcomes associated with musculoskeletal pain in the end of life period, and intervention research that provides an evidence base for treatment.

Genome-wide association study meta-analysis of chronic widespread pain: evidence for involvement of the 5p15.2 region

BACKGROUND AND OBJECTIVES

Chronic widespread pain (CWP) is a common disorder affecting ∼10% of the general population and has an estimated heritability of 48-52%. In the first large-scale genome-wide association study (GWAS) meta-analysis, we aimed to identify common genetic variants associated with CWP.

METHODS

We conducted a GWAS meta-analysis in 1308 female CWP cases and 5791 controls of European descent, and replicated the effects of the genetic variants with suggestive evidence for association in 1480 CWP cases and 7989 controls. Subsequently, we studied gene expression levels of the nearest genes in two chronic inflammatory pain mouse models, and examined 92 genetic variants previously described associated with pain.

RESULTS

The minor C-allele of rs13361160 on chromosome 5p15.2, located upstream of chaperonin-containing-TCP1-complex-5 gene (CCT5) and downstream of FAM173B, was found to be associated with a 30% higher risk of CWP (minor allele frequency=43%; OR=1.30, 95% CI 1.19 to 1.42, p=1.2×10(-8)). Combined with the replication, we observed a slightly attenuated OR of 1.17 (95% CI 1.10 to 1.24, p=4.7×10(-7)) with moderate heterogeneity (I2=28.4%). However, in a sensitivity analysis that only allowed studies with joint-specific pain, the combined association was genome-wide significant (OR=1.23, 95% CI 1.14 to 1.32, p=3.4×10(-8), I2=0%). Expression levels of Cct5 and Fam173b in mice with inflammatory pain were higher in the lumbar spinal cord, not in the lumbar dorsal root ganglions, compared to mice without pain. None of the 92 genetic variants previously described were significantly associated with pain (p>7.7×10(-4)).

CONCLUSIONS

We identified a common genetic variant on chromosome 5p15.2 associated with joint-specific CWP in humans. This work suggests that CCT5 and FAM173B are promising targets in the regulation of pain.

Association of HTR2A polymorphisms with chronic widespread pain and the extent of musculoskeletal pain: results from two population-based cohorts

OBJECTIVE

The aim of the current study was to investigate whether genetic variation in genes across the serotoninergic system is associated with chronic widespread pain (CWP) and the number of pain sites reported.

METHODS

A discovery cohort, with pain data at 3 time points, was used to investigate genetic associations with 2 phenotypes: 1) CWP (at ≥ 2 time points; n = 164) compared with pain-free controls (at 3 time points; n = 172), and 2) the maximum number of pain sites reported at any 1 of the 3 time points (range of sites 0-29; n = 989). A cohort of 2,285 men for whom a DNA sample and pain data were available (including 203 CWP cases and 929 controls) was used for validation. Pairwise tagging (r(2) > 0.8) single-nucleotide polymorphisms (SNPs) were genotyped. Logistic and zero-inflated negative binomial regression analyses were used to test for SNP associations with CWP and the number of pain sites, respectively.

RESULTS

SNPs in HTR2A were associated with both pain phenotypes in the discovery cohort, and a number of these SNP associations were replicated in the validation cohort, some of which were attenuated after adjustment for depression. There was an increased likelihood of having CWP in subjects with 1 or 2 copies of the T allele of rs12584920 (odds ratio [OR] 1.64, 95% confidence interval [95% CI] 1.01-2.60 [P = 0.03] in the discovery cohort, and OR 1.46, 95% CI 1.07-2.00 [P = 0.018] in the validation cohort). A similar association was observed between rs17289394 and the maximum number of pain sites reported in both cohorts. Results from a meta-analysis of the data from the 2 cohorts further strengthened these findings.

CONCLUSION

The findings of this study support the role of HTR2A in the genetic predisposition to musculoskeletal pain.

The non-synonymous SNP, R1150W, in SCN9A is not associated with chronic widespread pain susceptibility

Background

Mutations in SCN9A, encoding the alpha subunit of the voltage-gated sodium channel (Na_v1.7), have caused severe pain disorders and congenital insensitivity to pain. The aim of this study was to validate the previously reported association between a common non-synonymous polymorphism (R1150W, rs6746030) in SCN9A and chronic widespread pain (CWP), in independent population-based cohorts.

Findings

Genotype data for rs6746030 was available in four population-based cohorts (EPIFUND, the European Male Ageing Study (EMAS), the Framingham study and the Dyne Steel DNA Bank of Ageing and Cognition). Pain was assessed using body manikins and CWP was scored using American College of Rheumatology (ACR) criteria in all cohorts, except the Framingham study which assessed widespread pain (WP) using ACR criteria on a joint pain homunculus. Controls were subjects who reported no pain. Logistic regression (additive genetic model) was used to test for association between rs6746030 and CWP compared to controls, adjusting for study centre in EMAS. Generalised estimating equation regression was used to test for association between rs6746030 and WP, whilst accounting for relatedness between subjects in the Framingham study.

Genotype data for rs6746030 was available for 1071 CWP cases and 3212 controls. There was no significant association between CWP and rs6476030 in individual cohorts or when combined in a fixed-effects meta-analysis (Odds Ratio = 0.96 (95% confidence interval 0.82, 1.11) p = 0.567).

Conclusions

In contrast to a previous study, no association between a non-synonymous polymorphism in SCN9A and CWP was observed in multiple population-based cohorts.

Obesity is a risk factor for musculoskeletal pain in adolescents: findings from a population-based cohort

Obesity is a risk factor for fibromyalgia in adults, but whether a similar relationship exists in children is uncertain. This study examined whether obesity is associated with reporting of musculoskeletal pain, including chronic regional pain (CRP) and chronic widespread pain (CWP), in adolescents, in a population-based setting. A pain questionnaire was administered to offspring of the Avon Longitudinal Study of Parents and Children at age 17, asking about site, duration, and pain intensity, from which participants with different types of musculoskeletal pain were identified. Relationships between obesity and pain were examined by calculating odds ratios stratified by gender and adjusted for socioeconomic status as reflected by level of maternal education. A total of 3376 participants (1424 boys) with complete data were identified, mean age 17.8; 44.7% of participants reported any pain within the last month lasting 1day or longer; 16.3% reported lower back pain, 9.6% shoulder pain, 9.4% upper back pain, 8.9% neck pain, 8.7% knee pain, 6.8% ankle/foot pain, 4.7% CRP, and 4.3% CWP; 7.0% of participants were obese. Obesity was associated with increased odds of any pain (odds ratio [OR] 1.33, P=.04), CRP (OR 2.04, P=.005), and knee pain (OR 1.87, P=.001), but not CWP (OR 1.10, P=.5). Compared with non obese participants, those with any pain, knee pain, and CRP reported more severe average pain (P<.01). Obese adolescents were more likely to report musculoskeletal pain, including knee pain and CRP. Moreover, obese adolescents with knee pain and CRP had relatively high pain scores, suggesting a more severe phenotype with worse prognosis.

Investigating the role of pain-modulating pathway genes in musculoskeletal pain

AIMS

The aim of this study was to determine if genetic variation in the pain-modulating gene DREAM and its pathway genes influence susceptibility to reporting musculoskeletal pain in the population.

METHODS

Pairwise tag single nucleotide polymorphisms (SNPs) in DREAM, PDYN and OPRK1 were genotyped in a UK population-based discovery cohort in whom pain was assessed using blank body manikins at three time points. Depression and anxiety symptoms were assessed at the first time point. Zero-inflated negative binomial regression was used to test for association between SNPs and the maximum number of pain sites reported (0-29) across the three time points. Significantly associated SNPs (p < 0.05) were subsequently genotyped for validation in a cohort of European men with pain assessed at two time points.

RESULTS

Thirty-five SNPs were genotyped in 1055 subjects, of whom 83% reported pain, in the discovery cohort. SNPs in each gene were associated with the maximum number of pain sites reported, were independent of symptoms of anxiety and depression and had a significant cumulative effect (p = 7.0 × 10(-5) ). Significantly associated SNPs were successfully genotyped in 1733 men, 76% of whom reported pain, in the validation cohort, but did not show significant association with the number of pain sites.

CONCLUSIONS

Genetic variation in the DREAM pathway genes was associated with the extent of pain reporting in a population-based cohort. These findings were not replicated in a single independent cohort; however, given the potential of this pathway as a therapeutic target, further investigation in additional cohorts is warranted.

Recent advances in the understanding of genetic susceptibility to chronic pain and somatic symptoms

Regional (e.g., low back) and widespread chronic pain disorders are common in the general population and are known to be heritable. Recent research suggests that genetic factors increase the risk of developing chronic pain independent of the site of pain. Candidate gene studies have been conducted on key pathways to elucidate susceptibility genes that are likely to be involved in both the sensory and affective components of pain. Findings have been largely equivocal, predominantly due to small sample size, but larger studies of pain in general population samples are being conducted. Interesting candidate genes from animal models and monogenic pain disorders are beginning to emerge. Recent advances in genetics research have yet to make an impact in the pain field but provide considerable scope for future research efforts.

Cognitive behavior therapy, exercise, or both for treating chronic widespread pain

BACKGROUND

The clinical impact of telephone-delivered cognitive behavioral therapy (TCBT), exercise, or a combined intervention in primary care patients with chronic widespread pain (CWP) is unclear.

METHODS

A total of 442 patients with CWP (meeting the American College of Rheumatology criteria) were randomized to receive 6 months of TCBT, graded exercise, combined intervention, or treatment as usual (TAU). The primary outcome, using a 7-point patient global assessment scale of change in health since trial enrollment (range: very much worse to very much better), was assessed at baseline and 6 months (intervention end) and 9 months after randomization. A positive outcome was defined as "much better" or "very much better." Data were analyzed using logistic regression according to the intention-to-treat principle.

RESULTS

The percentages reporting a positive outcome at 6 and 9 months, respectively, were TAU group, 8% and 8%; TCBT group, 30% and 33%; exercise group, 35% and 24%; and combined intervention group, 37% and 37% (P < .001). After adjustment for age, sex, center, and baseline predictors of outcome, active interventions improved outcome compared with TAU: TCBT (6 months: odds ratio [OR], 5.0 [95% CI, 2.0-12.5]; 9 months: OR, 5.4 [95% CI, 2.3-12.8]), exercise (6 months: OR, 6.1 [95% CI, 2.5-15.1]; 9 months: OR, 3.6 [95% CI, 1.5-8.5]), and combined intervention (6 months: OR, 7.1 [95% CI, 2.9-17.2]; 9 months: OR, 6.2 [95% CI, 2.7-14.4]). At 6 and 9 months, combined intervention was associated with improvements in the 36-Item Short Form Health Questionnaire physical component score and a reduction in passive coping strategies. Conclusions on cost-effectiveness were sensitive to missing data.

CONCLUSION

TCBT was associated with substantial, statistically significant, and sustained improvements in patient global assessment.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: ISRCTN67013851.

The prevalence and management of low back pain across adulthood: results from a population-based cross-sectional study (the MUSICIAN study)

The aim of the current study was to determine: the prevalence of low back pain (LBP) and associated disability; the frequency of consultation to general practice; whether there were differences in management by age. We conducted a cross-sectional population study in Aberdeen city and Cheshire County, UK. Participants were 15,272 persons aged 25 years and older. The 1-month period prevalence of LBP was 28.5%. It peaked at age 41-50 years, but at ages over 80 years was reported by 1 in 4 persons. Older persons were more likely to consult, and the prevalence of severe LBP continued to increase with age. Management by general practitioners differed by age of the patient. Older persons (> 70 vs ≤ 40 years) were more likely to only have been prescribed painkillers (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.28-2.35) or only pain killers with other medications (OR 1.45, 95% CI 1.07-1.98). They were less likely to be prescribed physiotherapy or exercise (OR 0.63, 95% CI 0.46-0.85) or to be referred to a specialist (OR 0.77, 95% CI 0.57-1.04). Older persons were more likely to have previously received exercise therapy for pain, were less likely to be enthusiastic about receiving it now (P<0.0001), and were less likely to think it would result in improved symptoms (P<0.0001). It is important that older persons, who have the highest prevalence of LBP with disability and are most likely to consult, are receiving optimal pharmacological and nonpharmacological management.

Elevated levels of gonadotrophins but not sex steroids are associated with musculoskeletal pain in middle-aged and older European men

The aim of this study was to determine the association of hormone levels with the occurrence of musculoskeletal pain. Men ages 40 to 79 years were recruited from population registers in 8 European centres. Subjects were asked to complete a postal questionnaire, which enquired about lifestyle and the occurrence of musculoskeletal pain over the past month. Total testosterone (T), oestradiol (E2), luteinising hormone (LH), and follicle-stimulating hormone (FSH) were assayed from a fasting blood sample. The association between pain status and hormone levels was assessed using multinomial logistic regression with results expressed as relative risk ratios (RRR) and 95% confidence intervals (CI). A total of 3206 men had complete data on pain status. Of these, 8.7% reported chronic widespread pain (CWP), whereas 50% had some pain although not CWP and were classified as having some pain. T and E2 were not associated with musculoskeletal pain, whereas significant differences in LH and FSH levels were found between pain groups. After adjustment for age and other possible confounders, the association between pain status and both LH and FSH persisted. Compared with those in the lowest tertile of LH, those in the highest tertile were more likely to report some pain (vs no pain, RRR = 1.28; 95% CI 1.09 to 1.50) and also CWP (vs no pain, RRR = 1.51; 95% CI 1.10 to 2.07). Similar results were found for FSH. Gonadotrophins, but not sex steroid hormone levels, are associated with musculoskeletal pain in men.

Higher levels of gonadotrophins but not androgens were significantly associated with musculoskeletal pain in men. Alterations in hypothalamic–pituitary–testicular feedback mechanisms may play a role in the onset of chronic widespread pain.