The effect of long-term poor sleep quality on risk of back-related disability and the modifying role of physical activity

Sleep characteristics and intervertebral disc degeneration risk: an observational and Mendelian randomization study

OBJECTIVES

Sleep disorders are considered a risk factor for aging and skeletal degeneration, but their impact on intervertebral disc degeneration (IDD) remains unclear. The aim of this study was to assess associations between sleep characteristics and IDD, and to identify potential causal relationships.

METHODS

Exposure factors included six unhealthy sleep characteristics: insomnia, short sleep duration (< 7 h), long sleep duration (≥ 9 h), evening chronotype, daytime sleepiness, and snoring. The primary outcomes included cervical disc degeneration (CDD) and lumbar disc degeneration (LDD). Firstly, we examined the associations between sleep characteristics and IDD risk in 368,348 participants from the UK Biobank using Cox proportional hazards model. Two-sample Mendelian randomization (MR) analyses were conducted to validate associations found in observational analyses, using genome-wide association data from the UK Biobank and FinnGen consortia.

RESULTS

During a median follow-up time of 13.8 years, a total of 1,637 cases of CDD and 7,654 cases of LDD were identified. Observational analyses found that almost all unhealthy sleep characteristics were associated with an elevated risk of IDD, except snoring. Conversely, the risk of IDD decreased linearly with an increasing number of healthy sleep characteristics. MR analyses supported a causal association between genetically determined insomnia and increased risk of LDD (OR 1.25 [1.07-1.47]), and between short sleep duration and increased risk of both IDD phenotypes (OR 5.41 [1.95-15.01] for CDD; OR 3.48 [1.76-6.89] for LDD). However, long sleep duration was causally associated with a reduced risk of LDD (OR 0.13 [0.03-0.53]), which contrasts with the observational findings.

CONCLUSION

We found associations between multiple sleep characteristics and IDD risk and confirmed that insomnia and short sleep duration increased IDD risk. Although more research is needed to confirm the underlying mechanisms, prioritizing interventions to improve sleep quality and ensure adequate sleep could help mitigate IDD.

Implications of circadian disruption on intervertebral disc degeneration: The mediating role of sympathetic nervous system

The circadian clock orchestrates a broad spectrum of physiological processes, crucially modulating human biology across an approximate 24-hour cycle. The circadian disturbances precipitated by modern lifestyle contribute to the occurrence of low back pain (LBP), mainly ascribed to intervertebral disc degeneration (IVDD). The intervertebral disc (IVD) exhibits rhythmic physiological behaviors, with fluctuations in osmotic pressure and hydration levels that synchronized with the diurnal cycle of activity and rest. Over recent decades, advanced molecular biology techniques have shed light on the association between circadian molecules and IVD homeostasis. The complex interplay between circadian rhythm disruption and IVDD is becoming increasingly evident, with the sympathetic nervous system (SNS) emerging as a potential mediator. Synchronized with circadian rhythm through suprachiasmatic nucleus, the SNS regulates diverse physiological functions and metabolic processes, profoundly influences the structural and functional integrity of the IVD. This review synthesizes the current understanding of circadian regulation and sympathetic innervation of the IVD, highlighting advancements in the comprehension of their interactions. We elucidate the impact of circadian system on the physiological functions of IVD through the SNS, advocating for the adoption of chronotherapy as a brand-new and effective strategy to ameliorate IVDD and alleviate LBP.

The Impact of Diagnosed Chronic Sleep Disorders on Outcomes Following Total Knee Arthroplasty

BACKGROUND

Up to 20% of patients undergoing total knee arthroplasty (TKA) remain dissatisfied with their outcome, leading to the identification of risk factors for poor outcomes. The purpose of this study was to analyze the effect of chronic sleep disorders on patient-reported outcomes after primary TKA.

METHODS

A retrospective review of patients undergoing primary TKA was conducted using a prospectively collected database of patients from a single institution between 2018 and 2022. The cohort was split based on the presence of documented chronic sleep disorders, identified preoperatively from the electronic medical record using current procedural terminology codes. The sample was further restricted to include all patients who have sleep disorders (SDs), as well as a 3:1 propensity-matched (on age, sex, body mass index, and American Society of Anesthesiologists class) cohort of patients who had no documented SDs (NSDs) prior to surgery. The final sample included 172 patients (SD: 43; NSD: 129). Repeated-measures linear mixed model analysis was used to analyze the progression of Knee Injury and Osteoarthritis Outcome Score (KOOS) through time between groups.

RESULTS

Those who had SDs had a lower preoperative mean total KOOS score (40.2) than the NSD group (44.1); however, this was not significantly different (P = .108). At 1 year postoperatively, those who had an SD had a significantly higher mean total KOOS score (87.2) than the NSD group (80.4), P = .005. When comparing total KOOS scores by group, over each time period, the SD group showed a better progression when compared to the NSD group, P = .001.

CONCLUSIONS

Compared to patients who did not have documented chronic sleep disorders, patients who had a prior history of chronic sleep disorders reported significantly greater improvements in most KOOS domains in the 12-month period following TKA.

The association between insomnia and musculoskeletal problems in employees of an automotive company in Tehran, Iran

OBJECTIVES

The purpose of this study was to examine the association between insomnia and the number of pain areas among employees of an automotive company. Secondary aim was to examine the association between depression, anxiety, and stress, and musculoskeletal pain independent of insomnia.

MATERIAL AND METHODS

We performed a cross-sectional study conducted in an automobile manufacturing factory. To collect data, we used the Nordic Musculoskeletal Questionnaire, ISI (Insomnia Severity Index), and DASS-21 (Depression, Anxiety, and Stress Scale). The univariate and multiple association analyses were performed using ordinal logistic regression adjusted for gender, age, industrial/non-industrial, sport activity, pack year, educational level, years of employment, anxiety, stress, and depression.

RESULT

In individuals with insomnia, the lower back was the most common area where pain was reported (59.5%). In all areas, pain symptoms were significantly more prevalent in individuals with insomnia compared to those without insomnia. Insomnia was associated with having pain with an increased odds of number of pain sites (odds ratio [OR] 2.81,95%CI 2.34-3.39). In ordinal logistic regression, there was an association between insomnia and pain, independent of the effects of depression, anxiety, and stress (OR 2.21,95%CI 1.52-3.23).

DISCUSSION

Insomnia was associated with pain in all regions of the body and a higher prevalence of pain in multiple areas. The insomnia-pain association was independent of depression, anxiety, and stress.

The association between sleep disorder, sleep duration and chronic back pain: results from National Health and Nutrition Examination Surveys, 2009-2010

BACKGROUND

Back pain is a typical condition, and the association among sleep disorders, sleep duration and back pain is currently being investigated. The purpose of this research is to explore the connection between sleep disorders, sleep duration and chronic back pain as well as confounding factors.

METHODS

Our data were obtained from the National Health and Nutrition Examination Survey (NHANES) data set of the USA and 1,131 participants were included in the study. Multivariable logistic regression was employed to investigate the relationship between sleep disorders, sleep duration and chronic back pain. And subgroup analysis conducted by gender, age, race, education, marital status, PIR, BMI, awakening events, hypertension condition and diabetes condition was also performed.

RESULTS

Our study includes 1131 participants, 513 are men (45.4%) and 618 are women (54.6%), 151 participants with sleep disorders (13.4%) and 980 participants without (86.6%). The fully adjusted model with adjustment variables including age, gender, race, BMI, PIR, drink, smoke, education, marital status, awakening conditions, hypertension, diabetes and part of back pain constructed through multiple logistic regression shows that chronic back pain is associated with sleep disorders [OR = 3.71, 95% CI: (1.25, 10.99), p < 0.05]. Using normal sleep duration as a reference, there is no statistical difference between short sleep duration [OR=-0.35, 95% CI: (-0.95, 0.24), p = 0.241], long sleep duration [OR = 0.81, 95% CI: (-1.61, 3.24), p = 0.513] and chronic back pain. It can be found through subgroup analysis that age between 40 and 60 years, age larger than 60 years, different race, marital status and BMI >30 kg/m2 are associated with chronic back pain and sleep disorders. We also find a nonlinear relation which is likely to be rotated S-shape among chronic back pain and sleep duration by fitting smooth curves.

CONCLUSION

Our results suggest a substantial positive relationship between chronic back pain and sleep disorders and there is no statistical association between sleep duration and chronic back pain. The findings drawn from our study provide a basis for future exploration of the causal association between chronic back pain and sleep disorders, and provide references for timely elimination of interfering factors.

The joint association of insomnia disorder and lifestyle on the risk of activity-limiting spinal pain: the HUNT Study

OBJECTIVES

To investigate whether the combination of multiple healthy lifestyle factors modify the well-established association between insomnia disorder and risk of activity-limiting spinal pain.

METHODS

We conducted a prospective study of 10,228 individuals who participated in two surveys over ∼11 years and were free of chronic pain in the neck, upper back, and lower back at baseline. Adjusted risk ratios (RRs) were calculated for the risk of activity-limiting chronic spinal pain (i.e., pain that impairs daily activities at work or leisure time) at follow-up associated with the joint association of insomnia disorder and the combination of five lifestyle factors (body mass index, leisure time physical activity, alcohol consumption, diet, and smoking) at baseline.

RESULTS

Our data indicate an additive interaction between insomnia disorder and lifestyle on risk of activity-limiting spinal pain, i.e., compared with participants without insomnia disorder and the best lifestyle score, participants with insomnia disorder and the worst lifestyle score had a RR of activity-limiting spinal pain of 3.57 (95 % CI: 2.65-4.80); participants with insomnia disorder and the best lifestyle score had a RR of 1.56 (95 % CI: 0.97-2.50); and those without insomnia disorder and the worst lifestyle score had a RR of 1.32 (95 % CI: 1.12-1.55).

CONCLUSIONS

Poor lifestyle behaviour amplifies the adverse effect of insomnia disorder on the risk of activity-limiting chronic spinal pain.

Temporal stability in the prevalence and pattern of co-occurring musculoskeletal pain among people with persistent low back pain: population-based data from the Norwegian HUNT Study, 1995 to 2019

ABSTRACT

People with persistent low back pain (LBP) often report co-occurring persistent musculoskeletal (MSK) pain in other body regions that may influence prognosis as well as treatment approaches and outcomes. This study describes the prevalence and patterns of co-occurring persistent MSK pain among people with persistent LBP based on consecutive cross-sectional studies over 3 decades in the population-based HUNT Study, Norway. The analyses comprised 15,375 participants in HUNT2 (1995-1997), 10,024 in HUNT3 (2006-2008), and 10,647 in HUNT4 (2017-2019) who reported persistent LBP. Overall, ∼90% of participants in each of the HUNT surveys with persistent LBP reported persistent co-occurring MSK pain in other body sites. The age-standardized prevalence of the most common co-occurring MSK pain sites was consistent across the 3 surveys: 64% to 65% report co-occurring neck pain, 62% to 67% report shoulder pain, and 53% to 57% report hip or thigh pain. Using latent class analysis (LCA), we identified 4 distinct patterns of persistent LBP phenotypes that were consistent across the 3 surveys: (1) "LBP only," (2) "LBP with neck or shoulder pain," (3) "LBP with lower extremity or wrist or hand pain," and (4) "LBP with multisite pain," with conditional item response probabilities of 34% to 36%, 30% to 34%, 13% to 17%, and 16% to 20%, respectively. In conclusion, 9 of 10 adults in this Norwegian population with persistent LBP report co-occurring persistent MSK pain, most commonly in the neck, shoulders, and hips or thighs. We identified 4 LCA-derived LBP phenotypes of distinct MSK pain site patterns. In the population, both the prevalence and pattern of co-occurring MSK pain and the distinct phenotypic MSK pain patterns seem stable over decades.