Moderate or severe low back pain is associated with body mass index amongst community-dwelling older Australians

Longitudinal associations of body mass index and abdominal circumference with back pain among community-dwelling adults: data from the Osteoarthritis Initiative

BACKGROUND CONTEXT

Back pain is the most common musculoskeletal problem in both developed and developing countries. The prevalence and burden of back pain increases with age, and the management of back pain becomes increasingly important in the context of global aging. There is increasing evidence that obesity is a modifiable risk factor for musculoskeletal pain in different locations. Understanding the role of obesity in back pain holds great potential for improving understanding of the mechanisms of back pain and for developing new preventive and therapeutic approaches.

PURPOSE

To evaluate the role of weight, body mass index (BMI) and abdominal circumference (AC) in risk of back pain over 96 months.

DESIGN

Prospective cohort study.

PATIENT SAMPLE

The sample was from 4,793 adults in the Osteoarthritis Initiative (OAI) database who had or were at increased risk for knee Osteoarthritis.

OUTCOME MEASURES

Outcome variables included the presence, severity, and frequency of back pain, using the past 30 days as the time frame.

METHODS

Longitudinal analysis of data from 4,793 participants enrolled in the Osteoarthritis Initiative, assessed every 12 or 24 months for weight, BMI (kg/m2), AC (cm), and presence, severity (none, mild, moderate, severe), and frequency (none, rarely, sometimes, often, always) of back pain. BMI and AC were decomposed into between-person and with-person components. Data analyses were performed using mixed-effects logistic (for presence of back pain) or ordered logistic regression (for severity and frequency of back pain) models.

RESULTS

Back pain was reported in 58% of participants at baseline; 70% of those without back pain had incident back pain over 96 months. Both between-person (average value across a participant's all measurements) and within-person (deviations from the participant's average) effects of weight and BMI increased risk of presence, severity, and frequency of back pain (Odds radios (OR) per kg/m2: 1.010-1.046, p<.05) in females but not males, with statistically significant weight*sex and BMI*sex interactions. Similar findings were observed for between-person effects of AC on back pain, and the within-person effect of AC was only associated with back pain severity (OR per cm: 1.009, 95% confidence interval 1.002-1.017, p=.019) in females.

CONCLUSIONS

Greater average weight and BMI and increases in them increased odds of presence, severity, and frequency of back pain over 96 months in middle aged and older women but not men. Only average AC increased odds of back pain over time, in women. These findings suggest that preventing obesity and slowing weight gain is important for the management of back pain.

Relationship between body mass index and spinal pathology in community-dwelling older adults

PURPOSE

To clarify the relationship between body mass index (BMI) and spinal pathologies including spinal sagittal balance, back extensor strength (BES), paraspinal muscle mass, prevalent vertebral fracture, disc degeneration, Modic changes, low back pain, and quality of life (QOL) in community-dwelling older adults.

METHODS

This study included 380 participants (age: ≥ 65 years, male/female: 152/228) from the Shiraniwa Study. Multivariate nonlinear regression analysis was used to investigate the relationship between BMI and sagittal vertical axis (SVA), BES, paraspinal muscle mass, visual analog scale (VAS) for low back pain, Oswestry Disability Index (ODI), and EuroQoL-5 Dimension (EQ5D) score after adjusting for sex, age, Hospital Anxiety and Depression Scale score, and Charlson Comorbidity Index. In addition, multiple logistic regression analysis was used to investigate the association between BMI and prevalent vertebral fracture, disc degeneration, and Modic changes.

RESULTS

BMI was significantly correlated with SVA, BES, paraspinal muscle mass, VAS, ODI, and EQ5D score. The increase in BMI was associated with the deterioration of all outcomes, which accelerated when the BMI increased from approximately 22-23 kg/m². Moreover, overweight/obesity was significantly correlated with disc degeneration and Modic changes.

CONCLUSION

Increased BMI is significantly associated with spinal pathologies such as SVA, BES, paraspinal muscle mass, VAS, QOL, disc degeneration, and Modic changes. The findings suggest that measures for controlling overweight and obesity among older adults can play an important role in the prevention and treatment of spinal pathologies.

Severe low back or lower limb pain is associated with recurrent falls amongst older Australians

Background

Few studies have explored the impact of low back or lower limb pain severity on recurrent (≥2) falls in older adults.

Objectives

Investigate the association between the severity of low back or lower limb pain, and ≥2 falls or falls‐related injuries.

Methods

Community‐dwelling Australian males and females in the ASPREE Longitudinal Study of Older Persons (ALSOP), aged ≥70 years. Self‐reported, cross‐sectional questionnaire data regarding number of falls and falls‐related injuries in the last 12 months; and sites and severity of pain experienced on most days. Adjusted relative risks (RR) were estimated from multivariable Poisson regression models, for males and females separately.

Results

Of 14,892 ALSOP participants, 13% (n = 1983) reported ≥2 falls (‘recurrent fallers’) in the last 12 months. Males and females who reported severe low back, or severe lower limb pain on most days were more likely to report ≥2 falls in the last 12 months compared to those with mild pain (lower back: males RR = 1.70 and females RR = 1.5, p = 0.001; lower limb: males RR = 2.0, p < 0.001 and females RR = 1.4, p = 0.003). Female recurrent fallers who reported severe low back (RR = 1.3, p = 0.029) or lower limb (RR = 1.2, p = 0.024) pain on most days were more likely to report a falls‐related injury in the last 12 months compared to females with mild pain.

Conclusion

Severe low back or lower limb pain was associated with an increased likelihood of recurrent falls (males/females) or falls‐related injuries (females only). Assessment of severe low back and lower limb pain should be considered as a priority when undertaking falls‐risk evaluation.

Significance

Severe low back pain, or severe lower limb pain is associated with an increased likelihood of recurrent falls in older males and females, and an increased likelihood of falls‐related injuries in older female recurrent fallers. Assessment and management of severe low back and lower limb pain should be prioritized when undertaking falls‐risk assessment. Future longitudinal research is required to further interrogate this relationship and its underlying mechanisms.

Scoliosis and skeletal muscle mass are strongly associated with low back pain-related disability in humans: An evolutionary anthropology point of view

OBJECTIVES

To clarify the potential risk factors and etiology of low back pain (LBP)-related disability, including structural changes of the spine (spinal scoliosis) and body composition components in a population with a high prevalence of LBP.

METHODS

In this cross-sectional study, two self-reported validated questionnaires were used to collect back pain and disability data in an ethnically homogeneous family-based population sample (N = 1078). The scoliosis angle of trunk rotation was measured by a scoliometer on three spinal levels while the patient was bent forward. Body composition parameters, including relative to weight (WT), fat, relative skeletal muscle mass (SMM/WT), and total body water were determined by bioelectrical impedance analysis. Statistical analysis was conducted, accounting for the familial composition of the sample.

RESULTS

The mixed multiple regression analyses with several LBP-related phenotypes as dependent variables consistently showed significant independent associations with scoliosis and SMM/WT, irrespective of other covariates. The odds ratios (OR)/95% CI for scoliosis ranged between 1.40 (1.19-1.64) and 1.51 (1.27-1.80), and from 0.61(0.51-0.72), to 0.71(0.58-0.87) for SMM/WT, depending on the LBP phenotype. The genetic components of the respective correlations between the LBP-phenotypes and scoliosis or SMM/WT were negligible.

CONCLUSIONS

The associations between LBP-related conditions and postured scoliosis and SMM/WT were consistent and significant and therefore may serve as markers in predicting the development of LBP-related disability. We interpret the origin of these correlations as the evolutionary event due to the imperfect spine anatomy adaptation to a vertical posture resulting from a quick transition to bipedalism from a quadrupedal ancestor.

Evaluation of the Pain Impact Index for Community-Dwelling Older Adults Through the Application of Rasch Modelling

OBJECTIVE

Evaluate the Pain Impact Index, a simple, brief, easy-to-use, and novel tool to assess the impact of chronic pain in community-dwelling older adults.

METHODS

A Rasch modelling analysis was undertaken in Stata using a partial credit model suited to the Likert-type items that comprised the Index. The Index was evaluated for ordering of category thresholds, unidimensionality, overall fit to the Rasch model, measurement bias (Differential Item Functioning, DIF), targeting, and construct validity.

RESULTS

The four-item Pain Impact Index was self-completed by 6454 community-dwelling Australians who were aged at least 70 years and experienced pain on most days. Two items showed evidence of threshold disordering, and this was resolved by collapsing response categories (from 5 to 3) for all items. The rescored Index conformed to the unidimensionality assumption and had satisfactory fit with the Rasch model (analyses conducted on a reduced sample size to mitigate the potential for overpowering: n = 377, P > 0.0125, power > 77%). When considering uniform DIF, the most frequent sources of measurement bias were age, knee pain, and upper back pain. When considering nonuniform DIF, the most frequent source of measurement bias was knee pain. The Index had good ability to differentiate between respondents with different levels of pain impact and had highest measurement precision for respondents located around the average level of pain impact in the study sample. Both convergent and discriminant validity of the Index were supported.

CONCLUSION

The Pain Impact Index showed evidence of unidimensionality, was able to successfully differentiate between levels of pain impact, and had good evidence of construct validity.