Effects of body weight and fat mass on back pain - direct mechanical or indirect through inflammatory and metabolic parameters?

Prevalence, incidence, and re-occurrence risk of musculoskeletal pain in older adults in the United Kingdom: a population-based study

Background

Throughout the literature, pain burden has been assessed by asking different questions, often cross-sectionally, different populations of interest. We know little about pain re-occurrence and how to translate knowledge between pain questions within the population of interest. We aimed to estimate the burden of musculoskeletal pain by estimating prevalence, incidence rates, and re-occurrence risk of back, hand, hip, knee, and foot pain using different questions from UK population-based samples and predict the number of affected individuals in the UK in 2030.

Methods

We used two UK population-representative studies, with two eight-year-apart follow-ups and two pain questions assessing recent pain episodes and often troubled pain when walking. We estimated prevalence, 8-year incidence rates, and 8-year pain re-occurrence risk for women and men aged 50 years and older and the relation between the two pain questions.

Results

Among UK individuals older than 50 years, the prevalence of musculoskeletal pain episode was 20%-50%, and the incidence was 20-40/1,000 person-years, while the prevalence of pain when walking was 10%-25%, and the incidence was 6-12/1,000 person-years. The most prevalent musculoskeletal pain types were back and knee pain; of five women experiencing back or knee pain episodes, three are expected to be often troubled by pain. Hip and foot pain had similar estimates in both questions. Hand pain peaked in women aged 50-65 years. Women had higher prevalence and incidence rates, but men had higher 8-year re-occurrence risk of all types of musculoskeletal pain. Reporting a pain episode was associated with two times higher risk, but often troubled by pain when walking was associated with four to seven times times higher risk of the same pain in 8 years. Women and men with a body mass index (BMI) of ≥27 kg/m2 were twice as likely to experience musculoskeletal pain than those with BMI<27 kg/m2. In 2030, we expect 2-7 million people older than 50 years in the United Kingdom to seek site-specific musculoskeletal pain-focused healthcare.

Conclusions

In individuals older than 50 years, the experience of musculoskeletal pain at least doubles the chance of experiencing it again. Women report musculoskeletal pain more often, but men report more persistent pain. Musculoskeletal pain presents a significant burden to public health.

Non-Specific Low Back Pain, Dietary Salt Intake, and Posterior Lumbar Subcutaneous Edema

Low back pain is the world’s leading disability, but the etiology of the majority of low back pain is non-specific with no known cause. Moreover, overuse of opioids to treat low back pain is a widespread problem. This paper proposes that non-specific low back pain may be associated with excessive intake of dietary salt, potentially mediated by posterior lumbar subcutaneous edema. In addition to pain, symptoms of edema include swelling, tightness, and stiff joints, which are common complaints of people with low back pain, along with restricted lumbar range of motion and impaired mobility. Many global populations consume excess sodium chloride, which can lead to fluid overload in hypervolemia, and cause swelling and temporary weight gain associated with low back pain. Numerous conditions comorbid with low back pain are also potentially mediated by excessive salt intake, including migraine headache, hypertension, cardiovascular disease, venous thromboembolism, liver disease, respiratory disorders, chronic kidney disease, pregnancy complications, and multiple sclerosis. Novel approaches to identify and prevent the cause of non-specific low back pain have potential to reduce disability worldwide by reducing low back pain prevalence. More research is needed to confirm the involvement of dietary salt and posterior lumbar subcutaneous edema in non-specific low back pain.