Body fat distribution, lipoprotein metabolism, and insulin resistance: A lifetime of research on the pathophysiology of the human metabolic syndrome

Physical Activity to Reduce Systemic Inflammation Associated With Chronic Pain and Obesity: A Narrative Review

INTRODUCTION

The increasing prevalence of chronic pain and obesity has significant health and cost implications for economies in the developed and developing world. Evidence suggests that there is a positive correlation between obesity and chronic pain and the link between them is thought to be systemic inflammation.

OBJECTIVES

The aim of this narrative review was to explore the physiological links between chronic musculoskeletal pain and obesity and to consider the potential role of regular physical activity in providing a means of managing obesity-related chronic pain.

DISCUSSION

Systemic inflammation, mechanical overload, and autonomic dysfunction are associated with increased prevalence and severity of chronic pain in individuals with obesity. It has been proposed, therefore, that interventions that target systemic inflammation could help to reduce chronic pain in obese individuals. Reduction in abdominal fat has been shown to alleviate pain and reduce the systemic markers of inflammation that contribute to chronic pain. Interventions that include exercise prescription have been shown to reduce both abdominal fat and systemic inflammation. Furthermore, exercise is also known to reduce pain perception and improve mental health and quality of life that also improves pain outcomes. However, adherence to formal exercise prescription is poor and therefore exercise programmes should be tailored to the interests, needs, and abilities of individuals to reduce attrition.

Pressure and cold pain threshold reference values in a large, young adult, pain-free population

Background and aims

Currently there is a lack of large population studies that have investigated pain sensitivity distributions in healthy pain free people. The aims of this study were: (1) to provide sex-specific reference values of pressure and cold pain thresholds in young pain-free adults; (2) to examine the association of potential correlates of pain sensitivity with pain threshold values.

Methods

This study investigated sex specific pressure and cold pain threshold estimates for young pain free adults aged 21–24 years. A cross-sectional design was utilised using participants (n =617) from the Western Australian Pregnancy Cohort (Raine) Study at the 22-year follow-up. The association of site, sex, height, weight, smoking, health related quality oflife, psychological measures and activity with pain threshold values was examined. Pressure pain threshold (lumbar spine, tibialis anterior, neck and dorsal wrist) and cold pain threshold (dorsal wrist) were assessed using standardised quantitative sensory testing protocols.

Results

Reference values for pressure pain threshold (four body sites) stratified by sex and site, and cold pain threshold (dorsal wrist) stratified by sex are provided. Statistically significant, independent correlates of increased pressure pain sensitivity measures were site (neck, dorsal wrist), sex (female), higher waist-hip ratio and poorer mental health. Statistically significant, independent correlates of increased cold pain sensitivity measures were, sex (female), poorer mental health and smoking.

Conclusions

These data provide the most comprehensive and robust sex specific reference values for pressure pain threshold specific to four body sites and cold pain threshold at the dorsal wrist for young adults aged 21–24 years. Establishing normative values in this young age group is important given that the transition from adolescence to adulthood is a critical temporal period during which trajectories for persistent pain can be established.

Implications

These data will provide an important research resource to enable more accurate profiling and interpretation of pain sensitivity in clinical pain disorders in young adults. The robust and comprehensive data can assist interpretation of future clinical pain studies and provide further insight into the complex associations of pain sensitivity that can be used in future research.