Excess abdominal fat tied to widespread chronic pain

Key takeaways:

• Greater VAT, SAT and the ratio of the two were associated with a higher number of chronic pain sites.
• Higher levels of adipose tissue were also tied to greater odds of reporting chronic pain.

Excessive abdominal fat was tied to chronic pain across multiple sites, particularly in women, an analysis published in Regional Anesthesia & Pain Medicine showed.

As a result, reducing abdominal adiposity could be a strategy for chronic pain management, especially if the pain is widespread, according to researchers.

“While the link between obesity and musculoskeletal pain is well established, the specific role of fat distribution — particularly visceral and subcutaneous adipose tissue — in relation to chronic pain was less understood,” Feng Pan, PhD, a senior research fellow from the University of Tasmania Menzies Institute for Medical Research in Australia, told Healio. “This prompted us to explore whether these distinct fat deposits were associated with multisite and widespread chronic pain.”

In a first-of-its-kind study, the researchers assessed the data of 32,409 participants from the U.K. Biobank who underwent MRI scans of their abdomen to determine their amount of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT).

Participants (mean age, 55 years; 50.8% women) were also given pain questionnaires, which asked if they had experienced any pain in their back, hip, knee, neck, shoulder or all over the body for more than 3 months.

A total of 638 participants had a repeat MRI and pain assessment over 2 years later.

Pan and colleagues found a dose-response association between the number of chronic pain sites and VAT (OR = 2.04; 95% CI, 1.85-2.26), SAT (OR = 1.6; 95% CI, 1.5-1.7) and the ratio of the two (OR = 1.6; 95% CI 1.37-1.87) among women.

They also observed this link between VAT (OR = 1.34; 95% CI, 1.26-1.42), SAT (OR = 1.39; 95% CI, 1.29-1.49) and the VAT:SAT ratio (OR = 1.13; 95% CI, 1.07-1.2) and the number of chronic pain sites in men, although it was less pronounced.

The researchers noted that higher levels of adipose tissue were also tied to greater odds of reporting chronic pain in both men and women.

The associations remained even after Pan and colleagues adjusted for several factors like height, ethnicity, age, alcohol intake, household income, smoking status, physical activity and comorbid conditions and sleep duration.

Multiple mechanisms may explain the sex differences in the effect sizes, “including the influence of sex hormones on adipose tissue distribution, function and storage,” they wrote.

There were still notable study limitations, according to the researchers. The study could not determine cause and effect due to its observational design. Meanwhile, MRIs were conducted only twice, and more imaging visits “may allow more information on patterns and fluctuations in the number of chronic pain sites,” the researchers wrote.

For primary care providers, “these findings highlight the importance of educating patients about the link between excess fat and chronic musculoskeletal pain, encouraging lifestyle changes to reduce adipose tissue,” Pan said.

“Weight management, through a healthy diet and physical activity, could help alleviate pain,” he continued. “Additionally, since women are more affected, care plans may need to incorporate gender-specific strategies to address these differences effectively.”

Future research “should focus on understanding the mechanisms that connect visceral and subcutaneous fat to chronic pain, particularly the biological pathways that explain the observed sex differences,” Pan added. “This could lead to more targeted interventions for managing chronic pain and obesity.”

References:

• Abdominal fat linked to widespread chronic pain, especially in women. Available at: https://www.eurekalert.org/news-releases/1057103. Published Sept. 10, 2024. Accessed Sept. 10, 2024.
• Kifle Z, et al. Reg Anesth Pain Med. 2024;doi:10.1136/rapm-2024-105535.