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25-02-2022 | Osteoarthritis | News

BMI linked to pain severity in hand osteoarthritis

Author: Laura Cowen


medwireNews: Higher BMI is associated with increased hand pain in people with hand osteoarthritis, which researchers suggest could be partly mediated by increased leptin levels.

Marthe Gløersen (University of Oslo, Norway) and co-investigators also found that high BMI was linked to increased pain overall, as well as in the feet and knees or hips, but were unable to identify specific systemic inflammatory biomarkers that may mediate these associations.

In their analysis of data for 281 Nor-Hand study participants, of whom 34% were overweight and 21% were obese, they found that each 5 kg/m2 increase in BMI was associated with a significant 0.64-point increase in hand pain when assessed using the Australian/Canadian Osteoarthritis Hand Index (range 0–20 points).

The same BMI increase was associated with a 0.46-point increase in hand pain measured on a numeric rating scale (NRS; range 0–10 points), a 0.65-point increase in NRS foot pain (range 0–10 points), a 1.31-point increase in WOMAC knee or hip pain (range 0–20 points), and a 1.15-point increase in painful total body joint count (range: 0–18 points), all of which were statistically significant.

However, the researchers point out that the minimal clinically important difference for NRS pain is 1 point and therefore, using the current models, “two persons would need to have a difference of approximately 10 units in their BMI to have a clinically meaningful difference in hand pain,” they remark.

Mediation analyses suggested that the proinflammatory adipokine leptin is a significant mediator of the BMI effect on hand pain but has no significant impact on the relationship between BMI and pain in the lower extremities.

Gløersen et al say in Arthritis & Rheumatology that this may be because “the systemic effects of obesity on pain are more important in hands than in lower extremities, where the biomechanical effects of obesity may play a more important role.”

The team also observed that, after adjustment for potential confounders, high-sensitivity C-reactive protein (hs-CRP) may mediate the association between BMI and painful total body joint count.

“These results may suggest that low-grade inflammation in overweight/obese individuals, reflected by increased levels of hs-CRP, contribute to more generalized pain,” say the investigators.

They conclude: “Despite modest strengths of associations, our results suggest that weight loss may be a strategy to prevent or treat pain in people with hand [osteoarthritis], which should be further explored in future studies.”

medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2022 Springer Healthcare Ltd, part of the Springer Nature Group

Arthritis Rheumatol 2022; doi:10.1002/art.42056