A PRELIMINARY INVESTIGATION OF THE RELATIONSHIP BETWEEN PAIN SENSITIVITY, BODY FAT DISTRIBUTION AND BLOOD LEVELS OF IL-6, CRP, TNF-Α AND LEPTIN.

Background and aims: Obese individuals have increased concentrations of pro-inflammatory cytokines and some other markers of inflammationand an increased risk of metabolic disorders. The relationship between obesity, pro-inflammatory cytokines and pain sensitivity response is not fully understood. Aim of the Study:To investigate associations between body fat distribution, C reactive protein (CRP), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-a), leptin and pain sensitivity in adults. Methods: 38 adults (n=18 women) were grouped as normal weight(n=22) or obese (n=16), based on body mass index (BMI).Measurements of pressure pain and cold pressor pain sensitivity response, biomarkers (venous blood), and body composition (dual X-ray absorptiometry) were evaluated for each participant. Results: Pressure pain threshold was significantly lower in obese(mean+SD=340.93±93.58 kpa)compared to the normal weight group(447.45±203.72 kpa, p=0.039, t-test). Forward regression suggested that high gynoid fat (g)was associated with lower pressure pain thresholds (ß=-0.383, p=0.028), high lower limb fat (g) was associated with lower cold pain thresholds (ß=-0.495, p=0.003)and high IL-6 predicted higher cold pain tolerance (ß=0.345, p = 0.049). Women were more sensitive to pressure pain (P=0.03). Conclusion: Gynoid and lower limb fat content correlated with pain sensitivity response in adults, whereby those with greater fat content were more sensitive to pain. However, this may be a reflection of the sex differences in pain sensitivity as women have greater gynoid and leg fat contents.