Obesity, but not overweight, is associated with plantar light touch sensation in children aged 8 to 16 years: A cross‐sectional study

OBJECTIVE: Increased foot‐ground contact loading engenders adaptive glabrous skin thickening and can decrease mechanoreceptor acuity and alter plantar cutaneous sensation. There has not been any research on whether overweight and obesity are similarly associated with normal plantar cutaneous sensation scores in children. This study investigated the associations between normal plantar cutaneous sensation scores and weight status (i.e., healthy weight, overweight, and obesity) in a sample of youth. METHODS: Plantar sensation was tested among 122 participants aged 8 to 16 years (10.3 ± 1.8 years; 140.0 ± 11.2 cm; 44.2 ± 16.0 kg) across the forefoot, midfoot, and rearfoot using Semmes‐Weinstein pressure aesthesiometry (0.07 g and 0.4 g monofilaments). Weight status was determined using the Centers for Disease Control and Prevention growth charts. Age‐ and sex‐adjusted models were used to explore the relationships between normal plantar sensation scores and weight status. Significant two‐tailed tests were set at p < .05. RESULTS: Only obesity was inversely associated with normal plantar sensation scores on the left (β = −.241; p = .009) and right (β = −.222; p = .018) forefeet, left (β = −.322; p = .001) and right (β = −.253; p = .007) midfeet, and left (β = −.286; p = .002) and right (β = −.228; p = .014) wholefeet (relative to healthy weight) when using the 0.07 g monofilament. There was no association between obesity and plantar sensation when using the 0.4 g monofilament. CONCLUSIONS: Obesity is associated with diminished light touch plantar sensation. Considering previously reported higher mechanical loading and the fact that Merkel cells and the Aβfibers that innervate them are superficial to the hypodermis, adaptive glabrous skin thickening (rather than fat pad thickness) may underlie this association. Contrary to previous suggestions, overweight is not associated with decreased plantar cutaneous sensation.