Effect of 635nm Low-level Laser Therapy on Upper Arm Circumference Reduction: A Double-blind, Randomized,...

To assess the safety and efficacy of low-level laser therapy as a noninvasive method for reducing upper arm circumference.

Randomized, double-blind study whereby healthy subjects (N=40) with a body mass index of 20 to 35kg/m(2) received three 20-minute low-level laser therapy (N=20) or sham treatments (N=20) each week for two weeks.

Upper arm circumference was measured after three and six treatments and two weeks post-treatment. Primary success criterion was the proportion of subjects achieving a combined reduction in arm circumference of ≥1.25cm measured at three equally spaced points between the elbow and the shoulder. Secondary outcomes included total measurement change at each time point and subjective satisfaction ratings.

After six treatments, the low-level laser therapy group showed a combined reduction in arm circumference of 3.7cm versus 0.2cm in the sham treatment group (p<0.0001). Significantly more subjects in the low-level laser therapy group (N=12; 60%) achieved ≥1.5cm total decrease in upper arm circumference versus sham-treated subjects (N=0; 0%) (p<0.0005). Low-level laser therapy treatment resulted in a combined reduction in arm circumference of 2.2cm after three treatments and 3.7cm after six treatments (for each, p<0.0001) indicating a progressive and cumulative treatment effect. Body mass index remained unchanged for all subjects. A significantly greater number of subjects in the low-level laser therapy treatment group were satisfied with their results (p<0.05), believed their upper arm appearance improved (p<0.0005), and indicated the results exceeded expectations (p<0.05). The treatments were painless and no adverse events were reported.

Noninvasive low-level laser therapy is safe, painless, and effective in reducing upper arm circumference and is associated with a high degree of subject satisfaction.