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

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

Design: 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.

Measurements: 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.

Results: 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.

Conclusion: 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.