The effect of monochromatic infrared energy on sensation in patients with diabetic peripheral neuropathy: a double-blind, placebo-controlled study.

OBJECTIVE The purpose of this study was to determine the effect of monochromatic infrared energy (MIRE) on plantar sensation in subjects with diabetic peripheral neuropathy. RESEARCH DESIGN AND METHODS In this randomized, double-blind, placebo-controlled study, 39 subjects with diabetic peripheral neuropathy completed the 8-week study. Subjects received 30 min of active or placebo MIRE three times a week for 4 weeks. Plantar sensation was tested with monofilaments at the beginning of the study (M1), following 4 weeks of treatment (M2), and after an additional 4 weeks of nontreatment (M3). The number of sites that could sense the 5.07 monofilament was totaled at M1, M2, and M3. Data were analyzed using a special repeated-measures statistic followed by a post hoc Tukey-Kramer test. RESULTS The average number of sites that patients could sense the 5.07 monofilament increased for both the active and placebo groups. There were significant gains from M1 to M2 (P < 0.002), no significant gains from M2 to M3 (P = 0.234), and significant gains from M1 to M3 (P < 0.002) for both the active and placebo groups. There were no significant differences between active and placebo groups at any measurement. CONCLUSIONS Thirty minutes of active MIRE applied 3 days per week for 4 weeks was no more effective than placebo MIRE in increasing sensation in subjects with diabetic peripheral neuropathy. Clinicians should be aware that MIRE may not be an effective modality for improving sensory impairments in patients with diabetic neuropathy.