Low-level laser in the treatment of patients with hypothyroidism induced by chronic autoimmune thyroiditis: a randomized, placebo-controlled clinical trial

Abstract

Chronic autoimmune thyroiditis (CAT) is the most common cause of acquired hypothyroidism, which requires lifelong levothyroxine replacement therapy. Currently, no effective therapy is available for CAT. Thus, the objective of this study was to evaluate the efficacy of low-level laser therapy (LLLT) in patients with CAT-induced hypothyroidism by testing thyroid function, thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TgAb), and ultrasonographic echogenicity. A randomized, placebo-controlled trial with a 9-month follow-up was conducted from 2006 to 2009. Forty-three patients with a history of levothyroxine therapy for CAT-induced hypothyroidism were randomly assigned to receive either 10 sessions of LLLT (830 nm, output power of 50 mW, and fluence of 707 J/cm(2); L group, n=23) or 10 sessions of a placebo treatment (P group, n=20). The levothyroxine was suspended 30 days after the LLLT or placebo procedures. Thyroid function was estimated by the levothyroxine dose required to achieve normal concentrations of T3, T4, free-T4 (fT4), and thyrotropin after 9 months of postlevothyroxine withdrawal. Autoimmunity was assessed by measuring the TPOAb and TgAb levels. A quantitative computerized echogenicity analysis was performed pre- and 30 days postintervention. The results showed a significant difference in the mean levothyroxine dose required to treat the hypothyroidism between the L group (38.59 ± 20.22 μg/day) and the P group (106.88 ± 22.90 μg/day, P<0.001). Lower TPOAb (P=0.043) and greater echogenicity (P<0.001) were also noted in the L group. No TgAb difference was observed. These findings suggest that LLLT was effective at improving thyroid function, promoting reduced TPOAb-mediated autoimmunity and increasing thyroid echogenicity in patients with CAT hypothyroidism.

Mechanisms and applications of the anti-inflammatory effects of photobiomodulation

“…Patients required a lower dosage of levothyroxine, and showed an increased echogenicity by ultrasound. The next study [90] was a randomized, placebo-controlled trial of 43 patients with a 9-month follow-up. In addition to improved thyroid function they found reduced autoimmunity evidenced by lower thyroid peroxidase antibodies (TPOAb), and thyroglobulin antibodies (TgAb).…”

Effect of Three Different Protocols of Low-Level Laser Therapy on Thyroid Hormone Production After Dental Implant Placement in an Experimental Rabbit Model

“…These procedures would not be possible in rats or mice. 9,10,13,40 In accordance with the most recent literature, LLLT was delivered by an infrared laser [7][8][9][10][11][12][13][14][15][26][27][28]35,38 of 830 nm wavelength 7,10,[12][13][14][15] and 50 mW output power in two sites near the mandibular implant, in seven sessions 7,11,12,15 every 48 h, using three different doses. The use of a sham surgery and sham LLLT control group (C-I), as well as a baseline surgery but sham LLLT group (C-II), enabled us to isolate both the influence of baseline surgery and the systemic effects of LLLT.…”

“…It is also important to consider samples composed of subjects with thyroid comorbidities, such as hyperthyroidism or hypothyroidism. 35 …”

“…Studies on the effect of infrared laser irradiation directly on the thyroid gland have shown increased mitotic activity in follicular cells, transient hyperactivity of some thyroid follicles, 32,33 and changes in circulating serum levels of the hormones secreted by the thyroid gland, triiodothyronine (T3) and thyroxine (T4). [34][35][36] These findings prompted the present study, as the thyroid gland is located near the mandibular region, a frequent site of irradiation after dental procedures. The objective of this study was to assess the side effects or systemic effects of LLLT used after mandibular dental implant insertion to improve osseointegration through a systematic assessment of circulating serum levels of T3, T4, and calcium in a rabbit model after three different protocols of low-level laser irradiation of the area of implantation of the osseointegrated implant placed immediately into the fresh extraction socket of the mandibular left incisor.…”

Luz de baixa potência como proposta terapêutica à síndrome metabólica em modelo animal

“…Com isso em vista, nossos parâmetros de irradiação foram baseados na aplicação da LLLT em condições de inflamação crônica, que geralmente adotam menores densidades de energia e de potência [22,24,25,27,35] do que foi adotado por Aquino e colaboradores [90]. Reconhecemos oportunidade para aprimorar o uso da LLLT no tratamento da SM, e outros protocolos de irradiação devem ser avaliados.…”