Effects of electromagnetic fields on bone loss in hyperthyroidism rat model.

Bioelectromagnetics · 2017 · Benefit · Low evidence

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BenefitLow evidencePaper 4811

Study snapshot

PublicationBioelectromagnetics · 2017

Study typeanimal

Reported directionBenefit

Evidence ratingLow

Abstract

Optimal therapeutics for hyperthyroidism-induced osteoporosis are still lacking. As a noninvasive treatment, electromagnetic fields (EMF) have been proven to be effective for treating osteoporosis in non-hyperthyroidism conditions. We herein systematically evaluated the reduced effects of EMF on osteoporosis in a hyperthyroidism rat model. With the use of Helmholtz coils and an EMF stimulator, 15 Hz/1 mT EMF was generated. Forty-eight 5-month-old male Sprague-Dawley rats were randomly divided into four different groups: control, levothyroxine treated (L-T4), EMF exposure + levothyroxine (EMF + L-T4), and EMF exposure without levothyroxine administration (EMF). All rats were treated with L-T4 (100 mg/day) except those in control and EMF groups. After 12 weeks, the results obtained from bone mineral density analyses and bone mechanical measurements showed significant differences between L-T4 and EMF + L-T4 groups. Micro CT and bone histomorphometric analyses indicated that trabecular bone mass and architecture in distal femur and proximal tibia were augmented and restored partially in EMF + L-T4 group. In addition, bone thyroid hormone receptors (THR) expression of hyperthyroidism rats was attenuated in EMF + L-T4 group, compared to control group, which was not observed in L-T4 group. According to these results, we concluded that 15 Hz/1 mT EMF significantly inhibited bone loss and micro architecture deterioration in hyperthyroidism rats, which might occur due to reduced THR expression caused by EMF exposure. Bioelectromagnetics. 38:137-150, 2017. © 2016 Wiley Periodicals, Inc.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal

Effect directionbenefit

Population5-month-old male Sprague-Dawley rats; hyperthyroidism model induced with levothyroxine (L-T4)

Sample size48

ExposureELF · 12 weeks

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Using Helmholtz coils to generate 15 Hz/1 mT EMF, rats receiving levothyroxine plus EMF showed significant differences versus levothyroxine-only rats in bone mineral density and bone mechanical measures after 12 weeks. Micro-CT and histomorphometry indicated trabecular bone mass and architecture were augmented and partially restored in the EMF+L-T4 group, and THR expression was attenuated in the EMF+L-T4 group compared with control (an effect not observed in the L-T4 group).

Outcomes measured

Bone mineral density
Bone mechanical measurements
Trabecular bone mass and architecture (micro-CT; histomorphometry) in distal femur and proximal tibia
Bone thyroid hormone receptor (THR) expression

Limitations

Mechanistic interpretation is suggested (THR reduction) but causality is not established in the abstract
Animal model; generalizability to humans not addressed in the abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "other",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "12 weeks"
  },
  "population": "5-month-old male Sprague-Dawley rats; hyperthyroidism model induced with levothyroxine (L-T4)",
  "sample_size": 48,
  "outcomes": [
    "Bone mineral density",
    "Bone mechanical measurements",
    "Trabecular bone mass and architecture (micro-CT; histomorphometry) in distal femur and proximal tibia",
    "Bone thyroid hormone receptor (THR) expression"
  ],
  "main_findings": "Using Helmholtz coils to generate 15 Hz/1 mT EMF, rats receiving levothyroxine plus EMF showed significant differences versus levothyroxine-only rats in bone mineral density and bone mechanical measures after 12 weeks. Micro-CT and histomorphometry indicated trabecular bone mass and architecture were augmented and partially restored in the EMF+L-T4 group, and THR expression was attenuated in the EMF+L-T4 group compared with control (an effect not observed in the L-T4 group).",
  "effect_direction": "benefit",
  "limitations": [
    "Mechanistic interpretation is suggested (THR reduction) but causality is not established in the abstract",
    "Animal model; generalizability to humans not addressed in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "electromagnetic fields",
    "ELF EMF",
    "15 Hz",
    "1 mT",
    "Helmholtz coils",
    "hyperthyroidism",
    "levothyroxine",
    "osteoporosis",
    "bone loss",
    "micro-CT",
    "histomorphometry",
    "bone mineral density",
    "thyroid hormone receptor"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1002/bem.22022
PubMed: 27973686

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