Effects of four kinds of electromagnetic fields (EMF) with different frequency spectrum bands on ovariectomized osteoporosis in mice.

Scientific reports · 2017 · Mixed · Low evidence

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MixedLow evidencePaper 4926

Study snapshot

PublicationScientific reports · 2017

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

Electromagnetic fields (EMF) was considered as a non-invasive modality for treatment of osteoporosis while the effects were diverse with EMF parameters in time domain. In present study, we extended analysis of EMF characteristics from time domain to frequency domain, aiming to investigate effects of four kinds of EMF (LP (1-100 Hz), BP (100-3,000 Hz), HP (3,000-50,000 Hz) and AP (1-50,000 Hz)) on ovariectomized (OVX) osteoporosis (OP) in mice. Forty-eight 3-month-old female BALB/c mice were equally assigned to Sham, OVX, OVX + LP, OVX + BP, OVX + HP and OVX + AP groups (n = 8). After 8-week exposure (3 h/day), LP and BP significantly increased serum bone formation markers and osteogenesis-related gene expressions compared with OVX. Bedsides, LP and BP also slightly increased bone resorption activity compared with OVX, evidenced by increased RANKL/OPG ratio. HP sharply decreased serum bone formation and resporption markers and osteogenesis and osteoclastogenesis related gene expressions compared with OVX. AP had accumulative effects of LP, BP and HP, which significantly increased bone formation and decreased bone resporption activity compared with OVX. As a result, LP, BP and HP exposure did not later deterioration of bone mass, microarchitecture and mechanical strength in OVX mice with OP. However, AP stimulation attenuated OVX-induced bone loss.

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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 directionmixed

Population3-month-old female BALB/c mice with ovariectomy-induced osteoporosis model

Sample size48

ExposureELF · 8-week exposure (3 h/day)

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

In ovariectomized mice, LP (1–100 Hz) and BP (100–3,000 Hz) increased serum bone formation markers and osteogenesis-related gene expression versus OVX, and slightly increased bone resorption activity (increased RANKL/OPG ratio). HP (3,000–50,000 Hz) decreased both bone formation and resorption markers and related gene expression versus OVX. AP (1–50,000 Hz) increased bone formation and decreased bone resorption activity versus OVX, and attenuated OVX-induced bone loss; LP, BP, and HP did not worsen bone mass, microarchitecture, or mechanical strength versus OVX.

Outcomes measured

Serum bone formation markers
Serum bone resorption markers
Osteogenesis-related gene expression
Osteoclastogenesis-related gene expression
RANKL/OPG ratio
Bone mass
Bone microarchitecture
Mechanical strength
OVX-induced bone loss attenuation

Limitations

Exposure intensity/dose metrics (e.g., field strength) not reported in the abstract
Small group sizes (n=8 per group)
Animal model (ovariectomized mice) may not generalize to humans
Some outcomes show opposing changes across frequency bands (e.g., LP/BP increased formation but also slightly increased resorption)

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "other",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "8-week exposure (3 h/day)"
  },
  "population": "3-month-old female BALB/c mice with ovariectomy-induced osteoporosis model",
  "sample_size": 48,
  "outcomes": [
    "Serum bone formation markers",
    "Serum bone resorption markers",
    "Osteogenesis-related gene expression",
    "Osteoclastogenesis-related gene expression",
    "RANKL/OPG ratio",
    "Bone mass",
    "Bone microarchitecture",
    "Mechanical strength",
    "OVX-induced bone loss attenuation"
  ],
  "main_findings": "In ovariectomized mice, LP (1–100 Hz) and BP (100–3,000 Hz) increased serum bone formation markers and osteogenesis-related gene expression versus OVX, and slightly increased bone resorption activity (increased RANKL/OPG ratio). HP (3,000–50,000 Hz) decreased both bone formation and resorption markers and related gene expression versus OVX. AP (1–50,000 Hz) increased bone formation and decreased bone resorption activity versus OVX, and attenuated OVX-induced bone loss; LP, BP, and HP did not worsen bone mass, microarchitecture, or mechanical strength versus OVX.",
  "effect_direction": "mixed",
  "limitations": [
    "Exposure intensity/dose metrics (e.g., field strength) not reported in the abstract",
    "Small group sizes (n=8 per group)",
    "Animal model (ovariectomized mice) may not generalize to humans",
    "Some outcomes show opposing changes across frequency bands (e.g., LP/BP increased formation but also slightly increased resorption)"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "electromagnetic fields",
    "frequency domain",
    "low-pass",
    "band-pass",
    "high-pass",
    "all-pass",
    "ovariectomy",
    "osteoporosis",
    "mice",
    "bone formation",
    "bone resorption",
    "RANKL/OPG",
    "bone microarchitecture",
    "mechanical strength"
  ],
  "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: 10.1038/s41598-017-00668-w
PubMed: 28373666

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