Exposure to cell phones reduces heart rate variability in both normal-weight and obese normotensive medical students

2020 · Harm · Low evidence

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HarmLow evidencePaper 1544

Study snapshot

Publicationmanual · 2020

Study typeother

Reported directionHarm

Evidence ratingLow

Abstract

Exposure to cell phones reduces heart rate variability in both normal-weight and obese normotensive medical students Alassiri M, Alanazi A, Aldera H, Alqahtani SA, Alraddadi AS, Alberreet MS, Alhussaini AI, Alotaibi Y, Alkhateeb MA, Shatoor AS. Exposure to cell phones reduces heart rate variability in both normal-weight and obese normotensive medical students. Explore (NY). 2020 Mar 2. pii: S1550-8307(20)30087-2. doi: 10.1016/j.explore.2020.02.006. Abstract BACKGROUND: We investigated and compared the effect of the radiofrequency electromagnetic field (RF-EM) emitted by a cell phone on the electrocardiogram and heart rate variability (HRV) of normotensive normal- weight and obese medical students. METHOD: Twenty medical student volunteers, normal weight (age = 23 ± 2, BMI = 23.05 ± 1.72) or obese (age = 24 ± 2, BMI = 32.39 ± 4.78), were exposed to a cell phone (1) close to the heart in silent mode, no ringing or vibrating; (2) close to the heart in ring and vibration mode; (3) next to the ear (brain) while listening; and (4) next to the ear while listening and speaking. RESULTS: The average basal HR of obese students significantly increased, while the PR interval; time domains, including standard deviation (SD) of all normal R-R intervals (SDNN), mean of the SD of all normal R-R intervals (SDNNi), SD of the average of normal R-R intervals (SDANN), and percentage of R-R intervals at least 50 ms different from the previous interval (pNN50); and high-power frequency (HF) decreased. The LF/HF ratio also significantly increased. The SDNN, SDNNi, SDANN, pNN50, and HF levels significantly decreased and the LF/HF significantly increased in normal-weight and obese individuals only when the phone was near the apex of the heart in ring and vibration mode. All changes were more profound in obese students. CONCLUSION: Keeping the phone in a chest pocket reduced the HRV of normal-weight and obese medical students and exaggerated the effect of obesity on sympathetic activation. ncbi.nlm.nih.gov

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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 typeother

Effect directionharm

PopulationNormotensive normal-weight and obese medical student volunteers

Sample size20

ExposureRF

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In obese students, average basal heart rate increased and PR interval, multiple HRV time-domain measures (SDNN, SDNNi, SDANN, pNN50), and HF decreased, while LF/HF increased. In both normal-weight and obese students, SDNN, SDNNi, SDANN, pNN50, and HF decreased and LF/HF increased only when the phone was near the apex of the heart in ring and vibration mode; changes were more pronounced in obese students.

Outcomes measured

electrocardiogram measures (e.g., PR interval)
heart rate (HR)
heart rate variability (HRV) time-domain measures (SDNN, SDNNi, SDANN, pNN50)
HRV frequency-domain measures (HF, LF/HF ratio)

Limitations

Small sample size (n=20)
Frequency/SAR and exposure duration not reported in the abstract

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Normotensive normal-weight and obese medical student volunteers",
  "sample_size": 20,
  "outcomes": [
    "electrocardiogram measures (e.g., PR interval)",
    "heart rate (HR)",
    "heart rate variability (HRV) time-domain measures (SDNN, SDNNi, SDANN, pNN50)",
    "HRV frequency-domain measures (HF, LF/HF ratio)"
  ],
  "main_findings": "In obese students, average basal heart rate increased and PR interval, multiple HRV time-domain measures (SDNN, SDNNi, SDANN, pNN50), and HF decreased, while LF/HF increased. In both normal-weight and obese students, SDNN, SDNNi, SDANN, pNN50, and HF decreased and LF/HF increased only when the phone was near the apex of the heart in ring and vibration mode; changes were more pronounced in obese students.",
  "effect_direction": "harm",
  "limitations": [
    "Small sample size (n=20)",
    "Frequency/SAR and exposure duration not reported in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "radiofrequency electromagnetic field",
    "RF-EM",
    "cell phone",
    "mobile phone",
    "heart rate variability",
    "HRV",
    "electrocardiogram",
    "ECG",
    "obesity",
    "sympathetic activation",
    "medical students"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones",
      "weight": 0.9,
      "reason": "Study evaluates RF-EM exposure from a cell phone and cardiovascular/HRV outcomes."
    }
  ]
}

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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: 10.1016/j.explore.2020.02.006
PubMed: Not supplied

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