Electromagnetic fields promote severe and unique vascular calcification in an animal model of ectopic calcification.

Abstract

BACKGROUND: The effects of electromagnetic fields (EMFs) on cardiovascular calcification is unknown. We sought to evaluate the effects of EMF on vascular calcification in normal rats and in rats with chronic kidney disease (CKD) - a condition which promotes calcification. METHODS: We used four groups of rats: group 1 - exposed to EMF, group 2 - not exposed to EMF, group 3 - rats with CKD exposed to EMF, group 4 - rats with CKD not exposed to EMF. In order to induce CKD, groups 3 and 4 rats were fed with a uremia-inducing diet. Groups 1 and 3 rats were continuously exposed to EMF using a system similar to an electrical transformer, which consists of a primary coil, a ferrite ring, and a secondary coil. The system transmitter emitted a series of exponentially decaying electromagnetic sine waves (continuous exposure with pulsed peaks) in randomly selected frequencies between 150 and 155 kHz, with random exposure intensities between 4 and 7 mG. Clinical investigations included multislice computed tomography of the aortic roots. Pathological examinations of the aortas included histological characterization, and antigen expression analyses. RESULTS: No calcification was found in either group of rats with normal kidney function. Aortic root calcification was significantly higher in rats exposed to EMF (group 3) compared with group 4 rats - with a mean Agatston score of 138 ± 25 vs. 80 ± 20 respectively (p<0.05). Pathological examination showed massive aortic calcification in group 3 rats. The calcification pattern was unique as it formed circular rings along the length of the aortic media. Although increased calcification was noticed in group 3 rats, antigen expression of osteoblast markers was significantly decreased in group 3 compared with group 4. CONCLUSIONS: EMF exposure may have potential harmful effects on the cardiovascular system, as it promotes severe vascular calcification in CKD miliue.

AI evidence extraction

Main findings

No calcification was found in rats with normal kidney function regardless of EMF exposure. In CKD rats, aortic root calcification was significantly higher with EMF exposure versus no EMF (mean Agatston score 138 ± 25 vs 80 ± 20; p<0.05), with massive and unique ring-like calcification along the aortic media on pathology; osteoblast marker antigen expression was significantly decreased in EMF-exposed CKD rats compared with unexposed CKD rats.

Outcomes measured

• Aortic root/aortic calcification (multislice CT; Agatston score)
• Histological characterization of aortic calcification pattern
• Antigen expression of osteoblast markers

Limitations

• Sample size not reported in abstract
• Animal model; generalizability to humans is uncertain
• Exposure described in mG with randomly selected frequencies/intensities; dosimetry beyond this (e.g., SAR) not provided
• Calcification absent in normal rats; effect observed only in CKD model

Suggested hubs

• occupational-exposure (0.25)
  Exposure system described as similar to an electrical transformer; could relate to transformer-like EMF sources, though setting is experimental.

{
    "study_type": "animal",
    "exposure": {
        "band": "unknown",
        "source": "other",
        "frequency_mhz": 0.1499999999999999944488848768742172978818416595458984375,
        "sar_wkg": null,
        "duration": "continuous exposure with pulsed peaks"
    },
    "population": "Rats (normal kidney function and chronic kidney disease model)",
    "sample_size": null,
    "outcomes": [
        "Aortic root/aortic calcification (multislice CT; Agatston score)",
        "Histological characterization of aortic calcification pattern",
        "Antigen expression of osteoblast markers"
    ],
    "main_findings": "No calcification was found in rats with normal kidney function regardless of EMF exposure. In CKD rats, aortic root calcification was significantly higher with EMF exposure versus no EMF (mean Agatston score 138 ± 25 vs 80 ± 20; p<0.05), with massive and unique ring-like calcification along the aortic media on pathology; osteoblast marker antigen expression was significantly decreased in EMF-exposed CKD rats compared with unexposed CKD rats.",
    "effect_direction": "harm",
    "limitations": [
        "Sample size not reported in abstract",
        "Animal model; generalizability to humans is uncertain",
        "Exposure described in mG with randomly selected frequencies/intensities; dosimetry beyond this (e.g., SAR) not provided",
        "Calcification absent in normal rats; effect observed only in CKD model"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "electromagnetic fields",
        "EMF",
        "vascular calcification",
        "aortic calcification",
        "chronic kidney disease",
        "rat model",
        "150-155 kHz",
        "milligauss",
        "Agatston score",
        "computed tomography",
        "histology",
        "osteoblast markers"
    ],
    "suggested_hubs": [
        {
            "slug": "occupational-exposure",
            "weight": 0.25,
            "reason": "Exposure system described as similar to an electrical transformer; could relate to transformer-like EMF sources, though setting is experimental."
        }
    ]
}

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