Multiple sclerosis and environmental risk factors: a case-control study in Iran

2017 · Harm · Low evidence

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HarmLow evidencePaper 2353

In this Iranian case-control study (660 MS cases, 421 controls), microwave exposure was reported more often in the MS group and was associated with higher odds of MS (adjusted OR = 3.55, 95% CI 2.24–5.63; P ≤ 0.001). The excerpt notes 44.3% of MS cases used a…

Study snapshot

Publicationmanual · 2017

Study typecase_control

Reported directionHarm

Evidence ratingLow

Abstract

Multiple sclerosis and environmental risk factors: a case-control study in Iran Abbasi M, Nabavi SM, Fereshtehnejad SM, Jou NZ, Ansari I, Shayegannejad V, Mohammadianinejad SE, Farhoudi M, Noorian A, Razazian N, Abedini M, Faraji F. Multiple sclerosis and environmental risk factors: a case-control study in Iran. Neurol Sci. 2017 Aug 10. doi: 10.1007/s10072-017-3080-9. Abstract Studies have shown an increase in the incidence of MS in Iran. The aim of our study was to evaluate the relationship between environmental exposure and MS in Iran. This case-control study was conducted on 660 MS patients and 421 controls. Many environmental factors are compared between the two groups. Our findings demonstrated that prematurity ([OR = 4.99 (95% CI 1.34-18.68), P = 0.017]), history of measles and mumps ([OR = 1.60 (95% CI 1.05-2.45), P = 0.029; OR = 1.85 (95% CI 1.22-2.78), P = 0.003, respectively]), breast feeding [OR = 2.90 (95% CI 1.49-5.65), P = 0.002], head trauma in childhood ([OR = 8.21 (95% CI 1.56-43.06), P = 0.013]), vaccination in adulthood ([OR = 4.57 (95% CI 1.14-18.41), P = 0.032, respectively]), migraine ([OR = 3.50 (95% CI 1.61-7.59), P = 0.002]), family history of MS, IBD, migraine, and collagen vascular diseases ([OR = 2.73 (95% CI 1.56-4.78), P < 0.001], [OR = 3.14 (95% CI 1.460-6.78), P = 0.004; OR = 3.18 (95% CI 1.83-5.53), P < 0.001; OR = 1.81 (95% CI 1.03-3.20), P = 0.040, respectively]), stressful events ([OR = 32.57 (95% CI 17.21-61.64), P < 0.001]), and microwave exposure ([OR = 3.55 (95% CI 2.24-5.63), P ≤0.001]) were more in the MS group. Sun exposure ([OR = 0.09 (95% CI 0.02-0.38), P = 0.001]), dairy and calcium consumption ([OR = 0.44 (95% CI 0.27-0.71), P = 0.001]), diabetes mellitus ([OR = 0.11 (95% CI 0.01-00.99), P = 0.049], and complete vaccination during childhood appeared to decreased MS risk. Our results investigated many risk factors and protective factors in Iran. ncbi.nlm.nih.gov Excerpts [44.3% of the MS cases used a microwave oven more than 3 times a week compared to 19.9% of the controls (adjusted OR = 3.55, 95% CI= 2.24 - 5.63)]. Conclusions It seems that the increase in MS prevalence is due to environmental factors. As a result of disability and high cost, prevention of environmental risk factors is important. The result demonstrated that the most modifiable risk factors in Iranian population were stressful event and microwave exposure. Also, the most protective modifiable factors were sun exposure and calcium supplement consumption. However, more studies are required to evaluate the potential risk factors in a geographical area such as Iran with increasing prevalence in MS.

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 typecase_control

Effect directionharm

PopulationMS patients and controls in Iran

Sample size1081

Exposuremicrowave

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Outcomes measured

Multiple sclerosis (MS) risk/association

Limitations

Observational case-control design (cannot establish causality)
Exposure assessment details (e.g., measurement method, timing, intensity) not described in the provided abstract
Potential confounding and recall bias not addressed in the provided abstract

View raw extracted JSON

{
  "study_type": "case_control",
  "exposure": {
    "band": "microwave",
    "source": "microwave oven use",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "MS patients and controls in Iran",
  "sample_size": 1081,
  "outcomes": [
    "Multiple sclerosis (MS) risk/association"
  ],
  "main_findings": "In this Iranian case-control study (660 MS cases, 421 controls), microwave exposure was reported more often in the MS group and was associated with higher odds of MS (adjusted OR = 3.55, 95% CI 2.24–5.63; P ≤ 0.001). The excerpt notes 44.3% of MS cases used a microwave oven >3 times/week vs 19.9% of controls.",
  "effect_direction": "harm",
  "limitations": [
    "Observational case-control design (cannot establish causality)",
    "Exposure assessment details (e.g., measurement method, timing, intensity) not described in the provided abstract",
    "Potential confounding and recall bias not addressed in the provided abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "multiple sclerosis",
    "Iran",
    "case-control",
    "environmental risk factors",
    "microwave exposure",
    "microwave oven",
    "odds ratio"
  ],
  "suggested_hubs": [
    {
      "slug": "rf-health",
      "weight": 0.6,
      "reason": "Reports an association between microwave exposure (microwave oven use) and MS in a case-control study."
    }
  ]
}

AI can be wrong. Always verify against the paper.

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: 10.1007/s10072-017-3080-9
PubMed: Not supplied

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