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. 2019 Apr 23;2019(4):CD013315. doi: 10.1002/14651858.CD013315

Ren 2015.

Methods Design: parallel (2 arms)
Country: China
Multisite: no
International: no
Treatment duration: 1 dose
Follow up: 5 days
Rate of ascent (m/h): unclear
Final altitude reached: 3650 m
AMS scale: Lake Louise score
Participants

  1. 61 healthy Chinese adult male and female volunteers residing in Beijing (low altitude, altitude of 20 to 60 meters) for more than 10 years were enrolled in the study.

  2. Exclusion criteria, participants with:

    1. coronary heart disease;

    2. severe hypertension (systolic/diastolic blood pressure higher than 140/90 mmHg);

    3. uncontrolled diabetes (fasting blood glucose higher than 7.0 mmol/L);

    4. anaemia (haemoglobin less than 120 g/L);

    5. bronchial asthma;

    6. chronic obstructive pulmonary disease (COPD);

    7. liver or kidney dysfunction;

    8. history of allergies.

  3. 41 participants were excluded under exclusion criteria

  4. Participants randomized to

    1. Iron group (n = 21, 51.2%)

    2. Placebo group (n = 20, 48.7%)

  5. 2 participants in the ISS group and 1 in the control group abandoned the study for personal reasons. 38 subjects were analysed.

  6. Main characteristics of patients

    1. Age (mean, SD): ISS group = 41.4 ± 8.83; placebo group = 40.6 ± 7.74

    2. Number of men (%): ISS group = 9 (47.4%); placebo group = 9 (47.4%)

    3. Body mass index (mean, SD): ISS group = 25.6 ± 3.42; placebo group = 24.1 ± 3.74
Interventions Iron group (Intervention A) = intravenous iron hydroxide sucrose dose of 200 mg in 100 ml saline (Venofer, Impfstoffwerk Dessau‐Tornau GmbH, Germany), at Day 0
Placebo group (Control group) = 100 ml normal saline at Day 0
Outcomes Primary outcome

  1. Incidence of acute mountain sickness


Secondary outcomes

  1. Blood pressure and heart rate

  2. laboratory indices (oxygen saturation, haemoglobin, serum iron and transferrin saturation)

  3. Adverse events (such as metallic taste, headache, nausea, vomiting, hypotension, parasympathetic nerve stimulation, gastrointestinal dysfunction, muscle pain, fever, varicose veins, or spasm at the infusion site)
Notes

  1. Trial registration: ChiCTR‐TRC‐13003590

  2. Sponsor: this study was supported by grants from the Study of Early Warning and Intervention of Acute Heart and Lung Injury in the Plateau Region

  3. Role of sponsor: financial support

  4. A priori sample size estimation: no

  5. Conducted: not stated

  6. Declared conflicts of interest: yes. No conflicts of interest were identified
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk Insufficient information to score this item as low or high risk of bias
Quote: "this was a perspective, randomized, double‐blinded, placebo controlled study" Page 2051
Allocation concealment (selection bias) Low risk Quote: "each participant was attributed a computer‐generated 4‐digit serial number with the grouping information hidden in the third digit, which was blinded to both participants and researchers" Page 2051
Blinding of participants and personnel (performance bias) 
 All outcomes Low risk Quote: "drug administration was carried out by nurses blinded to the study, and iron supplement and placebo were injected in separate rooms. Intravenous fluids containing drug or saline were labelled with the serial number; because the drug solution was not clear, a brown light‐shading infusion apparatus (Weigao Medical Group, Weihai, China) was used to mask the grouping. Nurses performed injections according to serial number of participants and I.V. fluid labels" Page 2051
Blinding of outcome assessment (detection bias) 
 All outcomes Unclear risk Insufficient information to score this item as low or high risk of bias
Incomplete outcome data (attrition bias) 
 All outcomes Low risk 3 patients were lost at follow‐up (7%)
Selective reporting (reporting bias) Low risk No selective reporting was identified
Other bias Low risk No other biases were identified