The Claim

Serum IGF-1 levels in healthy Korean men aged 19–40 years are significantly higher in winter and spring compared to autumn, with mean concentrations of 237.4 ng/mL in winter versus 168.5 ng/mL in autumn, suggesting a seasonal association with ambient temperature that may influence growth hormone activity.

Source: Serum IGF-1 and IGFBP-3 levels in healthy Korean men aged 19–40 years: a cross-sectional analysis of reference ranges and seasonal variation

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
44score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

In young Korean men, the level of a growth-related hormone in the blood tends to be higher during winter and spring than in autumn, and this might be linked to changes in the weather.

See the scientific wording

Serum IGF-1 levels in healthy Korean men aged 19–40 years are significantly higher in winter and spring compared to autumn, with mean concentrations of 237.4 ng/mL in winter versus 168.5 ng/mL in autumn, suggesting a seasonal association with ambient temperature that may influence growth hormone activity.

What the research says

1 study
  1. Study: Serum IGF-1 and IGFBP-3 levels in healthy Korean men aged 19–40 years: a cross-sectional analysis of reference ranges and seasonal variation

    This study found that young Korean men have more IGF-1 (a growth-related hormone) in winter and spring than in autumn, which matches the claim. It suggests that seasons — maybe because of colder weather — affect this hormone.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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