IGF-1: what your result means.

A growth-factor hormone reflecting growth hormone activity and tissue repair capacity. IGF-1 is measured by blood test as part of the Hormonal panel in the HodieLabs Health Blueprint.

Why IGF-1 matters

IGF-1 reflects growth hormone (GH) activity. It is the primary effector of the GH-IGF axis. Declines naturally with age (~14% per decade after 30); age-adjusted reference ranges are essential.

Associated risks when out of range: Low IGF-1 is associated with frailty, sarcopenia, and cognitive decline. Very high IGF-1 may promote cancer cell proliferation. The longevity paradox: moderate levels seem optimal, neither too high nor too low.

What the clinical evidence shows

The evidence base behind how the HodieLabs Evidence-Based Clinical Library interprets IGF-1, from randomised trials, prospective cohorts and genetic (Mendelian randomisation) studies. Full citations in the reference list below.

• Dose-response meta-analysis (Burgers et al. JCEM 2011): IGF-1 showed a U-shaped relationship with mortality, both low and high levels associated with increased risk, which is why evidence-based interpretation targets the mid-range rather than 'more is better'.

Evidence-based reference ranges

The HodieLabs Evidence-Based Clinical Library interprets IGF-1 against published clinical authority standards, never arbitrary "optimal" ranges. Measured in nmol/L or ng/mL (lab dependent):

Clinical interpretation

• IGF-1 reflects growth hormone (GH) activity. It is the primary effector of the GH-IGF axis.
• Declines naturally with age (~14% per decade after 30); age-adjusted reference ranges are essential.
• Observational data suggests mid-range IGF-1 for age may be associated with the best outcomes. Both extremes are associated with increased mortality in some cohorts. This is an observational finding, not a guideline-endorsed target.

What improves it: the evidence-based levers

• Protein/training optimisation
• Clinical interpretation in context

Recommended testing frequency: Annual, as part of a comprehensive panel. Single markers are always interpreted in context.

How IGF-1 testing works at HodieLabs

IGF-1 is measured in every Health Blueprint at our Melbourne Preventative Health & Longevity Clinic, interpreted by a doctor against the guideline-cited ranges above and tracked over time through your HodieLabs membership.

References

1. Burgers AM, et al. Meta-analysis and dose-response metaregression: circulating insulin-like growth factor I (IGF-I) and mortality. J Clin Endocrinol Metab. 2011;96:2912–2920.

This page is general information from the HodieLabs Evidence-Based Clinical Library, not medical advice. Speak with your GP about what testing and care is appropriate for you.