Temporal variation in circulating GDF15 over 24 h in healthy young males.
Level 4 - case-series / case-control
Prospective single-arm physiological study with repeated measures
PubMed 41277741 · doi:10.14814/phy2.70672
What was done
Twenty-two healthy young men were monitored over 24 hours in a controlled setting approximating daily living conditions. Blood samples were drawn every three hours to measure plasma GDF15 levels. Temporal variation was evaluated using cosinor rhythmometry and one-way repeated-measures ANOVA.
What was found
Cosinor rhythmometry of the full cohort (n = 22) did not detect a statistically significant 24-hour rhythm in plasma GDF15 (p = 0.0944), though repeated-measures ANOVA demonstrated a statistically significant modest effect of time across the 24 hours (p < 0.001). An exploratory post hoc cosinor analysis in a subgroup of 14 participants with evening-peaking patterns showed modest rhythmic fluctuations (p = 0.0467). These fluctuations were small compared to normal variations seen in other metabolic hormones or clinical elevations seen in disease states.
Why it matters
This study indicates that 24-hour diurnal fluctuations in GDF15 under normal daily conditions are modest at most. This suggests that time-of-day variations are unlikely to confound clinical interpretations of GDF15 when assessing large pathological changes.
Limits
The study is limited by a small sample size (n = 22) restricted exclusively to young healthy males. Blood sampling frequency was limited to three-hour intervals, which may miss rapid pulsatile variations, and evidence for circadian rhythmicity relied on exploratory post hoc subgrouping.
Cited by
- supports Circulating GDF15 levels increase progressively over the course of the day.