Temporal variation in circulating GDF15 over 24 h in healthy young males

Area of Science:

• Endocrinology
• Metabolism
• Chronobiology

Background:

• Growth Differentiation Factor 15 (GDF15) has diverse functions, including roles in metabolism, cell survival, immune response, and appetite regulation.
• Previous studies suggested temporal variations in GDF15 over 24 hours, but these were conducted under specific conditions (fasting or overfeeding).

Purpose of the Study:

• To investigate the presence and characteristics of a 24-hour rhythm in plasma GDF15 concentrations in healthy young men under normal daily life conditions.

Main Methods:

• Twenty-two healthy young men participated in a 24-hour study with blood sampling every three hours.
• Plasma GDF15 concentrations were analyzed using cosinor rhythmometry and repeated measures ANOVA.

Main Results:

• Overall cosinor analysis did not reveal a statistically significant 24-hour rhythm for GDF15 in the full cohort (p=0.0944).
• However, ANOVA indicated a significant, albeit modest, effect of time on plasma GDF15 concentrations (p<0.001).
• Exploratory analysis of a subgroup suggested potential modest rhythmic fluctuations in some individuals.

Conclusions:

• The study did not provide definitive evidence for a consistent 24-hour rhythm of GDF15 in healthy young men.
• Post hoc findings suggest that some individuals might exhibit modest daily fluctuations, warranting further investigation.
• Larger studies are required to confirm these observations and elucidate the clinical significance of GDF15 temporal variations.