Serum Levels of Human MIC-1/GDF15 Vary in a Diurnal Pattern, Do Not Display a Profile Suggestive of a Satiety Factor and Are Related to BMI.
Level 4 - case-series / case-control
Observational monozygotic twin correlation and physiological profiling study
PubMed 26207898 · doi:10.1371/journal.pone.0133362
What was done
Researchers measured circulating serum MIC-1/GDF15 over a 24-hour period to assess diurnal variation and responses to food intake. They also evaluated whether within-pair differences in serum MIC-1/GDF15 concentrations correlated with within-pair differences in BMI in human monozygotic twin pairs.
What was found
Serum MIC-1/GDF15 exhibited a bimodal diurnal variation altering levels by approximately ±10% from the mesor. Levels changed slightly after a meal, consistent with diurnal background fluctuations rather than an acute meal response. Within monozygotic twin pairs, differences in serum MIC-1/GDF15 significantly correlated with differences in BMI (numerical correlation statistics and sample size were not reported in the abstract).
Why it matters
The results indicate that GDF15 is involved in long-term energy homeostasis and body mass regulation in humans rather than acting as a short-term postprandial satiety factor.
Limits
The abstract does not state the sample size, participant demographics, exact correlation values, or p-values. The cross-sectional observational twin design cannot prove causality between GDF15 levels and BMI.
Cited by
- supports Circulating GDF15 levels increase progressively over the course of the day.