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Updated: Jun 14, 2026
A RAPID Method for Blood Processing to Increase the Yield of Plasma Peptide Levels in Human Blood
Published on: April 28, 2016
Plasma Ghrelin and Risks of Sex-Specific, Site-Specific, and Early-Onset Colorectal Cancer: A Mendelian Randomization
Emma Hazelwood1,2, Catalina Lopez Manzano2, Emma E Vincent1,2,3
1MRC Integrative Epidemiology Unit at the University of Bristol, Bristol, United Kingdom.
Background:
Epidemiological and laboratory-based studies have provided conflicting evidence for a role of ghrelin in colorectal cancer development. We conducted two-sample Mendelian randomization (MR) analyses to evaluate evidence for an association of circulating ghrelin and colorectal cancer risk overall and by sex, cancer subsite, and age at diagnosis.
Methods:
Genetic instruments proxying plasma total ghrelin levels were obtained from a recent genome-wide association study of 54,219 participants. Summary data for colorectal cancer risk were obtained from a recent meta-analysis of several genetic consortia (up to 73,673 cases and 86,854 controls). A two-sample MR approach and several sensitivity analyses were applied.
Results:
We found no evidence for an association of genetically predicted plasma total ghrelin levels and colorectal cancer risk (0.95, 95% confidence interval, 0.81-1.12; R2 of ghrelin genetic instruments: 4.6%), with similarly null results observed when stratified by sex, anatomical subsite, and for early-onset colorectal cancer.
Conclusions:
Our study suggests that plasma ghrelin levels are unlikely to have a causal relationship with overall, early-onset, and sex- and cancer subsite-stratified colorectal cancer risk.
Impact:
This large-scale analysis adds to the growing body of evidence that plasma total ghrelin levels are not associated with colorectal cancer risk.
