Increased colorectal cancer risk in prediabetes: A meta-analysis

Previous research yielded conflicting results regarding the association between prediabetes and colorectal cancer (CRC).

To systematically assess the incidence of CRC in individuals with prediabetes compared with individuals with normoglycemia via a meta-analysis.

Relevant cohort studies were acquired by searching MEDLINE, Web of Science, and EMBASE. A random-effects model was applied to combine the findings after accounting for heterogeneity. Several subgroup analyses were conducted to assess the impact of study characteristics on the results.

Eleven cohort studies involving 4996352 participants, including 383917 (7.7%) with prediabetes at baseline, were analyzed in this meta-analysis. Over a mean follow-up period of 6.5 years, the combined findings revealed that individuals with prediabetes at baseline had a higher likelihood of developing CRC than those with normoglycemia [risk ratio (RR) = 1.18, 95% confidence interval = 1.11 to 1.25, P < 0.001] with low statistical heterogeneity (I ² = 27%). Subgroup analyses indicated that the association between prediabetes and an increased risk of CRC was mainly observed in studies defining prediabetes using impaired fasting glucose (RR = 1.24) and slightly elevated hemoglobin A1c levels (RR = 1.18) but not in those that defined prediabetes using impaired glucose tolerance (RR = 1.06). Other study characteristics such as design, country, participant age and sex, the duration of follow-up, or adjustment for body mass index did not significantly impact the results (all P > 0.05).

People with prediabetes might have a higher likelihood of developing CRC than individuals with normoglycemia.