The association between clock gene polymorphisms and type 2 diabetes: A systematic review and meta-analysis
Abstract
Background: Misalignment of the endogenous circadian system may contribute to the risk of type 2 diabetes. This systematic review and meta-analysis examined the association between clock gene polymorphisms and glycemic parameters and type 2 diabetes.
Methods: Embase, Medline, and Web of Science databases were searched from inception to August 20, 2024. Empirical studies examining the association between core clock gene polymorphisms and type 2 diabetes and glycemic parameters, and studies examining non-core clock genes with information on environmental factors were included. A multi-level meta-analytical approach was used, and a weighted odds ratio was reported (PROSPERO, CRD42022337706).
Results: In total, 37 studies comprising 535,063 participants were included. CRY2 was associated with higher fasting blood glucose (OR: 1.07, 95 % CI: 1.03-1.11) and impaired glucose tolerance (OR: 1.02, CI: 1.00-1.04). Polymorphisms in MTNR1B were associated with a greater risk of type 2 diabetes. CLOCK was associated with lower risk of type 2 diabetes (OR: 0.94, CI: 0.89-1.00), and PER3 was associated with lower fasting insulin (OR: 0.94, CI: 0.91-0.97) and lower risk of insulin resistance (OR: 0.92, CI: 0.88-0.95). These associations reflect pooled variant-level effects within genes, and the effects of certain variants were modified by diet, alcohol consumption, physical activity, sleep, and length of daylight.
Conclusions: Specific polymorphisms in circadian genes, including CRY2,…
How strong is the evidence?
Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 535,063 participants or records.
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