Abstract
BACKGROUND: Glucokinase activators (GKAs) are an emerging class of glucose lowering drugs that activate the glucose-sensing enzyme glucokinase (GK). Pending formal cardiovascular outcome trials, we applied two-sample Mendelian randomisation (MR) to investigate the impact of GK activation on risk of cardiovascular diseases. METHODS: We used independent genetic variants in or around the glucokinase gene meanwhile associated with HbA(1c) at genome-wide significance (P < 5 × 10(-8)) in the Meta-Analyses of Glucose and Insulin-related traits Consortium study (N = 146,806; European ancestry) as instrumental variables (IVs) to mimic the effects of GK activation. We assessed the association between genetically proxied GK activation and the risk of coronary artery disease (CAD; 122,733 cases and 424,528 controls), peripheral arterial disease (PAD; 7098 cases and 206,541 controls), stroke (40,585 cases and 406,111 controls) and heart failure (HF; 47,309 cases and 930,014 controls), using genome-wide association study summary statistics of these outcomes in Europeans. We compared the effect estimates of genetically proxied GK activation with estimates of genetically proxied lower HbA(1c) on the same outcomes. We repeated our MR analyses in East Asians as validation. RESULTS: Genetically proxied GK activation was associated with reduced risk of CAD (OR 0.38 per 1% lower HbA(1c), 95% CI 0.29-0.51, P = 8.77 × 10(-11)) and HF (OR 0.54 per 1% lower HbA(1c), 95% CI 0.41-0.73, P = 3.55 × 10(-5)). The genetically proxied protective effects of GKA on CAD and HF exceeded those due to non-targeted HbA(1c) lowering. There was no causal relationship between genetically proxied GK activation and risk of PAD or stroke. The estimates in sensitivity analyses and in East Asians were generally consistent. CONCLUSIONS: GKAs may protect against CAD and HF which needs confirmation by long-term clinical trials.