PCSK9 and diabetes mellitus: A recent MR study using genetic variants for proprotein convertase subtilisin-kexin type 9 (PCSK9) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), that mimic the effects of lowering LDL-C levels, showed an increased risk of diabetes with lower LDL-C.