Mutations in a gene targeted by a new wave of medicines for lowering cholesterol levels may protect against heart attacks, but perhaps also increase the risk of diabetes.

Drugs that inhibit a protein called PCSK9 lower cholesterol, but have not yet been shown definitively to reduce the risk of heart disease. Brian Ference of Wayne State University School of Medicine in Detroit, Michigan, and his colleagues, gathered data from 112,772 participants in 14 studies, focusing on DNA sequence variants that are associated with lowered cholesterol. The variants were in the PCSK9 gene and in HMGCR, which encodes the target of commonly used statin drugs.

Variants in both genes were associated with nearly equal protection from cardiovascular events such as heart attacks, and this effect seemed to be additive. The results suggest that drugs targeting PCSK9 could improve heart health, and may work together with statins for even greater benefit. The increased risk of diabetes seems to be limited to certain patients, the authors say.

N. Engl. J. Med. 375, 2144–2153 (2016)