Genetically elevated gamma-glutamyltransferase and Alzheimer's disease.

"Declarations of interest None."

"Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Dr. Setor Kunutsor acknowledges support from the NIHR Biomedical Research Centre at the University Hospitals Bristol NHS Foundation Trust and the University of Bristol. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health. Dr. Stephen Burgess is supported by a Sir Henry Dale Fellowship jointly funded by the Wellcome Trust and the Royal Society (Grant Number 204623/Z/16/Z) and by core funding to the Medical Research Council Biostatistics Unit (MC_UU_00002/7)."