GWAS Central has released over 500 additional studies that have been submitted directly by researchers and imported from the NHGRI-EBI GWAS Catalog.
This update is accompanised with a meta-data file available for use in data citation research, tracking researcher contributions, and data discovery projects. See http://help.gwascentral.org/data/gwas-central-study-meta-data/ for more details and to gain access to the August 2019 meta-data release.