Thyroid dysfunction and electrocardiographic changes in subjects without arrhythmias: a cross-sectional study of primary healthcare subjects from Copenhagen oleh Gunnar Hilmar Gislason, Jonas Bille Nielsen, Claus Graff, Kristian Hay Kragholm, Adrian Holger Pietersen, Bhupendar Tayal, Christian Selmer, Magnus Kihlstrom, Anne-Marie Schjerning Olsen, Anders G Holst, Peter Søgaard, Christine Benn Christiansen, Steen M Hansen