1. From St Michael’s Hospital Health Sciences Research Centre, Toronto (R.A.H., F.S., P.W.C.); Departments of Medicine (R.A.H., P.W.C., B.Z.), Clinical Biochemistry (R.A.H., P.W.C.), and Biochemistry (P.W.C.), University of Toronto; Thames Valley Family Practice Research Unit, University of Western Ontario, London (S.B.H.); and Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto (A.J.G.H., B.Z.), Ontario, Canada.