1. From the Department of Medical Gerontology, The Irish Longitudinal Study on Ageing (TILDA), Lincoln Gate, Trinity College, Dublin, Ireland (E.J.L., T.M., A.M.O., D.C., C.O., R.A.K.)
2. Department of Biochemistry, St James’s Hospital, Dublin, Ireland (M.H.)
3. School of Medicine, Trinity College Dublin, Ireland (A.M.M.)
4. Mercer’s Institute for Successful Ageing, St James’s Hospital, Dublin, Ireland (K.M., R.A.K.).