[1] Univ Calgary, Med, Calgary, AB T2N 1N4, Canada
[2] BHF Glasgow Cardiovasc Res Ctr, Inst Cardiovasc & Med Sci, Glasgow, Lanark, Scotland
[3] Med Univ S Carolina, Biometry & Epidemiol, Charleston, SC 29425 USA
[4] World Hypertens League, Corvallis, MT 59828 USA