Classification of hypertension of study subjects Classification Hypertension Tien Lang An Lao Vinh Bao Chung n% n% n% n% Optimal and normal 24 4, 1 32 5, 6 38 6, 7 94 5, 5 High normal 48 8, 3 35 6, 1 30 5, 3 113 6, 6 Grade 1 hypertension 326 56, 2 265 46, 4 283 49, 8 874 50, 8 Grade 2 hypertension 110 19, 0 169 29, 6 153 26, 9 432 25, 1 Grade 3 hypertension 72 12, 4 70 12, 3 64 11, 3 206 12, 0 Total 580 100 571 100 568 100 1.719 100 SBP ± SD 150, 6 ± 15, 8 152, 4 ± 18, 7 149, 9 ± 16, 8 151, 0 ± 17, 2 p 0, 003 DBP: ± SD 88, 8 ± 10, 9 89, 1 ± 10, 5 92, 6 ± 11, 1 90, 2 ± 10, 9 p 0, 545 Remarks: 50, 8% patient with Grade 1 hypertension, Grade 2 hypertension, Grade 3 hypertension respectively: 25, 1% and 12, 0%.