Identification of Normal Blood Pressure in Different Age Group

The concept of using single criterion of normal blood pressure with systolic blood pressure (SBP) < 140 mmHg and diastolic blood pressure (DBP) < 90 mmHg for all ages is still disputable. The aim of the study is to identify the cutoff value of normotension in different age and sex groups. Totally, 127,922 (63,724 men and 64,198 women) were enrolled for the analysis. Finally, four fifths of them were randomly selected as the study group and the other one fifths as the validation group. Due the tight relationship with comorbidities from cardiovascular disease (CVD), metabolic syndrome (MetS) was used as a surrogate to replace the actual cardiovascular outcomes in the younger subjects. For SBP, MetS predicted by our equation had a sensitivity of 55% and specificity of 67% in males and 65%, 83% in females, respectively. At the same time, they are 61%, 73% in males and 73%, 86% in females for DBP, respectively. These sensitivity, specificity, odds ratio, and area under the receiver operating characteristic curve from our equations are all better than those derived from the criteria of 140/90 or 130/85 mmHg in both genders. By using the presence of MetS as the surrogate of CVD, the regression equations between SBP, DBP, and age were built in both genders. These new criteria are proved to have better sensitivity and specificity for MetS than either 140/90 or 130/85 mmHg. These simple equations should be used in clinical settings for early prevention of CVD.