Impact of the number of office visits on diagnosing hypertension phenotypes in young individuals

Objective: To investigate the impact of measuring office blood pressure (BP) in an increasing number of visits on diagnosing hypertension phenotypes in young individuals. Design and method: Young individuals referred for elevated BP and healthy volunteers aged 6-25 years were evaluated with office BP measurements (3 visits; triplicate measurements; average of the last 2) and 24-hour ambulatory BP monitoring (ABP). Normotension (NT) was defined as normal office and ABP; Sustained hypertension (HT) as elevated office and ABP; White-coat hypertension (WCH) as elevated office but normal ABP; Masked hypertension (MH) as normal office with elevated ABP. Results: Analysis included 273 individuals (mean age 13.9±3.8 years, 69.6% males, BMI 24.6±4.8 kg/m 2 ). Average office BP at 1st visit was 122.0±16.4/72.9±10.7 mmHg, systolic/diastolic, average of first 2 visits 120.6±15.4/72.3±10.2 and average of 3 visits 119.8±15.1/72.0±9.7 mmHg. The prevalence of NT, HT, MH and WCH was: 1st visit 55/17/8/20% respectively; average of first 2 visits 61/16/10/13%; average of 3 visits 63/15/11/11% respectively. The agreement between the 1st and the average of 1st-2nd visit was 92% for NT diagnosis (kappa = 0.83), 98% for HT (kappa = 0.92), 98% (kappa = 0.87) for MH and 92% for WCH (kappa = 0.70). The agreement between the 1st visit and the average of all 3 visits was 91% for NT (kappa = 0.81), 97% for HT (kappa = 0.89), 97% for MH (kappa = 0.83) and 91% for WCH (kappa = 0.64). Last, the agreement between ABP and office BP measurements for BP elevation was 72% for the 1st visit (kappa = 0.35), 77% for the average of the 1st-2nd visit (kappa = 0.41) and 78% for the average of 3 visits (kappa = 0.44). Conclusions: These findings suggest that in young individuals at least 2 office visits are required for optimal office BP evaluation which has reasonable agreement with ABP.