Prevalence and clinical characteristics of isolated systolic hypertension in young: analysis of 24 h ambulatory blood pressure monitoring database

Isolated systolic hypertension (ISHT) is common in elderly patients, whilst its prevalence and clinical impact in young adults are still debated. We aimed to estimate prevalence and clinical characteristics of ISHT and to evaluate out-of-office BP levels and their correlations with office BP in young adults. A single-center, cross-sectional study was conducted at our Hypertension Unit, by including treated and untreated individuals aged 18-50 years, who consecutively underwent home, clinic and 24h ambulatory BP assessment. All BP measurements were performed and BP thresholds were set according to European guidelines: normotension (NT), clinic BP <140/<90mmHg; ISHT, BP ≥140/<90mmHg; isolated diastolic hypertension (IDHT), BP <140/≥90mmHg; systolic-diastolic hypertension (SDHT), BP ≥140/≥90mmHg. European SCORE, vascular and cardiac HMOD were also assessed. From an overall sample of 13,053 records, we selected 2127 young outpatients (44.2% female, age 40.5±7.4 years, BMI 26.7±5.0kg/m2, clinic BP 141.1±16.1/94.1±11.8mmHg, 24h BP 129.0±12.8/82.4±9.8mmHg), among whom 587 (27.6%) had NT, 391 (18.4%) IDHT, 144 (6.8%) ISHT, and 1005 (47.2%) SDHT. Patients with ISHT were predominantly male (61.1%), younger and with higher BMI compared to other groups. They also showed higher home and 24h ambulatory SBP levels than those with NT or IDHT (P<0.001), though similar to those with SDHT. ISHT patients showed significantly higher pulse pressure (PP) levels than other groups, at all BP measurements (P<0.001 for all comparisons), and significantly higher proportion (65.3%) of patients with ISHT had PP >60mmHg. European SCORE resulted significantly higher in patients with ISHT (1.6±2.9%) and SDHT (1.5±2.7%) compared to those with IDHT (0.9±1.5%) or NT (0.8±1.9%) (P=0.017). Though relatively rare, ISHT should be not viewed as a benign condition, being associated with sustained SBP elevation, high European SCORE risk, and vascular HMOD.