Author + information
- 1Department of Cardiology, the Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
- 2Shaanxi Engineering Research Center of Medical and Health BIG DATA, Xi'an Jiaotong University School of Management, Xi'an, China
- 3Department of Emergency Medicine, the Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
Grading of essential hypertension according to blood pressure may not adequately reflect clinical heterogeneity of hypertensive patients. This study was carried out to explore clinical phenotypes in essential hypertensive patients using cluster analysis.
In this cross-sectional study, BP variations of 362 hypertensive patients (195 males and 167 females) were evaluated with ambulatory blood pressure monitoring (ABPM). All other hypertensive patients were excluded if they (1) were <18 or >90 years old; (2) were under antihypertensive treatment; (3) had a BP over 160/100 mmHg; (4) were night workers; (5) had acute stroke or myocardial infarction within the past 6 months; (6) had sleep apnea syndrome; (7) were diagnosed as secondary hypertension; (8) could not tolerate the ABPM; (9) had other chronic diseases. A cluster analysis was performed on BP variations and other baseline clinical variables to identify patient subgroups. After cluster analysis, chi-squared test and analysis of variance (ANOVA) were performed to check the significance of variables between different clusters.
Three clusters were presented here. Cluster 1 (C1, n=143, 40%) has largest number of patients, most of which were male (99%) and most likely to be smokers (57%). They had no diabetes and lowest mean level of high density lipoprotein (1.20mmol/L) while the 24h-diastolic BP (DBP, 81.18mmHg), daytime DBP (82.41mmHg) and night-time DBP (76.82mmHg) were the highest than the other two clusters. C2 (n=131, 36%) were all female, the least likely to be smokers (1.5%) and have no diabetes. In this group, the level of triglyceride (0.95mmol/L) was the lowest while the high density lipoprotein (1.34mmol/L) was the highest. Moreover, patients in C2 had the lowest 24h-systolic BP (SBP, 132.03mmHg), 24h-DBP (75.17mmHg), daytime SBP (133.47mmHg), daytime DBP (76.40mmHg), night-time SBP (126.54mmHg), night-time DBP (70.22mmHg) among the three clusters, respectively. Conversely, C3 (n=88, 24%) were all diabetes and had the highest level of triglyceride (1.02mmol/L). Similarly, 24h-SBP (139.13mmHg), daytime SBP (140.53mmHg) and night-time SBP (135.72mmHg) were the highest compared to the other two groups.
Cluster analysis of diverse variables in essential hypertensive patients identified three different clinical phenotypes. These findings highlight the significant heterogeneity that exists within patients with hypertension and may promote the patient-centered clinical management.