Different types of blood pressure variability in hypertensive patients with chronic lower airway diseases

Abstract

In hypertensive patients, blood pressure variability (BPV) and comorbidity are associated with prognosis. However, there have been no complex prospective studies of BPV in patients with hypertension and chronic lower airway diseases (CLAD). Aim. To investigate specific features of different BPV types and their prognostic value in hypertensive patients with and without CLAD in a prospective study. Material and methods. This prospective cohort study included hypertensive patients, approximately half of whom had asthma or chronic obstructive pulmonary disease (COPD). Clinic blood pressure (BP) measurements, ambulatory and home BP monitoring (ABPM, HBPM), spirometry, clinical blood analysis and blood chemistry, and a standard questionnaire and physical examination were performed at baseline and 12 months later. Clinical BP measurements and HBPM were also repeated 6 months after the baseline visit. At 12 months from the last study visit, we collected the information about cardiovascular complications and deaths. Statistical methods included ANOVA and survival analysis. The BPV indices were calculated as SD for different time periods, ARV (average real variability), and VIM (variation independent of mean). The inter-group comparisons were adjusted for age and sex. The assessment of intra-visit and long-term BPV was based on clinical BP measurement. The assessment of 24-hour BPV and mid-term BPV was based on ABPM and HBPM, respectively. Results. The BPV levels, assessed by ABPM and HBPM, were higher in patients with CLAD. There were no long-term BPV differences between two groups, in according to clinical BP data. Higher levels of daytime BPV were associated with orthostatic systolic BP, baseline forced expiratory volume in 1 second (FEV 1 ), and glomerular filtration rate (GFR). An increase in nighttime BPV was associated with COPD, serum creatinine, FEV 1 after β 2 -agonist inhalation, and GFR. In the CLAD group, the cumulative survival was lower, while the total risk was higher. The following endpoint predictors were identified: supraventricular arrhythmias, SD of nighttime diastolic BP, blood leukocyte count and nocturnal BP fall (Wald Chi-Square 14.780-4.257; p<0.0001-0.026). Conclusion. The main BPV indices are higher in patients with asthma and COPD, in comparison with CLAD-free hypertensive patients. ABPM is the most reliable method of BPV assessment in hypertensive patients with CLAD, according to our data. The increase in BPV is associated with irreversible airway obstruction and renal function. Adverse outcomes were associated with both nighttime BPV and nocturnal BP fall, as well as with rhythm disorders and leukocyte count as a marker of systemic inflammation. BPV in patients with CLAD warrants further investigation.