Uncomplicated hypertension was associated with altered respiratory pattern variability during supine wakefulness, driven by more frequent periodic behavior and hypopneas.
Case-Control (n=218)
Is uncomplicated hypertension associated with altered wakeful respiratory pattern variability compared to healthy subjects?
Uncomplicated hypertension is associated with altered respiratory pattern variability during supine wakefulness, suggesting early respiratory control changes that are partly independent of obesity.
Objective: Studies on cardiovascular regulation in hypertension usually focus on blood pressure and heart rate levels and variability. Respiration, although fundamental, is comparatively understudied as a potential mechanism underlying development and progression of cardiovascular disease. We tested the hypothesis that alterations in the respiratory pattern during supine wakefulness are associated with hypertension in patients without overt cardiovascular complications, including heart failure. Design and method: The study included 135 hypertensive patients without overt cardiovascular complications (52±11 years; 78 male; HTN group) and 83 healthy subjects (51±11 years; 37 male; CON). In each subject twenty-minute recording of respiratory pattern was performed in the supine position with a respiratory belt and transducer (TN1132/ST, ADInstruments). Respiratory variability was assessed using conventional indices and novel measures designed to quantify respiratory pattern periodicity and irregularity. Among others the Hilbert transform was applied to estimate the envelope of the respiratory signal, which was subsequently presented as an Argand diagram and quantified using numeric parameters. We also evaluated parameters derived from spectral analysis of the respiratory signal's envelope. Results: There were no significant differences between HTN and CON in mean respiratory frequency, phase durations, or respiratory amplitude, nor in standard linear/non-linear variability measures of these parameters. In contrast, HTN patients showed altered respiratory pattern variability, driven mainly by more frequent periodic behavior. Furthermore, HTN patients presented a higher number of hypopneas per minute and a lower frequency of sighs followed by post-sigh apnea. Respiratory pattern variability was altered in hypertensive patients and the association persisted after adjustment for sex and obesity status, suggesting a respiratory phenotype at least partly independent of obesity. Nevertheless, when BMI was analyzed as a continuous variable in univariable logistic models, BMI showed low-to-modest correlations with respiratory pattern variability and modest correlations with model deviance residuals (r∼0.26–0.29). Conclusions: In supine wakefulness, hypertension is associated with altered respiratory pattern variability quantified using advanced pattern metrics of periodicity and irregularity, suggesting that respiratory control changes may emerge early in hypertension and may contribute to its progression. The findings suggest a respiratory phenotype partly independent of obesity, with BMI contributing additional hypertension-related effects.
Graff et al. (2026) conducted a case-control in Hypertension (n=218). Hypertension vs. Healthy subjects was evaluated on Respiratory pattern variability (periodicity and irregularity). Uncomplicated hypertension was associated with altered respiratory pattern variability during supine wakefulness, driven by more frequent periodic behavior and hypopneas.