Dados do Trabalho

Título

EFFECT OF ACUTE AEROBIC EXERCISE AT DIFERRENT TIMES OF DAY ON CLINIC AND CENTRAL BLOOD PRESSURE IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA

Introdução

Post-aerobic exercise hypotension (PEH) is an important phenomenon with significant clinical implications. Aerobic exercise performed in the morning promotes greater PEH than afternoon in pre-hypertensives. However, whether this occurs in patients with obstructive sleep apnea (OSA), who have a high cardiovascular risk, remains unclear.

Objetivo

To verify the effects of aerobic exercise at different times of the day on blood pressure in patients with sleep apnea.

Métodos

Twenty-two participants with a prior diagnosis of OSA were recruited. All participants underwent a cardiopulmonary exercise test using the Bruce protocol to identify the garget heart rate for the exercise session. Participants randomly completed four experimental sessions in the morning (8:00-11:00 AM) and afternoon (3:30-6:30 PM). The sessions were: morning exercise and morning control as well as afternoon exercise and afternoon control. The exercise sessions consisted of 40 minutes of walking or running on a treadmill at 54%-59% of the heart rate reserve, while the control sessions involved sitting for 40 minutes. Clinical blood pressure was measured using a validated automatic monitor, while central blood pressure was assessed via radial artery applanation tonometry. Both measurements were taken before and 30 minutes after the experimental sessions. Linear Mixed Models were used to determine the effects of the sessions on clinical and central blood pressure. The Bonferroni post-hoc test was employed when significance was detected. A p-value<0.05 was considered statistically significant.

Resultados

A decrease in clinical systolic blood pressure was observed after the exercise sessions in both Morning (-16.1 mmHg; 95%CI = -22.5 to -9.7 mmHg; p<0.001) and Afternoon (-11.4 mmHg; 95%CI = -16.8 to -5.9 mmHg; p=0.03). However, central systolic blood pressure decreased only after the afternoon exercise session (-13.9 mmHg; 95%CI = -20.1 to -7.7 mmHg; p<0.001). A statistically significant difference in central systolic blood pressure between morning and afternoon sessions was observed (Morning = -2.1 mmHg; 95%CI = -7.2 to 11.4 mmHg vs. Afternoon = -13.9 mmHg; 95%CI = -20.1 to -7.7 mmHg; p<0.05).

Conclusões

An aerobic exercise session promotes PEH regardless of the time of day, but only exercise in the afternoon reduces central blood pressure.

Palavras -chave

Time of day; Aerobic exercise; Blood pressure; Obstructive sleep apnea.