RESUMO
Abstract Background Exercise training (ET) is an adjunctive treatment for obstructive sleep apnea (OSA) and its consequences. However, the effects of exercise on heart remodeling are unknown in the population with OSA. Objective We investigated the effect of ET on markers of diastolic function, sleep parameters, and functional capacity in patients with OSA. Methods Sedentary patients with OSA (apnea-hypopnea index, AHI ≥15 events/hr) were randomly assigned to untrained (n=18) and trained (n=20) strategies. Polysomnography, cardiopulmonary exercise test, and echocardiography were evaluated at the beginning and end of the study. ET consisted of 3 weekly sessions of aerobic exercise, resistance exercises, and flexibility training (72 sessions, completed in 11.65±0.86 months). A two-way analysis of variance (ANOVA) was used, followed by Tukey's post-hoc test. The level of statistical significance was set at p<0.05 for all analyses. Result Thirty-eight patients were included (AHI:45±29 events/hr, age:52±7 y, body mass index: 30±4 kg/m2). They had similar baseline parameters. ET caused a significant change in OSA severity (AHI:4.5±18 versus -5.7±13 events/hr; arousal index:1.5±8 versus -6.1±13 events/hr, in untrained and trained groups respectively, p<0.05). The trained patients had an increase in functional capacity after intervention. ET improved isovolumetric relaxation time (IVRT, untrained=6.5±17.3 versus trained=-5.1±17.1 msec, p<0.05). There was a significant correlation between changes in IVRT and arousal index in the trained group (r =-0.54, p<0.05). No difference occurred in the other diastolic function parameters evaluated. Conclusion ET promotes modest but significant improvement in AHI, functional capacity, and cardiac IVRT, a validated parameter of diastolic function.
RESUMO
O ecocardiograma sob estresse com dobutamina é um método bem estabelecido para avaliar doença arterial coronária, cuja sensibilidade tem sido potencializada pela adição de atropina no final do protocolo. Indivíduos com glaucoma, doença com alta prevalência em pacientes cardiopatas com mais de 40 anos, não podem se beneficiar do uso de atropina por ser contra-indicada neste grupo. Além disso, estes indivíduos são tratados freqüentemente com betabloqueadores tópicos (colírios), que podem exercer efeitos sistêmicos diminuindo a freqüência cardíaca, pressão arterial e capacidade pulmonar. O objetivo do nosso trabalho foi verificar se a ocorrência de um possível efeito sistêmico causado por estes colírios, causando baixa resposta cronotrópica, poderia determinar resultados inconclusivos no ecocardiograma sob estresse pela dobutamina nestes pacientes com glaucoma.
Dobutamine stress echocardiography is a well-established method to assess coronary artery disease, of which sensitivity has been enhanced by adding atropine at the end of the protocol. Individuals with glaucoma, a disease with a high prevalence in patients with cardiac diseases older than 40 years, cannot benefit from the use of atropine as it is contraindicated for this group of patients. Additionally, these individuals are often treated with topical betablockers (eye drops), which can have systemic effects by decreasing cardiac frequency, blood pressure and pulmonary capacity. The aim of our study was to verify whether a possible systemic effect caused by the use of these eye drops, yielding a low chronotropic response, could result in inconclusive dobutamine stress echocardiography in patients with glaucoma.