Obstructive sleep apnea is highly prevalent among patients with hypertrophic cardiomyopathy. The severity of the condition in this group of patients has been found to be independently associated with metabolic abnormalities, such as obesity, hypertension, and elevated triglycerides. This is according to a study published in a recent edition of the Journal of Clinical Endocrinology and Metabolism.
Obstructive sleep apnea is closely related to metabolic syndrome in the general population and it is highly prevalent among patients with hypertrophic cardiomyopathy affecting an estimated 32-71% of those patients, studies show. In this study, Chinese researchers investigated the association and severity of obstructive sleep apnea with obesity, elevated blood pressure, elevated glucose and dyslipidemia in patients with hypertrophic cardiomyopathy.
The study included 587 patients with hypertrophic cardiomyopathy who underwent overnight diagnostic sleep assessments at a single hospital in China. Researchers collected data on clinical characteristics as well as data from polysomnography studies and metabolic measurements. Patients in this study were diagnosed with hypertrophic cardiomyopathy if they had an unexplained maximal left ventricle wall thickness at least 15 mm in the absence of other cardiac or systemic diseases.
Investigators identified 344 patients (58.6%) with obstructive sleep apnea. The severity of obstructive sleep apnea was assessed on apnea-hypopnea index and percentage of total sleep time spent with oxygen saturation of less than 90%.
Compared with patients without obstructive sleep apnea, patients diagnosed with obstructive sleep apnea were significantly older, more often male, and had a greater number of clinical comorbidities. According to multivariate analysis, moderate-to-severe obstructive sleep apnea held independent associations with obesity (odds ratio [OR], 2.42; 95% CI, 1.48–3.95), elevated blood pressure (OR, 1.99; 95% CI, 1.42–3.26), and elevated triglycerides (OR, 1.71; 95% CI, 1.05–2.78).
In addition, increasing log (AHI + 1) was associated with increasing BMI (P <.001), systolic blood pressure (P =.039), diastolic blood pressure (P =.030), and triglycerides (P =.033) in a multivariate linear analysis.
Limitations of this study included its cross-sectional nature, single-center design, and the lack of data on waist circumference and metabolic syndrome diagnoses. “Our study showed that severity of obstructive sleep apnea was independently associated with obesity. In addition, results also showed that patients with obstructive sleep apnea had higher BMI levels compared with those with no obstructive sleep apnea in different BMI categories. These results suggest that obstructive sleep apnea might be a predisposing risk factor for obesity in patients with hypertrophic cardiomyopathy,” the authors wrote.
The authors suggest that physicians regularly screen patients with hypertrophic cardiomyopathy for obstructive sleep apnea.
Wang J, Xu H, Yuan J, et al. Association between obstructive sleep apnea and metabolic abnormalities in patients with hypertrophic cardiomyopathy. Published online January 9, 2021. J Clin Endocrinol Metab. doi:10.1210/clinem/dgab015