A Study on Prevalence of Asymptomatic Pulmonary Hypertension in Patients of Metabolic Syndrome with Obstructive Sleep Apnea.

Aim: To find out the prevalence of asymptomatic pulmonary hypertension (PHT) in metabolic syndrome patients who have obstructive sleep apnea (OSA).

Objectives: To find out the presence of asymptomatic PHT by two-dimensional echocardiography (2D ECHO) who have metabolic syndrome by WHO diagnostic criteria and OSA done by polysomnography. In this study, we also assessed the glycemic status in patients with metabolic syndrome with OSA and asymptomatic PHT.

Materials and methods: Study population: All patients attending tertiary care outpatient department for type 2 diabetes/prediabetes/dyslipidemia/hypertension/obesity were screened for metabolic syndrome features.

Results: In a pilot study, 34 consecutive patients were found to have metabolic syndrome by the WHO diagnostic criteria. 28 (82%) of metabolic syndrome patients had OSA. 14 out of 28 patients (50%) had PHT by 2D ECHO. Prediabetes was more prevalent, 22 (65%) among patients with metabolic syndrome than diabetes (32%). All but one patient who had no OSA was found to have moderate PHT. Asymptomatic PHT was found in 6/12 (50%) of diabetics and in 8/22 (36%) in prediabetes. Except for one, diabetes duration of all was <10 years and all prediabetes were recently detected within 1 year.

Conclusion: Our findings suggest that PHT is associated with a 4-fold higher occurrence of metabolic syndrome than patients with OSA. It is more prevalent in prediabetes and diabetes. The detection of the association of diabetes mellitus, OSA, and asymptomatic PHT in the pathophysiology of heart failure with preserved ejection fraction requires further longitudinal studies. The prevalence of PHT increases with increasing severity of OSA; therefore, early detection is beneficial.