Chi-Hang Lee

We investigated the effects of Continuous Positive Airway Pressure (CPAP) on blood pressure (BP) and vigilance in taxi drivers with obstructive sleep apnea (OSA). This pilot study recruited taxi drivers aged ≥60 years to undergo polysomnography. Those diagnosed with OSA underwent 6 months of CPAP therapy. Baseline and follow-up assessments included 24 h ambulatory blood pressure monitoring (ABPM) and the psychomotor vigilance test (PVT). Among the 32 participants, 22 (68.8%) were diagnosed with OSA (median age 63.0 [62.0–65.0] years; 21 males). The average CPAP adherence was 3.1 ± 2.3 h per night, with 23.5% using CPAP for more than 4 h per night. There were no significant changes in 24 h mean systolic ABPM (125.9 [116.8–134.9] mmHg to 126.0 [118.3–133.7] mmHg; p = 0.93) or reaction times measured by PVT (2.0 [0.0–3.0] lapses to 2.0 [1.0–3.0] lapses; p = 0.82) after CPAP therapy. A high prevalence of OSA was observed among taxi drivers. CPAP adherence was suboptimal and did not result in significant improvements in BP or vigilance.

Objectives: We investigated the effects of Continuous Positive Airway Pressure (CPAP) on blood pressure (BP) and vigilance in taxi drivers with obstructive sleep apnea (OSA). Methods: Taxi drivers aged ≥60 years were recruited for polysomnography. Those diagnosed with OSA underwent 6 months of CPAP therapy. Baseline and follow-up assessments included 24-hour ambulatory blood pressure monitoring (ABPM) and the psychomotor vigilance test (PVT). Results: Among the 32 participants, 22 (68.8%) were diagnosed with OSA (median age 63.0 [62.0–65.0] years; 21 males). The average CPAP adherence was 3.1±2.3 hours per night, with 23.5% using CPAP for more than 4 hours per night. There were no significant changes in 24-hour mean systolic ABPM (125.9 [116.8–134.9] mmHg to 126.0 [118.3–133.7] mmHg; p=0.93) or reaction times measured by PVT (2.0 [0.0–3.0] lapses to 2.0 [1.0–3.0] lapses; p=0.82) after CPAP therapy. Conclusion: A high prevalence of OSA was observed among taxi drivers. CPAP adherence was suboptimal and did not result in significant improvements in BP or vigilance.

Introduction In addition to hypertension, the constellation of metabolic abnormalities (diabetes mellitus, dyslipidaemia and/or obesity) independently increases the incidence and severity of cardiovascular diseases, and this is compounded by the modern lifestyle and ageing society. The prevalence of metabolic syndrome is high and non-hypertensive heart failure is common in Asians. Adverse cardiac remodelling is an important substrate for cardiac dysfunction in the onset and progression of heart failure and its amelioration improves outcomes and prognosis. A better understanding of metabolic-driven cardiac remodelling is warranted due to the rising prevalence and complexity of metabolic syndrome and strong interests in targeted therapy. Methods and analysis Response of the myocardium to hypertrophic conditions in the adult population is a prospective observational cohort study with an aim to establish the significance of cardiac remodelling by cardiovascular magnetic resonance (CMR). The current recruitment target is 2000 participants. Expanding from the initial population with hypertension, the study examines adults with cardiometabolic conditions, including diabetes, dyslipidaemia, obesity and fatty liver disease. Eligible patients are identified at National Heart Centre Singapore, primary care clinics and through public outreach. Physical, clinical, imaging and biochemical data are collected. Cardiac remodelling features pertaining to hypertrophy, fibrosis and functional changes are assessed on CMR. Body adiposity is mapped by MRI across the heart, liver and abdomen. Outcome data are adjudicated and follow-up assessment will be available in a subset of participants. Blood biomarkers will be investigated in relation to imaging findings. Cross-sectional analysis will establish the implication of cardiometabolic disease towards cardiac remodelling, while follow-up and outcome analysis will infer on disease progression and prognosis. Ethics and dissemination The study was approved by the SingHealth Centralised Institutional Review Board (2015/2603). Written informed consent is obtained from all participants. Study findings will be reported in peer-reviewed journals and at scientific conferences. Trial registration number ClinicalTrials.gov, NCT02670031.