Finger volume pulse waveforms facilitate reliable assessment of heart rate variability, but not blood pressure variability or baroreflex function.

BACKGROUND: We sought to determine whether heart rate variability (HRV), blood pressure (BP) variability, and baroreceptor-heart rate reflex sensitivity can be reliably assessed using finger volume pulse waveforms obtained from the commercially available EndoPAT device. METHODS: Non-invasive BP (Finometer Pro as a non-invasive standard) and finger volume (EndoPAT) waveforms were recorded in 65 adults (37 ± 14 years; 60% female) and systolic BP and heart rate (HR) time series were derived after calibrating the EndoPAT signal based on systolic and diastolic BP values obtained by a sphygomomanometer. Transfer function analyses were performed to test for coherence between systolic BP and HR time series derived from the Finometer and EndoPAT devices. Time-domain HRV parameters, frequency domain HR and systolic BP variability parameters, and baroreflex sensitivity (sequence technique) were computed from Finometer- and EndoPAT-derived time series and intraclass correlation coefficients (ICC) were calculated. RESULTS: Squared coherence between systolic BP time series derived from the Finometer and EndoPAT devices was low, suggesting poor correlation. In contrast, squared coherence between HR time series derived from the two devices was excellent [High Frequency (HF) = 0.80, Low Frequency (LF) = 0.81], with gain values close to 1.0. ICC values for time- and frequency-domain HRV parameters were excellent (>0.9 except for relative HF HRV, which was 0.77), while ICC values for frequency-domain BP variability parameters and baroreceptor-HR reflex sensitivity were low. CONCLUSIONS: Finger volume pulse waveforms can be used to reliably assess both time-domain and frequency-domain HR variability. However, frequency domain BP variability parameters cannot be reliably assessed from finger volume pulse waveforms using the simple calibration technique used in this study.

Emerging drugs for obesity: linking novel biological mechanisms to pharmaceutical pipelines.

Obesity is associated with hypertension, diabetes, dyslipidaemias and metabolic syndrome, and causes substantial morbidity and mortality from cardiovascular and other diseases. The cost to treat obesity and its complications in the US has increased steeply and is currently estimated to be USD 100 billion. Current therapy for obesity is mainly based on changes in lifestyle that often fail. Existing pharmacological treatment is marginally efficient and poorly tolerated. The discovery of leptin and related neural mechanisms of energy metabolism regulation has opened the doors to potential targets for new antiobesity drugs. In this review, new pharmacological targets are discussed and an update on the development of emerging antiobesity drugs is provided. Despite intense investigation, the pipelines for antiobesity drugs in late stages of development are relatively empty. Breakthrough treatments for obesity may take some years to emerge. Clinical trials will be necessary to clarify the impact of new antiobesity drugs on hard cardiovascular and metabolic end points.