Effects of auditory sleep modulation approaches on brain oscillatory and cardiovascular dynamics

Slow waves, the hallmark feature of deep nonrapid eye movement sleep, do potentially drive restorative effects of sleep on brain and body functions. Sleep modulation techniques to elucidate the functional role of slow waves thus have gained large interest. Auditory slow wave stimulation is a promising tool; however, directly comparing auditory stimulation approaches within a night and analyzing induced dynamic brain and cardiovascular effects are yet missing. Here, we tested various auditory stimulation approaches in a windowed, 10 s ON (stimulations) followed by 10 s OFF (no stimulations), within-night stimulation design and compared them to a SHAM control condition. We report the results of three studies and a total of 51 included nights and found a large and global increase in slow-wave activity (SWA) in the stimulation window compared to SHAM. Furthermore, slow-wave dynamics were most pronouncedly increased at the start of the stimulation and declined across the stimulation window. Beyond the changes in brain oscillations, we observed, for some conditions, a significant increase in the mean interval between two heartbeats within a stimulation window, indicating a slowing of the heart rate, and increased heart rate variability derived parasympathetic activity. Those cardiovascular changes were positively correlated with the change in SWA, and thus, our findings provide insight into the potential of auditory slow wave enhancement to modulate cardiovascular restorative conditions during sleep. However, future studies need to investigate whether the potentially increased restorative capacity through slow-wave enhancements translates into a more rested cardiovascular system on a subsequent day

Biomarker-based phenotyping of myocardial fibrosis identifies patients with heart failure with preserved ejection fraction resistant to the beneficial effects of spironolactone: results from the Aldo-DHF trial

Background: Myocardial fibrosis is characterized by excessive cross‐linking and deposition of collagen type I and is involved in left ventricular stiffening and left ventricular diastolic dysfunction (LVDD). We investigated whether the effect of spironolactone on LVDD in patients with heart failure with preserved ejection fraction (HFpEF) depends on its effects on collagen cross‐linking and/or deposition. Methods and results: We investigated 381 HFpEF patients from the multicentre, randomized, placebo‐controlled Aldo‐DHF trial with measures of the E:e' ratio. The ratio of serum carboxy‐terminal telopeptide of collagen type I to serum matrix metalloproteinase‐1 (CITP:MMP‐1, an inverse index of myocardial collagen cross‐linking) and serum carboxy‐terminal propeptide of procollagen type I (PICP, a direct index of myocardial collagen deposition) were determined at baseline and after 1‐year treatment with spironolactone 25 mg once daily or placebo. Patients were classified by CITP:MMP‐1 and PICP tertiles at baseline. While CITP:MMP‐1 tertiles at baseline interacted (P < 0.05) with spironolactone effect on E:e', PICP tertiles did not. In fact, while spironolactone treatment did not modify E:e' in patients with lower CITP:MMP‐1 levels, this ratio was significantly reduced in the remaining spironolactone‐treated patients. In addition, PICP was unchanged in patients with lower CITP:MMP‐1 levels but was reduced in the remaining spironolactone‐treated patients. Conclusions: A biochemical phenotype of high collagen cross‐linking identifies HFpEF patients resistant to the beneficial effects of spironolactone on LVDD. It is suggested that excessive collagen cross‐linking, which stabilizes collagen type I fibres, diminishes the ability of spironolactone to reduce collagen deposition in these patients

Effects of auditory sleep modulation approaches on brain oscillatory and cardiovascular dynamics

Slow waves, the hallmark feature of deep nonrapid eye movement sleep, do potentially drive restorative effects of sleep on brain and body functions. Sleep modulation techniques to elucidate the functional role of slow waves thus have gained large interest. Auditory slow wave stimulation is a promising tool; however, directly comparing auditory stimulation approaches within a night and analyzing induced dynamic brain and cardiovascular effects are yet missing. Here, we tested various auditory stimulation approaches in a windowed, 10 s ON (stimulations) followed by 10 s OFF (no stimulations), within-night stimulation design and compared them to a SHAM control condition. We report the results of three studies and a total of 51 included nights and found a large and global increase in slow-wave activity (SWA) in the stimulation window compared to SHAM. Furthermore, slow-wave dynamics were most pronouncedly increased at the start of the stimulation and declined across the stimulation window. Beyond the changes in brain oscillations, we observed, for some conditions, a significant increase in the mean interval between two heartbeats within a stimulation window, indicating a slowing of the heart rate, and increased heart rate variability derived parasympathetic activity. Those cardiovascular changes were positively correlated with the change in SWA, and thus, our findings provide insight into the potential of auditory slow wave enhancement to modulate cardiovascular restorative conditions during sleep. However, future studies need to investigate whether the potentially increased restorative capacity through slow-wave enhancements translates into a more rested cardiovascular system on a subsequent day.ISSN:1550-9109ISSN:0161-810

Impulsive laser-induced alignment of OCS molecules at FERMI

We demonstrate the experimental realization of impulsive alignment of carbonyl sulfide (OCS) molecules at the Low Density Matter Beamline (LDM) at the free-electron laser FERMI. OCS molecules in a molecular beam were impulsively aligned using 200 fs pulses from a near-infrared laser. The alignment was probed through time-delayed ionization above the sulphur 2p edge, resulting in multiple ionization via Auger decay and subsequent Coulomb explosion of the molecules. The ionic fragments were collected using a time-of-flight mass spectrometer and the analysis of ion-ion covariance maps confirmed the correlation between fragments after Coulomb explosion. The analysis of the CO+ and S+ channels allowed us to extract the rotational dynamics, which is in agreement with our theoretical description as well as with previous experiments. This result opens the way for a new class of experiments at LDM within the field of coherent control of molecules with the possibilities that a precisely synchronized optical-pump XUV-probe laser setup like FERMI can offer

Impulsive laser-induced alignment of OCS molecules at FERMI

We demonstrate the experimental realization of impulsive alignment of carbonyl sulfide (OCS) molecules at the Low Density Matter Beamline (LDM) at the free-electron laser FERMI. OCS molecules in a molecular beam were impulsively aligned using 200 fs pulses from a near-infrared laser. The alignment was probed through time-delayed ionization above the sulphur 2p edge, resulting in multiple ionization via Auger decay and subsequent Coulomb explosion of the molecules. The ionic fragments were collected using a time-of-flight mass spectrometer and the analysis of ion-ion covariance maps confirmed the correlation between fragments after Coulomb explosion. The analysis of the CO+and S+channels allowed us to extract the rotational dynamics, which is in agreement with our theoretical description as well as with previous experiments. This result opens the way for a new class of experiments at LDM within the field of coherent control of molecules with the possibilities that a precisely synchronized optical-pump XUV-probe laser setup like FERMI can offer

Investigating a biomarker-driven approach to target collagen turnover in diabetic heart failure with preserved ejection fraction patients. Effect of torasemide vs. furosemide on serum C-terminal propeptide of procollagen type I (DROP-PIP trial)

Aim: Heart failure with preserved ejection fraction (HFpEF) is associated with myocardial remodelling including severe pro-fibrotic changes contributing to an increase in left ventricular stiffness and diastolic dysfunction. Serum C-terminal propeptide of procollagen type I (PIP) strongly correlates with the turnover of extracellular cardiac matrix proteins and fibrosis. Torasemide, but not furosemide, was described to reduce collagen type I synthesis in clinically unstable patients with heart failure with reduced ejection fraction. We evaluated whether its effect translated to HFpEF patients with type 2 diabetes mellitus (T2DM) and abnormal basal PIP levels. Methods and results: We performed a relatively small, single-centre, randomised, double-blind, two-arm parallel-group, active controlled clinical trial in 35 HFpEF patients with T2DM to determine the effects of a 9-month treatment with torasemide vs. furosemide on changes of serum PIP levels. Patients with increased PIP levels (≥110 ng/mL), or evidence of structural changes with a left atrial volume index (LAVI) >29 mL/m2 and abnormal PIP levels (≥70 ng/mL), were eligible to participate. Fifteen patients were female (42%), mean age was 69 years, body mass index was 34.7 kg/m2, 83% were in New York Heart Association class II/III. Echocardiographic characteristics showed a mean left ventricular ejection fraction of >60%, a left ventricular mass index >120 g/m2, an E/e' ratio of 14, and a LAVI of 40 mL/m2 with a NT-proBNP of 174 ng/L and a 6-minute walk distance of 421 m. Mean per cent change in PIP was 2.63 ± 5.68% (±SEM) in torasemide vs. 2.74 ± 6.49% in furosemide (P = 0.9898) treated patients. Torasemide was not superior to furosemide in improving functional capacity, diastolic function, quality of life, or neuroendocrine activation. Conclusion: In this hypothesis-generating, mechanistic trial in stable HFpEF patients with T2DM, neither long-term administration of torasemide nor furosemide was associated with a significant effect on myocardial fibrosis, as assessed by serum PIP. Further studies are urgently needed in this field. More specific diuretic and anti-fibrotic treatment strategies in T2DM and/or HFpEF are warranted