Oxytocin moderates the association between testosterone-cortisol ratio and trustworthiness:A randomized placebo-controlled study

Oxytocin has been proposed to enhance feelings of trust, however, these findings have been difficult to replicate. Environmental or hormonal factors might influence this association. We studied whether oxytocin moderates the association between the testosterone-cortisol ratio, which is associated with risk taking behavior and aggression, and trustworthiness, while controlling for the general level of trust. A randomized double-blind placebo-controlled study with 53 healthy males was performed in which 32IU oxytocin (n = 27) or placebo (n = 26) was administered intranasally. Participants subsequently played the Trust Game in which they were allocated to the role of trustee. In the third phase of the Trust Game, we found a positive association between the testosterone-cortisol-ratio and the proportion of the amount that is returned to the investor (P=<0.01). However, administration of oxytocin reduced reciprocity in those with a high testosterone-cortisol ratio after reciprocity restoration (a significant interaction effect between administration of oxytocin and the testosterone-cortisol ratio in the third phase of the Trust Game, P = 0.015). The third phase of the Trust Game represents the restoration of reciprocity and trustworthiness, after this is violated in the second phase. Therefore, our data suggest that oxytocin might hinder the restoration of trustworthiness and diminish risk-taking behavior when trust is violated, especially in those who are hormonally prone to risk-taking behavior by a high testosterone-cortisol ratio

Positive End-Expiratory Pressure may alter breathing cardiovascular variability and baroreflex gain in mechanically ventilated patients

<p>Abstract</p> <p>Background</p> <p>Baroreflex allows to reduce sudden rises or falls of arterial pressure through parallel RR interval fluctuations induced by autonomic nervous system. During spontaneous breathing, the application of positive end-expiratory pressure (PEEP) may affect the autonomic nervous system, as suggested by changes in baroreflex efficiency and RR variability. During mechanical ventilation, some patients have stable cardiorespiratory phase difference and high-frequency amplitude of RR variability (HF-RR amplitude) over time and others do not. Our first hypothesis was that a steady pattern could be associated with reduced baroreflex sensitivity and HF-RR amplitude, reflecting a blunted autonomic nervous function. Our second hypothesis was that PEEP, widely used in critical care patients, could affect their autonomic function, promoting both steady pattern and reduced baroreflex sensitivity.</p> <p>Methods</p> <p>We tested the effect of increasing PEEP from 5 to 10 cm H2O on the breathing variability of arterial pressure and RR intervals, and on the baroreflex. Invasive arterial pressure, ECG and ventilatory flow were recorded in 23 mechanically ventilated patients during 15 minutes for both PEEP levels. HF amplitude of RR and systolic blood pressure (SBP) time series and HF phase differences between RR, SBP and ventilatory signals were continuously computed by complex demodulation. Cross-spectral analysis was used to assess the coherence and gain functions between RR and SBP, yielding baroreflex-sensitivity indices.</p> <p>Results</p> <p>At PEEP 10, the 12 patients with a stable pattern had lower baroreflex gain and HF-RR amplitude of variability than the 11 other patients. Increasing PEEP was generally associated with a decreased baroreflex gain and a greater stability of HF-RR amplitude and cardiorespiratory phase difference. Four patients who exhibited a variable pattern at PEEP 5 became stable at PEEP 10. At PEEP 10, a stable pattern was associated with higher organ failure score and catecholamine dosage.</p> <p>Conclusions</p> <p>During mechanical ventilation, stable HF-RR amplitude and cardiorespiratory phase difference over time reflect a blunted autonomic nervous function which might worsen as PEEP increases.</p

The association between neuroticism and heart rate variability is not fully explained by cardiovascular disease and depression

Neuroticism is associated with cardiovascular disease, autonomic reactivity, and depression. Here we address the extent to which neuroticism accounts for the excess heart disease risk associated with depression and test whether cardiac autonomic tone plays a role as mediator. Subjects were derived from a nationally representative sample (n = 1,255: mean age 54.5, SD = 11.5). Higher neuroticism was associated with reduced heart rate variability equally under rest and stress. The baseline structural equation model revealed significant paths from neuroticism to heart rate variability, cardiovascular disease and depression, and between depression and cardiovascular disease, controlling for age, sex, height, weight, and BMI. Dropping both the neuroticism to heart rate variability, and neuroticism to heart disease paths significantly reduced the model fit (p < .001 in each case). We conclude that neuroticism has independent associations with both autonomic reactivity and cardiovascular disease, over and above its associations with depression and other related variables

Heart rate variability spectra based on non-equidistant sampling:The spectrum of counts and the instantaneous heart rate spectrum

This paper compares two methods to estimate heart rate variability spectra i.e., the spectrum of counts and the instantaneous heart rate spectrum. Contrary to Fourier techniques based on equidistant sampling of the interbeat intervals, the spectrum of counts of the instantaneous heart rate spectrum are based on non-equidistant sampling: the values are determined at R-wave moments. A consequence of the non-equidistant occurrence of the R-peaks in a heart rate signal is the appearance of the sidebands of the harmonic components of the mean heart rate in the spectra. These sidebands contaminate the signal components in the spectrum. The sideband distortion in the instantaneous heart rate spectrum was found to be smaller than in the spectrum of counts. Simulations using the IPFM-model were mead to quantify this difference. On the basis of these simulations, sideband distortion appeared to be dependent on the mean heart rate, the modulation depth and the modulation frequency

Low body mass index is associated with an increased risk of neuropsychiatric adverse events and concentration impairment in women on mefloquine

Aims: We performed a prospective cohort study to gain more insight into risk factors for neuropsychiatric effects of mefloquine among tourists travelling to tropical areas. Methods: We enrolled all patients who consulted the Travel Clinic of the Havenziekenhuis & Institute for Tropical Diseases Rotterdam for mefloquine prophylaxis during the period between 1 May 1999 and 7 March 2000. Each patient was followed from baseline (prior to starting mefloquine) up to 3 weeks after starting weekly intake of 250 mg mefloquine. We compared the intraindividual change in scores between baseline and follow-up visit on the Dutch shortened Profile of Mood States, and on the Continuous Performance Test (CPT) which measures sustained attention. Results: The final cohort consisted of 151 subjects with a mean age of 38 years. In this population, a significant impairment of mood state was observed in those with a body mass index (BMI) ≤20 kg m -2. Stratification for gender showed that the total mood disturbance in females in the lowest BMI category significantly increased by 8.42 points [95% confidence interval (CI) 3.33, 13.50], whereas BMI did not affect the risk in males. Stratification for history of use of mefloquine showed that the risks were highest in first-time users. Analyses of the CPT showed that reaction time in women with a BMI ≤20 kg m -2 increased significantly by 22.5 ms (95% CI 7.80, 37.20), whereas reaction time in men showed a slight and nonsignificant decrease. Conclusion: Risk factors for mefloquine-associated neuropsychiatric adverse events and concentration impairment are female gender, low BMI, and first-time use. The frequency of neuropsychiatric effects is highest in women with a BMI ≤20 kg m -2

Fatigue in primary Sjögren's syndrome

OBJECTIVE—To assess fatigue in relation to depression, blood pressure, and plasma catecholamines in patients with primary Sjögren's syndrome (SS), in comparison with healthy controls and patients with rheumatoid arthritis.
METHODS—For the assessment of fatigue the Multidimensional Fatigue Inventory (MFI) was used, a 20 item questionnaire, covering the following dimensions: general fatigue, physical fatigue, mental fatigue, reduced motivation, and reduced activity. Furthermore, the Zung depression scale was used to quantify aspects of depression. Forty nine female primary SS patients, 44 female patients with rheumatoid arthritis (RA), and 32 healthy women filled in both questionnaires. In addition, supine values of blood pressure and plasma catecholamines were measured in the patients with primary SS.
RESULTS—Primary SS patients were more fatigued compared with the healthy controls on all the five dimensions of the MFI. When the analyses were repeated using depression as a covariate, group differences disappeared for the dimensions of reduced motivation and mental fatigue. In the primary SS patients, significant positive correlations between depression and the dimensions of reduced motivation and mental fatigue were found. Comparing patients with primary SS with those with RA, using depression as covariate, no statistically significant differences were found between these groups. No relation between fatigue and blood pressure was found, but a negative correlation was observed between the general fatigue subscale of the MFI and plasma noradrenaline.
CONCLUSION—Patients with primary SS report more fatigue than healthy controls on all the dimensions of the MFI and when controlling for depression significant differences remain on the dimensions of general fatigue, physical fatigue, and reduced activity. The negative correlations between levels of noradrenaline and general fatigue in patients with primary SS may imply the involvement of the autonomic nervous system in chronic fatigue.

 Keywords: Sjögren's syndrome; fatigu

Diurnal cortisol patterns of young male patients with schizophrenia

Aims: it has been suggested that schizophrenic patients are more vulnerable to stress than healthy persons, and that stressors can trigger a psychotic episode or worsen symptoms. The biological system often studied in relation to stress is the hypothalamic–pituitary–adrenal (HPA) axis, which controls the release of cortisol. We investigated whether the diurnal basal activity of the HPA axis differed between young male patients with schizophrenia and healthy controls.Methods: twenty-seven male patients (mean age 22 ± 5 years) and 38 healthy male control subjects (mean age 22 ± 3 years) were included in the present study. Saliva was sampled at five time points during the day: directly after awakening, 30 min thereafter, and at 12.00 hours, 16.00 hours and 22.00 hours.Results: the cortisol concentration decreased significantly more during the day in the patient group thanin the control group. Patients also showed a significantly decreased area under the curve with respect to the increase, again indicating that the cortisol concentrations decreased more during the day in patients than in controls. Both the morning increase and the area under the curve with respect to the increase were significantly negatively correlated with negative symptom severity.Conclusions: patients with schizophrenia showed a different daytime sensitivity of the HPA axis. Our findings further suggest that an increase in negative symptom severity is related to a decreased HPA axis sensitivit

Quantifying the impact of mass vaccination programmes on notified cases in the Netherlands.

Vaccination programmes are considered a main contributor to the decline of infectious diseases over the 20th century. In recent years, the national vaccination coverage in the Netherlands has been declining, highlighting the need for continuous monitoring and evaluation of vaccination programmes. Our aim was to quantify the impact of long-standing vaccination programmes on notified cases in the Netherlands. We collected and digitised previously unavailable monthly case notifications of diphtheria, poliomyelitis, mumps and rubella in the Netherlands over the period 1919-2015. Poisson regression models accounting for seasonality, multi-year cycles, secular trends and auto-correlation were fit to pre-vaccination periods. Cases averted were calculated as the difference between observed and expected cases based on model projections. In the first 13 years of mass vaccinations, case notifications declined rapidly with 82.4% (95% credible interval (CI): 74.9-87.6) of notified cases of diphtheria averted, 92.9% (95% CI 85.0-97.2) cases of poliomyelitis, and 79.1% (95% CI 67.1-87.4) cases of mumps. Vaccination of 11-year-old girls against rubella averted 49.9% (95% CI 9.3-73.5) of cases, while universal vaccination averted 68.1% (95% CI 19.4-87.3) of cases. These findings show that vaccination programmes have contributed substantially to the reduction of infectious diseases in the Netherlands