This study aimed to create a better understanding of the neurobiological mechanisms underlying the induction of nocebo hyperalgesia. Nocebo hyperalgesia refers to an increased pain perception...Show moreThis study aimed to create a better understanding of the neurobiological mechanisms underlying the induction of nocebo hyperalgesia. Nocebo hyperalgesia refers to an increased pain perception resulting from negative outcome expectations, a phenomenon that can negatively influence a patient’s clinical outcome. Much concerning the mechanisms underlying the induction of nocebo hyperalgesia is still unknown, although it can be hypothesized that NMDA receptor-dependent learning may play a role. The current study tested this hypothesis by pharmacologically manipulating NMDA receptor- dependent learning in healthy participants, expecting that the pharmacological manipulation would facilitate the induction of nocebo hyperalgesia. Participants (n = 50) received either a placebo or an 80 mg dose of D-cycloserine (DCS), a partial NMDA receptor agonist. Nocebo hyperalgesia was induced in both groups with verbal suggestions and a classical conditioning paradigm consisting of an induction and evocation phase. In the induction phase, high intensity heat-pain stimuli were given during trials where a sham electrical stimulation device was supposedly turned on (nocebo trials), while moderate heat-pain stimuli were given during trials where a sham electrical stimulation device was supposedly turned off (control trials). During the evocation phase, only moderate pain stimuli were given. Nocebo hyperalgesia was indicated when participants rated their pain higher during nocebo trials compared to control trials. A significant paired-samples t-test (t (49) = -8.55, p < .001) suggested that nocebo hyperalgesia was successfully induced in both groups, further confirming that nocebo hyperalgesia can be induced by classical conditioning and verbal suggestions. Nevertheless, the pharmacological manipulation of NMDA receptor-dependent learning with 80 mg DCS did not facilitate the magnitude of the induced nocebo hyperalgesia more than a placebo, as indicated by a one-way ANOVA (F (1, 49) = 0.028, p = 0.867). The usability of DCS in nocebo research was discussed, and further research was recommended. It is important that the current study is replicated, possibly with the use of another glutamatergic agent. The results from future studies could play a significant role in diminishing the impact of nocebo hyperalgesia on clinical practice.Show less
Objective: The goal of the current study is to investigate and quantify the association of the demographic factors of age and sex as risk factors in the psychosocial domain of post-intensive care...Show moreObjective: The goal of the current study is to investigate and quantify the association of the demographic factors of age and sex as risk factors in the psychosocial domain of post-intensive care syndrome (PICS) by conducting a meta-analysis and systematic review. It is expected that the current meta-analysis will shed more light on which patients are more likely to experience (increased) psychosocial problems post-intensive care based on these two demographic factors. This is needed to continue to improve and optimise the care for intensive care survivors. The hypotheses being postulated are that female sex and older age are respective risk factors for developing problems in the psychosocial domain of PICS. Review methods: The psychosocial domain of PICS was defined as anxiety, depression, or post-traumatic stress disorder (PTSD) after intensive care. PubMed, Web of Science, and Embase were searched for relevant articles and the selection of articles was based on the algorithm of ASReview. 22 relevant articles were selected. Of the included studies, 15 studies reported relevant information on the relation between sex and post-intensive care psychosocial problems, and 12 of the included studies reported relevant information on the relation of age and post-intensive care psychosocial problems. For the demographic factor of sex, a meta-analysis was conducted with odds ratios. The demographic factor of patient age was studied by conducting a systematic review because the available data did not lend itself to statistical pooling. Results: Log OR was calculated for female sex in comparison to male sex for the odds of experiencing psychosocial problems after intensive care with a result of 2.58 [2.03; 3.28]. Odds ratios calculated for anxiety, depression, and PTSD all show female patients to be more than two times as likely to suffer from these conditions compared to males. In the systematic review for patient age, eight of the studies reported younger patients being more at risk of developing psychosocial problems after intensive care, while four show older patients being more at risk for general psychosocial problems after intensive care. When it comes to the individual studied disorders, four studies found that younger patients were more at risk for anxiety, and two found older patients to be more at risk. For depression, three studies found younger patients to be more at risk, and four studies found older patients to be more at risk. For PTSD, seven studies found younger patients to be more at risk, and three studies found older patients to be more at risk. Conclusions: Statistical pooling and analysis show that women’s odds of developing these problems are more than twice as high compared to their male counterparts. For patient age, statistical analysis was not possible in the current study. Overall, eight studies stated that younger patients were more at risk, and four studies stated that older patients were more at risk of developing negative psychosocial outcomes after intensive care. Much variation of disorder prevalence and severity is seen between studies and types of disorders, preventing the possibility of drawing a uniform conclusion on the matter. It is unclear what factors cause these variances. These results found in the current study give more insight in which demographic groups of ICU patients are more likely to require additional care for psychosocial problems after hospital release. In future research, the underlying reasons that cause these trends in demographic groups should be investigated.Show less
Background: People with type 1 diabetes (T1D) often experience problems with their glucose regulation (glucose variability and glucose control), sleep quality, and cognitive functioning. However,...Show moreBackground: People with type 1 diabetes (T1D) often experience problems with their glucose regulation (glucose variability and glucose control), sleep quality, and cognitive functioning. However, their interrelation has not often been investigated. The aim of this study was to investigate how sleep quality and cognitive functioning are associated with glucose regulation in people with T1D. Method: Continuous glucose monitoring (CGM) data was collected over two weeks, in 18 participants, while each day subjective sleep quality (once in the morning) and cognitive functioning (e.g., ability to concentrate, finding words) (up to five times during the day) was measured using ecological momentary assessments (EMAs). Based on the CGM data, glycemic parameters (glucose variability and glucose control) during the night and day were calculated and a mean value of cognitive functioning per day was composed. Linear mixed model analyses were used to test for 1) whether sleep quality was influenced by glycemic parameters during the night and 2) whether cognitive functioning during the day was influenced by sleep quality and whether cognitive functioning was associated with glycemic parameters during the day. In addition, an interaction effect between sleep quality and glucose variability on cognitive functioning was explored. Lastly, visual plots were used to explore the associations on an individual level. Results: No statistically significant main effects were found for either association. However, an interaction trend (ß = -2.07, p = .070) between sleep quality and glucose variability on cognitive functioning scores was found. For days with normal fluctuations in glucose levels, better sleep quality was associated with better cognitive functioning, whereas for days with high glucose variability, this association could not be found. Regarding the individual plots, both, positive and negative relationships between all mentioned variables were apparent, exemplifying important inter-individual differences. Conclusion: For people with T1D, the relationships between glucose parameters, sleep quality, and cognitive functioning, vary from person to person. This finding advocates for looking at the individual level when implementing possible treatment methods for increasing sleep quality and cognitive functioning. More research in a larger sample is warranted to further examine the inter-individual factors in these associations.Show less
