Effects of the mediterranean diet on the components of metabolic syndrome

Metabolic syndrome, also as known as Syndrome X or Insulin Resistance Syndrome, is a complex health problem featuring visceral obesity (the main diagnostic criterion), insulin resistance, dyslipidemia and high blood pressure. Currently, this health condition has gained a momentum globally while raising concerns among health-related communities. The World Health Organization, American Heart Association and International Diabetes Federation have formulated diagnostic criteria for metabolic syndrome. Diet and nutrition can influence this syndrome: for example, the Western diet is associated with increased risk of metabolic syndrome, whereas the Nordic and Mediterranean diets and the Dietary Approach to Stop Hypertension are potentially beneficial. The Mediterranean diet can affect the components of metabolic syndrome due to its high dietary fiber, omega 3 and 9 fatty acids, complex carbohydrates, antioxidants, minerals, vitamins and bioactive substances, such as polyphenols. These nutrients and bioactive substances can combat obesity, dyslipidemia, hypertension and diabetes mellitus. The mechanisms by which they do so are generally related to oxidative stress, inflammation (the most common risk factors for metabolic syndrome) and gastrointestinal function. The literature also shows examples of positive effects of the Mediterranean diet on the metabolic syndrome. In this review of the literature, we shed light on the effects, mechanisms and dynamic relationship between the Mediterranean diet and metabolic syndrome

Sleep Is a Refreshing Process: An fNIRS Study

Sleep is a very critical process that constitutes up to one third of daytime of a healthy adult. It is known to be an active period where body and brain is refreshed for the next day. It is both part of a larger cycle, i.e., circadian rhythm, and has subcsycles in it, i.e., sleep stages. Although hemodynamics of these stages have been investigated especially in the last two decades, there are still points in the hemodynamics to be illuminated especially in terms of refreshment. This study aims to investigate refreshing property of sleep in terms of sleep stages using functional near-infrared spectroscopy (fNIRS) for measuring prefrontal cortex (PFC) hemodynamics. Nine healthy subjects slept in sleep laboratories, monitored by polysomnography and fNIRS before, during, and after night sleep. REM stage had lower oxyhemoglobin (HbO) and total hemoglobin (HbT) than the other sleep stages and wakefulness. Deoxyhemoglobin (HbR) did not differ between any stages. All sleep stages and wakefulness stage at the end of the sleep had higher HbO and lower HbR than the beginning of the sleep. HbT levels did not differ between the beginning and the end of the sleep for any stages. During REM sleep, PFC seems to get lower blood supply, possibly due to increased demand in other brain regions. Regardless of the stage, PFC has higher oxygenation toward the end of sleep, indicating refreshment. Overall, our brain seems to be on duty during sleep throughout the night for “cleaning” and “refreshing” itself. Hemodynamic changes from the beginning to end of sleep might be the indicator of this work. Thus, accordingly REM stage seems to be at a central point for this work

Spectral Pattern Analysis of Propofol Induced Spindle Oscillations in the Presence of Auditory Stimulations

This study’s primary objective is to analyze human EEG spindle oscillations during propofol-induced anesthesia and to address possible activation sources. Such an analysis also has a secondary role of investigating the short- term spectral patterns and their functional role

Brain function assessment in different conscious states

Background: The study of brain functioning is a major challenge in neuroscience fields as human brain has a dynamic and ever changing information processing. Case is worsened with conditions where brain undergoes major changes in so-called different conscious states. Even though the exact definition of consciousness is a hard one, there are certain conditions where the descriptions have reached a consensus. The sleep and the anesthesia are different conditions which are separable from each other and also from wakefulness. The aim of our group has been to tackle the issue of brain functioning with setting up similar research conditions for these three conscious states.Methods: In order to achieve this goal we have designed an auditory stimulation battery with changing conditions to be recorded during a 40 channel EEG polygraph (Nuamps) session. The stimuli (modified mismatch, auditory evoked etc.) have been administered both in the operation room and the sleep lab via Embedded Interactive Stimulus Unit which was developed in our lab. The overall study has provided some results for three domains of consciousness. In order to be able to monitor the changes we have incorporated Bispectral Index Monitoring to both sleep and anesthesia conditions.Results: The first stage results have provided a basic understanding in these altered states such that auditory stimuli have been successfully processed in both light and deep sleep stages. The anesthesia provides a sudden change in brain responsiveness; therefore a dosage dependent anesthetic administration has proved to be useful. The auditory processing was exemplified targeting N1 wave, with a thorough analysis from spectrogram to sLORETA. The frequency components were observed to be shifting throughout the stages. The propofol administration and the deeper sleep stages both resulted in the decreasing of N1 component. The sLORETA revealed similar activity at BA7 in sleep (BIS 70) and target propofol concentration of 1.2 μg/mL.Conclusions: The current study utilized similar stimulation and recording system and incorporated BIS dependent values to validate a common approach to sleep and anesthesia. Accordingly the brain has a complex behavior pattern, dynamically changing its responsiveness in accordance with stimulations and states. © 2010 Ozgoren et al; licensee BioMed Central Ltd

Primed Tactile Stimulus Processing during Sleep

The aim was to investigate how the primed and unprimed non-painful tactile stimuli during sleep would be processed. A total of 22 healthy subjects (19.55 ± 1.10 years) were randomly divided into two groups. The same stimuli were applied to both groups, but the study group (SG) received them twice (daytime and sleep), whereas the control group (CG) received them only during sleep. A 40-channel PSG and a pneumatic tactile stimulator unit were used. Evoked potential components of the CZ electrode were examined in four sleep stages (N1, N2, N3, and REM). The Mann–Whitney U test was used for group comparison, and the Wilcoxon test was used for in-group evaluations. The P50 and N300 response components were observed in all sleep stages in both groups. P50 decreased as sleep deepened in the SG. The N300 increased as sleep deepened and started to decrease again in the REM stage. Moreover, in N1, the amplitudes of P200-N300 and N300-P450 in the SG were significantly greater than those in the CG. The fact that P50 was observed even in N3 indicates that bottom-up sensory processing continues during sleep. Moreover, the central processing of primed and unprimed stimuli exhibited dynamic differences. Furthermore, an increase in N300 amplitude suggests suppressive processes to facilitate and maintain sleep

Sleep Electrophysiology Via the Scope of Bispectral Index

Objective: The goal of this study was to investigate the changes in the responses to auditory stimuli, which were sorted according to the Bispectral Index (BIS) during sleep. This is the first known research study that incorporated full-scale analysis of sleep auditory evoked potentials (AEP) under the scope of BIS. Material and Methods: The measurements were conducted in twelve subjects (18-32 ages, mean: 24.5 +/- 4.1; 2 female). Recordings were done by using NuAmps 40 channel system [electroencephalography (EEG), electrooculography (EOG), and chin electromyography (EMG)], auditory stimulation unit, video and BIS monitor. Sleep data was acquired while (1500 Hz, 80 dB and 500 ms) auditory stimulations were applied into the ear channels (etymotic). The continuous EEG data were grouped according to the BIS index. In this sub-group of recordings, AEPs were analyzed. The evolution of N1, P2, N300, P450, N550 and P900 waveforms recorded from Cz electrode were investigated with regard to correlation of BIS and sleep stages. Results: The reduction of BIS values were followed by the decrease of NI component, whereas N300 and P900 components were found to be increased (Wilcoxon, p<0.05). AEPs dynamically evolved according to the changes in BIS values. The present findings support and advance the outcome of classical designs, which are based solely on the system Rechtschaffen & Kales (R&K) system. Conclusion: The present study investigated sleep states in extended number of levels with the BIS system, which provided higher time resolution. Based on the results, BIS may be suggested as a useful tool for sleep dynamic research studies also in pathological states

The Development of A Psychomotor Vigilance Test Battery and the Assesment of Vigilance Change in Reaction to Mental Work Load

This study aims to establish a battery for assessing vigilance by bringing together tests assessing various cognitive functions and to evaluate vigilance change in reaction to cognitive workload