- Email: [email protected]
Modulation of cerebral blood flow parameters in humans following consumption of nitrate-rich beetroot juice
Abstracts / Appetite 59 (2012) 618–638
Prevalence of post traumatic stress disorder among patients with substance use disorder: It is higher than clinicians think it is N. GIELEN, R.C. HAVERMANS, M. TEKELENBURG, A. JANSEN. Mondriaan, John F. Kennedylaan 305, 6419 XZ Heerlen, The Netherlands. [email protected] The prevalence of Post Traumatic Stress Disorder (PTSD) and trauma exposure was compared between individuals with and without Substance Use Disorder (SUD). This study examined whether clinicians diagnosed PTSD in SUD patients without using a questionnaire. Finally, an analysis was made of the characteristics of SUD/PTSD patients. The sample consisted of 423 SUD patients and 206 control participants. All individuals were screened on PTSD using the Self Rating Inventory for PTSD. Significant higher numbers of PTSD and trauma exposure were found in the SUD group (resp. 36.9% and 97%). PTSD went frequently unnoticed when no standardised questionnaire was used. SUD/ PTSD patients were significantly more often unemployed and had a lower educational level. Axis I comorbidity and especially depressive disorders were more common in the SUD/PTSD group. It is concluded that SUD/PTSD patients are a substantial and vulnerable subgroup in addiction treatment facilities and that systematically screening for PTSD is required. http://dx.doi.org/10.1016/j.appet.2012.05.067 Are genetic association studies useful for obesity research? The cases of DRD2 and OPRMI C.A. HARDMAN, P.J. ROGERS, M. MUNAFÒ. School of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK. [email protected] Obesity is highly heritable and a growing number of studies have attempted to identify candidate genes that are associated with BMI. The dopamine D2 receptor (DRD2) gene and the mu-opioid receptor (OPRM1) gene appear promising candidates in this respect due to evidence that both the dopaminergic and opioid systems are involved in obesity and over-eating. However, studies conducted to date have yielded inconsistent results – it is not clear, for example, whether the minor allele of the OPRM1 gene predisposes to obesity or alternatively is a protective factor. The current study aimed to determine whether associations exist between these candidate genes and body weight in a large representative sample (the Avon Longitudinal Study of Parents and Children). Importantly, this cohort permits examination of associations both cross-sectionally and longitudinally, and in children and parents (n = 3700 and n = 2638, respectively). Our analyses show a lack of association between DRD2 and OPRM1 genotypes and change in BMI and waist circumference (e.g., for DRD2, per allele dosage effect on BMI = 0.01 kg/m2, 95% CI: 0.14, 0.15). We suggest that previous inconsistent results are due to low power of genetic association studies, and a tendency for their findings to become immune to refutation by empirical research. The history of genetic association studies in psychiatry is one of initial promise followed by subsequent disappointment (due in large part to insufficiently powered studies). It is imperative to avoid these mistakes from being repeated in the obesity literature. http://dx.doi.org/10.1016/j.appet.2012.05.068
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Modulation of cerebral blood flow parameters in humans following consumption of nitrate-rich beetroot juice C.F. HASKELL, D.O. KENNEDY, F. DODD, L. TURNER, A.M. JONES, J. PRICHARD, P. BELL, K.G. THOMPSON. Brain, Performance and Nutrition Research Centre, School of Life Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK. crystal.haskell@ northumbria. ac.uk Nitrate, abundant in beetroot, has been shown to reduce blood pressure and the oxygen cost of sub-maximal exercise; improve endothelial function and modulate regional perfusion in the brain. In this randomised, placebo-controlled, double-blind, crossover study, 16 physically active healthy young adult males received either 450 ml of beetroot juice (~5.5 mmol nitrate) or a fruit flavoured placebo drink. Following a 90-min absorption period participants performed Stroop and Rapid Visual Information Processing tasks (9-min each) at rest, and during cycling at 50% and 70% VO2max and finally following exercise. Pre-frontal cerebral haemodynamics, as indexed by concentration changes in oxygenated and deoxygenated haemoglobin, were assessed throughout using Near Infrared Spectroscopy. Dietary nitrate modulated the haemodynamic response to task performance/exercise, with a significant interaction effect revealing lower cerebral deoxygenated haemoglobin relative to placebo during each task within each of the four post-intervention assessments. Dietary nitrate also significantly reduced systolic blood pressure post-exercise and time to limit of tolerance during 90% VO2max was significantly increased. Cognitive performance was unaffected. These data support previous reports of modulation of blood pressure and lowered deoxygenated haemoglobin in muscle following dietary nitrate and demonstrate that this effect on deoxygenated haemoglobin extends to the frontal cerebral cortex. Taken together these findings suggest a decrease in oxygen extraction during mental and physical performance with no resultant detrimental effects on cognitive performance and a positive effect on physical performance, suggesting a decrease in oxygen cost. http://dx.doi.org/10.1016/j.appet.2012.05.069 Sensory-specific satiety and the variety effect R. HAVERMANS. Department of Clinical Psychological Science, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands. r.havermans@ maastrichtuniversity.nl The variety effect refers to the observation that one is inclined to eat more from a varied meal than from a monotonous meal. A common explanation for this effect is that the variety of foods comprising a varied meal undermines the development of meal satiation. More precisely, the different foods dishabituate sensory-specific satiety for any one food within the meal. Sensory-specific satiety is the decrease in pleasure derived from eating a specific food relative to other uneaten foods. In other words, the variety effect is the result of experiencing different flavours interfering with satiation for any one of these flavours. It can be argued though that this interference is not due to dishabituation of sensory-specific satiety, but the result of a delay in exposure to any one of different foods comprising the meal. According to this alternative explanation, meal variety will not necessarily disturb sensory satiation. http://dx.doi.org/10.1016/j.appet.2012.05.070
Prevalence of post traumatic stress disorder among patients with substance use disorder: It is higher than clinicians think it is N. GIELEN, R.C. HAVERMANS, M. TEKELENBURG, A. JANSEN. Mondriaan, John F. Kennedylaan 305, 6419 XZ Heerlen, The Netherlands. [email protected] The prevalence of Post Traumatic Stress Disorder (PTSD) and trauma exposure was compared between individuals with and without Substance Use Disorder (SUD). This study examined whether clinicians diagnosed PTSD in SUD patients without using a questionnaire. Finally, an analysis was made of the characteristics of SUD/PTSD patients. The sample consisted of 423 SUD patients and 206 control participants. All individuals were screened on PTSD using the Self Rating Inventory for PTSD. Significant higher numbers of PTSD and trauma exposure were found in the SUD group (resp. 36.9% and 97%). PTSD went frequently unnoticed when no standardised questionnaire was used. SUD/ PTSD patients were significantly more often unemployed and had a lower educational level. Axis I comorbidity and especially depressive disorders were more common in the SUD/PTSD group. It is concluded that SUD/PTSD patients are a substantial and vulnerable subgroup in addiction treatment facilities and that systematically screening for PTSD is required. http://dx.doi.org/10.1016/j.appet.2012.05.067 Are genetic association studies useful for obesity research? The cases of DRD2 and OPRMI C.A. HARDMAN, P.J. ROGERS, M. MUNAFÒ. School of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK. [email protected] Obesity is highly heritable and a growing number of studies have attempted to identify candidate genes that are associated with BMI. The dopamine D2 receptor (DRD2) gene and the mu-opioid receptor (OPRM1) gene appear promising candidates in this respect due to evidence that both the dopaminergic and opioid systems are involved in obesity and over-eating. However, studies conducted to date have yielded inconsistent results – it is not clear, for example, whether the minor allele of the OPRM1 gene predisposes to obesity or alternatively is a protective factor. The current study aimed to determine whether associations exist between these candidate genes and body weight in a large representative sample (the Avon Longitudinal Study of Parents and Children). Importantly, this cohort permits examination of associations both cross-sectionally and longitudinally, and in children and parents (n = 3700 and n = 2638, respectively). Our analyses show a lack of association between DRD2 and OPRM1 genotypes and change in BMI and waist circumference (e.g., for DRD2, per allele dosage effect on BMI = 0.01 kg/m2, 95% CI: 0.14, 0.15). We suggest that previous inconsistent results are due to low power of genetic association studies, and a tendency for their findings to become immune to refutation by empirical research. The history of genetic association studies in psychiatry is one of initial promise followed by subsequent disappointment (due in large part to insufficiently powered studies). It is imperative to avoid these mistakes from being repeated in the obesity literature. http://dx.doi.org/10.1016/j.appet.2012.05.068
627
Modulation of cerebral blood flow parameters in humans following consumption of nitrate-rich beetroot juice C.F. HASKELL, D.O. KENNEDY, F. DODD, L. TURNER, A.M. JONES, J. PRICHARD, P. BELL, K.G. THOMPSON. Brain, Performance and Nutrition Research Centre, School of Life Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK. crystal.haskell@ northumbria. ac.uk Nitrate, abundant in beetroot, has been shown to reduce blood pressure and the oxygen cost of sub-maximal exercise; improve endothelial function and modulate regional perfusion in the brain. In this randomised, placebo-controlled, double-blind, crossover study, 16 physically active healthy young adult males received either 450 ml of beetroot juice (~5.5 mmol nitrate) or a fruit flavoured placebo drink. Following a 90-min absorption period participants performed Stroop and Rapid Visual Information Processing tasks (9-min each) at rest, and during cycling at 50% and 70% VO2max and finally following exercise. Pre-frontal cerebral haemodynamics, as indexed by concentration changes in oxygenated and deoxygenated haemoglobin, were assessed throughout using Near Infrared Spectroscopy. Dietary nitrate modulated the haemodynamic response to task performance/exercise, with a significant interaction effect revealing lower cerebral deoxygenated haemoglobin relative to placebo during each task within each of the four post-intervention assessments. Dietary nitrate also significantly reduced systolic blood pressure post-exercise and time to limit of tolerance during 90% VO2max was significantly increased. Cognitive performance was unaffected. These data support previous reports of modulation of blood pressure and lowered deoxygenated haemoglobin in muscle following dietary nitrate and demonstrate that this effect on deoxygenated haemoglobin extends to the frontal cerebral cortex. Taken together these findings suggest a decrease in oxygen extraction during mental and physical performance with no resultant detrimental effects on cognitive performance and a positive effect on physical performance, suggesting a decrease in oxygen cost. http://dx.doi.org/10.1016/j.appet.2012.05.069 Sensory-specific satiety and the variety effect R. HAVERMANS. Department of Clinical Psychological Science, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands. r.havermans@ maastrichtuniversity.nl The variety effect refers to the observation that one is inclined to eat more from a varied meal than from a monotonous meal. A common explanation for this effect is that the variety of foods comprising a varied meal undermines the development of meal satiation. More precisely, the different foods dishabituate sensory-specific satiety for any one food within the meal. Sensory-specific satiety is the decrease in pleasure derived from eating a specific food relative to other uneaten foods. In other words, the variety effect is the result of experiencing different flavours interfering with satiation for any one of these flavours. It can be argued though that this interference is not due to dishabituation of sensory-specific satiety, but the result of a delay in exposure to any one of different foods comprising the meal. According to this alternative explanation, meal variety will not necessarily disturb sensory satiation. http://dx.doi.org/10.1016/j.appet.2012.05.070