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Dive into the research topics where Stan Van Uum is active.

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Featured researches published by Stan Van Uum.


Psychoneuroendocrinology | 2012

Hair cortisol as a biological marker of chronic stress: current status, future directions and unanswered questions.

Evan Russell; Gideon Koren; Michael J. Rieder; Stan Van Uum

The detrimental effects of stress on human health are being increasingly recognized. There is a critical need for the establishment of a biomarker that accurately measures its intensity and course over time. Such a biomarker would allow monitoring of stress, increase understanding of its pathophysiology and may help identify appropriate and successful management strategies. Whereas saliva and urine cortisol capture real-time levels, hair cortisol analysis presents a complementary means of monitoring stress, capturing systemic cortisol exposure over longer periods of time. This novel approach for cortisol quantification is being increasingly used to identify the effects of stress in a variety of pathological situations, from chronic pain to acute myocardial infarctions. Because of its ability to provide a long-term, month-by-month measure of systemic cortisol exposure, hair cortisol analysis is becoming a useful tool, capable of answering clinical questions that could previously not be answered by other tests. In this paper we review the development, current status, limitations and outstanding questions regarding the use of hair cortisol as a biomarker of chronic stress.


Endocrine Reviews | 2010

The Effects of Opioids and Opioid Analogs on Animal and Human Endocrine Systems

Cassidy Vuong; Stan Van Uum; Laura E. O'Dell; Kabirullah Lutfy; Theodore C. Friedman

Opioid abuse has increased in the last decade, primarily as a result of increased access to prescription opioids. Physicians are also increasingly administering opioid analgesics for noncancer chronic pain. Thus, knowledge of the long-term consequences of opioid use/abuse has important implications for fully evaluating the clinical usefulness of opioid medications. Many studies have examined the effect of opioids on the endocrine system; however, a systematic review of the endocrine actions of opioids in both humans and animals has, to our knowledge, not been published since 1984. Thus, we reviewed the literature on the effect of opioids on the endocrine system. We included both acute and chronic effects of opioids, with the majority of the studies done on the acute effects although chronic effects are more physiologically relevant. In humans and laboratory animals, opioids generally increase GH and prolactin and decrease LH, testosterone, estradiol, and oxytocin. In humans, opioids increase TSH, whereas in rodents, TSH is decreased. In both rodents and humans, the reports of effects of opioids on arginine vasopressin and ACTH are conflicting. Opioids act preferentially at different receptor sites leading to stimulatory or inhibitory effects on hormone release. Increasing opioid abuse primarily leads to hypogonadism but may also affect the secretion of other pituitary hormones. The potential consequences of hypogonadism include decreased libido and erectile dysfunction in men, oligomenorrhea or amenorrhea in women, and bone loss or infertility in both sexes. Opioids may increase or decrease food intake, depending on the type of opioid and the duration of action. Additionally, opioids may act through the sympathetic nervous system to cause hyperglycemia and impaired insulin secretion. In this review, recent information regarding endocrine disorders among opioid abusers is presented.


American Journal of Epidemiology | 2009

Stress Pathways to Spontaneous Preterm Birth: The Role of Stressors, Psychological Distress, and Stress Hormones

Michael S. Kramer; John E. Lydon; Louise Séguin; Lise Goulet; Susan R. Kahn; Helen McNamara; Jacques Genest; Clément Dassa; Moy Fong Chen; Shakti Sharma; Michael J. Meaney; Steven Thomson; Stan Van Uum; Gideon Koren; Mourad Dahhou; Julie Lamoureux; Robert W. Platt

The authors investigated a large number of stressors and measures of psychological distress in a multicenter, prospective cohort study of spontaneous preterm birth among 5,337 Montreal (Canada)-area women who delivered from October 1999 to April 2004. In addition, a nested case-control analysis (207 cases, 444 controls) was used to explore potential biologic pathways by analyzing maternal plasma corticotrophin-releasing hormone (CRH), placental histopathology, and (in a subset) maternal hair cortisol. Among the large number of stress and distress measures studied, only pregnancy-related anxiety was consistently and independently associated with spontaneous preterm birth (for values above the median, adjusted odds ratio = 1.8 (95% confidence interval: 1.3, 2.4)), with a dose-response relation across quartiles. The maternal plasma CRH concentration was significantly higher in cases than in controls in crude analyses but not after adjustment (for concentrations above the median, adjusted odds ratio = 1.1 (95% confidence interval: 0.8, 1.6)). In the subgroup (n = 117) of participants with a sufficient maternal hair sample, hair cortisol was positively associated with gestational age. Neither maternal plasma CRH, hair cortisol, nor placental histopathologic features of infection/inflammation, infarction, or maternal vasculopathy were significantly associated with pregnancy-related anxiety or any other stress or distress measure. The biologic pathways underlying stress-induced preterm birth remain poorly understood.


Stress | 2011

Hair cortisol and the risk for acute myocardial infarction in adult men.

David Pereg; Rachel Gow; Morris Mosseri; Michael Lishner; Michael J. Rieder; Stan Van Uum; Gideon Koren

Acute stress is increasingly recognized as a precipitant of acute myocardial infarction (AMI). However, the role of chronic stress in developing AMI is less clear. We have developed a method to measure cortisol in hair, which allows longitudinal assessment of cortisol levels prior to an acute event. We aimed to evaluate the hypothesis that chronic stress, as assessed by hair cortisol content, is associated with the development of AMI. A prospective case–control study included 56 patients admitted to hospital with AMI and 56 control patients, admitted to internal medicine wards for other indications. An enzyme immunoassay technique was used to measure cortisol in the most proximal 3 cm of hair, considered to represent the most recent 3 months of exposure. Median hair cortisol contents (range) were 295.3 (105.4–809.3)ng/g in AMI patients and 224.9 (76.58–949.9)ng/g in controls (p = 0.006, Mann–Whitney U-test). After controlling for other risk factors for AMI using multiple logistic regression, log-transformed hair cortisol content remained the strongest predictor (OR 17.4, 95% CI 2.15–140.5; p = 0.007). We demonstrated elevated hair cortisol concentrations in patients with AMI. This suggests that chronic stress, as assessed by increased hair cortisol in the 3 months prior to the event, may be a contributing factor for AMI.


Proceedings of the National Academy of Sciences of the United States of America | 2011

Heparan sulfate 6-O-sulfotransferase 1, a gene involved in extracellular sugar modifications, is mutated in patients with idiopathic hypogonadotrophic hypogonadism

Janne Tornberg; Gerasimos P. Sykiotis; Kimberly Keefe; Lacey Plummer; Xuan Hoang; Janet E. Hall; Richard Quinton; Stephanie B. Seminara; Virginia A. Hughes; Guy Van Vliet; Stan Van Uum; William F. Crowley; Hiroko Habuchi; Koji Kimata; Nelly Pitteloud; Hannes E. Bülow

Neuronal development is the result of a multitude of neural migrations, which require extensive cell-cell communication. These processes are modulated by extracellular matrix components, such as heparan sulfate (HS) polysaccharides. HS is molecularly complex as a result of nonrandom modifications of the sugar moieties, including sulfations in specific positions. We report here mutations in HS 6-O-sulfotransferase 1 (HS6ST1) in families with idiopathic hypogonadotropic hypogonadism (IHH). IHH manifests as incomplete or absent puberty and infertility as a result of defects in gonadotropin-releasing hormone neuron development or function. IHH-associated HS6ST1 mutations display reduced activity in vitro and in vivo, suggesting that HS6ST1 and the complex modifications of extracellular sugars are critical for normal development in humans. Genetic experiments in Caenorhabditis elegans reveal that HS cell-specifically regulates neural branching in vivo in concert with other IHH-associated genes, including kal-1, the FGF receptor, and FGF. These findings are consistent with a model in which KAL1 can act as a modulatory coligand with FGF to activate the FGF receptor in an HS-dependent manner.


Neuropsychiatric Disease and Treatment | 2010

relationship between hair cortisol concentrations and depressive symptoms in patients with coronary artery disease

Yekta Dowlati; Nathan Herrmann; Walter Swardfager; Steven Thomson; Paul Oh; Stan Van Uum; Gideon Koren; Krista L. Lanctôt

Objective Concentrations of cortisol in hair, a novel marker of longer-term cortisol status, were compared in depressed versus nondepressed patients with coronary artery disease (CAD). Methods 20 mg hair samples of 3 cm length were collected from 121 patients attending a cardiac rehabilitation program, 34 of whom suffered from depressive symptoms. Results Controlling for age, gender, coronary artery bypass grafting, history of depression, and time since most recent acute coronary syndrome, cortisol concentrations (P = 0.162) did not predict severity of depression. Younger age (P = 0.003) was a significant predictor of depressive symptoms. Perceived stress was not associated with long-term cortisol concentrations (P = 0.161). Conclusions Cortisol concentrations in hair do not predict depressive symptoms in CAD patients attending cardiac rehabilitation.


PLOS ONE | 2013

Neonatal Pain-Related Stress and NFKBIA Genotype Are Associated with Altered Cortisol Levels in Preterm Boys at School Age

Ruth E. Grunau; Ivan L. Cepeda; Cecil M. Y. Chau; Susanne Brummelte; Joanne Weinberg; Pascal M. Lavoie; Mihoko Ladd; Aaron F. Hirschfeld; Evan Russell; Gideon Koren; Stan Van Uum; Rollin Brant; Stuart E. Turvey

Neonatal pain-related stress is associated with elevated salivary cortisol levels to age 18 months in children born very preterm, compared to full-term, suggesting early programming effects. Importantly, interactions between immune/inflammatory and neuroendocrine systems may underlie programming effects. We examined whether cortisol changes persist to school age, and if common genetic variants in the promoter region of the NFKBIA gene involved in regulation of immune and inflammatory responses, modify the association between early experience and later life stress as indexed by hair cortisol levels, which provide an integrated index of endogenous HPA axis activity. Cortisol was assayed in hair samples from 128 children (83 born preterm ≤32 weeks gestation and 45 born full-term) without major sensory, motor or cognitive impairments at age 7 years. We found that hair cortisol levels were lower in preterm compared to term-born children. Downregulation of the HPA axis in preterm children without major impairment, seen years after neonatal stress terminated, suggests persistent alteration of stress system programming. Importantly, the etiology was gender-specific such that in preterm boys but not girls, specifically those with the minor allele for NFKBIA rs2233409, lower hair cortisol was associated with greater neonatal pain (number of skin-breaking procedures from birth to term), independent of medical confounders. Moreover, the minor allele (CT or TT) of NFKBIA rs2233409 was associated with higher secretion of inflammatory cytokines, supporting the hypothesis that neonatal pain-related stress may act as a proinflammatory stimulus that induces long-term immune cell activation. These findings are the first evidence that a long-term association between early pain-related stress and cortisol may be mediated by a genetic variants that regulate the activity of NF-κB, suggesting possible involvement of stress/inflammatory mechanisms in HPA programming in boys born very preterm.


Clinical Endocrinology | 2011

Hair cortisol content in patients with adrenal insufficiency on hydrocortisone replacement therapy

Rachel Gow; Gideon Koren; Michael J. Rieder; Stan Van Uum

Objective  Patients with adrenal insufficiency (AI) require life‐long replacement therapy with exogenous glucocorticoids. Several studies have shown impaired subjective health status in these patients as well as increased morbidity and mortality risk, which may be caused by glucocorticoid over‐replacement. As a measure of long‐term cortisol exposure, the usefulness of hair cortisol analysis in patients receiving glucocorticoid replacement therapy was investigated.


The Journal of Pediatrics | 2008

Impaired endothelial function in adolescents with type 1 diabetes mellitus.

Farid H. Mahmud; Stan Van Uum; Nimira Kanji; Heather Thiessen-Philbrook; Cheril L. Clarson

OBJECTIVE To evaluate the effect of a high-fat meal on endothelial function in adolescents with type 1 diabetes mellitus (T1D). STUDY DESIGN Twenty-three children with T1D, aged 12 to 18 years, and age- and sex-matched healthy control subjects were assessed for baseline macronutrient intake, and endothelial function was measured both fasting and after a standardized fast-food, high-fat breakfast. RESULTS Endothelial function, assessed noninvasively by peripheral arterial tonometry, was impaired in the T1D group in the fasting state as compared with control subjects (T1D 1.78 +/- 0.4, control subjects 2.06 +/- 0.4, P = .02), and worsened postprandially in both groups (T1D 1.45 +/- 0.3, control subjects 1.71 +/- 0.3, P = .01). Both groups demonstrated significantly elevated triglyceride levels 3.5 hours after ingestion of the high-fat meal (T1D 114.8 +/- 42.8 and control subjects 126.7 +/- 54.9 mg/dL). Nutrient intake in both groups showed higher than recommended intakes of total fat, saturated fat, and cholesterol. CONCLUSIONS Patients with T1D exhibited worse endothelial function both before and after a high-fat breakfast than their peers. This suggests that patients with T1D are at greater risk of vascular impairment after a high-fat meal, the cumulative effect of which may contribute to the higher atherosclerotic burden observed in T1D.


Stress | 2014

Associations of hair cortisol concentration with self-reported measures of stress and mental health-related factors in a pooled database of diverse community samples.

Samantha Wells; Paul F. Tremblay; Andrea Flynn; Evan Russell; James L. Kennedy; Jürgen Rehm; Stan Van Uum; Gideon Koren; Kathryn Graham

Abstract A pooled database from diverse community samples was used to examine the associations of hair cortisol concentration (HCC) with self-reported stress and stress-linked mental health measures, including depression, anxiety, alcohol and drug use, disability and experiences with aggression. As part of innovative research using a mobile laboratory to study community mental health, data were pooled from five sub-studies: a random sample of the general population (n = 70), people who had received treatment for a mental health and/or substance use problem (n = 78), family members of people treated for mental health and/or substance use problems (n = 49), community volunteers who sometimes felt sad or blue or thought they drank too much (n = 83) and young adults in intimate partner relationships (n = 44). All participants completed a computerized questionnaire including standard measures of perceived stress, chronic stress, depression, anxiety, hazardous drinking, tobacco use, prescription drug use, illicit drug use, disability and intimate partner aggression. HCC was significantly associated with use of antidepressants, hazardous drinking, smoking and disability after adjusting for sub-study and potential confounders (sex, body-mass index, use of glucocorticoids and hair dyed). In addition, preliminary analyses suggest a significant curvilinear relationship between HCC and perceived stress; specifically, HCC increased with higher perceived stress but decreased at the highest level of stress. Overall, HCC was associated with mental health-related variables mainly reflecting substance use or experiencing a disability. The relationship between HCC and self-reported stress is unclear and needs further research.

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Evan Russell

University of Western Ontario

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Robert A. Hegele

University of Western Ontario

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Michael J. Rieder

University of Western Ontario

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Robert Gros

University of Western Ontario

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Ross D. Feldman

Memorial University of Newfoundland

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Chantelle A. Nielson

University of Western Ontario

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J. Kevin Shoemaker

Penn State Milton S. Hershey Medical Center

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Tamara I. Gimon

University of Western Ontario

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Torri A. Luchyshyn

University of Western Ontario

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