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Dive into the research topics where Suzanne Barsness is active.

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Featured researches published by Suzanne Barsness.


Sleep Medicine | 2009

A randomized clinical trial of valerian fails to improve self-reported, polysomnographic, and actigraphic sleep in older women with insomnia

Diana M. Taibi; Michael V. Vitiello; Suzanne Barsness; Gary W. Elmer; Gail D. Anderson; Carol A. Landis

OBJECTIVE To test the effects of nightly valerian (Valeriana officinalis) extract to improve sleep of older women with insomnia. METHODS Participants in this phase 2 randomized, double-blind, crossover controlled trial were 16 older women (mean age=69.4+/-8.1 years) with insomnia. Participants took 300 mg of concentrated valerian extract or placebo 30 min before bedtime for 2 weeks. Sleep was assessed in the laboratory by self-report and polysomnography (PSG) at baseline and again at the beginning and end of each treatment phase (total of nine nights in the laboratory) and at home by daily sleep logs and actigraphy. RESULTS There were no statistically significant differences between valerian and placebo after a single dose or after 2 weeks of nightly dosing on any measure of sleep latency, wake after sleep onset (WASO), sleep efficiency, and self-rated sleep quality. In comparing each treatment to baseline in separate comparisons, WASO significantly increased (+17.7+/-25.6 min, p=.02) after 2 weeks of nightly valerian, but not after placebo (+6.8+/-26.4 min, NS). Side effects were minor and did not differ significantly between valerian and placebo. CONCLUSION Valerian did not improve sleep in this sample of older women with insomnia. Findings from this study add to the scientific evidence that does not support use of valerian in the clinical management of insomnia.


JAMA Neurology | 2013

Growth Hormone–Releasing Hormone Effects on Brain γ-Aminobutyric Acid Levels in Mild Cognitive Impairment and Healthy Aging

Seth D. Friedman; Laura D. Baker; Soo Borson; J. Eric Jensen; Suzanne Barsness; Suzanne Craft; Randolph K. Otto; Edward Novotny; Michael V. Vitiello

IMPORTANCE Growth hormone-releasing hormone (GHRH) has been previously shown to have cognition-enhancing effects. The role of neurotransmitter changes, measured by proton magnetic resonance spectroscopy, may inform the mechanisms for this response. OBJECTIVE To examine the neurochemical effects of GHRH in a subset of participants from the parent trial. DESIGN Randomized, double-blind, placebo-controlled substudy of a larger trial. SETTING Clinical research unit at the University of Washington School of Medicine. PARTICIPANTS Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study. INTERVENTIONS Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks. At baseline and weeks 10 and 20, participants underwent brain magnetic resonance imaging and spectroscopy protocols and cognitive testing and provided blood samples after fasting. Participants also underwent glucose tolerance tests before and after intervention. MAIN OUTCOMES AND MEASURES Brain levels of glutamate, inhibitory transmitters γ-aminobutyric acid (GABA) and N-acetylaspartylglutamate (NAAG), and myo-inositol (MI), an osmolyte linked to Alzheimer disease in humans, were measured in three 2 × 2 × 2-cm3 left-sided brain regions (dorsolateral frontal, posterior cingulate, and posterior parietal). Glutamate, GABA, and MI levels were expressed as ratios to creatine plus phosphocreatine, and NAAG was expressed as a ratio to N-acetylaspartate. RESULTS After 20 weeks of GHRH administration, GABA levels were increased in all brain regions (P < .04), NAAG levels were increased (P = .03) in the dorsolateral frontal cortex, and MI levels were decreased in the posterior cingulate (P = .002). These effects were similar in adults with MCI and older adults with normal cognitive function. No changes in the brain levels of glutamate were observed. In the posterior cingulate, treatment-related changes in serum insulin-like growth factor 1 were positively correlated with changes in GABA (r = 0.47; P = .001) and tended to be negatively correlated with MI (r = -0.34; P = .06). Consistent with the results of the parent trial, a favorable treatment effect on cognition was observed in substudy participants (P = .03). No significant associations were observed between treatment-related changes in neurochemical and cognitive outcomes. Glucose homeostasis in the periphery was not reliably affected by GHRH administration and did not account for treatment neurochemical effects. CONCLUSIONS Twenty weeks of GHRH administration increased GABA levels in all 3 brain regions, increased NAAG levels in the frontal cortex, and decreased MI levels in the posterior cingulate. To our knowledge, this is the first evidence that 20 weeks of somatotropic supplementation modulates inhibitory neurotransmitter and brain metabolite levels in a clinical trial, and it provides preliminary support for one possible mechanism to explain favorable GHRH effects on cognition in adults with MCI and in healthy older adults. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00257712.


Phytotherapy Research | 2010

Pharmacokinetics of Valerenic Acid After Single and Multiple Doses of Valerian in Older Women

Gail D. Anderson; Gary W. Elmer; Diana M. Taibi; Michael V. Vitiello; Eric D. Kantor; Thomas F. Kalhorn; William N. Howald; Suzanne Barsness; Carol A. Landis

Insomnia is a commonly reported clinical problem with as many as 50% of older adults reporting difficulty in falling and/or remaining asleep. Valerian (Valeriana officinalis) is a commonly used herb that has been advocated for promoting sleep. Valerenic acid is used as a marker for quantitative analysis of valerian products with evidence of pharmacological activity relevant to the hypnotic effects of valerian. The objective of this study was to determine the pharmacokinetics of valerenic acid in a group of elderly women after receiving a single nightly valerian dose and after 2 weeks of valerian dosing. There was not a statistically significant difference in the average peak concentration (Cmax), time to maximum concentration (Tmax) area under the time curve (AUC), elimination half‐life (T1/2) and oral clearance after a single dose compared with multiple dosing. There was considerable inter‐ and intra‐subject variability in the pharmacokinetic parameters. Cmax and AUC deceased and T1/2 increased with increased body weight. The variability between the capsules was extremely low: 2.2%, 1.4% and 1.4%, for hydroxyvalerenic acid, acetoxyvalerenic acid and valerenic acid, respectively. In conclusion, large variability in the pharmacokinetics of valerenic acid may contribute to the inconsistencies in the effect of valerian as a sleep aid. Copyright


Journal of Anti-aging Medicine | 2001

Growth Hormone Releasing Hormone Treatment in Normal Aging

Suzanne Barsness; David M. Buchner; Monica Kletke; Lawrence H. Larsen; Karen E. Moe; Robert S. Schwartz; Michael V. Vitiello

Because the aging pituitary remains responsive to stimulation by growth hormone (GH) secretagogues - GHRH, ghrelin, and their mimetics - these compounds could potentially be used instead of GH itse...


The Journal of Clinical Endocrinology and Metabolism | 2004

Diet-Induced Weight Loss Is Associated with an Improvement in β-Cell Function in Older Men

Kristina M. Utzschneider; Darcy B. Carr; Suzanne Barsness; Steven E. Kahn; Robert S. Schwartz


JAMA Neurology | 2012

Effects of Growth Hormone–Releasing Hormone on Cognitive Function in Adults With Mild Cognitive Impairment and Healthy Older Adults: Results of a Controlled Trial

Laura D. Baker; Suzanne Barsness; Soo Borson; Seth D. Friedman; Suzanne Craft; Michael V. Vitiello


Today's Therapeutic Trends | 2000

Growth hormone-releasing hormone in normal aging: An update

Monica Kletke; Suzanne Barsness; David M. Buchner; V. Hirth; Karen E. Moe; Robert S. Schwartz; Michael V. Vitiello


Alzheimers & Dementia | 2011

Tesamorelin, a growth hormone-releasing hormone analogue, improves cognitive function in MCI and healthy aging: Results of a randomized controlled trial

Laura D. Baker; Soo Borson; Suzanne Barsness; Seth D. Friedman; Michael V. Vitiello


Investigative Ophthalmology & Visual Science | 1996

Effects of GHRH treatment on 24-hour GH secretion in healthy older men

S. Galt; G. Drolet; Suzanne Barsness; Karen E. Moe; Robert S. Schwartz; Michael V. Vitiello


Alzheimers & Dementia | 2012

Growth hormone-releasing hormone administration in mild cognitive impairment and healthy aging increases inhibitory neurotransmitter activity in brain as measured by MR spectroscopy

Laura D. Baker; Seth D. Friedman; Soo Borson; Suzanne Barsness; Suzanne Craft; Randolph K. Otto; Edward Novotny; Michael V. Vitiello

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Robert S. Schwartz

University of Colorado Denver

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Karen E. Moe

University of Washington

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Soo Borson

University of Washington

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Monica Kletke

University of Washington

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Diana M. Taibi

University of Washington

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