Showing papers by "Julie A. Dumas published in 2013"

Chemotherapy altered brain functional connectivity in women with breast cancer: a pilot study.

Abstract: Adjuvant chemotherapy is associated with improvements in long-term cancer survival. However, reports of cognitive impairment following treatment emphasize the importance of understanding the long-term effects of chemotherapy on brain functioning. Cognitive deficits found in chemotherapy patients suggest a change in brain functioning that affects specific cognitive domains such as attentional processing and executive functioning. This study examined the processes potentially underlying these changes in cognition by examining brain functional connectivity pre- and post-chemotherapy in women with breast cancer. Functional connectivity examines the temporal correlation between spatially remote brain regions in an effort to understand how brain networks support specific cognitive functions. Nine women diagnosed with breast cancer completed a functional magnetic resonance imaging (fMRI) session before chemotherapy, 1 month after, and 1 year after the completion of chemotherapy. Seed-based functional connectivity analyses were completed using seeds in the intraparietal sulcus (IPS) to examine connectivity in the dorsal anterior attention network and in the posterior cingulate cortex (PCC) to examine connectivity in the default mode network. Results showed decreased functional connectivity 1 month after chemotherapy that partially returned to baseline at 1 year in the dorsal attention network. Decreased connectivity was seen in the default mode network at 1 month and 1 year following chemotherapy. In addition, increased subjective memory complaints were noted at 1 month and 1 year post-chemotherapy. These findings suggest a detrimental effect of chemotherapy on brain functional connectivity that is potentially related to subjective cognitive assessment.

Substituting dietary monounsaturated fat for saturated fat is associated with increased daily physical activity and resting energy expenditure and with changes in mood123

Abstract: BACKGROUND The Western diet increases risk of metabolic disease. OBJECTIVE We determined whether lowering the ratio of saturated fatty acids to monounsaturated fatty acids in the Western diet would affect physical activity and energy expenditure. DESIGN With the use of a balanced design, 2 cohorts of 18 and 14 young adults were enrolled in separate randomized, double-masked, crossover trials that compared a 3-wk high-palmitic acid diet (HPA; similar to the Western diet fat composition) to a low-palmitic acid and high-oleic acid diet (HOA; similar to the Mediterranean diet fat composition). All foods were provided by the investigators, and the palmitic acid (PA):oleic acid (OA) ratio was manipulated by adding different oil blends to the same foods. In both cohorts, we assessed physical activity (monitored continuously by using accelerometry) and resting energy expenditure (REE). To gain insight into a possible mood disturbance that might explain changes in physical activity, the Profile of Mood States (POMS) was administered in cohort 2. RESULTS Physical activity was higher during the HOA than during the HPA in 15 of 17 subjects in cohort 1 (P = 0.008) (mean: 12% higher; P = 0.003) and in 12 of 12 subjects in the second, confirmatory cohort (P = 0.005) (mean: 15% higher; P = 0.003). When the HOA was compared with the HPA, REE measured during the fed state was 3% higher for cohort 1 (P < 0.01), and REE was 4.5% higher in the fasted state for cohort 2 (P = 0.04). POMS testing showed that the anger-hostility score was significantly higher during the HPA (P = 0.007). CONCLUSIONS The replacement of dietary PA with OA was associated with increased physical activity and REE and less anger. Besides presumed effects on mitochondrial function (increased REE), the dietary PA:OA ratio appears to affect behavior. The second cohort was derived from a study that was registered at clinicaltrials.gov as R01DK082803.

Protocol to assess the neurophysiology associated with multi-segmental postural coordination

Abstract: Anticipatory postural adjustments (APAs) stabilize potential disturbances to posture caused by movement. Impaired APAs are common with disease and injury. Brain functions associated with generating APAs remain uncertain due to a lack of paired tasks that require similar limb motion from similar postural orientations, but differ in eliciting an APA while also being compatible with brain imaging techniques (e.g., functional magnetic resonance imaging; fMRI). This study developed fMRI-compatible tasks differentiated by the presence or absence of APAs during leg movement. Eighteen healthy subjects performed two leg movement tasks, supported leg raise (SLR) and unsupported leg raise (ULR), to elicit isolated limb motion (no APA) versus multi-segmental coordination patterns (including APA), respectively. Ground reaction forces under the feet and electromyographic activation amplitudes were assessed to determine the coordination strategy elicited for each task. Results demonstrated that the ULR task elicited a multi-segmental coordination that was either minimized or absent in the SLR task, indicating that it would serve as an adequate control task for fMRI protocols. A pilot study with a single subject performing each task in an MRI scanner demonstrated minimal head movement in both tasks and brain activation patterns consistent with an isolated limb movement for the SLR task versus multi-segmental postural coordination for the ULR task.

Substituting dietary monounsaturated fat for saturated fat is associated with increased daily physical activity and resting energy expenditure

Abstract: Background: The Western diet increases risk of metabolic disease. Objective: We determined whether lowering the ratio of saturated fatty acids to monounsaturated fatty acids in the Western diet would affect physical activity and energy expenditure. Design: With the use of a balanced design, 2 cohorts of 18 and 14 young adults were enrolled in separate randomized, double-masked, crossover trials that compared a 3-wk high–palmitic acid diet (HPA; similar to the Western diet fat composition) to a low–palmitic acid and high–oleic acid diet (HOA; similar to the Mediterranean diet fat composition). All foods were provided by the investigators, and the palmitic acid (PA):oleic acid (OA) ratio was manipulated by adding different oil blends to the same foods. In both cohorts, we assessed physical activity (monitored continuously by using accelerometry) and resting energy expenditure (REE). To gain insight into a possible mood disturbance that might explain changes in physical activity, the Profile of Mood States (POMS) was administered in cohort 2. Results: Physical activity was higher during the HOA than during the HPA in 15 of 17 subjects in cohort 1 (P = 0.008) (mean: 12% higher; P = 0.003) and in 12 of 12 subjects in the second, confirmatory cohort (P = 0.005) (mean: 15% higher; P = 0.003). When the HOA was compared with the HPA, REE measured during the fed state was 3% higher for cohort 1 (P , 0.01), and REE was 4.5% higher in the fasted state for cohort 2 (P = 0.04). POMS testing showed that the anger-hostility score was significantly higher during the HPA (P = 0.007). Conclusions: The replacement of dietary PA with OA was associated with increased physical activity and REE and less anger. Besides presumed effects on mitochondrial function (increased REE), the dietary PA:OA ratio appears to affect behavior. The second cohort was derived from a study that was registered at clinicaltrials. gov as R01DK082803. Am J Clin Nutr 2013;97:689–97.

Lifetime hormone exposure and cognition in postmenopausal women with breast cancer.

Abstract: B reast cancer risk increases after menopause. The American Cancer Society in 2011 estimated that 80% of breast cancers are diagnosed in women aged 50 years or older. As women live to older ages after breast cancer treatment, quality-of-life issues have become important to understand. One common complaint before, during, and after breast cancer treatment involves cognitive changes from precancer levels of functioning, sometimes referred to by survivors as Bchemobrain.[ Recent research has focused on describing changes in cognitive functioning after chemotherapy. Although longitudinal studies have shown that chemotherapy may impair cognition in some women, they have also shown that women with breast cancer have decreased cognitive performance at baseline/prechemotherapy assessment compared with healthy controls. Thus, understanding the factors underlying decreased cognition in women with breast cancer is important in interpreting further decreases after chemotherapy and in preventing and treating cognitive changes. In an effort to understand the mechanisms underlying cognitive changes after cancer diagnosis, it is important to examine the role of hormones, in particular gonadal steroids, in cognition. Prior literature has shown the importance of gonadal steroids in cognition across the life span and in breast cancer development. A large body of literature shows the influence of hormones on cognition in postmenopausal women. In addition, greater lifetime estrogen exposure is related to increased breast cancer risk. In this issue of Menopause, Bender et al examined the influence of lifetime hormone exposure on cognition in postmenopausal women with breast cancer. As breast cancer is primarily a disease of older women, issues of cognitive aging are combined with the cognitive effects of cancer and cancer treatments that perhaps impair cognition in postmenopausal women to a greater extent than in younger women. Thus, understanding how hormones affect cognition and interact with breast cancer and cancer treatment is important as women are living well into older ages as breast cancer survivors. The brain is a major target of circulating gonadal steroids, and lifetime hormone exposure has implications for cognitive functioning. A number of clinical and preclinical studies have linked gonadal steroids and cognition. Studies have shown benefits of increased lifetime hormone exposure on cognition. In addition, some studies have found decreased cognitive performance in specific cognitive domains, including memory, attention, problem solving, and motor skills, after menopause (when circulating estradiol levels dramatically decrease from premenopausal levels). Other studies have not found objective changes in cognition after menopause. Evidence indicates that postmenopausal estrogen therapy maintains the premenopausal levels of cognitive functioning. However, a number of studies have shown that postmenopausal hormone treatment has no benefit on cognition. Studies published as part of the Women’s Health Initiative examined the impact of conjugated estrogens (CEE) plus progestin and conjugated estrogens alone on postmenopausal women and found that combined hormone treatment in older postmenopausal women increased breast cancer risk and dementia. No study has thus far considered the relationship between hormone exposure before menopause, cognition, and cancer. Women with cancer have long reported adverse effects of cancer and cancer treatments on cognition, and a number of studies have shown negative effects of chemotherapy on cognition. Much of the work has focused on women with breast cancer and has found that women report subjective complaints of cognitive impairment and show objective impairment during neuropsychological testing. Interestingly, in longitudinal studies that assessed cognition before and after chemotherapy, women with breast cancer performed worse than noncancer controls at prechemotherapy assessment. Bender et al examined the role of lifetime hormone exposure in this pretreatment difference in cognitive performance between postmenopausal women with breast cancer and controls. They proposed that greater lifetime exposure to hormones might underlie differences in cognition between women with cancer and women without breast cancer. Lifetime hormone exposure is measured by endogenous factors such as age at menarche, age at menopause, and parity, as well as exogenous factors such as hormonal birth control and postmenopausal hormone therapy. In healthy women, greater lifetime estrogen exposure was associated with better verbal memory. Bender et al hypothesized that differences in lifetime estrogen exposure are related to pretreatment cognitive impairment in women with breast cancer, such that greater hormone exposure would be related to better cognitive performance, in general, and better verbal memory, in particular. Bender et al examined cognition in 264 postmenopausal women with breast cancer before they began chemotherapy treatment and compared it with cognition in 95 healthy controls. All participants performed a neurocognitive test battery