BACKGROUND:Aromatase inhibitor-induced musculoskeletal syndrome (AIMSS) leads to discontinuation of aromatase inhibitor therapy in a significant proportion of patients with breast cancer. Acupuncture is popular among cancer patients and has previously been shown to improve symptoms in a range of musculoskeletal complaints.

AIM:To determine the effectiveness and safety of acupuncture for the management of AIMSS in postmenopausal women with early-stage breast cancer.

METHODS:A literature search was carried out for randomised controlled trials (RCTs) on acupuncture for AIMSS in postmenopausal women with early-stage breast cancer. Characteristics of trials and outcomes were extracted from the retrieved articles, which were also assessed for risk of bias and quality of reporting.

RESULTS:Four RCTs were retrieved of sample size 32-67 (totalling 190 participants). Compliance with treatment was high and rates of adverse events were low. Of the three two-arm RCTs, two found no difference between acupuncture and sham acupuncture and one found that acupuncture was statistically superior to sham acupuncture. The fourth RCT, which incorporated three arms, found acupuncture and sham acupuncture to be statistically superior to usual care but there was no difference between true and sham acupuncture. Three trials that used non-penetrating sham as the control found no effect of acupuncture over sham, but the one trial that used superficial needle insertion found acupuncture to be superior.

CONCLUSIONS:Acupuncture is safe and results in improvement in AIMSS symptoms, but similar benefits are also elicited by non-penetrating sham acupuncture. Future research should seek to establish the durability of improvements.

BACKGROUND:Aromatase inhibitor-induced musculoskeletal syndrome (AIMSS) leads to discontinuation of aromatase inhibitor therapy in a significant proportion of patients with breast cancer. Acupuncture is popular among cancer patients and has previously been shown to improve symptoms in a range of musculoskeletal complaints.

AIM:To determine the effectiveness and safety of acupuncture for the management of AIMSS in postmenopausal women with early-stage breast cancer.

METHODS:A literature search was carried out for randomised controlled trials (RCTs) on acupuncture for AIMSS in postmenopausal women with early-stage breast cancer. Characteristics of trials and outcomes were extracted from the retrieved articles, which were also assessed for risk of bias and quality of reporting.

RESULTS:Four RCTs were retrieved of sample size 32-67 (totalling 190 participants). Compliance with treatment was high and rates of adverse events were low. Of the three two-arm RCTs, two found no difference between acupuncture and sham acupuncture and one found that acupuncture was statistically superior to sham acupuncture. The fourth RCT, which incorporated three arms, found acupuncture and sham acupuncture to be statistically superior to usual care but there was no difference between true and sham acupuncture. Three trials that used non-penetrating sham as the control found no effect of acupuncture over sham, but the one trial that used superficial needle insertion found acupuncture to be superior.

CONCLUSIONS:Acupuncture is safe and results in improvement in AIMSS symptoms, but similar benefits are also elicited by non-penetrating sham acupuncture. Future research should seek to establish the durability of improvements.

BACKGROUND:Patients irradiated for brain tumors often suffer from cerebral edema and are usually treated with dexamethasone, which has various side effects. To investigate the activity of Boswellia serrata (BS) in radiotherapy-related edema, we conducted a prospective, randomized, placebo-controlled, double-blind, pilot trial.

METHODS:Forty-four patients with primary or secondary malignant cerebral tumors were randomly assigned to radiotherapy plus either BS 4200 mg/day or placebo. The volume of cerebral edema in the T2-weighted magnetic resonance imaging (MRI) sequence was analyzed as a primary endpoint. Secondary endpoints were toxicity, cognitive function, quality of life, and the need for antiedematous (dexamethasone) medication. Blood samples were taken to analyze the serum concentration of boswellic acids (AKBA and KBA).

RESULTS:Compared with baseline and if measured immediately after the end of radiotherapy and BS/placebo treatment, a reduction of cerebral edema of>75% was found in 60% of patients receiving BS and in 26% of patients receiving placebo (P = .023). These findings may be based on an additional antitumor effect. There were no severe adverse events in either group. In the BS group, 6 patients reported minor gastrointestinal discomfort. BS did not have a significant impact on quality of life or cognitive function. The dexamethasone dose during radiotherapy in both groups was not statistically different. Boswellic acids could be detected in patients' serum.

CONCLUSIONS:BS significantly reduced cerebral edema measured by MRI in the study population. BS could potentially be steroid-sparing for patients receiving brain irradiation. Our findings will need to be further validated in larger studies.

Depression, anxiety and sleep disturbances are known problems in patients with breast cancer. The effect of melatonin as an antidepressant in humans with cancer has not been investigated. We investigated whether melatonin could lower the risk of depressive symptoms in women with breast cancer in a three-month period after surgery and assessed the effect of melatonin on subjective parameters: anxiety, sleep, general well-being, fatigue, pain and sleepiness. Randomized, double-blind, placebo-controlled trial undertaken from July 2011 to December 2012 at a department of breast surgery in Copenhagen, Denmark. Women, 30-75 years, undergoing surgery for breast cancer and without signs of depression on Major Depression Inventory (MDI) were included 1 week before surgery and received 6 mg oral melatonin or placebo for 3 months. The primary outcome was the incidence of depressive symptoms measured by MDI. The secondary outcomes were area under the curve (AUC) for the subjective parameters. 54 patients were randomized to melatonin (n = 28) or placebo (n = 26) and 11 withdrew from the study (10 placebo group and 1 melatonin group, P = 0.002). The risk of developing depressive symptoms was significantly lower with melatonin than with placebo (3 [11 %] of 27 vs. 9 [45 %] of 20; relative risk 0.25 [95 % CI 0.077-0.80]), giving a NNT of 3.0 [95 % CI 1.7-11.0]. No significant differences were found between AUC for the subjective parameters. No differences in side effects were found (P = 0.78). Melatonin significantly reduced the risk of depressive symptoms in women with breast cancer during a three-month period after surgery.

OBJECTIVE:To investigate the effects of Korean red ginseng (KRG) on semen parameters in male infertility patients in a randomized, double-blind, placebo-controlled study.

METHODS:A total of 80 male infertility patients with varicocele were recruited from April 2011 to February 2012. The subjects were then divided into the following four groups: non-varicocelectomy (V)+placebo (P) group, V+P group, non-V+KRG group (1.5-g KRG daily), and V+KGR group (1.5-g KRG daily). Semen analysis was performed and hormonal levels were measured in each treatment arm after 12 weeks.

RESULTS:All groups but not the non-V+P group, showed significant improvements in sperm concentrations, motility, morphology, and viability at the end of the study. However, there were no significant differences in serum follicle-stimulating hormone, luteinizing hormone, and testosterone among groups. The incidence of adverse events was low, and all events were assumed to be unrelated to the treatments administered.

CONCLUSIONS:Although the exact mechanism by which KRG improves spermatogenesis remains unclear, KRG may be a useful agent for the treatment of male infertility. Nevertheless, additional studies to evaluate the optimal dose and duration of treatment are needed.

Ayahuasca, a South American psychotropic plant tea obtained from Banisteriopsis caapi and Psychotria viridis, combines monoamine oxidase-inhibiting beta-carboline alkaloids with N,N-dimethyltryptamine (DMT), a psychedelic agent showing 5-HT(2A) agonist activity. In a clinical research setting, ayahuasca has demonstrated a combined stimulatory and psychedelic effect profile, as measured by subjective effect self-assessment instruments and dose-dependent changes in spontaneous brain electrical activity, which parallel the time course of subjective effects. In the present study, the spatial distribution of ayahuasca-induced changes in brain electrical activity was investigated by means of low-resolution electromagnetic tomography (LORETA). Electroencephalography recordings were obtained from 18 volunteers after the administration of a dose of encapsulated freeze-dried ayahuasca containing 0.85 mg DMT/kg body weight and placebo. The intracerebral power density distribution was computed with LORETA from spectrally analyzed data, and subjective effects were measured by means of the Hallucinogen Rating Scale (HRS). Statistically significant differences compared to placebo were observed for LORETA power 60 and 90 min after dosing, together with increases in all six scales of the HRS. Ayahuasca decreased power density in the alpha-2, delta, theta and beta-1 frequency bands. Power decreases in the delta, alpha-2 and beta-1 bands were found predominantly over the temporo-parieto-occipital junction, whereas theta power was reduced in the temporomedial cortex and in frontomedial regions. The present results suggest the involvement of unimodal and heteromodal association cortex and limbic structures in the psychological effects elicited by ayahuasca.

BACKGROUND:The use of placebo interventions outside clinical trials is ethically, professionally and legally controversial. Little is known about the frequency and circumstances of placebo use in clinical practice. Our aim was to summarize the available empirical studies addressing these issues.

METHODS:We searched PubMed and EMBASE from inception to July 2009 in order to identify cross-sectional surveys, qualitative or longitudinal studies among health care professionals, students or patients which investigated at least one of the following issues--frequency of placebo use or attitudes to, or motivations for, the use of placebo interventions. At least two reviewers extracted information on the study methods, participants and findings. Descriptive summaries were prepared in an iterative process by at least two reviewers per study.

RESULTS:Twenty-two studies from 12 different countries met the inclusion criteria. Most studies had relevant shortcomings. The proportion of respondents reporting that they had applied 'pure' placebos (for example, saline injection) during their professional life varied between 17% and 80% among physicians and between 51% and 100% among nurses, but it seems that the actual frequency of such use seems to be rare. The use of 'impure' or 'active' placebos (for example, antibiotics for viral infections) is likely to be much more frequent. However, it is impossible to make a reliable estimation because there is no agreement of what an impure placebo might be. Studies using qualitative methods or asking participants to judge case examples suggest that motivations and attitudes towards placebo use are complex and health care providers are often faced with a dilemma.

CONCLUSIONS:Although the available evidence is incomplete and confusing at times there can be little doubt that the prevalence of placebo use outside of clinical trials is not negligible and that views and attitudes on placebos use differ considerably among individuals, both health care professionals and patients. Further research is needed to clarify these issues.

Hypericum extract (HE) might be favourably active in depressed patients with reversed vegetative signs (RVS). Therefore, we performed an exploratory subgroup analysis of a three-armed study to compare HE, fluoxetine, and placebo in patients with major depressive disorder (MDD) in a 12 wk trial. A total of 135 patients were randomized to 12 wk treatment with HE LI 160 (900 mg/d), fluoxetine (20 mg/d), or placebo. Patients with RVS were defined in two steps, according to DSM-IV. First, patients with melancholy-related vegetative signs were excluded. Secondly, patients had to have at least one score of 2 for the items 22-26 of the HAMD-28 scale, which are related to hypersomnia and hyperphagia. Twenty-seven patients remained in the group. Analysis of covariance (ANCOVA) was applied using the HAMD-17 score. Secondly a chi2 test for response was performed, using the same and further an adapted criterium as in recently published studies. ANCOVA revealed a trend to a global difference. Post-hoc analysis showed a trend to superiority of HE compared to placebo and to fluoxetine, but a very large effect size for both differences. Fluoxetine was not different from placebo. The adapted response criterium showed a significant global difference as well as a significant superiority of HE over placebo and over fluoxetine. These data are based on a small sample size and must be considered tentative. A characterization of vegetative features of patients with depression could lead to an overall increased effect size in the treatment with HE.

Physical complaints, such as pain, can be effectively reduced by placebo effects through induction of positive expectations, or increased by nocebo effects through induction of negative expectations. In the present study, verbally induced nocebo and placebo effects on itch were experimentally investigated for the first time. In part 1, the role of verbal suggestions in inducing nocebo effects on itch and pain was investigated. All subjects received the same somatosensory quantitative sensory testing stimuli, that is, mechanical and electrical stimuli and application of histamine, and verbal suggestions to manipulate expectations regarding the stimuli. The suggestions were designed to produce either high expectations for itch (itch nocebo) or pain (pain nocebo) or low expectations for itch (itch nocebo control) or pain (pain nocebo control). Results showed that high itch and pain expectations resulted in higher levels of itch and pain, respectively. When comparing nocebo effects, induced by verbal suggestions, results were more pronounced for itch than for pain. In part 2, verbal suggestions designed to produce a placebo effect on itch (itch placebo) or pain (pain placebo), or neutral suggestions (itch placebo control and pain placebo control) were given regarding a second application of histamine and compared with the first application applied in part 1. Results of placebo effects only showed a significantly larger decrease in itch in the itch placebo condition than in the pain placebo condition. In conclusion, we showed for the first time that nocebo and possibly placebo responses can be induced on itch by verbal suggestions. Experiments of nocebo and placebo effects on itch and pain demonstrated that particularly nocebo effects can be induced on itch and pain by verbal suggestions.

BACKGROUND:There appears to be a significant placebo response rate in clinical trials for gastro-oesophageal reflux disease. Little is known about the determinants and the circumstances associated with placebo response in the treatment of gastro-oesophageal reflux disease (GERD).

AIMS:To estimate the magnitude of the placebo response rate in randomized controlled trials for GERD and to identify factors that influence this response.

METHODS:A meta-analysis of randomized, double-blind, placebo-controlled trials, published in English language, which included>20 patients with GERD, treated with either a proton pump inhibitor or H(2)-receptor antagonist for at least 2 weeks. Medline, Cochrane and EMBASE databases were searched, considering only studies that reported a global response for 'heartburn'.

RESULTS:A total of 24 studies included 9989 patients with GERD. The pooled odds ratio (OR) for response to active treatment vs. placebo was 3.71 (95% CI: 2.78-4.96). The pooled estimate of the overall placebo response was 18.85% (range 2.94%-47.06%). Patients with erosive oesophagitis had a non-significantly lower placebo response rate than patients without it (11.87% and 18.31%, respectively; P = 0.246). Placebo response was significantly lower in studies of PPI therapy vs. studies of H(2) RAs (14.51% vs. 24.69%, respectively; P = 0.05).

CONCLUSIONS:The placebo response rate in randomized controlled trials for GERD is substantial. A lower placebo response was associated with the testing of PPIs, but not the presence of erosive oesophagitis.

OBJECTIVE: To establish whether the timing of delivery between 37 and 42 weeks gestation influences neonatal respiratory outcome and thus provide information which can be used to aid planning of elective delivery at term. DESIGN: All cases of respiratory distress syndrome or transient tachypnoea at term requiring admission to the neonatal intensive care unit were recorded prospectively for nine years. SETTING: Rosie Maternity Hospital, Cambridge. SUBJECTS: During this time 33,289 deliveries occurred at or after 37 weeks of gestation. MAIN OUTCOME MEASURES: This information enabled calculation of the relative risk of respiratory morbidity for respiratory distress syndrome or transient tachypnoea in relation to mode of delivery and onset of parturition for each week of gestation at term. RESULTS: The incidence of respiratory distress syndrome at term was 2.2/1000 deliveries (95% CI; 1.7-2.7). The incidence of transient tachypnoea was 5.7/1000 deliveries (95% CI; 4.9-6.5). The incidence of respiratory morbidity was significantly higher for the group delivered by caesarean section before the onset of labour (35.5/1000) compared with caesarean section during labour (12.2/1000) (odds ratio, 2.9; 95% CI 1.9-4.4; P<0.001), and compared with vaginal delivery (5.3/1000) (odds ratio, 6.8; 95% CI 5.2-8.9; P<0.001). The relative risk of neonatal respiratory morbidity for delivery by caesarean section before the onset of labour during the week 37+0 to 37+6 compared with the week 38+0 to 38+6 was 1.74 (95% CI 1.1-2.8; P<0.02) and during the week 38+0 to 38+6 compared with the week 39+0 to 39+6 was 2.4 (95% CI 1.2-4.8; P<0.02). CONCLUSIONS: A significant reduction in neonatal respiratory morbidity would be obtained if elective caesarean section was performed in the week 39+0 to 39+6 of pregnancy.

Pain is a negative emotional experience that is modulated by a variety of psychological factors through different inhibitory systems. For example, endogenous opioids and cannabinoids have been found to be involved in stress and placebo analgesia. Here we show that when the meaning of the pain experience is changed from negative to positive through verbal suggestions, the opioid and cannabinoid systems are co-activated and these, in turn, increase pain tolerance. We induced ischemic arm pain in healthy volunteers, who had to tolerate the pain as long as possible. One group was informed about the aversive nature of the task, as done in any pain study. Conversely, a second group was told that the ischemia would be beneficial to the muscles, thus emphasizing the usefulness of the pain endurance task. We found that in the second group pain tolerance was significantly higher compared to the first one, and that this effect was partially blocked by the opioid antagonist naltrexone alone and by the cannabinoid antagonist rimonabant alone. However, the combined administration of naltrexone and rimonabant antagonized the increased tolerance completely. Our results indicate that a positive approach to pain reduces the global pain experience through the co-activation of the opioid and cannabinoid systems. These findings may have a profound impact on clinical practice. For example, postoperative pain, which means healing, can be perceived as less unpleasant than cancer pain, which means death. Therefore, the behavioral and/or pharmacological manipulation of the meaning of pain can represent an effective approach to pain management.

BACKGROUND:Placebo treatment can significantly influence subjective symptoms. However, it is widely believed that response to placebo requires concealment or deception. We tested whether open-label placebo (non-deceptive and non-concealed administration) is superior to a no-treatment control with matched patient-provider interactions in the treatment of irritable bowel syndrome (IBS).

METHODS:Two-group, randomized, controlled three week trial (August 2009-April 2010) conducted at a single academic center, involving 80 primarily female (70%) patients, mean age 47± 18 with IBS diagnosed by Rome III criteria and with a score ≥ 150 on the IBS Symptom Severity Scale (IBS-SSS). Patients were randomized to either open-label placebo pills presented as"placebo pills made of an inert substance, like sugar pills, that have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes"or no-treatment controls with the same quality of interaction with providers. The primary outcome was IBS Global Improvement Scale (IBS-GIS). Secondary measures were IBS Symptom Severity Scale (IBS-SSS), IBS Adequate Relief (IBS-AR) and IBS Quality of Life (IBS-QoL).

FINDINGS:Open-label placebo produced significantly higher mean (±SD) global improvement scores (IBS-GIS) at both 11-day midpoint (5.2 ± 1.0 vs. 4.0 ± 1.1, p<.001) and at 21-day endpoint (5.0± 1.5 vs. 3.9 ± 1.3, p = .002). Significant results were also observed at both time points for reduced symptom severity (IBS-SSS, p = .008 and p = .03) and adequate relief (IBS-AR, p = .02 and p = .03); and a trend favoring open-label placebo was observed for quality of life (IBS-QoL) atthe 21-day endpoint (p = .08).

CONCLUSION:Placebos administered without deception may be an effective treatment for IBS. Further research is warranted in IBS, and perhaps other conditions, to elucidate whether physicians can benefit patients using placebos consistent with informed consent.

TRIAL REGISTRATION:ClinicalTrials.gov NCT01010191.

OBJECTIVE:This study's objective was to assess the relationship of empathy in medical office visits to subsequent outcomes of the common cold.

METHODS:A total of 350 subjects ? 12 years of age received either a standard or enhanced physician visit as part of a randomized controlled trial. Enhanced visits emphasized empathy on the part of the physician. The patient-scored Consultation and Relational Empathy (CARE) questionnaire assessed practitioner-patient interaction, especially empathy. Cold severity and duration were assessed from twice-daily symptom reports. Nasal wash was performed to measure the immune cytokine interleukin-8 (IL-8).

RESULTS:Eighty-four individuals reported perfect (score of 50) CARE scores. They tended to be older with less education but reported similar health status, quality of life, and levels of optimism. In those with perfect CARE scores, cold duration was shorter (mean 7.10 days versus 8.01 days), and there was a trend toward reduced severity (mean area under receiver-operator characteristics curve 240.40 versus 284.49). After accounting for possible confounding variables, cold severity and duration were significantly lower in those reporting perfect CARE scores. In these models, a perfect score also correlated with a larger increase in IL-8 levels.

CONCLUSIONS:Clinician empathy, as perceived by patients with the common cold, significantly predicts subsequent duration and severity of illness and is associated with immune system changes.

OBJECTIVE:This study's objective was to assess the relationship of empathy in medical office visits to subsequent outcomes of the common cold.

METHODS:A total of 350 subjects ? 12 years of age received either a standard or enhanced physician visit as part of a randomized controlled trial. Enhanced visits emphasized empathy on the part of the physician. The patient-scored Consultation and Relational Empathy (CARE) questionnaire assessed practitioner-patient interaction, especially empathy. Cold severity and duration were assessed from twice-daily symptom reports. Nasal wash was performed to measure the immune cytokine interleukin-8 (IL-8).

RESULTS:Eighty-four individuals reported perfect (score of 50) CARE scores. They tended to be older with less education but reported similar health status, quality of life, and levels of optimism. In those with perfect CARE scores, cold duration was shorter (mean 7.10 days versus 8.01 days), and there was a trend toward reduced severity (mean area under receiver-operator characteristics curve 240.40 versus 284.49). After accounting for possible confounding variables, cold severity and duration were significantly lower in those reporting perfect CARE scores. In these models, a perfect score also correlated with a larger increase in IL-8 levels.

CONCLUSIONS:Clinician empathy, as perceived by patients with the common cold, significantly predicts subsequent duration and severity of illness and is associated with immune system changes.

OBJECTIVE:The aim of this study was to evaluate predictors of the placebo response in a randomized, placebo-controlled, double-blind trial of a phytotherapeutic combination for the treatment of menopausal symptoms.

METHODS:A post hoc analysis was conducted on data from 46 placebo participants completing the study. Variables at baseline were investigated for prediction of improvement on any of the endpoints of flushing, depression measured on the Hamilton Depression Inventory, and menopausal symptoms measured on the Greene Climacteric Scale. Hierarchical linear regression analyses were carried out on the individual endpoints, controlling for baseline scores. Multivariate linear regression analysis was also conducted on these three endpoints in combination.

RESULTS:Higher anxiety at study entry predicted placebo response on all three outcome measures individually (flushing: R = 0.33, P = 0.03; depression: R = 0.34, P<0.001; and Greene Climacteric score: R = 0.24, P = 0.04); and in combination (P = 0.002), as did total Greene Climacteric scores at study entry (R = 0.24, P = 0.005). Improvement during nontreatment run-in predicted placebo response for depression (P = 0.005), menopausal symptoms (R = 0.28, P = 0.013), and the three combined endpoints (P = 0.015). Severity of scores at baseline predicted subsequent improvement on the Greene Climacteric scores only (r = 0.038, P = 0.009).

CONCLUSIONS:These findings may facilitate identification of potential placebo responders in future randomized controlled trials on menopausal symptoms and have relevance to study design in this context. Further research is required.

OBJECTIVE:To describe the attitudes and behaviours regarding placebo treatments, defined as a treatment whose benefits derive from positive patient expectations and not from the physiological mechanism of the treatment itself.

DESIGN:Cross sectional mailed survey.

SETTING:Physicians' clinical practices.

PARTICIPANTS:1200 practising internists and rheumatologists in the United States.

MAIN OUTCOME MEASURES:Investigators measured physicians' self reported behaviours and attitudes concerning the use of placebo treatments, including measures of whether they would use or had recommended a"placebo treatment,"their ethical judgments about the practice, what they recommended as placebo treatments, and how they typically communicate with patients about the practice.

RESULTS:679 physicians (57%) responded to the survey. About half of the surveyed internists and rheumatologists reported prescribing placebo treatments on a regular basis (46-58%, depending on how the question was phrased). Most physicians (399, 62%) believed the practice to be ethically permissible. Few reported using saline (18, 3%) or sugar pills (12, 2%) as placebo treatments, while large proportions reported using over the counter analgesics (267, 41%) and vitamins (243, 38%) as placebo treatments within the past year. A small but notable proportion of physicians reported using antibiotics (86, 13%) and sedatives (86, 13%) as placebo treatments during the same period. Furthermore, physicians who use placebo treatments most commonly describe them to patients as a potentially beneficial medicine or treatment not typically used for their condition (241, 68%); only rarely do they explicitly describe them as placebos (18, 5%).

CONCLUSIONS:Prescribing placebo treatments seems to be common and is viewed as ethically permissible among the surveyed US internists and rheumatologists. Vitamins and over the counter analgesics are the most commonly used treatments. Physicians might not be fully transparent with their patients about the use of placebos and might have mixed motivations for recommending such treatments.

BACKGROUND:Leg swelling is a modern-day affliction of sedentary working women. The aim of this study was to evaluate the effectiveness of the intake of grape seed extract (GSE) on leg swelling in healthy Japanese women while sitting.

RESULTS:Single intake trials and 14 day intake trials were held in a double-blind, placebo-controlled, crossover clinical study. A prolonged sedentary position was maintained for 6 h after GSE or placebo administration. Leg volume distension, increase in body extracellular fluid, and leg water were significantly suppressed in the GSE groups.

CONCLUSION:The intake of GSE is a contributing factor in the inhibition of leg swelling in healthy women during prolonged sitting.