The effect of a short-term mental stressor on neutrophil activation

Autonomic, endocrine, and psychological stress responses to different forms of blood draw

Background

Although fingerstick is often favorably compared to venipuncture as a less invasive method of drawing blood for clinical labs, there is little empirical research that compares physical and psychological stress responses to fingerstick vs. venipuncture (blood draw using a needle in the arm) within the same person.

Methods and findings

We assessed changes in cortisol (a stress hormone), heart rate variability (a marker of autonomic stress), and psychological stress in 40 healthy women who completed both venipuncture and fingerstick. Contrary to our predictions, there was a significant decline in cortisol across conditions, with greater decline from pre- to post-draw in response to venipuncture than fingerstick. There were similar patterns of rise and fall in heart rate variability in both types of blood draw, suggestive of mild vasovagal responses. Psychological measures of stress (such as negative emotion and perceived stress) were generally stronger predictors of participant’s reported pain and blood draw preferences than physical stress measures.

Conclusions

These findings challenge the characterization of fingerstick as necessarily “less invasive” than venipuncture, as participant’s stress responses to fingerstick were equivalent to (and for some measures greater than) their response to venipuncture. Heart rate variability response to fingerstick significantly predicted that individual’s vasovagal-like responses to venipuncture, suggesting that measuring heart rate variability during pre-donation hemoglobin testing may identify donors at risk for adverse events during venipuncture.

The influence of the Great East Japan earthquake on microscopic polyangiitis: A retrospective observational study

BACKGROUND

Antineutrophil cytoplasmic antibody-associated vasculitis is triggered by environmental factors, including silica dust exposure. Repeated tsunami waves brought a large volume of silica-containing sludge inland after the Great East Japan earthquake in 2011. We aimed to determine if the serious disaster influenced the clinical features of the microscopic polyangiitis.

METHODS

This is an observational retrospective study conducted in a single institute. A total of 43 patients were included based on the CHCC2012 criteria for microscopic polyangiitis from 2007 to 2015. We used the Poisson regression model to determine the incidence of microscopic polyangiitis within the annual population of the medical district. The participants were selected during a 3-year period from before (N = 13) to after the disaster (N = 20). The differences of parameters and the overall survival between the groups were analyzed.

RESULTS

The incidence of microscopic polyangiitis increased after the disaster (λ = 17.4/million/year [95%CI: 7.66-39.6] before the disaster and λ = 33.1/million/year [17.7-61.7] after the disaster, P = 0.044). A high Birmingham Activity Score was associated with a high incidence of microscopic polyangiitis after the disaster. The overall survival of the patients with microscopic polyangiitis declined significantly after the disaster.

CONCLUSIONS

The Great East Japan earthquake influenced the development of the microscopic polyangiitis in our restricted area. The patients who developed after the disaster had severe symptoms and a high mortality rate.

Quantifying capture stress in free ranging European roe deer (Capreolus capreolus)

BACKGROUND

To understand and reduce the concomitant effects of trapping and handling procedures in wildlife species, it is essential to measure their physiological impact. Here, we examined individual variation in stress levels in non-anesthetized European roe deer (Capreolus capreolus), which were captured in box traps and physically restrained for tagging, biometrics and bio-sampling. In winter 2013, we collected venous blood samples from 28 individuals during 28 capture events and evaluated standard measurements for stress (heart rate, body temperature, neutrophil to lymphocyte ratio, lactate and total cortisol). Additionally, we assessed stress using the immunological tool, Leukocyte Coping Capacity (LCC), a real-time proxy for stress measuring oxygen radical production by leukocytes. Finally, the behavioral response to handling was recorded using a scoring system.

RESULTS

LCC and therefore stress levels were negatively influenced by the time animals spent in the box trap with human presence at the capture site prior to handling. In contrast, none of the classical stress measures, including total cortisol, nor the behavioral assessment, were correlated with the stressor tested (time of human presence prior to handling) and thus did not provide a clear depiction regarding the extent of the animals short-term stress response.

CONCLUSIONS

Overall our study verifies the LCC as a strong method to quantify short-term stress reactions in wildlife. Moreover, our results clearly show that human presence at the trapping site prior to handling should be kept to an absolute minimum in order to reduce stress levels.

Stress-induced release of matrix metalloproteinase-9 in patients with coronary artery disease: The possible influence of cortisol

Stress and inflammation are both important risk factors for coronary artery disease (CAD). However, the susceptibility to stress-induced inflammation and its determinants have been little explored in patients with CAD. Here, our aim was to study the stress-induced inflammatory response, more precisely the early release of matrix metalloproteinase (MMP)-9, and its association with cortisol response in patients with CAD. Sixty-four patients underwent a standardized laboratory stress test. The stress-induced release of MMP-9 was closely associated with the release of other neutrophil-associated proteins, MMP-8 and myeloperoxidase (MPO). It also showed a large variation among patients, as did cortisol. Twenty minutes after stress, a negative association between changes in MMP-9 and cortisol was seen (p<0.01). In vitro, dexamethasone reduced the IL-8-mediated release of MMP-9 from neutrophils, indicating that glucocorticoids may exert rapid effects on neutrophil activation. Further characterization of patients revealed that stress-induced release of MMP-9 was related to leukocyte telomere shortening and increased ultrasound-assessed plaque occurrence in the carotid arteries, but not to other characteristics such as age, gender or psychological background factors. The susceptibility to stress-induced release of MMP-9 may thus have impact on disease phenotype. Stress tests can be useful to identify CAD patients in need of novel prevention and treatment strategies.

LEUKOCYTE COPING CAPACITY AS A TOOL TO ASSESS CAPTURE- AND HANDLING-INDUCED STRESS IN SCANDINAVIAN BROWN BEARS (URSUS ARCTOS)

Brown bears (Ursus arctos) are often captured and handled for research and management purposes. Although the techniques used are potentially stressful for the animals and might have detrimental and long-lasting consequences, it is difficult to assess their physiological impact. Here we report the use of the leukocyte coping capacity (LCC) technique to quantify the acute stress of capture and handling in brown bears in Scandinavia. In April and May 2012 and 2013, we collected venous blood samples and recorded a range of physiological variables to evaluate the effects of capture and the added impact of surgical implantation or removal of transmitters and sensors. We studied 24 brown bears, including 19 that had abdominal surgery. We found 1) LCC values following capture were lower in solitary bears than in bears in family groups suggesting capture caused relatively more stress in solitary bears, 2) ability to cope with handling stress was better (greater LCC values) in bears with good body condition, and 3) LCC values did not appear to be influenced by surgery. Although further evaluation of this technique is required, our preliminary results support the use of the LCC technique as a quantitative measure of stress.

ACTH- and cortisol-associated neutrophil modulation in coronary artery disease patients undergoing stent implantation

Background

Psychosocial stress and activation of neutrophil granulocytes are increasingly recognized as major risk factors of coronary artery disease (CAD), but the possible relationship of these two factors in CAD patients is largely unexplored. Activation of neutrophils was reported to be associated with stenting; however, the issue of neutrophil state in connection with percutaneous coronary intervention (PCI) is incompletely understood from the aspect of stress and its hypothalamic-pituitary-adrenal axis (HPA) background. Thus, we aimed to study cortisol- and ACTH-associated changes in granulocyte activation in patients undergoing PCI.

Methodology/Principal Findings

Blood samples of 21 stable angina pectoris (SAP) and 20 acute coronary syndrome (ACS) patients were collected directly before (pre-PCI), after (post-PCI) and on the following day of PCI (1d-PCI). Granulocyte surface L-selectin, CD15 and (neutrophil-specific) lactoferrin were analysed by flow cytometry. Plasma cortisol, ACTH, and lactoferrin, IL-6 were also assayed. In both groups, pre- and post-PCI ratios of lactoferrin-bearing neutrophils were relatively high, these percentages decreased substantially next day; similarly, 1d-PCI plasma lactoferrin was about half of the post-PCI value (all p≤0.0001). Post-PCI ACTH was reduced markedly next day, especially in ACS group (SAP: p<0.01, ACS: p≤0.0001). In ACS, elevated pre-PCI cortisol decreased considerably a day after stenting (p<0.01); in pre-PCI samples, cortisol correlated with plasma lactoferrin (r∼0.5, p<0.05). In 1d-PCI samples of both groups, ACTH showed negative associations with the ratio of lactoferrin-bearing neutrophils (SAP: r = −0.601, p<0.005; ACS: r = −0.541, p<0.05) and with plasma lactoferrin (SAP: r = −0.435, p<0.05; ACS: r = −0.609, p<0.005).

Conclusions/Significance

Pre- and post-PCI states were associated with increased percentage of activated/degranulated neutrophils indicated by elevated lactoferrin parameters, the 1d-PCI declines of which were associated with plasma ACTH in both groups. The correlation of plasma cortisol with plasma lactoferrin in the extremely stressed ACS before stenting, however, suggests an association of cortisol with neutrophil activation.

Acute stress reduces wound-induced activation of microbicidal potential of ex vivo isolated human monocyte-derived macrophages

BACKGROUND

Psychological stress delays wound healing but the precise underlying mechanisms are unclear. Macrophages play an important role in wound healing, in particular by killing microbes. We hypothesized that (a) acute psychological stress reduces wound-induced activation of microbicidal potential of human monocyte-derived macrophages (HMDM), and (b) that these reductions are modulated by stress hormone release.

METHODS

Fourty-one healthy men (mean age 35 ± 13 years) were randomly assigned to either a stress or stress-control group. While the stress group underwent a standardized short-term psychological stress task after catheter-induced wound infliction, stress-controls did not. Catheter insertion was controlled. Assessing the microbicidal potential, we investigated PMA-activated superoxide anion production by HMDM immediately before and 1, 10 and 60 min after stress/rest. Moreover, plasma norepinephrine and epinephrine and salivary cortisol were repeatedly measured. In subsequent in vitro studies, whole blood was incubated with norepinephrine in the presence or absence of phentolamine (norepinephrine blocker) before assessing HMDM microbicidal potential.

RESULTS

Compared with stress-controls, HMDM of the stressed subjects displayed decreased superoxide anion-responses after stress (p's <.05). Higher plasma norepinephrine levels statistically mediated lower amounts of superoxide anion-responses (indirect effect 95% CI: 4.14-44.72). Norepinephrine-treated HMDM showed reduced superoxide anion-production (p<.001). This effect was blocked by prior incubation with phentolamine.

CONCLUSIONS

Our results suggest that acute psychological stress reduces wound-induced activation of microbicidal potential of HMDM and that this reduction is mediated by norepinephrine. This might have implications for stress-induced impairment in wound healing.

Reduced neutrophil superoxide production among healthy older adults in response to acute psychological stress

Ageing is associated with higher morbidity and mortality, and declining immune function, termed immunesenescence. The present study examined the effects of an acute laboratory psychological stress task on innate immunity, specifically neutrophil function, among older adults. The two functional assays used were phagocytosis of Escherichia coli and stimulated superoxide production. Participants were 17 (11 female) older adults (mean age 75.7, SD=7.06 years). Blood samples to determine neutrophil function by flow cytometry were taken at the end of resting baseline, during an acute stress task and during recovery. The stress task was an 8-minute time-pressured mental arithmetic challenge with social evaluation. There was a significant reduction in neutrophil superoxide production, p=.017, η(2)(p)=.240, associated with the stress task relative to baseline, but no effect on phagocytosis. The results of this study could contribute to explaining the increased risk of infection in older adults, particularly those subject to frequent stress exposures. Future research is needed to explore the underlying mechanisms of acute stress effects on human neutrophil function in older adults in greater detail.

Protein intake and stress levels in nurses and housewives of Pakistan

Stress has many biological effects on human daily life. In the present study, dietary protein intake was correlated with the investigated stress levels of nurses and housewives of the targeted urban population. Age group ranged from 30 to 45 years and both the groups belonged to middle socioeconomic status. After calculations of environmental, psychological and physiological stresses, it was observed that the levels of stress in housewives were significantly higher than those of nurses. Recommended dietary allowances, RDA and actual protein intakes, API were also compared in both the groups. The found protein intake was less in housewives as compared to that of nurses.

Altered human neutrophil function in response to acute psychological stress

OBJECTIVE

To examine the effects of an acute laboratory psychological stress task on neutrophil function, specifically phagocytosis of Escherichia coli and stimulated superoxide production in human neutrophils. There is mounting evidence that acute stress is associated with short-term increases in a number of immune indices.

METHODS

Participants were 40 (n = 20 females) university students (mean age, 25.9 ± 4.56 years). Blood samples to determine neutrophil function by flow cytometry were taken at the end of resting baseline, during an acute stress task, and during recovery. The stress task was a 10-minute time-pressured mental arithmetic challenge with social evaluation.

RESULTS

There was an acute increase in phagocytic ability, p = .047, η(2)p = 0.076, and a reduction of superoxide production, p = .026, η(2)p = 0.101, associated with the stress task relative to baseline.

CONCLUSION

These findings suggest that neutrophil bactericidal function may be sensitive to mental challenge tasks that provoke acute psychological stress. Further research is needed to replicate the observed psychological stress-induced changes in neutrophil function.

Haematological and biochemical responses of red foxes (Vulpes vulpes) to different capture methods and shooting

This paper sought to determine whether common haematology and blood biochemistry values might assist in determining the relative welfare outcomes arising from the capture of red foxes (Vulpes vulpes) by treadle-snares, Victor Soft Catch® (VSC) #3 traps, cage traps, netting and sampling by shooting. Compared to all other capture methods and shooting, treadle-snared foxes had significantly higher mean albumin (ALB), creatine kinase (CK), red cell count (RCC), neutrophil to lymphocyte (N:L) ratio, sodium (Na), total protein (TP), white cell counts (WCC) and lower glucose (Gl). Treadle-snares were also associated with higher chloride (Cl), haemoglobin (Hb) and packed cell volume (PCV) than cage trapping and netting. Treadle-snares produced indicators of possible muscle damage, exertion and dehydration compared to cage and VSC traps. Cage trapping and netting produced lower indications of exertion, possible muscle damage and dehydration compared to both treadle-snares and VSC traps. These data do not support previous conclusions that due to similar injury scores, treadle-snares and VSC traps produced equivalent welfare outcomes. In restraining traps, injury and death sustained during capture are end-points of poor trapping welfare. Monitoring stress using physiological indicators allows the comparison of the relative potential for different capture techniques to cause pathological and pre-pathological states. As the response of physiological indicators to stress is not independent of time, accurate data on the duration of captivity and the relative intensity of struggling behaviour should be routinely collected when assessing the comparative humaneness of different trap devices.

Impact of trapping and handling on Leukocyte Coping Capacity in bank voles (Clethrionomys glareolus) and wood mice (Apodemus sylvaticus)

Small mammals are routinely live-trapped and subsequently handled for a range of ecological and behavioural studies. Despite the techniques commonly employed being potentially stressful for the individual animals involved, it has hitherto been difficult to quantify the physiological impact. Here, we report on the first instance of using the Leukocyte Coping Capacity technique (LCC) in bank voles (Clethrionomys glareolus) and wood mice (Apodemus sylvaticus) to investigate the physiological impact of routine trapping and handling techniques. Twenty microlitres of blood were obtained from 40 animals, of which 25 were handled following standard protocols and 15 were not. We found that even a short period of acute stress is sufficient to trigger an immune response which was measurable using the LCC technique. These results further validate the use of the LCC technique for measuring the physiological impact of standard trapping and handling treatments on wild mammals.

Granulocyte activation in humans is modulated by psychological stress and relaxation

Our aim was to study the possible relationship between psychological stress and granulocyte activation primarily in healthy students during an examination period (n = 11) and also in chronically anxious patients (n = 15). We employed cell surface markers: lactoferrin, L-selectin, alphaMbeta2-integrin and CD15s and flow cytometry to detect changes in the activation state of granulocytes, with the start of the stressed state in students at the beginning of an examination period, which was associated with elevated blood plasma cortisol level, and following relaxation hypnosis in both students, during their examination term, and patients. The ratios of all four types of marker-carrier granulocytes increased at the start of the examination period in students; an especially dramatic (ca. 5-fold) enhancement was observed in the proportion of lactoferrin-bearing cells relatively to the pre-examination term value. After hypnosis, the percentage of lactoferrin-exposing granulocytes decreased considerably both in students and in patients, by about half; a similar decrease was observed in the ratio of CD15s-carrier cells in patients. No significant alteration was observed during the study in state or trait anxiety levels, and in total or differential leukocyte counts. Thus, granulocyte activation could be associated with stress, while relaxation may facilitate reducing activation of these cells. In both groups of subjects, granulocyte surface lactoferrin appeared to be a sensitive "stress indicator". This needs further evaluation.

The effect of acute psychologic stress on systemic and rectal mucosal measures of inflammation in ulcerative colitis

BACKGROUND & AIMS

Recent studies suggest that life events and chronic stress increase the risk of relapse in inflammatory bowel disease. Our aim was to study the effects of acute psychologic stress on systemic and rectal mucosal inflammatory responses in patients with inactive ulcerative colitis (UC).

METHODS

Twenty-five patients with inactive UC and 11 healthy volunteers (HV) underwent an experimental stress test. Ten patients with UC and 11 HV underwent a control procedure. Before and after each procedure, systemic inflammatory response was assessed by serum interleukin (IL)-6 and IL-13 concentrations, tumor necrosis factor (TNF)-alpha and IL-6 production by lipopolysaccharide (LPS)-stimulated whole blood, leukocyte count, natural killer (NK) cell numbers, platelet activation, and platelet-leukocyte aggregate (PLA) formation. In patients with UC, rectal mucosal inflammation was assessed by TNF-alpha, IL-13, histamine and substance P release, reactive oxygen metabolite (ROM) production, mucosal blood flow (RMBF) and histology.

RESULTS

Stress increased pulse (P < .0001) and systolic BP (P < .0001). In UC, stress increased LPS-stimulated TNF-alpha and IL-6 production by 54% (P = .004) and 11% (P = .04), respectively, leukocyte count by 16% (P = .01), NK cell count by 18% (P = .0008), platelet activation by 65% (P < .0001), PLA formation by 25% (P = .004), mucosal TNF-alpha release by 102% (P = .03), and ROM production by 475% (P = .001) and reduced rectal mucosal blood flow by 22% (P = .05). The control protocol did not change any of the variables measured. There were no differences between the responses of the patients with UC and HV.

CONCLUSIONS

Acute psychologic stress induces systemic and mucosal proinflammatory responses, which could contribute to exacerbations of UC in ordinary life.

Possible connections among job stress, depressive symptoms, lipid modulation and antioxidants

BACKGROUND

Oxidative/antioxidative status may be related to psychological stress or pathogenesis of depression.

SUBJECTS AND METHODS

Participants were selected from 381 female nurses working in a university hospital, and the Brief Job Stress Questionnaire was utilized to assess them. Nurses with high job stress (JS) (n = 18) and with low JS (n = 15) consented to participate in this study. Depressive symptoms were assessed by the Centre for Epidemiologic Studies Depression scale (CES-D). Cholesterols, lipid peroxidation (malondialdehyde, MDA) and antioxidants in the plasma were measured.

RESULTS

High JS participants exhibited significantly higher CES-D scores (t = 3.34, p < 0.005), and significantly lower concentrations of total cholesterol (TC), low density+very low density lipoprotein cholesterols (LDL+VLDL), alpha-tocopherol, and beta-carotene compared with low JS participants (t = 2.69, p < 0.05; t = 3.46, p < 0.005; t = 2.96, p < 0.05; t = 2.98, p < 0.05, respectively). However, the reductions in plasma indicators were substantially weakened after controlling for lifestyle factors with the exception of LDL+VLDL and alpha-tocopherol. In addition, the significance of alpha-tocopherol concentrations appeared to depend on cholesterol levels. CES-D scores correlated positively with plasma MDA levels, the MDA/TC ratio and the MDA/LDL+VLDL ratio among the low JS group (r = 0.69, p < 0.001; r = 0.79, p < 0.001; r = 0.75, p < 0.005, respectively), whereas there were no correlations among the high JS group. After controlling for lifestyle covariates, the relationship between CES-D scores and the MDA/LDL+VLDL ratio remained significant (beta = 0.95, p < 0.05) using a multiple linear regression model (F = 3.61, p < 0.05).

LIMITATIONS

Sample numbers in each JS group were relatively small.

CONCLUSIONS

Psychological stress may reduce the plasma levels of LDL+VLDL accompanying an alpha-tocopherol decrease. There appeared to be a correlation between elevated MDA and depressive symptoms in low JS participants.

Behavioural and physiological aspects of stress and aggression in nonhuman primates

There is considerable interest in the study of stress and aggression in primates as a model for their interpretation in humans. Despite methodological and interpretational problems associated with behavioural and physiological measurement and definition, a considerable body of literature exists on these phenomena in primates. In the course of reviewing this literature we examine examples of many of the sources of variation in stress and aggression, including species identity, sex, age, breeding and social status, individual temperament, background, learning and resource distribution. This is followed by an examination of the interaction between stress and aggression before reviewing the most important areas in which changes in both stress and aggression are measured. In particular we examine those studies covering social aspects of an animal's life, specifically relating to social isolation, crowding as well as group formation, composition and instability. This review reveals the complex and often contradictory nature of relationships, not just between an animal's physiology and its behaviour, but between its stress status and display or receipt of aggression.

Assessment of stress in non-human primates: application of the neutrophil activation test

A technique measuring leukocyte (neutrophil) activity was used to examine differences between stress levels in a breeding colony of rhesus macaques housed in either a traditional caging system or open-rooms. The leukocyte activation test measured the degree to which blood from the two treatment groups could launch a further neutrophil response (superoxide production) to an in vitro challenge. Animals housed in a traditional caging system produced a significantly lower leukocyte response than animals housed in open-rooms, indicating that there was a higher level of stress associated with caged housing than open-room housing. This was not influenced by whether animals were physically restrained or trained to stand for a sedating injection. No differences were found between treatment groups in leukocyte numbers or composition. This study validates the use of the leukocyte activation test to assess physiological stress levels in non-human primates and demonstrates the animal welfare benefits of open-room housing over traditional laboratory caging systems.

Temporal variation of acute stress responses in sympathetic nervous and immune systems

Sympathetic nervous activity plays a prominent role in acute stress responses in the immune system, enhancement of innate immunity and suppression of specific immunity. The present study was conducted to examine the temporal characteristics of such immune responses to acute stress and to determine their association with sympathetic activity in detail. For this purpose, 15 female undergraduates engaged in a continuous mental arithmetic task for 14 min, and we collected their blood samples for immune indices (CD3+ T cells, CD4+ T cells, NK cells) each 3 min during the task and saliva samples before and after the task. Our results showed that the proportion of Natural Killer cells (NK cells) increased even 2 min after initiation of the task, whereas proportions of CD3+ and CD4+ lymphocytes decreased 8 min after initiation of the task. Moreover, we found significant correlations between cardiovascular activity and the variations of immune indices.

The effect of transport stress on neutrophil activation in wild badgers (Meles meles)

Wild badgers (Meles meles) in Wytham woods, Oxfordshire, are routinely trapped, transported to a central field laboratory, studied and released as part of an on-going population study. These procedures have been carefully developed to minimise impact on the badgers' welfare; however they are potentially stressful, and, as part of our on-going welfare refinements, and our exploration to develop methods for quantifying stress in wild mammals, we studied the effects of transport stress on neutrophil activation in wild trapped badgers. Blood samples were obtained from 28 badgers. We compared three transport regimes: transported (n = 9), transported and rested for at least 30 mins (n = 11), and not transported (n = 8). Total and differential white cell counts were carried out and neutrophil activation was measured by the nitroblue tetrazolium test. Our goal was primarily to validate neutrophil activity as an indicator of stress, on the basis that the transport treatment was expected to be more stressful than the non-transport treatment. There were significant increases in % activated circulating neutrophils in response to transport. This study supports the proposition that stress affects circulating neutrophil numbers and the state of their activation, as determined by the nitroblue tetrazolium reduction assay, and therefore adds weight to the idea that neutrophil activation is a potential measure of stress in wild animals.

Depressive state relates to female oxidative DNA damage via neutrophil activation

This study investigated cancer risk due to psychological stress, particularly depression, and its underlying mechanism, using a biomarker of cancer-related oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OH-dG), in human leukocytes. We performed a cross-sectional study of 156 workers in which we examined the relationships of the 8-OH-dG levels to the scores of the General Health Questionnaire (GHQ) and the Center for Epidemiologic Studies Depression scale (CES-D). We also examined the possibility that 8-OH-dG synthesis might be associated with a stress-related increase in neutrophils, which have been reported to produce superoxide in response to psychological stress. The Severe depression scores of the GHQ in females were strongly and positively associated with the 8-OH-dG levels, whereas the CES-D scores in males were negatively associated. There was a positive correlation between the percentage of neutrophils and the 8-OH-dG levels in females. Psychological depression was related to cancer risk due to oxidative DNA damage in females, possibly via neutrophil activation.