C-reactive protein across the menstrual cycle

Premenstrual Dysphoric Disorder: Epidemiology and Treatment

Recently designated as a disorder in the DSM-5, premenstrual dysphoric disorder (PMDD) presents an array of avenues for further research. PMDD's profile, characterized by cognitive-affective symptoms during the premenstruum, is unique from that of other affective disorders in its symptoms and cyclicity. Neurosteroids may be a key contributor to PMDD's clinical presentation and etiology, and represent a potential avenue for drug development. This review will present recent literature on potential contributors to PMDD's pathophysiology, including neurosteroids and stress, and explore potential treatment targets.

Sympathetic activation is associated with increased IL-6, but not CRP in the absence of obesity: lessons from postural tachycardia syndrome and obesity

Sympathetic activation is thought to contribute to the inflammatory process associated with obesity, which is characterized by elevated circulating C-reactive protein (hsCRP) and interleukin-6 (IL-6). To evaluate whether sympathetic activation is associated with inflammation in the absence of obesity, we studied patients with postural tachycardia syndrome (POTS), a condition characterized by increased sympathetic tone in otherwise healthy individuals. Compared with 23 lean controls, 43 lean female POTS had greater vascular sympathetic modulation (low-frequency blood pressure variability, LFSBP, 3.2 ± 0.4 vs. 5.5 ± 0.6 mmHg(2), respectively, P = 0.006), lower cardiac parasympathetic modulation (high-frequency heart rate variability, 1,414 ± 398 vs. 369 ± 66 ms(2), P = 0.001), and increased serum IL-6 (2.33 ± 0.49 vs. 4.15 ± 0.54 pg/ml, P = 0.011), but this was not associated with increases in hsCRP, which was low in both groups (0.69 ± 0.15 vs. 0.82 ± 0.16 mg/l, P = 0.736). To explore the contribution of adiposity to inflammation, we then compared 13 obese female POTS patients and 17 obese female controls to matched lean counterparts (13 POTS and 11 controls). Compared with lean controls, obese controls had increased LFSBP (3.3 ± 0.5 vs. 7.0 ± 1.1 mmHg(2); P = 0.016), IL-6 (2.15 ± 0.58 vs. 3.92 ± 0.43 pg/ml; P = 0.030) and hsCRP (0.69 ± 0.20 vs. 3.47 ± 0.72 mg/l; P = 0.001). Obese and lean POTS had similarly high IL-6 but only obese POTS had increased hsCRP (5.76 ± 1.99 mg/l vs. 0.65 ± 0.26; P < 0.001). In conclusion, sympathetic activation in POTS is associated with increased IL-6 even in the absence of obesity. The coupling between IL-6 and CRP, however, requires increased adiposity, likely through release of IL-6 by visceral fat.

Sexual activity modulates shifts in TH1/TH2 cytokine profile across the menstrual cycle: an observational study

OBJECTIVE

To investigate if sexual activity moderated menstrual cycle-related shifts in cytokines associated with T-helper type 1 (TH1) cells (e.g., interferon [IFN] γ) and T-helper type 2 (TH2) cells (e.g., interleukin [IL] 4). Immune activity shifts across the menstrual cycle, with higher follicular-phase TH1-cell activity but higher luteal-phase TH2-cell activity. Little is known about how social behaviors alter TH1-TH2 ratios, despite evidence that psychosocial factors can influence immunity. Of particular interest is how sexual activity influences immune responses that may support conception, such as the TH1-TH2 balance.

DESIGN

Participants provided saliva samples at four time points (menstrual, follicular, ovulatory, and luteal phases), which were assayed by means of ELISA.

SETTING

Academic laboratory.

PARTICIPANT(S)

Thirty healthy premenopausal women (16 sexually abstinent, 14 sexually active) not taking hormonal or immunoactive medications.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Salivary E2, P, IFN-γ, and IL-4.

RESULT(S)

Sexually active, but not abstinent, women were significantly more likely to express TH2-like cytokine ratios (IFN-γ < IL-4) in the luteal phase than in other phases. Similarly, sexually active women had significantly higher P, and higher P-E2 ratios, in the luteal phase than did abstinent women. The P-E2 ratio mediated menstrual variations in cytokine ratios in sexually active women.

CONCLUSION(S)

These results support the hypothesis that shifts in immune response across the menstrual cycle may reflect tradeoffs between reproduction and immunity. These findings point to the need for further research on the interaction between sexual behavior, the menstrual cycle, and immune response.

C-Reactive Protein, Fecal Calprotectin, and Stool Lactoferrin for Detection of Endoscopic Activity in Symptomatic Inflammatory Bowel Disease Patients: A Systematic Review and Meta-Analysis

OBJECTIVES

Persistent disease activity is associated with a poor prognosis in inflammatory bowel disease (IBD). Therefore, monitoring of patients with intent to suppress subclinical inflammation has emerged as a treatment concept. As endoscopic monitoring is invasive and resource intensive, identification of valid markers of disease activity is a priority. The objective was to evaluate the diagnostic accuracy of C-reactive protein (CRP), fecal calprotectin (FC), and stool lactoferrin (SL) for assessment of endoscopically defined disease activity in IBD.

METHODS

Databases were searched from inception to November 6, 2014 for relevant cohort and case-control studies that evaluated the diagnostic accuracy of CRP, FC, or SL and used endoscopy as a gold standard in patients with symptoms consistent with active IBD. Sensitivities and specificities were pooled to generate operating property estimates for each test using a bivariate diagnostic meta-analysis.

RESULTS

Nineteen studies (n=2499 patients) were eligible. The pooled sensitivity and specificity estimates for CRP, FC, and SL were 0.49 (95% confidence interval (CI) 0.34-0.64) and 0.92 (95% CI 0.72-0.96), 0.88 (95% CI 0.84-0.90) and 0.73 (95% CI 0.66-0.79), and 0.82 (95% CI 0.73-0.88) and 0.79 (95% CI 0.62-0.89), respectively. FC was more sensitive than CRP in both diseases and was more sensitive in ulcerative colitis than Crohn's disease.

CONCLUSIONS

Although CRP, FC, and SL are useful biomarkers, their value in managing individual patients must be considered in specific clinical contexts.

Elevation of C-reactive protein during the luteal phase in healthy adolescents

INTRODUCTION

Variations in inflammatory markers have been reported in adult women during the luteal phase, but whether these findings are observed during adolescence is unknown. We postulate that higher ultrasensitive C-reactive protein (usCRP) and lower 2-hydroxyestrone (2OHE) levels, an estrogen metabolite with cardioprotective actions, are present during the luteal phase in young women.

AIM

To evaluate usCRP levels during the menstrual cycle and to determine its association with 2OHE and 16α-hydroxyestrone (16OHE) in adolescents.

METHODS

Healthy postmenarcheal adolescents (N = 37) were studied during one menstrual cycle in follicular phase (FP) and luteal phase-like period (LP-L).

RESULTS

Elevations in usCRP levels in the LP-L were observed in the entire group and in anovulatory cycles (1.9 ± 1.1 mg/L in FP to 2.5 ± 1.8 mg/L in LP-L; p < 0.0001). Increases in estrone, estradiol, free and bioavailable estradiol, testosterone, usCRP and 2OHE levels were observed in LP-L compared with FP (p < 0.01), with a borderline elevation in IFG-I levels (p = 0.06).

CONCLUSIONS

We report an elevation of usCRP and 2OHE levels during the luteal phase in healthy adolescents. Elevations of this inflammatory marker in anovulatory adolescents without an increase in 2OHE may play a role in metabolic risks associated with chronic anovulation.

Pre-diagnostic serum levels of inflammation markers and risk of ovarian cancer in the prostate, lung, colorectal and ovarian cancer (PLCO) screening trial

OBJECTIVE

Pro-inflammatory mechanisms may explain the increased ovarian cancer risk linked to more lifetime ovulations, endometriosis, and exposure to talc and asbestos, as well as decreased risk with non-steroidal anti-inflammatory drugs. Limited data are available to estimate ovarian cancer risk associated with levels of circulating inflammatory markers.

METHODS

We conducted a nested case-control study within the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Pre-diagnostic serum levels of 46 inflammation-related biomarkers (11 with a priori hypotheses; 35 agnostic) were measured in 149 incident ovarian cancer cases and 149 matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression and adjusted for identified covariates.

RESULTS

Increased ovarian cancer risk was associated with elevated levels of C-reactive protein (CRP) [tertile (T)3 vs. T1: OR (95% CI) 2.04 (1.06-3.93), p-trend=0.03], interleukin (IL)-1α [detectable vs. undetectable: 2.23 (1.14-4.34)] and tumor necrosis factor alpha (TNF-α) [T3 vs. T1: 2.21 (1.06-4.63), p-trend=0.04]. Elevated IL-8 was non-significantly associated with risk [T3 vs. T1: 1.86 (0.96-3.61), p-trend=0.05]. In analyses restricted to serous ovarian cancer (n=83), the associations with CRP and IL-8 remained or strengthened [CRP T3 vs. T1: 3.96 (1.14-11.14), p-trend=0.008; IL-8 T3 vs. T1: 3.05 (1.09-8.51), p-trend=0.03]. Elevated levels of CRP and TNF-α remained positively associated with ovarian cancer risk in analysis restricted to specimens collected at least 5years before diagnosis (n=56).

CONCLUSION

These results suggest that CRP, IL-1α, IL-8, and TNF-α are associated with increased risk of subsequently developing ovarian cancer.

Nutrient intakes associated with elevated serum C-reactive protein concentrations in normal to underweight breastfeeding women in Northern Kenya

OBJECTIVES

Low-grade elevation of C-reactive protein (CRP) is a non-specific inflammatory marker, used as a predictor for cardiovascular disease development and chronic inflammatory risks. Research investigating dietary influences on inflammation has focused primarily on the relationship between dietary characteristics, CRP elevation and BMI in the populations at greatest risk for cardiovascular disease, namely those in the overweight and obese ranges, often in clinical settings and/or among those middle aged or older, leaving little information about normal to underweight populations of reproductive age in ecological settings. This study evaluates impacts of dietary nutrients on serum CRP levels in a population of predominantly underweight to normal weight adult women experiencing the additional nutritional demands of lactation.

METHODS

Data from non-overweight breastfeeding Ariaal women of Kenya collected in 2006 were used (n = 194). Logistic regression models were applied using low-grade CRP elevation (hsCRP > 3 mg/L) as the outcome variable and dietary nutrients, age, BMI, and serum retinol as predictors.

RESULTS

Models showed that energy intake (Kcal) and age were positive predictors of CRP elevation while folate intake, total vitamin A intake, and serum retinol concentration were protective against CRP elevation. Unlike previous studies among higher BMI populations, this study found no significant effect of dietary lipids/fatty acids or BMI on CRP elevation.

CONCLUSIONS

The effects of specific dietary nutrients on inflammatory status may vary with BMI or, in women, reproductive status. Further research should investigate the role of dietary fats, fatty acids, and antioxidant vitamins across populations with a wide range of BMI, including postpartum women.

Effects of low-dose metformin and rosiglitazone on biochemical, clinical, metabolic and biophysical outcomes in polycystic ovary syndrome

The aim of this study was to compare the effect of low-dose metformin and rosiglitazone on clinical, biochemical, ultrasound features and endothelial function in patients with polycystic ovary syndrome (PCOS). After randomisation, a group of 17 women received metformin 500 mg b.d. (MG) and a group of 18 received rosiglitazone 4 mg o.d. (RG) for 3 months. Serum FSH, LH, testosterone, fasting glucose, insulin, IGF-1, IGFBP-3, CRP were measured at baseline and follow-up. Ovarian scan and microcirculation studies were also performed. It was found that there was a reduction in hyperandrogenaemia, insulin resistance, lipidaemia, CRP levels, ovarian volume and number of follicles in both groups. No improvement in endothelial- dependent function was noted but a significant improvement in endothelial-independent function in rosiglitazone group. It was concluded that low-dose therapeutic regimen with rosiglitazone and metformin, has comparable beneficial impacts on metabolic, hormonal and morphological features of PCOS but no obvious effect on vascular parameters in a population of predominantly mild PCOS.

A Prospective Study of Variability in Glycemic Control during Different Phases of the Menstrual Cycle in Type 2 Diabetic Women Using High Sensitivity C - Reactive Protein

INTRODUCTION

Diabetes mellitus (DM) is one of the metabolic syndromes prevalent worldwide, with more concentration in the Asian region. Many studies have been conducted in order to understand the complex pathogenesis of this disease. Yet, there exists a lacuna in our knowledge about DM. This study aims at establishing the reason for glycemic variation in menstruating Type-2 diabetic women by estimation of C-reactive protein, an inflammatory marker that exhibits significant association with changes in blood glucose levels.

METHODOLOGY

A prospective study was undertaken in Type-2 diabetic women of reproductive age group to assess the variability of glycemic control during different phases of menstrual cycle using high sensitivity C reactive protein (hs-CRP) as the biomarker. Fifty women were enrolled after satisfying a set of inclusion and exclusion criteria. The fasting blood glucose, hs-CRP concentration and endogenous female hormones were assayed in follicular and luteal phases of the cycle. The observed parameters were analyzed statistically for significant correlation. Observation and Result: The result showed that hs-CRP level significantly correlates with increasing levels of fasting blood glucose level in both the phases of menstrual cycle in Type-2 diabetic women. The significance is statistically stronger during luteal phase of the cycle (r = 0.807; p<0.05). The correlation observed between hs-CRP and Estrodiol in follicular phase (r = -0.311; p < 0.05) was not statistically significant. The hs-CRP level increased significantly with progesterone level during luteal phase (r = 0.826; p <0.05).

CONCLUSION

This study concludes that Type-2 diabetic women of reproductive age group encounter a period of poor glycemic control during luteal phase, as shown by statistically high hs-CRP level mediated by endogenous progesterone hormone. Therefore, this study advocates careful monitoring, life style adjustments and drug regime to reduce the fluctuation in glycemic level experienced by Type-2 diabetic premenopausal women in the luteal phase.

Significant sex difference in the association between C-reactive protein concentration and anthropometry among 13- to 19-year olds, but not 6- to 12-year olds in Nepal

Life history theory predicts a trade-off between immunostimulation and growth. Using a cross-sectional study design, this study aims to test the hypothesis that C-reactive protein (CRP) is negatively associated with height-for-age z-scores (HAZ scores) and BMI-for-age z-scores (BAZ scores) among 6- to 19-year olds (N = 426) residing in five Nepalese communities. Dried blood spot (DBS) samples were collected and assayed for CRP using an in-house enzyme immunoassay (EIA). Sex- and age-group-specific CRP quartiles were used to examine its association with growth in linear mixed-effects (LME) models. A significant difference was found in the proportion of elevated CRP (>2 mg/L, equivalent to ∼3.2 mg/L serum CRP) between 13- and 19-year-old boys (12%) and girls (4%). Concentrations of CRP were positively associated with HAZ score among adolescent (13-19 years) boys, which may indicate that individuals with greater energy resources have better growth and a better response to infections, thus eliminating the expected trade-off between body maintenance (immunostimulation) and growth. Adolescent boys with low BAZ and HAZ scores had low CRP values, suggesting that those who do not have enough energy for growth cannot increase their CRP level even when infected with pathogens. Among adolescent girls a positive association was observed between CRP and BAZ scores suggesting the possible effects of chronic low-grade inflammation due to body fat rather than infection. The association between CRP and growth was less evident among children (6-12 years) compared with adolescents, indicating that the elevated energy requirement needed for the adolescent growth spurt and puberty may play some role.

A review of peripheral biomarkers in major depression: the potential of inflammatory and oxidative stress biomarkers

Biomarkers are regularly used in medicine to provide objective indicators of normal biological processes, pathogenic processes or pharmacological responses to therapeutic interventions, and have proved invaluable in expanding our understanding and treatment of medical diseases. In the field of psychiatry, assessment and treatment has, however, primarily relied on patient interviews and questionnaires for diagnostic and treatment purposes. Biomarkers in psychiatry present a promising addition to advance the diagnosis, treatment and prevention of psychiatric diseases. This review provides a summary on the potential of peripheral biomarkers in major depression with a specific emphasis on those related to inflammatory/immune and oxidative stress/antioxidant defences. The complexities associated with biomarker assessment are reviewed specifically around their collection, analysis and interpretation. Focus is placed on the potential of peripheral biomarkers to aid diagnosis, predict treatment response, enhance treatment-matching, and prevent the onset or relapse of major depression.

Waist circumference and menopausal status are independent predictors of endothelial low-grade inflammation

BACKGROUND

The high-sensitivity C-reactive protein (hs-CRP) seems to be associated with the presence of atherosclerosis. The association between menopause-related changes in endogenous sex hormones and hs-CRP levels remains controversial.

OBJECTIVE

To compare the levels of hs-CRP in pre- and postmenopausal women and to evaluate the association of endogenous sex hormones, waist circumference (WC) and insulin resistance with the levels of hs-CRP.

METHODS

This cross-sectional study included 145 women (age range: 45-65 years), 56 premenopausal and 89 postmenopausal. Patients were evaluated for hormonal and lipid profile, HOMA-IR, hs-CRP and WC. Each variable was first assessed for correlation with log hs-CRP using a univariate model, and significant variables were then added to the multivariate regression model. A p value <0.05 was considered statistically significant.

RESULTS

The hs-CRP is higher in postmenopausal patients (3.6 ± 4.9 versus 2.6 ± 3.7, p = 0.004). The log hs-CRP was positively correlated with WC (r = 0.13, p = 0.005), HOMA-IR (r = 0.29, p = 0.001), and triglycerides (r = 0.50, p = 0.01). The menopausal status (p = 0.02) and WC (p = 0.00003) behaved as independent predictors of hs-CRP levels. No correlation was found between hs-CRP and the time since menopause (r = -0.1, p = 0.58).

CONCLUSIONS

The hs-CRP is higher in postmenopausal patients. The menopausal status and WC were independently associated with hs-CRP levels in this sample of pre and postmenopausal women.

Relationships between biomarkers of inflammation, ovarian steroids, and age at menarche in a rural Polish sample

OBJECTIVES

To test the hypothesis that life history trade-offs between maintenance and reproductive effort would be evident through inverse associations between levels of a biomarker of inflammation [C-reactive protein (CRP)], and ovarian hormones. Associations between CRP and age at menarche were also explored.

METHODS

Urinary CRP, salivary progesterone, and estradiol were measured over one menstrual cycle from rural Polish women (n = 25), representing a natural fertility sample. Age of menarche was assessed through interview recall methods. We used minimum second-order Akaike Information Criteria as a means of multiple regression model selection, and repeated measures ANOVA to test cycle-dependent hypotheses.

RESULTS

Comparisons of individuals in high and low CRP tertiles revealed that those with high CRP had significantly lower progesterone (luteal P = 0.03, mid luteal P = 0.007) but not estradiol (follicular P = 0.21, luteal P = 0.15) concentrations through the menstrual cycle. However, when the age at menarche was included in the analysis, both age at menarche and urinary CRP were negatively associated with estradiol (R(2) = 0.44, P = 0.0007). Age at menarche and estradiol were the strongest negative predictors of CRP (R(2) = 0.52, P = 0.0001).

CONCLUSIONS

Inflammation itself may suppress ovarian function, or indicate immune challenges that lead to ovarian suppression. The timing of menarche may also influence adult inflammatory sensitivity and ovarian hormone concentrations. This lends support to existing models of trade-offs between maintenance and reproduction in women.

Estrogen-dependent changes in serum iron levels as a translator of the adverse effects of estrogen during infection: a conceptual framework

Elevated levels of estrogen often associate with increased susceptibility to infection. This has been attributed to the ability of estrogen to concomitantly enhance the growth and virulence of pathogens and suppress host immunity. But the exact mechanism of how estrogen mediates such effects, especially in cases where the pathogen and/or the immune components in question do not express estrogen receptors, has yet to be elucidated. Here we propose that translating the adverse effects of estrogen during infection is dependent to a significant degree upon its ability to manipulate iron homeostasis. For elevated levels of estrogen alter the synthesis and/or activity of several factors involved in iron metabolism including hypoxia inducible factor 1α (HIF-1α) and hepcidin among others. This leads to the inhibition of hepcidin synthesis in hepatocytes and the maintenance of ferroportin (FPN) integrity on the surface of iron-releasing duodenal enterocytes, hepatocytes, and macrophages. Intact FPN permits the continuous efflux of dietary and stored iron into the circulation, which further enhances pathogen growth and virulence on the one hand and suppresses host immunity on the other. This new conceptual framework may help explain a multitude of disparate clinical and experimental observations pertinent to the relationship between estrogen and infection.

A prospective study of circulating C-reactive protein, interleukin-6, and tumor necrosis factor α receptor 2 levels and risk of ovarian cancer

Chronic inflammation may play a role in ovarian carcinogenesis. We examined associations between 3 plasma biomarkers of inflammation-C-reactive protein (CRP), interleukin 6, and tumor necrosis factor α receptor 2-and risk of invasive epithelial ovarian cancer in prospectively collected samples from the Nurses' Health Study (NHS; 1989-2010), Nurses' Health Study II (NHS II; 1996-2009), and the Women's Health Study (WHS; 1992-2011) and performed a meta-analysis including data from previous publications. Associations with ovarian cancer risk were calculated using logistic regression (NHS/NHS II; n = 217 cases) or Cox proportional hazards regression (WHS; n = 159 cases). Study-specific results were combined using random-effects meta-analysis. In the NHS/NHS II and WHS, we observed a 53% increased risk of invasive ovarian cancer when comparing women in the fourth quartile of CRP with women in the first quartile (95% confidence interval (CI): 1.05, 2.23). A CRP level of >10 mg/L versus a level of ≤1 mg/L was associated with a 2.16-fold increased risk (95% CI: 1.23, 3.78). In a meta-analysis of published studies, women in the third tertile of CRP had a 35% increased risk (95% CI: 1.10, 1.67) compared with women in the first tertile. There were no significant associations between interleukin 6 or tumor necrosis factor α receptor 2 and risk in the NHS/NHS II. Our results support the hypothesis that higher levels of circulating CRP are associated with increased risk of ovarian cancer, indicating that the role of inflammation in ovarian cancer requires further elucidation.

Failure to consider the menstrual cycle phase may cause misinterpretation of clinical and research findings of cardiometabolic biomarkers in premenopausal women

Biomarker assessment plays a critical role in the study and prevention of disease. However, variation in biomarkers attributable to the menstrual cycle in premenopausal women may impair understanding the role of certain biomarkers in disease development and progression. Thus, in light of the recently increasing evidence of menstrual cycle variability in multiple cardiometabolic biomarkers, a reexamination of approaches for appropriately studying and diagnosing cardiovascular disease in premenopausal women is warranted. We reviewed studies (from 1934 through 2012) evaluating changes in cardiometabolic biomarkers across phases of the menstrual cycle, including markers of oxidative stress, lipids, insulin sensitivity, and systemic inflammation. Each was observed to vary significantly during the menstrual cycle. For example, nearly twice as many women had elevated cholesterol levels warranting therapy (≥200 mg/dL) during the follicular phase compared with the luteal phase (14.3% vs. 7.9%), with only 3% having consistently high levels during all phases of the cycle. Similarly, nearly twice as many women were classified as being at an elevated risk of cardiovascular disease (high sensitivity C-reactive protein >3 mg/L) during menses compared with other phases (12.3% vs. 7.4%). Menstrual cycle-associated variability in cardiometabolic biomarkers is an important source of variability that should be accounted for in both research and clinical settings.

Systemic inflammation is associated with ovarian follicular dynamics during the human menstrual cycle

BACKGROUND

Ovarian processes and the timing of ovulation are important predictors of both female fertility and reproductive pathology. Multiple waves of antral follicular development have been documented during the menstrual cycle in women. However, the mechanisms underlying the development of follicular waves and their clinical significance are not fully understood. The objective of this study was to examine the relationship between C-reactive protein (CRP) and follicular waves in healthy women. We wanted to determine whether follicular wave dynamics influence systemic inflammation, as ovarian activity increases local inflammatory processes and blood flow. We tested the hypothesis that women with 3 follicular waves would have higher CRP concentrations than those with 2 waves. We further hypothesized that a greater number of major waves (those with a dominant follicle) would be positively associated with CRP.

METHODS/PRINCIPAL FINDINGS

Thirty-nine healthy women underwent daily transvaginal ultrasound examinations for one interovulatory interval, as part of an earlier study. Serum was collected every 3 days during the interovulatory interval (IOI). Enzyme-linked immunosorbent assays were conducted to quantify serum CRP concentrations. Women with 3 waves had higher average log CRP concentrations (n = 14, -0.43±0.35) over the IOI than those with 2 waves (n = 25, -0.82±0.47, p = 02). Average log CRP concentrations were greater in women with 3 (0.30±0.31) versus 1 (-0.71±0.55) or 2 (-0.91±0.47) major waves (p = 0.03). Greater average CRP over the IOI was attributed to greater CRP in the follicular, but not the luteal phase, of the IOI.

CONCLUSIONS/SIGNIFICANCE

A greater number of total antral follicular waves, in particular major waves, corresponded to greater serum concentrations of CRP. These findings suggest that women with a greater number of follicular waves exhibit greater tissue remodeling and therefore greater local and systemic inflammation.

C-reactive protein is elevated in atypical but not nonatypical depression: data from the National Health and Nutrition Examination survey (NHANES) 1999-2004

Little is known about the association of depression subtypes with inflammatory markers predictive of coronary artery disease. In a sample of younger adults representative of the U.S. population, we examined differences in serum C-reactive protein (CRP) among individuals with atypical major depressive disorder (MDD; n = 16), nonatypical MDD (n = 93), and no MDD (n = 1,682). Adults with atypical MDD exhibited higher CRP levels than those with no MDD (mean difference = 1.56 mg/L) or nonatypical MDD (mean difference = 1.40 mg/L), even after adjustment for potential cofounders, anxiety disorders, body mass, and smoking. Nearly twice as many adults with atypical MDD had CRP levels in the high cardiovascular risk range than did those with no MDD or nonatypical MDD. CRP levels of adults with nonatypical MDD or no MDD did not differ. Individuals with atypical depression may be partially driving the overall depression-inflammation relationship and may be a subgroup at elevated risk for coronary artery disease.

The transcription levels of ABCA1, ABCG1 and SR-BI are negatively associated with plasma CRP in Chinese populations with various risk factors for atherosclerosis

ATP binding cassette transporters (ABCA1, ABCG1) and scavenger receptor class B type I (SR-BI) are the three most important cellular cholesterol transporters that may prevent atherogenesis. The aim of this study was to investigate whether they were altered in Chinese populations with various risk factors for atherosclerosis and their potential associations with C-reactive protein (CRP). Healthy female controls (n = 30) and populations with various risk factors for atherosclerosis, such as type 2 diabetes (n = 17), hypertension (n = 12), overweight/obesity (n = 10), incipient nephropathy (n = 10), postmenopausal women (n = 9), male (n = 19), ageing male (n = 22), or smoking (n = 16), were recruited. ABCA1, ABCG1 and SR-BI mRNA levels in peripheral monocytes was determined. ABCG1 was decreased in all the risk populations except ageing. ABCA1 was decreased in all the risk populations except diabetes and male. SR-BI was decreased in those with overweight/obesity and incipient nephropathy. Circulating CRP was increased almost in all the risk populations except in males. The levels of ABCA1, ABCG1 and SR-BI were reduced in those with subclinically high CRP, and negatively associated with CRP level. These data indicates that ABCA1, ABCG1, and SR-BI are reduced in various populations under subclinically inflammatory conditions, which may potentially lead to impairing reverse cholesterol transport and developing atherosclerosis.

Sex, stroke, and inflammation: the potential for estrogen-mediated immunoprotection in stroke

Stroke is the third leading cause of death and the primary cause of disability in the developed world. Experimental and clinical data indicate that stroke is a sexually dimorphic disease, with males demonstrating an enhanced intrinsic sensitivity to ischemic damage throughout most of their lifespan. The neuroprotective role of estrogen in the female brain is well established, however, estrogen exposure can also be deleterious, especially in older women. The mechanisms for this remain unclear. Our current understanding is based on studies examining estrogen as it relates to neuronal injury, yet cerebral ischemia also induces a robust sterile inflammatory response involving local and systemic immune cells. Despite the potent anti-inflammatory effects of estrogen, few studies have investigated the contribution of estrogen to sex differences in the inflammatory response to stroke. This review examines the potential role for estrogen-mediated immunoprotection in ischemic injury.

The effects of estrogen in ischemic stroke

Stroke is a leading cause of death and the most common cause of long-term disability in the USA. Women have a lower incidence of stroke compared with men throughout most of the lifespan which has been ascribed to protective effects of gonadal steroids, most notably estrogen. Due to the lower stroke incidence observed in pre-menopausal women and robust preclinical evidence of neuroprotective and anti-inflammatory properties of estrogen, researchers have focused on the potential benefits of hormones to reduce ischemic brain injury. However, as women age, they are disproportionately affected by stroke, coincident with the loss of estrogen with menopause. The risk of stroke in elderly women exceeds that of men and it is clear that in some settings estrogen can have pro-inflammatory effects. This review will focus on estrogen and inflammation and its interaction with aging.

Endogenous reproductive hormones and C-reactive protein across the menstrual cycle: the BioCycle Study

C-reactive protein (CRP) is one of the most commonly used markers of acute phase reaction in clinical settings and predictors of cardiovascular risk in healthy women; however, data on its physiologic regulation in premenopausal women are sparse. The objective of this study was to evaluate the association between endogenous reproductive hormones and CRP in the BioCycle Study (2005-2007). Women aged 18-44 years from western New York were followed prospectively for up to 2 menstrual cycles (n = 259). Serum levels of CRP, estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone were measured up to 8 times per cycle, timed by fertility monitors. CRP levels varied significantly across the cycle (P < 0.001). More women were classified as being at elevated risk of cardiovascular disease (CRP, >3 mg/L) during menses compared with other phases (12.3% vs. 7.4%; P < 0.001). A 10-fold increase in estradiol was associated with a 24.3% decrease in CRP (95% confidence interval: 19.3, 29.0). A 10-fold increase in luteal progesterone was associated with a 19.4% increase in CRP (95% confidence interval: 8.4, 31.5). These results support the hypothesis that endogenous estradiol might have antiinflammatory effects and highlight the need for standardization of CRP measurement to menstrual cycle phase in reproductive-aged women.

Effects of exercise combined with caloric restriction on inflammatory cytokines

Chronic inflammation has been implicated in the pathogenesis of several chronic diseases, such as atherosclerosis and diabetes, as well as certain types of cancers. It has been suggested that circulating biomarkers for inflammation may be modified by exercise; however, few laboratory-based studies have been conducted in nonobese premenopausal women. The purpose of this investigation was to determine the impact of a 4-month exercise training and caloric-restriction intervention with the goal of weight loss on circulating biomarkers of inflammation in sedentary premenopausal women aged 25–40 years (weight, 57 ± 2 kg). Subjects were studied for 6 consecutive menstrual cycles: 1 Screening, 1 Baseline, then 4 interventions (Interventions 1–4). Supervised aerobic training, consisting primarily of treadmill running and elliptical machine exercise, was performed 4 times per week for 40–90 min at 79% ± 0.7% of maximal heart rate. Subjects also consumed 30% fewer calories vs. baseline (1863 ± 58 to 1428 ± 53 kcal·day–1 (1 kcal = 4.186 kJ), p < 0.0001). Circulating inflammatory biomarkers, including adiponectin, high-sensitivity (hs) C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interferon-gamma (IFN-γ), and leptin, as well as body composition, aerobic capacity, and energy balance, were measured before and after the intervention. Maximal aerobic capacity increased by 8.5 ± 1.7 mL·kg–1·min–1 (p < 0.001) and body mass declined by an average of 3.7 ± 0.5 kg (p < 0.001). Significant reductions in IL-6 (0.39 ± 0.04 to 0.30 ± 0.03 pg·mL–1, p = 0.025), IFN-γ (0.58 ± 0.83 to 0.42 ± 0.64 pg·mL–1, p = 0.030), and leptin (13.18 ± 1.28 to 6.28 ± 0.71 pg·mL–1, p < 0.001) were detected in response to the intervention. No significant changes in adiponectin, hs-CRP, or TNF-α were found. Weight loss in response to exercise training and caloric restriction is effective in reducing inflammatory markers, specifically IL-6 and leptin.

Whole grains are associated with serum concentrations of high sensitivity C-reactive protein among premenopausal women

In premenopausal women, elevated C-reactive protein (CRP) concentrations have been associated with an increased risk of negative reproductive outcomes. Whole grain consumption has been associated with lower CRP concentrations in older women; however, less is known about this relationship in younger women. We investigated whether whole grain intake was associated with serum high sensitivity CRP (hs-CRP) concentrations in young women. BioCycle was a prospective cohort study conducted at the University of Buffalo from 2005 to 2007, which followed 259 healthy women aged 18-44 y for <or= 2 menstrual cycles. hs-CRP concentrations were measured longitudinally <or= 8 times/cycle with visits standardized to menstrual cycle phase. Whole grain intake was estimated by 24-h recalls <or= 4 times/cycle. Servings were defined as 16 g or 125 mL of a 100% whole grain food. Whole grain intake was inversely associated with hs-CRP concentrations after adjusting for age, race, BMI, illness, and antiinflammatory drug use. Consumers of between 0 and 1 serving/d of whole grains had, on average, 11.5% lower hs-CRP concentrations (P = 0.02) and consumers of >or= 1 serving/d had 12.3% lower hs-CRP concentrations (P = 0.02) compared with nonconsumers. Women who consumed >or= 1 serving/d of whole grain had a lower probability of having moderate (P = 0.008) or elevated (P = 0.001) hs-CRP according to the AHA criteria compared with nonconsumers. Given that elevated concentrations of hs-CRP have been linked to adverse reproductive outcomes and pregnancy complications, interventions targeting whole grain consumption may have the potential to improve health status among young women.

Plasma levels of C-reactive protein, leptin and glycosaminoglycans during spontaneous menstrual cycle: differences between ovulatory and anovulatory cycles

PURPOSE

To assess the plasma levels of the inflammatory markers such as C-reactive protein (CRP), leptin, and glycosaminoglycans (GAGs) during the menstrual cycle.

METHODS

Eighteen healthy volunteers were divided into two groups according to the presence of ovulatory or anovulatory menstrual cycles. Blood samples were collected at different time points: at the menstrual phase (days 2-3), periovulatory phase (days 12-13), and luteal phase (days 23-24). CRP and leptin concentrations were measured by enzyme immunoassay. GAGs were isolated using ion-exchange chromatography on DEAE-Sephacel and quantified as hexuronate. The structural characterization of chondroitin sulfate (CS) isomers was performed by fluorophore-assisted carbohydrate electrophoresis (FACE).

RESULTS

In the women with ovulatory cycles, plasma GAG levels differed significantly during menstrual cycle, with increased values at the periovulatory with respect to the menstrual phase. No significant differences in CRP and leptin concentrations were observed through the menstrual cycle in both the examined cycles, but inter-group analysis revealed significant differences of CRP and leptin levels between the ovulatory and anovulatory cycles with higher values at periovulatory phase in the ovulatory cycles.

CONCLUSIONS

There are no fluctuations of both total GAG concentration and CS isomer content during menstrual cycle in the anovulatory cycles. A significant correlation between CRP and gonadotrophins was found. There is no significant difference in CRP across the menstrual cycle among ovulatory cycles, but there is a trend toward higher CRP at the periovulatory than the other phases, consistent with the significant difference in CRP between ovulatory and anovulatory cycles at the periovulatory phase. Both the trend and the significant result suggest an elevation in CRP with ovulation. These observations provide additional evidences to the hypothesis that the ovulation is an inflammatory-like phenomenon.

Banking of biological fluids for studies of disease-associated protein biomarkers

With the increasing demand of providing personalized medicine the need for biobanking of biological material from individual patients has increased. Such samples are essential for molecular research aimed at characterizing diseases at several levels ranging from epidemiology and diagnostic and prognostic classification to prediction of response to therapy. Clinically validated biomarkers may provide information to be used for diagnosis, screening, evaluation of risk/predisposition, assessment of prognosis, monitoring (recurrence of disease), and prediction of response to treatment and as a surrogate response marker. Many types of biological fluids or tissues can be collected and stored in biorepositories. Samples of blood can be further processed into plasma and serum, and tissue pieces can be either frozen or fixed in formalin and then embedded into paraffin. The present review focuses on biological fluids, especially serum and plasma, intended for study of protein biomarkers. In biomarker studies the process from the decision to take a sample from an individual to the moment the sample is safely placed in the biobank consists of several phases including collection of samples, transport of the samples, and handling and storage of samples. Critical points in each step important for high quality biomarker studies are described in this review. Failure to develop and adhere to robust standardized protocols may have significant consequences as the quality of the material stored in the biobank as well as conclusions and clinical recommendations based on analysis of such material may be severely affected.