Association of oxidative stress, iron, and centralized fat mass in healthy postmenopausal women

The Silent Threat to Women's Fertility: Uncovering the Devastating Effects of Oxidative Stress

Oxidative stress (OS), which arises through an imbalance between the formation of reactive oxygen species (ROS) and antioxidant defenses, plays a key role in the pathophysiology of female infertility, with the latter constituting just one of a number of diseases linked to OS as a potential cause. The aim of the present article is to review the literature regarding the association between OS and female infertility. Among the reproductive diseases considered are endometriosis and polycystic ovary syndrome (PCOS), while environmental pollutants, lifestyle variables, and underlying medical conditions possibly resulting in OS are additionally examined. Current evidence points to OS likely contributing to the pathophysiology of the above reproductive disorders, with the amount of damage done by OS being influenced by such variables as duration and severity of exposure and the individual's age and genetic predisposition. Also discussed are the processes via which OS may affect female fertility, these including DNA damage and mitochondrial dysfunction. Finally, the last section of the manuscript contains an evaluation of treatment options, including antioxidants and lifestyle modification, capable of minimizing OS in infertile women. The prime message underlined by this review is the importance of considering OS in the diagnosis and treatment of female infertility. Further studies are, nevertheless required to identify the best treatment regimen and its ideal duration.

Oxidative Stress in Postmenopausal Women with or without Obesity

Oxidative stress, a key mediator of cardiovascular disease, metabolic alterations, and cancer, is independently associated with menopause and obesity. Yet, among postmenopausal women, the correlation between obesity and oxidative stress is poorly examined. Thus, in this study, we compared oxidative stress states in postmenopausal women with or without obesity. Body composition was assessed via DXA, while lipid peroxidation and total hydroperoxides were measured in patient's serum samples via thiobarbituric-acid-reactive substances (TBARS) and derivate-reactive oxygen metabolites (d-ROMs) assays, respectively. Accordingly, 31 postmenopausal women were enrolled: 12 with obesity and 19 of normal weight (mean (SD) age 71.0 (5.7) years). Doubled levels of serum markers of oxidative stress were observed in women with obesity in women with obesity compared to those of normal weight (H₂O₂: 32.35 (7.3) vs. 18.80 (3.4) mg H₂O₂/dL; malondialdehyde (MDA): 429.6 (138.1) vs. 155.9 (82.4) mM in women with or without obesity, respectively; p < 0.0001 for both). Correlation analysis showed that both markers of oxidative stress increased with an increasing body mass index (BMI), visceral fat mass, and trunk fat percentage, but not with fasting glucose levels. In conclusion, obesity and visceral fat are associated with a greater increase in oxidative stress in postmenopausal women, possibly increasing cardiometabolic and cancer risks.

Systemic Oxidative Stress, Aging and the Risk of Cardiovascular Events in the General Female Population

Introduction: Menopause is associated with increased cardiovascular risk, in which oxidative stress plays a pivotal role. Systemic oxidative stress is reflected by decreased levels of free thiols (R-SH, sulfhydryl groups), which are key components of the extracellular antioxidant machinery. In this study, we investigated the relation between serum free thiols as marker of oxidative stress and the female cardiovascular phenotype, as well as potential associations with the risk of cardiovascular (CV) events in pre- and postmenopausal women from the general population.

Methods: Female participants (n = 2,980) of the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) cohort study were included. Serum free thiol concentrations were analyzed for associations with demographic, clinical, biochemical, and gynecological parameters, as well as with menopausal status and, prospectively, with the risk of CV events.

Results: Postmenopausal women had significantly reduced levels of serum free thiols (4.8 ± 1.0 vs. 5.2 ± 1.0 μmol/g, P < 0.001) compared to reproductive women. In multivariable analyses, serum free thiols were significantly associated with menopausal status (OR 0.70 [0.49–0.98], P = 0.039), even when adjusted for potential confounding factors, except for age (P = 0.550). Prospectively, serum free thiols were significantly associated with the risk of CV events (HR 0.52 [0.27–0.97], P = 0.040), even with covariate adjustment, although this disappeared when correcting for age.

Conclusion: In this study, we revealed serum free thiols to be strongly associated with the female cardiovascular phenotype as well as with female risk of CV events, where the influence of age itself seemed to outweigh that of female menopause. Future studies are warranted to further unravel the clinical utility of serum free thiol levels in the context of female cardiovascular risk management.

Oxidative and Cellular Stress Markers in Postmenopause Women with Diabetes: The Impact of Years of Menopause

Women live approximately one-third of their lives in postmenopause. Among postmenopausal women, type 2 diabetes mellitus (DM2) is one of the most prevalent chronic diseases. These conditions promote alterations in the oxidative, metabolic, and immune-inflammatory profiles marked by higher extracellular 72 kDa-heat shock protein (eHSP72). Here, we investigated whether the time of menopause is associated with oxidative cellular stress marker levels in postmenopausal women with DM2. Sixty-four women were recruited (56.7 ± 12.6 years old) in the pre- (n = 22) and postmenopause (n = 42) period, with (n = 19) or without DM2 (n = 45), and a fasting blood collection was made for the evaluation of metabolic, oxidative, and inflammatory markers. We found that menopause and DM2 influenced metabolic and oxidative parameters and presented synergistic effects on the plasma lipoperoxidation levels. Also, postmenopausal women had the highest eHSP72 concentration levels associated with the years in postmenopause. We conclude that the time of menopause impacts the markers of cellular stress and increases the risk of oxidative stress, mainly when it is associated with DM2.

Relationship between iron status markers and insulin resistance: an exploratory study in subjects with excess body weight

Background

Controversy exists on the relationship between iron metabolism and cardiometabolic risk. The aim of this study was to determine if there is a link between dysmetabolic iron and cardiometabolic markers in subjects with excess body weight.

Methods

Cross-sectional study with fifty participants presenting overweight or obesity and at least another metabolic syndrome factor. Determinations: anthropometry, body composition, blood pressure, lipids, glucose, insulin, leptin, areas under the curve (AUC) for glucose and insulin after an oral glucose tolerance test, hs-C reactive protein (hs-CRP), blood count, ferritin, transferrin, transferrin saturation (TSAT), soluble transferrin receptor (sTfR). Gender-adjusted linear correlations and two independent samples t tests were used.

Results

Ferritin was positively correlated with insulin-AUC (r = 0.547, p = 0.008) and TSAT was negatively correlated with waist-hip ratio (r =  − 0.385, p = 0.008), insulin (r =  − 0.551, p < 0.001), and insulin resistance (HOMA-IR, r =  − 0.586, p < 0.001). Subjects with TSAT ≤ 20% had higher insulin (p = 0.012) and HOMA-IR (p = 0.003) compared to those with TSAT > 20%. In conclusion, the observed results suggest that iron transport and storage are altered in subjects with overweight/obesity, at the same time that they exhibit the characteristic features of insulin resistance. Nevertheless, this occurs without iron overload or deficiency. These results should be validated in wider cohorts since they suggest that iron transport and storage should be assessed when performing the clinical evaluation of subjects with excess body weight.

Ovariectomy predisposes female rats to fine particulate matter exposure's effects by altering metabolic, oxidative, pro-inflammatory, and heat-shock protein levels

The reduction of estrogen levels, as a result of menopause, is associated with the development of metabolic diseases caused by alterations in oxidative stress (OS), inflammatory biomarkers, and 70-kDa heat-shock protein (HSP70) expression. Additionally, exposure to fine particulate matter air pollution modifies liver OS levels and predisposes organisms to metabolic diseases, such as type 2 diabetes (T2DM). We investigated whether ovariectomy affects hepatic tissue and alters glucose metabolism in female rats exposed to particulate air pollution. First, 24 female Wistar rats received an intranasal instillation of saline or particles suspended in saline 5 times per week for 12 weeks. The animals then received either bilateral ovariectomy (OVX) or false surgery (sham) and continued to receive saline or particles for 12 additional weeks, comprising four groups: CTRL, Polluted, OVX, and Polluted+OVX. Ovariectomy increased body weight and adiposity and promoted edema in hepatic tissue, hypercholesterolemia, glucose intolerance, and a pro-inflammatory profile (reduced IL-10 levels and increased IL-6/IL-10 ratio levels), independent of particle exposure. The Polluted+OVX group showed an increase in neutrophils and neutrophil/lymphocyte ratios, decreased antioxidant defense (SOD activity), and increased liver iHSP70 levels. In conclusion, alterations in the reproductive system predispose female organisms to particulate matter air pollution effects by affecting metabolic, oxidative, pro-inflammatory, and heat-shock protein expression.

Effect of iron supplementation during lactation on maternal iron status and oxidative stress: A randomized controlled trial

We examined the effect of iron-containing prenatal vitamin-mineral supplements taken postpartum on biomarkers of iron status and oxidative stress. Lactating women (n = 114) were randomly assigned to consume daily one iron-free prenatal vitamin-mineral supplement plus either 27 mg of iron or placebo for approximately 3.5 months. The placebo group took the tablets between meals, while those given iron took the tablets either with (Fe-W) or between meals (Fe-B). Blood and urine samples were collected before and after the supplementation period to analyze hemoglobin (Hb), ferritin, hepcidin, transferrin saturation (TfSat), total plasma iron, and biomarkers of oxidative stress (isoprostane and 8-hydroxy-2-deoxyguanosine (8-OHdG)) and inflammation (C-reactive protein (CRP) and alpha-1-acid glycoprotein (AGP)). There was a trend toward a greater change in Hb among women in the Fe-B group compared to placebo (+2.5 vs. -3.7 g/L, respectively, p = 0.063). When the iron groups were combined, there was a greater change in Hb (+1.4 g/L) compared to placebo (p = 0.010). There were trends toward greater changes in TfSat (p = 0.087) and total plasma iron (p = 0.065) in the iron groups compared to placebo, yet no significant differences between the three groups in change in hepcidin (p = 0.291), isoprostane (p = 0.319), or 8-OHdG (p = 0.659), nor in change in ferritin among those with elevated CRP at baseline (60% of women; p = 0.946); among those without elevated CRP (40% of women), ferritin increased more in the iron groups compared to placebo (p = 0.001). Iron consumption during lactation moderately increased iron status, particularly among women without elevated CRP, and increased Hb, but did not significantly increase oxidative stress.

Plasma F2-isoprostanes Are Positively Associated with Glycemic Load, but Inversely Associated with Dietary Polyunsaturated Fatty Acids and Insoluble Fiber in Postmenopausal Women

Background: Dietary factors, such as antioxidant nutrients, contribute significantly to the maintenance of an appropriate balance between antioxidant defense and free radical production in the body.Objective: The objective of this study was to examine the relation between oxidative stress as assessed by plasma F₂-isoprostane (IsoP) concentration, glycemic load (GL), glycemic index (GI), intake of antioxidant nutrients, dietary fiber, and polyunsaturated fatty acids (PUFAs).Methods: This study was a cross-sectional secondary analysis of baseline data collected from a random sample of 269 postmenopausal women participating in the Minnesota Green Tea Trial. GL, GI, and dietary variables were calculated from the diet history questionnaire. Subjects filled out surveys about the use of anti-inflammatory drugs and physical activity. Plasma IsoP concentration was assessed by GC-mass spectrometry. IsoP concentrations were compared across quartiles of GL, GI, insoluble fiber, PUFAs, and antioxidant nutrients with the use of linear regression.Results: Antioxidant supplement intake, including zinc, copper, vitamin C and vitamin E, was reported by >60% of the participants. Mean intake of PUFAs was 12.5 g. Mean plasma IsoP concentrations increased from 34 to 36.7 pg/mL in the lowest quartiles of GL and GI, respectively, to 45.2 and 41.6 pg/mL, respectively, in the highest quartiles (P-trend = 0.0014 for GL and P-trend = 0.0379 for GI), whereas mean IsoP concentrations decreased from 41.8 pg/mL in the lowest quartile of PUFAs to 34.9 pg/mL in the highest quartile (P-trend = 0.0416). Similarly, mean IsoP concentrations decreased from 44.4 pg/mL in the lowest quartile of insoluble fiber to 36 pg/mL in the highest quartile (P-trend = 0.0243) after adjustment for potential confounders.Conclusions: We concluded that dietary PUFAs and insoluble fiber are inversely associated with oxidative stress whereas GL and GI are positively associated with oxidative stress in postmenopausal women. This trial was registered at clinicaltrials.gov as NCT00917735.

Increased iron levels and lipid peroxidation in a Mediterranean population of Spain

BACKGROUND

Many chronic diseases are adversely affected by elevated iron levels. It has been speculated that this relationship is mediated by increased oxidative stress, due to the ability of iron to generate reactive oxygen species. The aim of this study was to assess the relationship between elevated iron levels and lipid peroxidation in Caucasian adults residing in the north-eastern Mediterranean region of Spain.

MATERIALS AND METHODS

This cross-sectional case-control study included 300 subjects: 150 adults displaying elevated iron levels (cases) selected from a representative sample of our general population and 150 age- and sex-matched adults exhibiting normal iron levels (controls). Dietary assessment (3-day food records), iron biomarkers (serum iron, ferritin and transferrin saturation) and lipid profile were determined. Elevated iron levels were defined by high serum ferritin (SF>110 μg/L in women and>200 μg/L in men) and/or transferrin saturation (TS)>45%. Oxidized low-density lipoprotein (oxLDL) plasma levels were measured, and oxLDL/LDL-cholesterol ratio was calculated to estimate lipid peroxidation. Multiple linear regression (MLR) models were applied.

RESULTS

Individuals with elevated serum iron levels showed increased oxLDL/LDL ratio, but not oxLDL levels, compared to control subjects (20·92 ± 4·89 U/mmol vs. 19·72 ± 3·573 U/mmol, P = 0·028). These results were further confirmed by the regression models adjusted for demographic characteristics, diet, lipid profile and inflammation. Importantly, higher serum levels of triglycerides, LDL-cholesterol and lower intake of Vitamin E increased lipid peroxidation.

CONCLUSIONS

In our general population, we have observed that higher circulating levels of iron, measured by serum ferritin and/or TS, increased lipid peroxidation (measured by oxLDL/LDL ratio).

Oxidative Stress and Antioxidant Levels in Patients with Anorexia Nervosa after Oral Re-alimentation: A Systematic Review and Exploratory Meta-analysis

Oxidative stress markers seem to be higher in patients with anorexia nervosa (AN) than healthy controls, but the potentially beneficial effects of weight gain is not known. We calculated random effects standardised mean differences (SMDs) as effect size measures of oxidative stress marker changes after re-alimentation reported in two or more studies, summarising others descriptively. Seven longitudinal studies (n = 104) were included. After a median follow-up period of 8 weeks, AN patients significantly increased their body mass index (15.1 ± 2.1 to 17.1 ± 2.2, p < 0.0001). This weight gain was followed by a significant increase in serum levels of the antioxidant albumin (studies = 6, SMD = 0.50, 95%CI = 0.18; 0.82, p = 0.002; I(2) = 16%) and a significant decrease in the oxidative stress marker Apolipoprotein B (studies = 2, n = 19, SMD = -0.85, 95%CI = -1.53; -0.17, p = 0.01; I(2) = 0). In one study, catalase and total antioxidant capacity increased, whilst superoxide dismutase significantly decreased. In conclusion, oral re-alimentation, even without full-weight normalisation, seems to improve oxidative stress in people with AN.

Serum ferritin levels are associated with carotid atherosclerosis in Chinese postmenopausal women: the Shanghai Changfeng Study

Postmenopausal women are at increased risk of CVD: the increased serum ferritin level may be involved in the pathogenesis. The aim of the present study is to investigate the relationship of ferritin and carotid atherosclerosis in postmenopausal women. A total of 1178 postmenopausal women (mean age, 60·8 years) were enrolled from the Changfeng Study. A standard interview, anthropometric measurements and laboratory analyses were performed for each participant. Bilateral CIMT (carotid intima–media thickness) were measured using ultrasonography, and the presence of carotid plaques was assessed. Serum ferritin was measured using electrochemiluminescence immunoassay. The results showed that serum ferritin was 181·9 (sd 65·8) ng/ml in the postmenopausal women. Multivariate, linear, stepwise regression analysis demonstrated that age (standardised β = 0·233, P< 0·001), alanine transaminase (standardised β = 0·194, P< 0·001), log homeostasis model assessment index for insulin resistance (standardised β = 0·181, P< 0·001), TAG (standardised β = 0·083, P= 0·003), Hb (standardised β = 0·080, P= 0·004) and PPG (2-h glucose levels following a 75-g oral glucose challenge) (standardised β = 0·079, P= 0·004) were independently associated with serum ferritin. Compared with the ferritin level of subjects in the first quartile, that in the fourth quartile had greater CIMT, and higher prevalence of carotid plaque. After adjusting for conventional CVD risk factors, Hb, leucocytes, log urine albumin:creatinine ratio and liver function, the ferritin level of postmenopausal women in the fourth quartile had a 1·587-fold increased risk of carotid plaques relative to those in the lowest quartile. In conclusion, these results suggest that serum ferritin is independently and positively associated with carotid atherosclerosis in postmenopausal women and that ferritin may be implicated in atherosclerosis.

The isoprostanes--25 years later

Isoprostanes (IsoPs) are prostaglandin-like molecules generated independent of the cyclooxygenase (COX) by the free radical-induced peroxidation of arachidonic acid. The first isoprostane species discovered were isomeric to prostaglandin F2α and were thus termed F2-IsoPs. Since the initial discovery of the F2-IsoPs, IsoPs with differing ring structures have been identified as well as IsoPs from different polyunsaturated fatty acids, including eicosapentaenoic acid and docosahexanenoic acid. The discovery of these molecules in vivo in humans has been a major contribution to the field of lipid oxidation and free radical research over the course of the past 25 years. These molecules have been determined to be both biomarkers and mediators of oxidative stress in numerous disease settings. This review focuses on recent developments in the field with an emphasis on clinical research. Special focus is given to the use of IsoPs as biomarkers in obesity, ischemia-reperfusion injury, the central nervous system, cancer, and genetic disorders. Additionally, attention is paid to diet and lifestyle factors that can affect endogenous levels of IsoPs. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance."

The incidental relationship between serum ferritin levels and hypertension

BACKGROUND AND OBJECTIVE

Although several studies have shown an association between ferritin level and hypertension, only a few studies have investigated the longitudinal relationship between them. Thus, we evaluated the incidental risk for hypertension according to baseline ferritin level.

PATIENTS AND METHODS

A total of 7104 healthy Korean men matched by a propensity score, who had participated in a medical health check-up program in 2005, were followed up from 2005 to 2010. They were divided into four groups according to baseline serum ferritin level (first quartile-fourth quartile). The incidence of hypertension was compared among the four groups, and the Cox-proportional hazard model was used to assess whether the development of hypertension was associated with higher baseline serum ferritin level.

RESULTS

A total of 1252 (17.6%) cases had newly developed hypertension during the 26,339.5 person-years of follow-up between 2006 and 2010. The adjusted hazard ratios (HRs) (95% confidence intervals, CIs) for incident hypertension were 1.00 (reference), 1.09 (0.91-1.30), 1.21 (1.01-1.45) and 1.28 (1.07-1.52), respectively (P for trend=0.003) through the quartiles of serum ferritin levels, respectively, after adjusting for multiple confounders. For the log-transformed serum ferritin levels as a continuous variable, adjusted HRs and 95% CIs for HTN were 1.15 (1.02-1.29).

CONCLUSIONS

Elevated serum ferritin level was independently associated with the incidental risk for hypertension in Korean men. This finding suggests the value of elevated ferritin level as an early predictor of hypertension.

Modulation of the activities of catalase, cu-zn, mn superoxide dismutase, and glutathione peroxidase in adipocyte from ovariectomised female rats with metabolic syndrome

The aim of this study was to evaluate the association between estrogen removal, antioxidant enzymes, and oxidative stress generated by obesity in a MS female rat model. Thirty two female Wistar rats were divided into 4 groups: Control (C), MS, MS ovariectomized (Ovx), and MS Ovx plus estradiol (E2). MS was induced by administering 30% sucrose to drinking water for 24 weeks. After sacrifice, intra-abdominal fat was dissected; adipocytes were isolated and lipid peroxidation, non-enzymatic antioxidant capacity, and the activities of Cu-Zn and Mn superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined. There were no significant differences in the activities of Cu-Zn, Mn SOD, CAT, and GPx between the C and MS groups, but in the MS Ovx group there was a statistically significant decrease in the activities of these enzymes when compared to MS and MS Ovx+E2. The increased lipid peroxidation and nonenzymatic antioxidant capacity found in MS Ovx was significantly decreased when compared to MS and MS Ovx+E2. In conclusion, the removal of E2 by ovariectomy decreases the activity of the antioxidant enzymes in the intra-abdominal tissue of MS female rats; this is reflected by increased lipid peroxidation and decreased nonenzymatic antioxidant capacity.

Association of inflammatory and oxidative stress biomarkers in subjects with cardiovascular risk

Cardiovascular disease is originated in the vascular endothelium, which controls the homeostasis and the filtration and diffusion of molecules from blood to the tissues. The classical cardiovascular risk factors (CRFs) act directly on the endothelium through an increase in the production of reactive oxygen species, promoting an endothelial activation mediated by the expression of adhesion and proinflammatory molecules, which lead to endothelial dysfunction, the progression of the atherosclerotic plaque, and the onset of cardiovascular disease. The objective of this study was to analyze the association of superoxide dismutase, catalase, gluthatione peroxidase, and lipoperoxidation with fibrinogen, interleukin (IL)-6, tumor necrosis factor-α, and vascular cell adhesion molecule (VCAM)-1 in subjects with cardiovascular risk (CVR) and CRF. This was a cross-sectional study of 114 individuals; oxidative stress (superoxide dismutase, catalase, gluthatione peroxidase, and lipoperoxidation) and inflammatory (fibrinogen, IL-6, tumor necrosis factor-α, and VCAM-1) biomarkers were measured; a CVR score (Framingham) and its CRF were taken into consideration to classify the participants. Twenty-nine subjects out of a total of 114 had high CVR. Smokers and subjects with diabetes (43 subjects) were excluded from the low CVR group. Significant decreases in lipoperoxidation, IL-6, and VCAM-1 and an increase in SOD were found in the high CVR group (P ≤ 0.05). Individual analysis of each CRF in the 114 subjects revealed a different pattern in the biomarkers' statistical differences. Concluding that the biomarkers show statistical differences in each CRF, especially IL-6, VCAM-1, and SOD; therefore, these are highly recommended to be used as biomarkers of the oxidative stress and inflammatory status in CVR.

Waist circumference and dual-energy X-ray absorptiometry measures of overall and central obesity are similarly associated with systemic oxidative stress in women

Growing evidence suggests that overall and abdominal obesity might lead to oxidative stress (OxS), which, in turn, plays a key role in the pathogenesis of a wide spectrum of diseases. In this study, for the first time, we compared the correlations of indirect, i.e. anthropometric, and direct, by dual energy X-ray absorptiometry (DXA), measures of body fat with circulatory OxS markers in women. To address this issue, we assessed central and total body fat mass (FM) by DXA, and serum levels of advanced oxidation protein products (AOPP), thiols and hydroperoxides in 275 healthy women (age 21-65 years; body mass index [BMI] 21.1-32.0 kg/m(2); waist circumference [WC] 60.1-109.9 cm). Among the markers considered in the study, only hydroperoxides levels, i.e. by-products of lipid peroxidation, were significantly (p < 0.05 for all) and positively correlated to body fat accumulation after controlling for confounding factors. In particular, this marker was found to be similarly associated with DXA-derived total FM, total FM % and trunk FM as well as with WC. Of note, hydroperoxides appeared to be correlated with abdominal but not with general obesity, as classified according to standard WC and BMI cut-offs, respectively. In conclusion, taken together our data demonstrated that, at least in women, the measurement of body FM by DXA has no advantage over the simpler and cheaper WC with regard to their associations with systemic OxS markers. Moreover, WC emerged as a superior potential predictor of OxS compared to the other most commonly used anthropometric measures (including BMI and waist to hip ratio).

Accumulation of central fat correlates with an adverse oxidative balance in non-obese postmenopausal women

The aim of the present study was to investigate whether accumulation of central fat is correlated with systemic oxidative stress (OxS) in non-obese apparently healthy postmenopausal women. Serum parameters of OxS (hydroperoxides and non-enzymatic antioxidants) along with body fat distribution, as assessed by dual-energy-X-ray absorptiometry (DXA), were evaluated in 134 non-obese postmenopausal women. Multiple regression analysis showed that central (trunk) fat significantly correlated with both markers of OxS independently of confounding factors (i.e. BMI, smoking, age, hypertension, legs and arms fat mass). In specific, the standardized regression coefficient was positive for hydroperoxides (β = 0.324, p < 0.05) and negative for antioxidants (β = -0.495, p < 0.01) level. In conclusion, the current data showed that the increase in central fat is an independent predictor of OxS condition among non-obese women in postmenopausal status. The possible pro-oxidant effects of the excess in central adiposity might be more harmful among post- than among pre-menopausal women, due to the postulated ability of E2 to contrast oxidative challenge and the related diseases.

Higher serum iron is associated with increased oxidant stress in HIV-infected men

BACKGROUND

F₂-isoprostanes (F₂-IsoP) are oxidant stress biomarkers that are higher in HIV-infected women than men. We explored whether the effect of hemoglobin (Hgb), serum iron, or anemia on F₂-IsoP is different between HIV-infected women and men.

METHODS

Plasma F₂-IsoP were quantified by gas chromatography/mass spectrometry; clinical and laboratory data were collected at enrollment or from the medical record. Multivariable linear regression was used to assess associations between F₂-IsoP and Hgb, anemia as a dichotomous variable, and serum iron with adjustment for age, sex, race, body mass index, CD4 lymphocyte count, self-reported current smoking status, and antiretroviral therapy.

RESULTS

Compared with men, women had lower Hgb [median: 12.7 (interquartile range: 11.8-13.9) vs. 14.9 (13.7-15.8) g/dL, P < 0.001], lower iron levels [75 (47-97) vs. 90 (69-121) µg/dL, P = 0.004], more anemia (29% vs. 10%, P < 0.001), and higher levels of F₂-IsoP [42 (32-62) vs. 36 (25-46) pg/mL, P < 0.001]. The relationship between iron and F₂-IsoP differed significantly between men and women (interaction P = 0.02). Men had a 21% (95% confidence interval: 8 to 36) increase in F₂-IsoP per interquartile increase in iron (P = 0.001), whereas no relationship was seen among women [-4% (-17 to 13, P = 0.65].

CONCLUSIONS

Although women have overall higher F₂-IsoP than men, a relationship between circulating F₂-IsoP and iron levels was observed in men but not in women with HIV infection. The association between female sex and higher F₂-IsoP is not explained by iron or Hgb levels because the association persists when controlling for these factors. The role of iron in oxidant stress and sex-specific differences among HIV-infected individuals require further study.

Joint effects of serum ferritin and body mass index on the risk of coronary artery disease: a case-control study

OBJECTIVES

Serum ferritin and body mass index (BMI) have been reportedly associated with coronary artery disease (CAD) risk. The aim of the present study was to explore the interaction between serum ferritin and BMI on CAD risk.

DESIGN

Hospital-based case-control study.

SETTING

Patients with CAD and the controls were recruited from Qilu Hospital, Shandong University.

PARTICIPANTS

258 CAD cases and 282 healthy controls.

METHODS

Multiplicative interaction was assessed through a cross-product interaction term in a multivariate logistic regression model. The effect of serum ferritin and BMI were evaluated per 50 µg/L and per 2 kg/m(2), respectively. The presence of additive interaction between serum ferritin and BMI was evaluated by calculation of the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S).

RESULTS

The ORs and 95% CI of the serum ferritin-BMI product term on a multiplicative scale in the univariate and multivariate models were 0.943 (0.904 to 0.984) and 1.004 (0.951 to 1.059), respectively. There was also evidence for interaction on an additive scale; the RERI (95% CI), AP (95% CI) and S (95% CI) in the univariate model were 0.314 (0.026 to 1.506), 0.107 (0.017 to 0.241) and 1.194 (1.053 to 1.406), respectively. After adjusting for the potential confounders, the estimates and 95% CIs for the aforementioned three measures were 0.004 (-0.016 to 0.311), 0.004 (-0.016 to 0.191) and 1.039 (0.774 to 1.285), respectively.

CONCLUSIONS

Serum ferritin and BMI had an additive interaction on the risk of CAD in Chinese population. Further investigations with big sample size are necessary for confirming this additive interaction.

Regional specificity of sex effects on subcortical volumes across the lifespan in healthy aging

When conceptualizing age-specific onsets and sex-specific characteristics of neuropsychiatric diseases in a neurobiological context, it may be crucially important to consider differential trajectories of aging. Here, we investigated effects of age, sex, and their interactions on absolute and relative volumes of subcortical structures with known involvement in psychiatric disorders, including the basal ganglia, thalamus, hippocampus, and amygdala. Structural MRI data of 76 healthy subjects (38 males, 19-70 years) from the ICBM database were analyzed. Age-related absolute atrophy was generally found in the basal ganglia and thalamus, while in the hippocampus decline was only observed in males, and was generally absent in the amygdala. Disproportionate degeneration in the basal ganglia and thalamus, exceeding cortical decline was specific for females. When allowing higher-order models, a quadratic model could better describe the negative relation of absolute volume and age in the basal ganglia in males, and generally in the hippocampus and amygdala. We could show that negative age-relations are highly specific for certain subcortical structures in either gender. Importantly these findings also emphasize the significant impact of analytical strategies when deciding for correction of subcortical volumes to the whole-brain decline. Specifically, in the basal ganglia disproportionate shrinkage in females was suggested by the relative analysis while absolute volume analysis rather stressed an accelerating decline in older males. Given strong involvement of the basal ganglia in both cognitive aging and emotional regulation, our findings may be crucial for studies investigating the onset and prevalence of dementia and depressive symptoms in male and female aging.

The effects of oxidative stress on female reproduction: a review

Oxidative stress (OS), a state characterized by an imbalance between pro-oxidant molecules including reactive oxygen and nitrogen species, and antioxidant defenses, has been identified to play a key role in the pathogenesis of subfertility in both males and females. The adverse effects of OS on sperm quality and functions have been well documented. In females, on the other hand, the impact of OS on oocytes and reproductive functions remains unclear. This imbalance between pro-oxidants and antioxidants can lead to a number of reproductive diseases such as endometriosis, polycystic ovary syndrome (PCOS), and unexplained infertility. Pregnancy complications such as spontaneous abortion, recurrent pregnancy loss, and preeclampsia, can also develop in response to OS. Studies have shown that extremes of body weight and lifestyle factors such as cigarette smoking, alcohol use, and recreational drug use can promote excess free radical production, which could affect fertility. Exposures to environmental pollutants are of increasing concern, as they too have been found to trigger oxidative states, possibly contributing to female infertility. This article will review the currently available literature on the roles of reactive species and OS in both normal and abnormal reproductive physiological processes. Antioxidant supplementation may be effective in controlling the production of ROS and continues to be explored as a potential strategy to overcome reproductive disorders associated with infertility. However, investigations conducted to date have been through animal or in vitro studies, which have produced largely conflicting results. The impact of OS on assisted reproductive techniques (ART) will be addressed, in addition to the possible benefits of antioxidant supplementation of ART culture media to increase the likelihood for ART success. Future randomized controlled clinical trials on humans are necessary to elucidate the precise mechanisms through which OS affects female reproductive abilities, and will facilitate further explorations of the possible benefits of antioxidants to treat infertility.

Increased MMP-2 in healthy postmenopausal women

Background

Matrix metalloproteases 2 (MMP-2) and 9 (MMP-9) are involved in the atherosclerosis process. The objective of the study was to evaluate MMP-2 and MMP-9 activities and other circulating inflammatory factors in healthy postmenopausal women (PMW) as a model of subclinical atherosclerosis.

Methods

Twenty-three PMW and 13 premenopausal women (PreMW) were selected following established criteria. The main measurements in plasma samples were: lipid–lipoprotein profile, high-sensitivity C-reactive protein (hs-CRP) (immunoturbidimetry), soluble vascular cellular adhesion molecules (sVCAM-1) enzyme-linked immunosorbent assay and MMP activity by zymography.

Results

The relative areas of MMP-2 were increased in PMW: 1.1 (0.1) versus 0.6 (0.05), P < 0.02. MMP-9 was only detected in three PMW and one PreMW. MMP-2 correlated with HDL-cholesterol ( r = −0.51), triglycerides ( r = 0.67), apolipoprotein B ( r = 0.47), hs-CRP ( r = 0.42), homeostasis model assessment ( r = 0.53) and waist circumference ( r = 0.40), at least P < 0.02. sVCAM-1 showed no difference between groups: 28.7 (5.5) versus 35.5 (20) ng/mL, but correlated with MMP-2 and hs-CRP ( r = 0.46 and r = 0.48 respectively, P < 0.05).

Conclusions

In postmenopause, the increase in MMP-2 reflects the systemic specific inflammatory process that accompanies atherogenesis.

Plasma ferritin levels, genetic variations in HFE gene, and coronary heart disease in Chinese: a case-control study

BACKGROUND

The association between body iron stores and coronary heart disease (CHD) was inconsistent. We sought to explore this association in Chinese Han population and further examine the association of the variations in hemochromatosis (HFE) gene and CHD risk.

METHODS

We conducted a case-control study including 1334 CHD patients and 1334 age- and sex-frequency matched controls. The plasma ferritin levels were measured by enzyme linked immunosorbent assay. Genotypes of the tagging single nucleotide polymorphisms (tagSNPs) were determined by TaqMan SNP allelic discrimination.

RESULTS

The plasma ferritin levels in CHD cases (197.9μg/L [2.7-932.9μg/L]) were higher than those in controls (179.9μg/L [21.1-878.2μg/L]; P=0.028). The odds ratios (ORs) across the tertiles of plasma ferritin levels were 1.0 (reference), 0.93 (0.76-1.13), and 1.23 (1.02-1.48; P for trend=0.028). Adjustment for the traditional risk factors attenuated the associations to null (P for trend=0.22). Compared with the TT genotype of tagSNP rs9366637, subjects with C allele had higher risk of CHD (OR=1.35 for TC and 1.76 for CC; P=0.001 and <0.001 respectively). After adjustment for the conventional risk factors the results remained unchanged. We did not find significantly different plasma ferritin levels among different genotypes of rs9366637 (P=0.52).

CONCLUSIONS

The plasma ferritin levels were not significantly associated with CHD risk. However, the SNP rs9366637 in HFE gene was associated with higher CHD risk in Chinese Han population. The underlie mechanism remained to be elucidated in further studies.

Hypertension with elevated levels of oxidized low-density lipoprotein and anticardiolipin antibody in the circulation of premenopausal Indian women chronically exposed to biomass smoke during cooking

This study aims to investigate whether indoor air pollution (IAP) from biomass fuel use was associated with hypertension, platelet hyperactivity, and elevated levels of oxidized low-density lipoprotein (oxLDL) and anticardiolipin antibody (aCL). We enrolled 244 biomass fuel-using (median age 34 year) and 236 age-matched control women who cooked with liquefied petroleum gas (LPG). Enzyme-linked immunosorbent assay was used to measure oxLDL in plasma and aCL in serum, flow cytometry for P-selectin expression on platelet and reactive oxygen species (ROS) generation by leukocytes, aggregometry for platelet aggregation, spectrophotometry for superoxide dismutase (SOD) in erythrocytes, and laser photometer for particulate matter <10 and 2.5 μm in diameter (PM(10) and PM(2.5), respectively) in cooking areas. Biomass users had three times more particulate pollution in kitchen, had higher prevalence of hypertension (29.5 vs. 11.0% in control, P < 0.05), elevated oxLDL (170.6 vs. 45.9 U/l; P < 0.001), platelet P-selectin expression (9.1% vs. 2.4%), platelet aggregation (23.2 vs. 15.9 Ohm), raised aCL IgG (28.7% vs. 2.1%), IgM (8.6% of vs. 0.4%), and ROS (44%) but depleted (13%) SOD. After controlling potential confounders, the changes were positively associated with PM(10) and PM(2.5) in indoor air, suggesting a positive association between IAP and increased cardiovascular risk.

PRACTICAL IMPLICATIONS

The study showing high risk of developing cardiovascular diseases (CVD) among poor, underprivileged women in their reproductive ages in rural India is important from public health perspectives. It may motivate the government and the regulatory agencies of the country to take a serious note of the indoor air pollution (IAP) from biomass fuel use as it threatens the health of millions of women, children, and the elderly who mostly stay indoor. We hope the findings will strengthen the demand for setting up a standard for indoor air quality in the country in the line of national ambient air quality standard. The findings may also inspire the authorities to take measures for the reduction in IAP by improving housing, kitchen ventilation, and cook stoves. Moreover, the parameters used in this study can be utilized for large, population-based studies to identify women at a higher risk of developing CVD so that medical intervention can be taken at the formative stage of a disease.