Gender differences in genetic risk profiles for cardiovascular disease

Background

Cardiovascular disease (CVD) incidence, complications and burden differ markedly between women and men. Although there is variation in the distribution of lifestyle factors between the genders, they do not fully explain the differences in CVD incidence and suggest the existence of gender-specific genetic risk factors. We aimed to estimate whether the genetic risk profiles of coronary heart disease (CHD), ischemic stroke and the composite end-point of CVD differ between the genders.

Methodology/Principal Findings

We studied in two Finnish population cohorts, using the case-cohort design the association between common variation in 46 candidate genes and CHD, ischemic stroke, CVD, and CVD-related quantitative risk factors. We analyzed men and women jointly and also conducted genotype-gender interaction analysis. Several allelic variants conferred disease risk for men and women jointly, including rs1801020 in coagulation factor XII (HR = 1.31 (1.08–1.60) for CVD, uncorrected p = 0.006 multiplicative model). Variant rs11673407 in the fucosyltransferase 3 gene was strongly associated with waist/hip ratio (uncorrected p = 0.00005) in joint analysis. In interaction analysis we found statistical evidence of variant-gender interaction conferring risk of CHD and CVD: rs3742264 in the carboxypeptidase B2 gene, p(interaction) = 0.009 for CHD, and rs2774279 in the upstream stimulatory factor 1 gene, p(interaction) = 0.007 for CHD and CVD, showed strong association in women but not in men, while rs2069840 in interleukin 6 gene, p(interaction) = 0.004 for CVD, showed strong association in men but not in women (uncorrected p-values). Also, two variants in the selenoprotein S gene conferred risk for ischemic stroke in women, p(interaction) = 0.003 and 0.007. Importantly, we identified a larger number of gender-specific effects for women than for men.

Conclusions/Significance

A false discovery rate analysis suggests that we may expect half of the reported findings for combined gender analysis to be true positives, while at least third of the reported genotype-gender interaction results are true positives. The asymmetry in positive findings between the genders could imply that genetic risk loci for CVD are more readily detectable in women, while for men they are more confounded by environmental/lifestyle risk factors. The possible differences in genetic risk profiles between the genders should be addressed in more detail in genetic studies of CVD, and more focus on female CVD risk is also warranted in genome-wide association studies.     

Elements in autopsy liver tissue samples from Greenlandic inuit and Danes. V. Selenium measured by X-ray fluorescence spectrometry

The content of selenium in normal liver tissue samples from Greenlandic Inuit was measured and the results compared with those obtained in normal liver tissue samples from Danes. Normal liver tissue samples were obtained at autopsy from 50 Greenlandic Inuit (27 men, 23 women) with a median age of 61 years (range 23–83) and from 74 Danes (44 men, 30 women) with a median age of 60 years (range 15–87). Total liver selenium content was measured by X-ray fluorescence spectrometry. The content of selenium (median) was in Inuit 26.6 mol/kg dry liver (5–95 percentile: 15.2–49.4) and in Danes 17.7 mol/kg dry liver (5–95 percentile: < 3.8–36.5) (p < 0.0001). Liver selenium content displayed no significant gender difference, either in Inuit or Danes. In Inuit men, there was a negative correlation between liver selenium content and age (r_s = −0.39, p < 0.05), whereas Danish men displayed a positive correlation between liver selenium content and age (r_s = 0.37, p = 0.02). There was no correlation in Inuit or Danish women. In Inuit, the median hepatic selenium index (liver selenium content divided by age) was 0.48 and in Danes 0.33 (p = 0.001). There was an inverse correlation between hepatic selenium index and age both in Inuit (r_s = −0.77, p < 0.0001) and in Danes (r_s = −0.47, p < 0.0001). In conclusion, Inuit had a higher liver content of selenium and a higher hepatic selenium index compared with Danes. The more favourable selenium status is due to a higher nutritional selenium intake with fish and meat from sea mammals.     

Importance of the proline residue to the functional activity and metabolic stability of the nematode FMRFamide-related peptide, KPNFIRFamide (PF4)

PF4 has previously been shown to have potent inhibitory effects on myoactivity of somatic muscle strips from the nematode, Ascaris suum. This study examined the bioactivity and metabolic stability of position 2- and position 5-modified analogues of PF4. Although the analogues [Leu⁵]PF4, [Ala²]PF4, [Gly²]PF4, [Ala²,Leu⁵]PF4, and [Gly²,Leu⁵]PF4 all had qualitatively similar inhibitory effects on A. suum somatic muscle strips, their effects were quantitatively distinguishable and had the order of potency: PF4 = [Leu⁵]PF4 [Al²]PF4 = [Ala²,Leu⁵]PF4 [Gly²]PF4 = [Gly²,Leu⁵]PF4. Leu⁵ for Ile⁵ substitutions in PF4 did not alter the activity of this peptide; however, Gly²/Ala² for Pro² substitutions reduced, bud did not abolish, peptide activity. Peptide stability studies revealed that [Gly²]PF4(2–7) and -(3–7) and [Ala²]PF4(2–7), -(3–7), and -(4–7) fragments were generated following exposure to A. suum somatic muscle strips. However, the parent peptide (PF4) was not metabolized and appeared to be resistant to the sequential cleavages of native aminopeptidases. Observed analogue metabolism appeared to be due to the activity of released aminopeptidases as identical fragments were generated by incubation in medium that had been exposed to somatic muscle strips and from which the strips had been removed prior to peptide addition. It was found that the muscle stretching and bath mixing characteristics of the tension assay led to more effective release of soluble enzymes from muscle strips and thus greater peptide degradation. These studies reveal that Pro² in PF4 is not essential for the biological activity of this peptide; however, it does render the peptide resistant to the actions of native nematode aminopeptidases.     

Sex-dependent toxoplasmosis-associated differences in testosterone concentration in humans

Several lines of indirect evidence suggest that subjects with latent infection of the coccidian parasite Toxoplasma gondii have a higher concentration of testosterone than uninfected controls. Here, we searched for direct evidence of latent toxoplasmosis-associated differences in testosterone concentration among a population of 174 female and 91 male students screened for Toxoplasma infection. We have found Toxoplasma-infected men to have a higher concentration of testosterone and Toxoplasma-infected women to have a lower concentration of testosterone than Toxoplasma-free controls. The opposite direction of the testosterone shift in men compared to women can explain the observed gender specificity of behavioural shifts in Toxoplasma-infected subjects.     

Increased risk of fragility fractures among HIV infected compared to uninfected male veterans

Background

HIV infection has been associated with an increased risk of fragility fracture. We explored whether or not this increased risk persisted in HIV infected and uninfected men when controlling for traditional fragility fracture risk factors.

Methodology/Principal Findings

Cox regression models were used to assess the association of HIV infection with the risk for incident hip, vertebral, or upper arm fracture in male Veterans enrolled in the Veterans Aging Cohort Study Virtual Cohort (VACS-VC). We calculated adjusted hazard ratios comparing HIV status and controlling for demographics and other established risk factors. The sample consisted of 119,318 men, 33% of whom were HIV infected (34% aged 50 years or older at baseline, and 55% black or Hispanic). Median body mass index (BMI) was lower in HIV infected compared with uninfected men (25 vs. 28 kg/m²; p<0.0001). Unadjusted risk for fracture was higher among HIV infected compared with uninfected men [HR: 1.32 (95% CI: 1.20, 1.47)]. After adjusting for demographics, comorbid disease, smoking and alcohol abuse, HIV infection remained associated with an increased fracture risk [HR: 1.24 (95% CI: 1.11, 1.39)]. However, adjusting for BMI attenuated this association [HR: 1.10 (95% CI: 0.97, 1.25)]. The only HIV-specific factor associated with fragility fracture was current protease inhibitor use [HR: 1.41 (95% CI: 1.16, 1.70)].

Conclusions/Significance

HIV infection is associated with fragility fracture risk. This risk is attenuated by BMI.     

Elements in autopsy liver tissue samples from Greenlandic Inuit and Danes. III. zinc measured by X-ray fluorescence spectrometry

The aim of the study was to measure the content of zinc (Zn) in liver tissue samples from Greenlandic Inuit using X-ray fluorescence spectrometry, and compare the results with those obtained in liver samples from Danes. Normal liver tissue samples was obtained at autopsy from 50 Greenlandic Inuit (27 men) with a median age of 61 years (range 23–83) and from 74 Danes (44 men) with a median age of 60 years (range 15–87). In the entire series, liver zinc content in Inuit was not significantly different compared with Danes. There was no significant gender difference in liver zinc content either in Inuit or in Danes. The content of zinc given as median (5–95 percentile) was in Inuit 3.809 mmol/kg dry liver (2.355–7.406), and in Danes 3.992 mmol/kg dry liver (2.499–8.645). There was a significant, positive correlation between liver zinc content and age in Danish women (r_s = 0.43, p = 0.02), which could not be demonstrated in Danish men or in Inuit. Median hepatic zinc index (zinc content in mmol/kg dry weight divided by age in years) in Inuit was 0.073, and in Danes 0.080 (p = 0.3) without any significant difference between the two genders. In Inuit and Danes there was an inverse correlation between hepatic zinc index and age both in the two genders and in the entire series: Inuit: r_s = −0.62, p < 0.0001; Danes: r_s = −0.70, p < 0.0001. The results indicate that Inuit have liver zinc levels, which are similar to those found in Danes.     

Gender differences in the decline in aerobic capacity and its physiological determinants during the later decades of life.

We investigated the hemodynamic determinants of the age-associated decline in maximal oxygen uptake (V(O2 max)) and the influence of gender on the decline in V(O2 max) and its determinants in old and very old men and women. Sedentary, 60- to 92-yr-old women (n = 71) and men (n = 29), with no evidence of cardiovascular disease, underwent maximal treadmill exercise tests during which V(O2 max) and maximal cardiac output (Q(max)) were determined. V(O2 max) and age were inversely related in both women (-23 +/- 2 ml.min(-1).yr(-1); P < 0.0001) and men (-57 +/- 5 ml.min(-1).yr(-1); P < 0.0001). The absolute slope of the V(O2 max) vs. age relationship was twofold steeper in men than in women (P < 0.0001). Q(max) was also inversely related to age in a gender-specific manner (women = -87 +/- 25 ml.min(-1).yr(-1), P = 0.0009; men = -215 +/- 50 ml.min(-1).yr(-1), P = 0.0002; P = 0.01 women vs. men). Age-related changes in maximal exercise arteriovenous oxygen content difference (a-vD(O2)) were marginally different (P = 0.08) between women (-0.12 +/- 0.03 ml.dl(-1).yr(-1), P = 0.0003) and men (-0.22 +/- 0.04 ml.dl(-1).yr(-1), P < 0.0001). Age-associated decreases in Q(max) and a-vD(O2) contributed equally to the declines in V(O2 max) in both men and women. In the later stages of life, V(O2 max), Q(max), and a-vD(O2) decrease with age more rapidly in older men than they do in older women. As a result, the gender differences dissipate in the later decades of life. Declines in Q(max) and a-vD(O2) contribute equally to the age-related decrease in V(O2 max) in men and women.     

Alpha-linolenic acid intake and 10-year incidence of coronary heart disease and stroke in 20,000 middle-aged men and women in the Netherlands

Background

Whether intake of alpha-linolenic acid (ALA), the plant-derived n-3 polyunsaturated fatty acid (PUFA), could prevent cardiovascular diseases is not yet clear. We examined the associations of ALA intake with 10-year incidence of coronary heart disease (CHD) and stroke in the Netherlands.

Methods

Data were collected from a general population of 20,069 generally healthy men and women, aged 20 to 65 years. Habitual diet was assessed at baseline (1993–1997) with a validated 178-item food frequency questionnaire. Incidences of CHD and stroke were assessed through linkage with mortality and morbidity registers. Hazard ratios (HR) were calculated with multivariable Cox proportional hazards models, adjusted for age, gender, lifestyle, and dietary factors.

Results

During 8–13 years of follow-up, we observed 280 incident CHD events (19% fatal) and 221 strokes (4% fatal). Intakes of energy-adjusted ALA in quintiles ranged from less than 1.0 g/d in the bottom quintile (Q1) to more than 1.9 g/d in the top quintile (Q5). ALA intake was not associated with incident CHD, with HRs varying between 0.89 and 1.01 (all p>0.05) in Q2–Q5 compared with the bottom quintile of ALA intake. For incident stroke, however, participants in Q2–Q5 had a 35–50% lower risk compared with the reference group. HRs were 0.65 (0.43–0.97), 0.49 (0.31–0.76), 0.53 (0.34–0.83), and 0.65 (0.41–1.04) for Q2–Q5 respectively.

Conclusion

In this general Dutch population, ALA intake was not associated with incident CHD. The data suggested that a low intake of ALA may be a risk factor for incident stroke. These results warrant confirmation in other population-based studies and in trials.     

Pairing success and sperm reserve of male Gammarus pulex infected by Cyathocephalus truncatus (Cestoda: Spathebothriidea)

Manipulative parasites with complex life cycles are known to induce behavioural and physiological changes in their intermediate hosts. Cyathocephalus truncatus is a manipulative parasite which infects Gammarus pulex as intermediate host. G. pulex males display pre-copulatory mate guarding as a response to male-male competition for access to receptive females. In this paper, we tested the influence that C. truncatus-infection might have on male G. pulex sperm number and pairing success. We considered 3 classes of G. pulex males in our experiments: (i) uninfected males found paired in the field, (ii) uninfected males found unpaired in the field, or (iii) infected males found unpaired in the field. Both infected males and uninfected unpaired males paired less with a new female than uninfected paired males did. Furthermore, infected males appear to be at a strong disadvantage when directly competing for females with a healthy rival male, and had fewer sperm in their testes. We discuss the potential effect of male and female mating strategies on such male host mating alteration.     

Gender differences in traditional Chinese medicine use among adults in Taiwan

Objectives

The increasing use of complementary, alternative medicine (CAM) and traditional Chinese medicine (TCM) has attracted attention. We report on the gender difference in TCM use among the general population in Taiwan in a population-based, cross-sectional study.

Methods

We collected data on socio-demographic factors, lifestyle and health behavior from the 2001 Taiwan National Health Interview Survey. The medical records of interviewees aged 20–69 years were obtained from National Health Insurance claims data with informed consent. The prevalence of TCM use and the average frequency of TCM use were compared between women and men.

Results

Among 14,064 eligible participants, the one-year prevalence of TCM use for women and men was 31.8% and 22.4%, respectively. Compared with men, women had a higher average TCM use frequency (1.55 visits vs. 1.04 visits, p<0.001). This significant difference remained evident after excluding gender-specific diseases (1.43 visits vs. 1.03 visits, p<0.001). The average TCM use frequency was significantly higher in women than in men across all age groups. TCM use correlates differed for women and men. Marital status (odds ratio [OR] = 1.55, 95% confidence interval [CI] = 1.30–1.85), family income and unhealthy lifestyle (OR = 1.50, 95% CI = 1.30–1.74) were factors associated with TCM use in men but not in women.

Conclusions

In Taiwan, women used more TCM services than men and the gender differences in the TCM use profile persisted across age groups.     

Spontaneous voice gender imitation abilities in adult speakers

Background

The frequency components of the human voice play a major role in signalling the gender of the speaker. A voice imitation study was conducted to investigate individuals'' ability to make behavioural adjustments to fundamental frequency (F0), and formants (Fi) in order to manipulate their expression of voice gender.

Methodology/Principal Findings

Thirty-two native British-English adult speakers were asked to read out loud different types of text (words, sentence, passage) using their normal voice and then while sounding as ‘masculine’ and ‘feminine’ as possible. Overall, the results show that both men and women raised their F0 and Fi when feminising their voice, and lowered their F0 and Fi when masculinising their voice.

Conclusions/Significance

These observations suggest that adult speakers are capable of spontaneous glottal and vocal tract length adjustments to express masculinity and femininity in their voice. These results point to a “gender code”, where speakers make a conventionalized use of the existing sex dimorphism to vary the expression of their gender and gender-related attributes.     

Gender differences in immune reconstitution: a multicentric cohort analysis in sub-Saharan Africa

Background

In sub-Saharan Africa, men living with HIV often start ART at more advanced stages of disease and have higher early mortality than women. We investigated gender difference in long-term immune reconstitution.

Methods/Principal Findings

Antiretroviral-naïve adults who received ART for at least 9 months in four HIV programs in sub-Saharan Africa were included. Multivariate mixed linear models were used to examine gender differences in immune reconstitution on first line ART.A total of 21,708 patients (68% women) contributed to 61,912 person-years of follow-up. At ART start,. Median CD4 at ART were 149 [IQR 85–206] for women and 125 cells/µL [IQR 63–187] for men. After the first year on ART, immune recovery was higher in women than in men, and gender-based differences increased by 20 CD4 cells/µL per year on average (95% CI 16–23; P<0.001). Up to 6 years after ART start, patients with low initial CD4 levels experienced similar gains compared to patients with high initial levels, including those with CD4>250cells/µL (difference between patients with <50 cells/µL and those with >250 was 284 cells/µL; 95% CI 272–296; LR test for interaction with time p = 0.63). Among patients with initial CD4 count of 150–200 cells/µL, women reached 500 CD4 cells after 2.4 years on ART (95% CI 2.4–2.5) and men after 4.5 years (95% CI 4.1–4.8) of ART use.

Conclusion

Women achieved better long-term immune response to ART, reaching CD4 level associated with lower risks of AIDS related morbidity and mortality quicker than men.     

Variants from the Diverse Virus Population Identified at Seroconversion of a Clade A Human Immunodeficiency Virus Type 1-Infected Woman Have Distinct Biological Properties

Development of effective therapeutics to prevent new infections with human immunodeficiency type 1 (HIV-1) is predicated on an understanding of the properties that provide a selective advantage to a transmitted viral population. In contrast to the homogeneous virus population that typifies early HIV-1 infection of men, the viral population in women recently infected with clade A HIV-1 is genetically diverse, based on evaluation of the envelope gene. A longitudinal study of viral envelope evolution in several women suggested that representative envelope variants detected at seroconversion had distinct biological properties that affected viral fitness. To test this hypothesis, a full-length, infectious molecular clone, Q23-17, was obtained from an infected woman 1 year following seroconversion, and chimeric viruses containing envelope genes representative of seroconversion and 27-month-postseroconversion populations were constructed. Dendritic cells (DC) could transfer infection of seroconversion variant Q23ScA, which dominated the viral population in the year following seroconversion, and the closely related 1-year isolate Q23-17 to resting peripheral blood mononuclear cells (PBMC). In contrast, resting PBMC exposed to DC pulsed with Q23ScB, which was detected infrequently in samples after seroconversion, or the 27-month chimeras were inconsistently infected. Additionally, quiescent PBMC infected with Q23ScA or Q23-17 proliferated more robustly than uninfected cells or cells infected with the other envelope chimeras in response to immobilized anti-CD3. Stimulation with tetanus toxoid led to an increased proportion of CD45RA+ cells and a decreased expression of CD28 on CD45RO+ cells in cultures of Q23-17-infected PBMC. These data demonstrate that variants from the heterogeneous seroconversion clade A HIV-1 population in a Kenyan woman have distinct biological features that may influence viral pathogenesis.     

The effects of Trichinella spiralis infection on social interactions in mixed groups of infected and uninfected male mice

The presence of Trichinella spiralis infection in groups of male mice caused behavioural changes in both infected and uninfected mice. Also, for some behaviours, the extent of behavioural change in infected mice appeared to be determined by the number of muscle larvae they harboured. Infected mice showed a reduced frequency of exploratory and social behaviours compared with uninfected mice while uninfected mice performed more social investigatory activities towards those that were infected. Social interactions between infected and uninfected mice were also affected by familiarity. Behavioural differences shown to result from infection in mice familiar with each other were similar but more pronounced when the mice were unfamiliar. These results suggest that other factors may influence the behavioural effects of parasites on their hosts. For some behaviours, the greatest alterations in behaviour apparently caused by infection coincided with the period of infectivity to another host. The significance of this in relation to parasite transmission is considered.     

Gender Differences in Survival among Adult Patients Starting Antiretroviral Therapy in South Africa: A Multicentre Cohort Study

Background

Increased mortality among men on antiretroviral therapy (ART) has been documented but remains poorly understood. We examined the magnitude of and risk factors for gender differences in mortality on ART.

Methods and Findings

Analyses included 46,201 ART-naïve adults starting ART between January 2002 and December 2009 in eight ART programmes across South Africa (SA). Patients were followed from initiation of ART to outcome or analysis closure. The primary outcome was mortality; secondary outcomes were loss to follow-up (LTF), virologic suppression, and CD4+ cell count responses. Survival analyses were used to examine the hazard of death on ART by gender. Sensitivity analyses were limited to patients who were virologically suppressed and patients whose CD4+ cell count reached >200 cells/µl. We compared gender differences in mortality among HIV+ patients on ART with mortality in an age-standardised HIV-negative population.Among 46,201 adults (65% female, median age 35 years), during 77,578 person-years of follow-up, men had lower median CD4+ cell counts than women (85 versus 110 cells/µl, p<0.001), were more likely to be classified WHO stage III/IV (86 versus 77%, p<0.001), and had higher mortality in crude (8.5 versus 5.7 deaths/100 person-years, p<0.001) and adjusted analyses (adjusted hazard ratio [AHR] 1.31, 95% CI 1.22–1.41). After 36 months on ART, men were more likely than women to be truly LTF (AHR 1.20, 95% CI 1.12–1.28) but not to die after LTF (AHR 1.04, 95% CI 0.86–1.25). Findings were consistent across all eight programmes. Virologic suppression was similar by gender; women had slightly better immunologic responses than men. Notably, the observed gender differences in mortality on ART were smaller than gender differences in age-standardised death rates in the HIV-negative South African population. Over time, non-HIV mortality appeared to account for an increasing proportion of observed mortality. The analysis was limited by missing data on baseline HIV disease characteristics, and we did not observe directly mortality in HIV-negative populations where the participating cohorts were located.

Conclusions

HIV-infected men have higher mortality on ART than women in South African programmes, but these differences are only partly explained by more advanced HIV disease at the time of ART initiation, differential LTF and subsequent mortality, and differences in responses to treatment. The observed differences in mortality on ART may be best explained by background differences in mortality between men and women in the South African population unrelated to the HIV/AIDS epidemic. Please see later in the article for the Editors'' Summary.     

Dynamics of regulatory T-cells during pregnancy: effect of HIV infection and correlations with other immune parameters

Objectives

Regulatory T cells (Treg) increase in the context of HIV infection and pregnancy. We studied Treg subpopulations in HIV-infected and uninfected women during pregnancy and their relationship with inflammation, activation and cell-mediated immunity (CMI).

Design and Methods

Blood obtained from 20 HIV-infected and 18 uninfected women during early and late gestation was used to measure Treg and activated T cells (Tact) by flow cytometry; plasma cytokines and inflammatory markers by ELISA and chemoluminescence; and CMI against varicella-zoster virus (VZV) by lymphocyte proliferation.

Results and Conclusions

Compared with uninfected women, HIV-infected participants had higher frequencies of Treg subpopulations in early pregnancy, including CD4+CD25+FoxP3+%, CD8+CD25+FoxP3+%, CD4+TGFβ+% and CD4+IL10+%. In contrast, Treg frequencies were lower during late pregnancy in HIV-infected compared with uninfected women, including CD8+TGFβ+%, CD4+CTLA4+% and CD8+CTLA4+%. VZV-CMI, which was lower in HIV-infected compared with uninfected pregnant women, was inversely correlated with CD4+FoxP3+%, CD8+FoxP3+% and CD8+TGFβ+% in HIV-infected, but not in uninfected pregnant women. β_2-microglobulin, neopterin, IL1, IL4, IL8, IL10, IFNγ and TNFα plasma concentrations as well as Tact were higher in HIV-infected compared with uninfected women throughout pregnancy. In HIV-infected, but not in uninfected women, inflammatory, Th1, Th2 and regulatory cytokines increased with higher Treg%, suggesting that inflammation and regulation have a common pathophysiologic origin in the context of HIV infection. In HIV-infected and more commonly in uninfected pregnant women, higher Treg% correlated with lower Tact%. We conclude that Treg have different dynamics during pregnancy in HIV-infected and uninfected women. Higher levels of inflammatory cytokines and lower Treg% during late pregnancy in HIV-infected women may contribute to their increased incidence of maternal-fetal morbidity.     

Plasma selenium levels in healthy blood bank donors in the central-eastern part of Belgium

Graphite furnace atomic absorption spectrometry, with Zeeman background correction and after improved matrix modification, was used to measure the plasma selenium content of healthy blood bank donors in the central part of Belgium.

The mean plasma selenium concentration of 80 men and 80 women was 79.7±4.4 ng/mL with a range of 55.0–117.4 ng/mL.

There was no gender difference observed. Plasma selenium level was significantly highest for the adult group, aged 45–64 years, compared to the others, except the young adults (18–24 years).

The mean plasma selenium concentration measured corresponded well with literature data for Belgium. The obtained values were found to be in the medium range, compared with recent literature values for the European countries.     

Effect of gender difference on platelet reactivity

Background

Previous studies have suggested that women do not accrue equal therapeutic benefit from antiplatelet medication as compared with men. The physiological mechanism and clinical implications behind this gender disparity have yet to be established.

Methods

On-treatment platelet reactivity was determined in 717 men and 234 women on dual antiplatelet therapy, undergoing elective coronary stent implantation. Platelet function testing was performed using arachidonic acid and adenosine diphosphate-induced light transmittance aggregometry (LTA) and the VerifyNow P2Y12 and Aspirin assays. Also the incidence of all-cause death, non-fatal acute myocardial infarction, stent thrombosis and ischaemic stroke was evaluated.

Results

Women had higher baseline platelet counts than men. Women exhibited a higher magnitude of on-aspirin platelet reactivity using LTA, but not using the VerifyNow Aspirin assay. The magnitude of on-clopidogrel platelet reactivity was significantly higher in women as compared with men with both tests used. The cut-off value to identify patients at risk as well as the incidence of clinical endpoints was similar between women and men (16/234[6.8%] vs. 62/717[8.6%], p = 0.38).

Conclusion

Although the magnitude of platelet reactivity was higher in women, the absolute difference between genders was small and both the cut-off value to identify patients at risk and the incidence of the composite endpoint were similar between genders. Thus, it is unlikely that the difference in platelet reactivity accounts for a worse prognosis in women.