Insomnia and nightmare profiles during the COVID-19 pandemic in Portugal: characterization and associated factors

Objective/background

To describe and characterize insomnia symptoms and nightmare profiles in Portugal during the first six weeks of a national lockdown due to COVID-19.

Patients/methods

An open cohort study was conducted to collect information of the general population during the first wave of SARS-CoV-2/COVID-19 pandemic in Portugal. We analyzed data from 5011 participants (≥16 years) who answered a weekly questionnaire about their well-being. Two questions about the frequency of insomnia and nightmares about COVID-19 were consecutively applied during six weeks (March–May 2020). Latent class analysis was conducted and different insomnia and nightmare profiles were identified. Associations between individual characteristics and both profiles were estimated using odds ratios (ORs) and 95% confidence intervals (CI).

Results

Five insomnia (No insomnia, Stable-mild, Decreasing-moderate, Stable-severe, Increasing-severe) and three nightmares profiles (Stable-mild, Stable-moderate, Stable-severe) were identified. Being female, younger, perceiving their income as insufficient and feelings of fear towards COVID-19 were associated with higher odds of insomnia (Women: OR = 6.98 95%CI: 4.18–11.64; ≥60 years: OR = 0.30 95%CI: 0.18–0.53; Insufficient income: adjusted OR (aOR) = 8.413 95%CI: 3.93–16.84; Often presenting fear of being infected with SARS-CoV-2 infection: aOR = 9.13 95%CI: 6.36–13.11), and nightmares (Women: OR = 2.60 95%CI: 1.74–3.86; ≥60 years: OR = 0.45 95%CI: 0.28–0.74; Insufficient income: aOR = 2.60 95%CI: 1.20–5.20; Often/almost always presenting fear of being infected with SARS-CoV-2 infection: aOR = 6.62 95%CI: 5.01–8.74). Having a diagnosis of SARS-CoV-2 virus infection was associated with worse patterns of nightmares about the pandemic.

Conclusions

Social and psychological individual factors are important characteristics to consider in the development of therapeutic strategies to support people with sleep problems during the COVID-19 pandemic.

Association between children’s food insecurity and a Healthy Eating Index in Portuguese children

Background

Evidence on the association between children's food insecurity (FI) and a priori-defined dietary patterns is scarce, particularly in Europe. This study assessed the association between children's FI and a diet quality index in a population-based sample of children.

Methods

A cross-sectional study including 2800 children from the 10-year-old follow-up of a Portuguese birth cohort, the Generation XXI study, was performed. Data on food security status, assessed by the Self-administered Food Security Survey Module for Children (SAFSSMC), dietary intake, assessed by a validated FFQ, and socio-demographic characteristics were collected. An adaptation of the Healthy Eating Index (HEI) was used, by including 7 food groups (fruit and vegetables, dairy products, fish and eggs, meat and meat products, sweet snacks, salty snacks and soft drinks) scored from 1 to 4 according to increasing quartiles of daily consumption. For the last 4 groups, a reverse score was assigned. Scores were summed up (the highest the score, the highest diet quality). Linear and logistic regression models (HEI score and its food groups divided by the sample median) were performed.

Results

The FI prevalence was 9.4%. The median (P25;P75) HEI score was 18.0 (15.0;21.0). Children's FI was inversely associated with diet quality (β=-0.671;95%CI:-1.129;-0.213), independently of maternal education, caregivers' unemployment and child's sex. By using the SAFSSMC raw score, FI increased the odds for lower (below the median) fruit and vegetables intake (OR = 1.069;95%CI:1.002-1.139), and higher intake (above the median) of meat and meat products (OR = 1.075;95%CI:1.011-1.144) and soft drinks (OR = 1.074;95%CI:1.008-1.145), independently of maternal education, caregivers' unemployment, child's sex and the other food groups consumption.

Conclusions

Food insecure children have poorer diet quality, specifically a lower fruit and vegetables consumption, and higher intake of meat and meat products, and soft drinks.

Key messages

FI was reported by 9.4% of children, and poorer diet quality was observed among food insecure children, when compared to food secure ones. Public health interventions targeting food insecure children should be developed to promote healthy dietary habits in the context of populations vulnerable to FI.

P–042 Impact of semen parameters, sperm DNA fragmentation and sperm aneuploidy in male infertility

Study question

Should sperm aneuploidies and sperm DNA fragmentation (sDNAfrag) be included as valid tests in the routine investigation of male infertility?

Summary answer

Sperm DNA fragmentation was associated with male age, oligozoospermia (OZ), oligoteratozoospermia (OT), astenoteratozoospermia (AT) and oligoastenoteratozoospermia (OAT). Sperm aneuploidies were associated with OT and OAT.

What is known already

Semen parameters assist male infertility diagnosis and treatment, but sDNAfrag and aneuploidy analysis could add useful information, as abnormal values compromise fertility. To include these tests in the routine diagnosis it should be determined if behave as informative parameter and add information regarding the fertility status. For that, further studies comparing these tests to semen parameters are needed, since previous results are not consensual. Additionally, standardization of a sDNAfrag cut-off is needed, as different sample sizes and techniques originate distinct results. Also, until a standardization of the protocol is missing, a cut-off value should be defined for each laboratory.

Study design, size, duration

A retrospective and prospective investigation was performed, within a 12 years period (April 2007-December 2019). A total of 835 infertile males with a normal karyotype (46,XY) were included. Karyotyping and evaluation of sDNAfrag and sperm aneuploidies were made at a public Genetic unit. All normozoospermic (NZ) patients with a born child and patients whose infertility treatments were done due to female factors were selected from our database and used as controls (60 individuals).

Participants/materials, setting, methods

Semen analysis followed WHO–2010 guidelines. sDNAfrag was evaluated using the TUNEL assay. Sperm aneuploidies were detected using FISH (chromosomes 13, 18, 21, X, Y). Several tests were applied: correlations for linear associations between numerical variables, ANOVA for comparisons between means, Dunn-test for post-hoc comparisons. To determine the sDNAfrag cut-off value, the area under the ROC curve, sensitivity and specificity, were calculated, with the Youden-Index used to find a threshold that maximizes both sensitivity and specificity.

Main results and the role of chance

Regarding male age, it was observed a positive correlation with sperm concentration, a negative correlation with sperm vitality (VT) and hypoosmolality, and a positive correlation with sDNAfrag. Regarding sDNAfrag, it was observed negative correlation with sperm concentration, total progressive motility (TPM), morphology, VT and hypoosmolality. Regarding sperm aneuploidies, both total sperm aneuploidy and total sperm disomy exhibited a negative association with sperm concentration, TPM and morphology. It was also investigated whose groups of individuals could be indicated for sDNAfrag or sperm aneuploidy testing. The NZ group evidenced significant lower sDNAfrag, total sperm aneuploidy and total sperm disomy in relation to the non-NZ group. In the NZ group, sDNAfrag was significantly lower in relation to the OZ, OT, AT and OAT groups. The NZ group presented significant lower percentages of sperm aneuploidy in relation to the OT and OAT groups, and significant lower percentages of sperm disomy in relation to the OAT group. Additionally, sDNAfrag was positively correlated with total sperm aneuploidy and total sperm disomy. From the present large population, ROC curve analysis allowed estimating a cut-off value of 18.8% for the TUNEL-assay (sDNAfrag), with 0.658 of area under the curve, 53.9% sensitivity and 76.7% specificity.

Limitations, reasons for caution

Although presenting a high number of cases and strict controls, the present study was unable to include as controls healthy men with proven fertility. Additionally, the present study did not take into account life-style factors and male associated pathologies besides infertility.

Wider implications of the findings: Semen parameters were shown to be negatively correlated with sDNAfrag and sperm aneuploidies. As sDNAfrag testing and sperm aneuploidy testing were associated with semen abnormalities and male age, it is suggested their inclusion in the routine evaluation of infertile men, thus adding important complementary information about the fertility status.

Trial registration number

Not Appliable

Antimicrobial resistance in companion animals - Veterinarians' attitudes and prescription drivers in Portugal

Antimicrobial resistance transmitted from companion animals is a threat to public health increased by the pet's relationship with humans. This study aims to understand the attitude and drivers of antimicrobial (AM) prescription among companion animal veterinarians in Portugal and identify actions to combat antimicrobial resistance (AMR). This cross-sectional study is based on a questionnaire with 417 respondents representing the Portuguese veterinary population. The results allowed grouping the respondents according to the attitude of prescription. Two types of veterinarians were identified: those who prefer to prescribe treatments based on the animals' signs and their own experience - empirical-oriented type - and those who refer to a guidance protocol to assist the prescription decision - protocol-oriented type. Respondents working in hospitals displayed a positive association with the use of guidance protocols. Efficacy was the main driver of prescription for both groups, suggesting that no matter the attitude in prescribing, the veterinarian's aim is achieving positive clinical results. Most respondents prefer empirical-oriented prescriptions, declare the absence of protocols for the prudent use of AM at the workplace and do not refer to AMR issues nor the need for hygiene reinforcement measures with owners. Owners are less likely to request AMs from veterinarians aged over 43 years old. It was discovered that communication between owners and veterinarians about risks associated with AMR was poor and must be improved and the adoption of a national guideline for the adequate use of AM directed for companion animals would be beneficial.

Trajectories of depressive symptoms through adolescence and young adulthood: social and health outcomes

Depressive symptoms display heterogeneous trajectories across adolescence, which can lead to different consequences. This study aimed to identify trajectories of depressive symptoms from adolescence to young adulthood, assessing the association with social and health outcomes at young adulthood. Adolescents born in 1990, enrolled in schools of Porto, Portugal, in 2003-2004 (EPITeen study) completed the Beck Depression Inventory II (BDI-II) at 13, 17 and 21 years. Mixed models and model-based clustering were used to describe the trajectories in the BDI-II score (n = 2010). Outcomes were assessed at age 21 years with self-administered questionnaires and face-to-face interviews (n = 1594). Odds ratios or regression coefficients, with 95% confidence intervals, were estimated using logistic and linear regression. Three trajectory classes of depressive symptoms were identified, similar in shape in both sexes: High (8.4%), Moderate (31.3%) and Low (60.2%). Participants in High or Moderate classes were more likely to describe lower scores of community involvement, more medical appointments during the last year, higher levels of pain and had higher probability of self-rating health as "good" or "fair or poor". Females in the High and Moderate classes were more likely to be current smokers, to describe ever using drugs and to report more sexual partners, emergency room visits and the use of antidepressants. The risk of depressive symptoms in adulthood is likely to be early determined in adolescence. The trajectory classes with higher levels of symptoms were associated with worse social and health outcomes.

Electives in the medical curriculum - an opportunity to achieve students' satisfaction?

BACKGROUND

Electives are perceived by medical students as a valuable, highly regarded experience, allowing them to customize learning experiences and enabling them to early differentiate during medical training. The present work aims to uncover students' major determinants of satisfaction and how they interfere with their future elective choices in order to identify the best approach to implement electives in medical curricula.

METHODS

A cross-sectional study was conducted through a written evaluation survey concerning the electives available in the academic year 2015-2016. Our institution provides 106 electives to students from the 2^nd to the 5^th year. Students' satisfaction was assessed through a validated questionnaire with eight sentences expressing opinions related to electives global satisfaction. Data from 538 inquiries from 229 students were analyzed quantitatively using regression and correlation models, and qualitatively through phenomenography.

RESULTS

Quantitative analysis of the questionnaires allowed to establish both: 1) The determinants of students' satisfaction with electives, which were Agreement with teaching and learning methodologies, followed by Agreement with assessment methodologies employed, Perception of the workload demanded and Requirement for continuous work and 2) The predictors of students preferences in the following years, namely, Agreement with assessment methodologies employed, Classes attendance and Ranking of the allocated elective established in the previous year. Qualitative analysis of questionnaires revealed that students consider electives as being innovative and interesting, claiming that some, for their relevant content, could be integrated into the medical core curriculum.

CONCLUSIONS

Our work raises awareness on the best practices when it comes to electives' organization to meet students' satisfaction. We can conclude that medical schools should measure students satisfaction as a tool to organize and predict future needs of electives and placements when designing and implementing this alternative student-centred curriculum or even to improve the existing practices regarding electives in medical courses.

Trajectories of cognitive performance over 5 years in a cohort of breast cancer patients (NEON-BC)

Purpose

Cancer-related cognitive impairment may affect 30-70% of cancer patients, either at baseline or during and after treatment. We aimed to identify trajectories of cognitive performance, from before any treatment to 5 years later, in a cohort of breast cancer (BCa) patients.

Methods

BCa women admitted to the Portuguese Institute of Oncology, Porto, were included in the NEON-BC study during 2012. They were evaluated with the Montreal Cognitive Assessment (MoCA) before any treatment, and after 1, 3 and 5 years (N = 506, 503, 475 and 466, respectively). Nlme R package was used to fit a mixed-effect model of the trends in MoCA scores over time, with age and education as fixed effect. Coefficients of this model were retrieved to calculate an age- and education-modified MoCA score (mMoCA). Mclust was used to obtain clusters of trajectories of mMoCA.

Results

Two trajectories were identified, one with higher scores and increasing over time, and the other showing a continuous decline (25.9% of the participants and 84% of the women with cognitive impairment confirmed by neuropsychological tests and clinical examination by neurologist at the 5 year follow-up). Each trajectory was split into 2, according to scoring above or below to the median value of mMoCA at baseline to account for the possibility of patients being in a declining pathway before treatment. In addition to trajectories characterized by the highest and lowest scores, respectively, relatively stable over time, two trajectories with middle-range scores were observed, one increasing over time and the other decreasing (12.7% of the participants); being older than 65 years, suffering from anxiety, depression or poor sleep after treatment were more frequent among the latter.

Conclusions

One quarter of the 5-year breast cancer survivors had a declining trajectory in cognitive performance. Anxiety, depression and sleep quality should be considered as targets for preventive or curative interventions of cognitive decline.

Key messages

Cognitive decline occurs during breast cancer care, affecting one quarter of the patients. Anxiety, depression and sleep quality should be considered as targets for preventive or curative interventions of cognitive decline.

Socioeconomic position and quality of life among older people: The mediating role of social support

Social support can obscure social gradients in health, but its role as a mediator between socioeconomic position (SEP) and quality of life (QoL) in older populations remains unknown. We aimed to examine to what extent social support mediates the association between SEP and overall QoL among older adults (aged 60-84 years). We studied a population-based cohort of 585 noninstitutionalized adults in Porto, Portugal, who were evaluated in 2009. Education, occupation, and perceived income adequacy were used as SEP indicators. The WHOQOL-OLD was used to determine overall QoL. Social support was assessed using the Multidimensional Scale of Perceived Social Support. Path analysis was conducted to quantify direct, indirect, and total effects of SEP on QoL. There was a positive total effect of education on QoL (β = 0.28; 95% CI: 0.05-0.48). In this model, we found an indirect effect through social support (β = 0.15; 95% CI: 0.05-0.26), explaining 54% of the pathway between education and QoL. A similar pattern was identified for the association between occupation and QoL. Perceived income adequacy had a total effect of 2.74 (95% CI: 1.68-3.93) on QoL. Although an indirect effect through social support was found (β = 0.98; 95% CI: 0.42-1.55), a direct effect from this variable remained (β = 1.76; 95% CI: 0.65-2.90). Social support can be a mechanism through which SEP impacts the QoL of older people. Strengthening social support ties may attenuate the impact of social inequalities and improve the QoL of this population.

Parental socioeconomic position and chronic inflammation during adolescence

Background

Early life adversity has been associated with increased risk of inflammation and inflammation-related diseases in adulthood. This study aimed to examine the association of parental socioeconomic position with chronic inflammation over adolescence.

Methods

We used information on 2942 members (1507 girls and 1435 boys) of the EPITeen cohort that was established in 2003 in Porto, Portugal, and included 13 years old adolescents that were further evaluated at 17 and 21 years. Mother’ and father’s education and occupation were used as indicators of parental socioeconomic position. High-sensitivity C-reactive protein (CRP) was measured at three points in time (13, 17 and 21 years). CRP levels were categorized in tertiles separately for each wave; chronic inflammation in adolescence was defined as having CRP levels in the highest tertile in at least 2 waves and never in the lowest tertile.

Results

Over adolescence, the prevalence of chronic inflammation was significantly higher among participants with low parental socioeconomic position. Low parental socioeconomic position was associated with chronic inflammation in adolescence, after adjustment for sex, perinatal and physical environment factors, health-related behaviours and health status in adolescence OR = 1.63; 95%CI: 1.11, 2.40 for lowest vs. highest mother’s education and OR = 1.61; 95%CI: 1.12, 2.30 for lowest vs. highest father’s education.

Conclusions

Low parental socioeconomic position is associated with chronic inflammation during adolescence. Our results suggest that the early life socioeconomic environment has an impact on inflammatory processes over adolescence.

Longitudinal association of adiposity and high-sensitivity C-reactive protein from adolescence into early adulthood

BACKGROUND AND AIMS

Longitudinal studies relating adiposity with low-grade inflammation are scarce. We aimed to examine the longitudinal association between the cumulative exposure to adiposity and low-grade inflammation from adolescence into early adulthood.

METHODS AND RESULTS

Data from a population-based cohort (EPITeen) (n = 1147) was analyzed. Body mass index (BMI), body fat percentage (BF%), waist circumference (WC), and waist-to-height ratio (WHtR) and high-sensitivity C-reactive protein (hsCRP) were ascertained at 13, 17 and 21 years of age and standardized for each wave. Generalized least squares models with a compound symmetry correlation structure were fitted to estimate the longitudinal effect of adiposity on hsCRP and results were presented as linear regression coefficients and 95% confidence intervals [β (95%CI)].The final model estimated the association between the difference in adiposity between two consecutive evaluations (13-17 and 17 to 21-years-old), adjusted for previous adiposity and hsCRP levels, sex, parental education, leisure-time physical activity and fruits and vegetables intake. A positive association between the cumulative exposure to adiposity and final hsCRP was observed, in which the difference between adiposity indicators of two consecutive study waves was independently associated with hsCRP: 0.382 (0.299; 0.465) for BMI, 0.234 (0.164; 0.304) for WC, 0.395 (0.314; 0.477) for BF% and 0.195 (0.133; 0.258) for WHtR.

CONCLUSION

A significant longitudinal effect of the accumulation of adiposity on low-grade inflammation was observed. The change in adiposity from consecutive study waves was shown to have a stronger effect on final hsCRP concentrations than both previous adiposity and hsCRP levels.

Duration and degree of adiposity: effect on cardiovascular risk factors at early adulthood

BACKGROUND/OBJECTIVES

The effect of adiposity dynamics throughout adolescence on adult cardiometabolic outcomes is not well known. We aimed to assess the effect of duration and degree of adiposity from adolescence to early adulthood on blood pressure and insulin resistance at 24 years.

SUBJECTS/METHODS

We used data from 2253 participants evaluated at 13, 17, 21 and 24 years of age in the EPITeen cohort, Porto, Portugal. The area under the curve of body mass index (BMI_AUC) was computed to summarize duration and degree of BMI for the 11-year period. Outcomes were systolic blood pressure (SBP) and insulin resistance at 24 years. The homeostasis model assessment of insulin resistance (HOMA-IR) was used as an indicator of insulin resistance and the variable was log-transformed. Associations between BMI_AUC and each outcome were estimated by linear regression models.

RESULTS

The median BMI_AUC was 243.1 (223.9-268.6) kg m^-2 in 11 years, corresponding to 22.1 kg m^-2 on average per year. In crude analyses, both BMI_AUC and BMI at 24 years were positively associated with SBP (β=0.096 mm Hg, 95% confidence interval (CI) 0.077; 0.115 for BMI_AUC; β=4.616 mm Hg, 95% CI 3.082; 6.151 for BMI at 24 years) and ln HOMA-IR (β=0.004, 95% CI 0.003; 0.005 for BMI_AUC; β=0.047, 95% CI 0.036; 0.057 for BMI at 24 years). After adjustment for confounders and for BMI at 24 years, the magnitude of the association of BMI_AUC attenuated for both outcomes, mostly for SBP, but the association remained statistically significant. Results using standardized variables confirmed that both outcomes were more strongly associated with BMI at 24 years than with BMI_AUC.

CONCLUSIONS

In addition to the effect of adult attained BMI, cumulative exposure to higher BMI throughout adolescence, taking into account duration and degree, was also relevant for adult cardiovascular risk factors, mainly for insulin resistance.

Life course path analysis of total and central adiposity throughout adolescence on adult blood pressure and insulin resistance

BACKGROUND AND AIM

We aimed to study whether the effect of adolescent adiposity on adult blood pressure and insulin resistance was mediated by adult adiposity.

METHODS AND RESULTS

Data from the EPITeen cohort at 13, 17 and 21 years was used (n = 2211). Sex- and age-specific body mass index z-scores (BMIz) and waist-to-hip ratio (WHR) were used as indicators of total and central adiposity, respectively. Systolic blood pressure (SBP), glucose and insulin were assessed at 21 years and the homeostasis model assessment (HOMA-IR) was used as a marker of insulin resistance. Path analysis was applied to evaluate direct and indirect effects of adiposity (13, 17 and 21y) on adult SBP and HOMA-IR, separately for total and central adiposity and for each outcome. Results are presented as standardized regression coefficients [β (95%CI)]. The total effect of BMIz at 13 years on SBP at 21 years was 0.211 (0.178; 0.244), totally mediated by adult BMIz. Total effect of BMIz 13y on HOMA-IR was 0.248 (0.196; 0.299). Although this effect was mostly mediated by BMIz 21y, an additional direct effect from BMIz 17y was found [β = -0.240 (-0.315; -0.164)]. Central adiposity was also positively associated with SBP and HOMA-IR at 21 years, and the effect of adolescent WHR was totally mediated by adult WHR for both outcomes.

CONCLUSIONS

The effect of adolescent adiposity on adult SBP and HOMA-IR was mostly mediated by adult adiposity. However, for HOMA-IR an additional direct effect from total adiposity at 17 years was found.

The impact of students and curriculum on self-study during clinical training in medical school: a multilevel approach

BACKGROUND

In higher education, the focus has shifted from the acquisition of knowledge to learning objectives and skills. This means that, the majority of student learning time is spent independently working outside the classroom. Students take an active role in setting goals, deciding how to achieve them, and planning individual study time. Although extensive research has recognized the importance of curriculum and students' characteristics in time devoted to self-study, it is still unclear to what extent these variables affect time to study. Due to the growing reliance on self-directed learning in medical education, and in an attempt to elucidate this issue, this research aims to evaluate self-study time during clinical training and assess whether this is more influenced by the student or the curriculum.

METHODS

A questionnaire was given to 1220 medical students (43.3% of the enrolled students). The students were asked to indicate the average number of study hours per week beyond the time allocated to classes for each clerkship (rotation) attended. Variation and generalizability of students' self-study were estimated using linear mixed models.

RESULTS

Findings showed that the intrinsic differences within students were a greater source of variation in self-study time than differences within clerkships (56.0% vs. 6.9%). If the amount of self-study dedicated to an individual clerkship is to be determined, at least 32 students are needed to achieve acceptable reliability. However, this data with two clerkships per student can used to retrospectively measure the self-study reported by students in clinical training.

CONCLUSIONS

The findings suggest that, both, curriculum and student characteristics influence self-study in undergraduate clinical training. Indeed, students' characteristics play a significant role in time devoted to study. Further research should be undertaken to investigate students' characteristics that may predict self-study during undergraduate medical training.

The role of prenatal exposures on body fat patterns at 7 years: Intrauterine programming or birthweight effects?

BACKGROUND AND AIMS

It remains unknown whether the effects of prenatal exposures on child's adiposity reflect entirely intrauterine programming. We aimed to assess the effects of maternal gestational weight gain, diabetes and smoking on the child's body fat patterns, disentangling the direct (through intrauterine programming) and indirect (through birthweight) effects.

METHODS AND RESULTS

We included 4747 singleton 7-year-old children from the Generation XXI birth cohort (Porto, Portugal). At birth, maternal and newborn's characteristics were obtained. Anthropometrics were measured at age 7 years and body fat patterns were identified by principal component analysis. Path analysis was used to quantify direct, indirect and total effects of gestational weight gain, diabetes and smoking on body fat patterns. Pattern 1 was characterized by strong factor loadings with body mass index, fat mass index and waist-to-height ratio (fat quantity) and pattern 2 with waist-to-hip ratio, waist-to-thigh ratio, and waist-to-weight ratio (fat distribution). The positive total effect of maternal gestational weight gain and diabetes on the child's fat quantity was mainly through a direct pathway, responsible for 91.7% and 83.7% of total effects, respectively (β = 0.022; 95% Confidence Interval (CI): 0.017, 0.027; β = 0.041; 95% CI: -0.011, 0.093). No effects on fat distribution were found. Maternal prenatal smoking had a positive direct effect on patterns 1 and 2, explaining 94.9% and 76.1% of total effects, respectively.

CONCLUSION

The effects of maternal gestational weight gain, diabetes and smoking on a child's fat quantity seem to be mainly through intrauterine programming. Maternal smoking also showed a positive direct effect on child's fat distribution.

Dietary patterns and asthma prevalence, incidence and control

BACKGROUND

The increased asthma prevalence in westernized societies has been suggested to be related to environment exposures and lifestyle changes, particularly diet. We aimed to explore the association between dietary patterns and asthma prevalence, incidence and control in a nationally representative population.

METHODS

Data from 32,644 adults, 53% female, from the 4th Portuguese National Health Survey were analysed. Prevalence of asthma was 5.3%; 'current asthma', defined by asthma symptoms within previous year, 3.5%; 'current medicated asthma' defined by use of asthma medication within previous year, 3.0%; 'current severe asthma' defined by emergency visit because of asthma within previous year, 1.4%; and 'incident asthma', 0.2%. Dietary patterns (DP) were identified by latent trait models based on dietary intake. Unconditional logistic regression models were performed to analyse association between DP and asthma. Age, gender, education, family income, proxy reporting information, smoking, body mass index and physical activity level were analysed as confounders.

RESULTS

Two of the five identified DP were associated with asthma: 'high fat, sugar and salt' DP (positively correlated with pastry, chocolate and sweet desserts, candies, salty snacks, chips, fruit juices, soft drinks and alcoholic beverages consumption at snacks) was associated with asthma prevalence (OR = 1.13, 95% CI = 1.03, 1.24) and current severe asthma (OR = 1.23, 95% CI = 1.03, 1.48), while 'fish, fruit and vegetables' DP (positively correlated with fish, vegetables and fruit intake at meals) was negatively associated with current (OR = 0.84, 95% CI = 0.73, 0.98), and current medicated asthma (OR = 0.84, 95% CI = 0.72, 0.98), after adjustment for confounders.

CONCLUSION & CLINICAL RELEVANCE

Our results suggest a protective association between 'fish, vegetables and fruit' DP and current asthma and current medicated asthma, and a detrimental association between 'high fat, sugar and salt' DP and severe asthma prevalence, further supporting the rational for diet and lifestyle intervention studies in asthma based on whole dietary patterns and physical activity.

The association between the 4G/5G polymorphism in the promoter of the plasminogen activator inhibitor-1 gene and deep venous thrombosis in young people

Objective: To evaluate the association between the 4G/5G polymorphism in the promoter of the plasminogen activator inhibitor-1 (PAI-1) gene and deep venous thrombosis (DVT) in young people.

Methods: Prevalence of the 4G/5G polymorphism was investigated using DNA analysis in a population of 81 consecutive and unrelated patients with an objectively documented first episode of DVT under 40 years old and in a control group of 88 healthy subjects.

Results: The frequency of genotypes among patients was 0.27 4G/4G, 0.49 4G/5G and 0.23 5G/5G, corresponding to a frequency of 0.52 for the 4G allele. In the control group the results were, respectively, 0.24, 0.44 and 0.32, corresponding to a frequency of 0.46 for the 4G allele. The odds ratio (OR) for homozygous 4G genotype was 1.5 (95% confidence interval: 0.7–3.6), which was not statistically significant ( P = 0.51).

Conclusion: In this study, the 4G/5G polymorphism in the promoter of the PAI-1 gene, including the homozygous 4G genotype, was not associated with a significantly increased risk of DVT in young people.

A new approach to estimating weight change and its reference intervals during the first 96 hours of life

AIM

We aimed to apply a novel model to estimate weight change and its reference intervals during the first 96 h of life and the time of weight nadir.

METHODS

This study involved 1288 full-term singletons, from the Generation XXI birth cohort. Recruitment occurred between 2005 and 2006 in all five public units providing obstetrical and neonatal care in Porto, Portugal. Birthweight was abstracted from clinical records, and the subsequent newborn anthropometrics were obtained by trained examiners. Longitudinal models to estimate postnatal weight were tested and the weight ratio was calculated as the weight during 96 h of life divided by birthweight.

RESULTS

The chosen model was (weight(t)~ 3241.442 + (-9.378) × t + 0.119 × t(2) + 0.000 × t(3) + b0i + b1i × t, where t represented the newborn infant's age in hours and bi represented the random coefficients. The curve inflection point (nadir) was achieved at 52.3 h of life, corresponding to a loss of 218 g and a weight ratio of 0.933. We estimated that at six, 12, 24 and 36 h of life the mean weight ratio and 10th-90th percentiles were 0.978 (0.968-0.988), 0.968 (0.953-0.983), 0.951 (0.928-0.974) and 0.939 (0.909-0.969), respectively.

CONCLUSION

This model allows a more accurate estimate of newborn weight change and its reference intervals, and estimated the nadir at 52.3 h of life, corresponding to a weight ratio of 0.933.

Developmental trajectories of adiposity from birth until early adulthood and association with cardiometabolic risk factors

OBJECTIVE

To identify developmental trajectories of adiposity from birth until early adulthood, and to investigate how they relate with cardiometabolic risk factors at 21 years of age.

METHODS

Participants' weight and height measurements were obtained using the EPITeen cohort protocol at 13, 17 and 21 years of age, and extracted from child health books as recorded during health routine evaluations since birth. Blood pressure, triglycerides, cholesterol and insulin resistance (HOMA-IR) were assessed at 21 years. Trajectories were defined using 719 participants contributing 11 459 measurements. The individual growth curves were modelled using mixed-effects fractional polynomial, and the trajectories were estimated using normal mixture modelling for model-based clustering. Differences in cardiometabolic risk factors at 21 years according to adiposity trajectories were estimated through analysis of covariance (ANCOVA), and adjusted means are presented.

RESULTS

Two trajectories-'Average body mass index (BMI) growth' (80.7%) and 'Higher BMI growth' (19.3%)-were identified. Compared with those in 'Average BMI growth', 'Higher BMI growth' participants were more frequently delivered by caesarean section, mothers were younger and had higher BMI, and parental education was lower; and at 21 years showed higher adjusted mean systolic (111.6 vs 108.3 mm Hg, P<0.001) and diastolic blood pressure (71.9 vs 68.4 mm Hg, P<0.001), and lower high-density lipoprotein cholesterol (53.3 vs 57.0 mg dl(-1), P=0.001). As there was a significant interaction between trajectories and sex, triglycerides and HOMA-IR were stratified by sex and we found significantly higher triglycerides, in males, and higher HOMA-IR in both sexes in 'Higher BMI growth' trajectory. All the differences were attenuated after adjustment for BMI at 21 years.

CONCLUSIONS

In this long-term follow-up, we were able to identify two adiposity trajectories, statistically related to the BMI and cardiometabolic profile in adulthood. Our results also suggest that the impact of the adiposity trajectory on cardiometabolic profile is mediated by current BMI.

Model-based patterns in prostate cancer mortality worldwide

Background:

Prostate cancer mortality has been decreasing in several high income countries and previous studies analysed the trends mostly according to geographical criteria. We aimed to identify patterns in the time trends of prostate cancer mortality across countries using a model-based approach.

Methods:

Model-based clustering was used to identify patterns of variation in prostate cancer mortality (1980–2010) across 37 European, five non-European high-income countries and four leading emerging economies. We characterised the patterns observed regarding the geographical distribution and gross national income of the countries, as well as the trends observed in mortality/incidence ratios.

Results:

We identified three clusters of countries with similar variation in prostate cancer mortality: pattern 1 (‘no mortality decline'), characterised by a continued increase throughout the whole period; patterns 2 (‘later mortality decline') and 3 (‘earlier mortality decline') depict mortality declines, starting in the late and early 1990s, respectively. These clusters are also homogeneous regarding the variation in the prostate cancer mortality/incidence ratios, while are heterogeneous with reference to the geographical region of the countries and distribution of the gross national income.

Conclusion:

We provide a general model for the description and interpretation of the trends in prostate cancer mortality worldwide, based on three main patterns.

Cross-sectional and longitudinal associations between serum uric acid and metabolic syndrome

Research on the importance of serum uric acid (SUA) as a contributing metabolic factor to cardiovascular diseases has conducted to conflicting results, with most studies assuming a cross-sectional design. The aim of this study was to evaluate the association of SUA and metabolic syndrome (MetS) and its features. A representative sample of 2,485 individuals aged ≥18 years was randomly selected from the non-institutionalized resident population of Porto, Portugal. A total of 1,054 eligible subjects were included for the longitudinal analyses. Hyperuricemia was defined as SUA ≥70 mg/L in men and ≥60 mg/L in women. MetS was defined according the Joint Interim (2009) criteria. Associations were estimated using Poison regression and binomial models. In the cross-sectional analysis, subjects with hyperuricemia had a 2.10-fold increased risk of MetS as compared with normouricemic subjects (PR = 2.10, 95% CI: 1.68-2.63). Among MetS features, high triglycerides presented the strongest association with hyperuricemia (PR = 2.32, 95% CI: 1.84-2.91). The MetS crude incidence rate was 4.5/100 person-year (95% CI: 3.9-5.2) in normal uricemic and 13.0/100 person-year (95% CI: 8.5-20.0) in hyperuricemic participants. Using a multivariate longitudinal approach, hyperuricemia was positively associated with MetS incidence rate ratios (IRR = 1.73, 95% CI: 1.08-2.76). One standard deviation increase of SUA concentration was associated with a 1.22-fold increase in MetS risk (IRR = 1.22, 95% CI: 1.05-1.42). Elevated SUA presented the strongest association with high-triglycerides concentration (IRR = 1.44, 95%: 1.22-1.71) and waist circumference (IRR = 1.25, 95%: 1.05-1.49). The independent positive association between SUA and MetS suggested by this longitudinal study supports that SUA might be a risk factor for MetS.

Body fat distribution and C-reactive protein--a principal component analysis

BACKGROUND AND AIMS

To assess, using principal component analysis, the independent associations of general, central and peripheral subcutaneous fat with high-sensitivity C-reactive protein (hs-CRP), in men and women from the general population.

METHODS AND RESULTS

We studied 833 women and 486 men, randomly selected from the non-institutionalized population of Porto, Portugal, with information on hs-CRP (≤10 mg/l) and anthropometrics (1999-2003). Body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and a skinfold composite index to estimate the proportion of arm subcutaneous fat (PSFA), were ascertained by trained personnel. Beta regression coefficients were obtained from generalized linear models with adjustment for the main confounders. Direct associations were found between BMI, WC, WHR and hs-CRP. PSFA was inversely associated with hs-CRP in women (β=-0.080, p-trend=0.010). Since the anthropometric measures were strongly correlated, we used principal component analysis to identify new independent anthropometric factors. The first one, representing a generalized fat distribution (high BMI and WC), was directly associated with hs-CRP (β=0.226, p-trend<0.001 in women; β=0.138, p-trend=0.002 in men). The second factor, characterized by a high PSFA, showed an inverse association with hs-CRP in women (β=-0.071, p-trend=0.048). The third factor, representing a central pattern of fat distribution (low BMI, but high WC and high WHR), was directly associated with hs-CRP in men (β=0.090, p-trend=0.005).

CONCLUSION

A central pattern of fat distribution is directly associated with hs-CRP levels in men, while a high proportion of peripheral subcutaneous fat seems to be inversely associated with hs-CRP, but only in women.

Translation of Berlin Questionnaire to Portuguese language and its application in OSA identification in a sleep disordered breathing clinic

BACKGROUND

Berlin Questionnaire (BQ), an English language screening tool for obstructive sleep apnea (OSA) in primary care, has been applied in tertiary settings, with variable results.

AIMS

Development of BQ Portuguese version and evaluation of its utility in a sleep disordered breathing clinic (SDBC).

MATERIAL AND METHODS

BQ was translated using back translation methodology and prospectively applied, previously to cardiorespiratory sleep study, to 95 consecutive subjects, referred to a SDBC, with OSA suspicion. OSA risk assessment was based on responses in 10 items, organized in 3 categories: snoring and witnessed apneas (category 1), daytime sleepiness (category 2), high blood pressure (HBP)/obesity (category 3).

RESULTS

In the studied sample, 67.4 % were males, with a mean age of 51 ± 13 years. Categories 1, 2 and 3 were positive in 91.6, 24.2 and 66.3 %, respectively. BQ identified 68.4 % of the patients as being in the high risk group for OSA and the remaining 31.6 % in the low risk. BQ sensitivity and specificity were 72.1 and 50 %, respectively, for an apnea-hipopnea index (AHI) > 5, 82.6 and 44.8 % for AHI > 15, 88.4 and 39.1 % for AHI > 30. Being in the high risk group for OSA did not influence significantly the probability of having the disease (positive likelihood ratio [LR] between 1.44-1.49). Only the items related to snoring loudness, witnessed apneas and HBP/obesity presented a statistically positive association with AHI, with the model constituted by their association presenting a greater discrimination capability, especially for an AHI > 5 (sensitivity 65.2 %, specificity 80 %, positive LR 3.26).

CONCLUSIONS

The BQ is not an appropriate screening tool for OSA in a SDBC, although snoring loudness, witnessed apneas, HBP/obesity have demonstrated being significant questionnaire elements in this population.

B-type natriuretic peptide measured in serum--calibration using plasma samples for research purposes

BACKGROUND

We aimed to establish an equation for the estimation of the BNP concentration in plasma when only serum is available.

METHODS

We enrolled 27 subjects aged at least 45 years, participating in a Portuguese cohort study. Blood samples were collected in plastic whole blood tubes, containing either ethylenediaminetetraacetic acid to obtain plasma or clot activator to obtain serum. The natural logarithm of serum BNP was calibrated with the natural logarithm of plasma BNP using a linear equation.

RESULTS

The estimated regression parameters were 0.58 (95 % CI: 0.23 - 0.93) for beta0 and 1.01 (95 % CI: 0.90 - 1.11) for beta1. The absolute agreement between plasma BNP and that predicted by the equation according to the cut-off points 30 and 100 pg/mL were 96.3% (kappa = 0.92) and 96.3% (kappa = 0.91), respectively.

CONCLUSIONS

Serum samples cannot be used to estimate absolute plasma concentrations, but serum BNP values and the calibration equation can be used to classify correctly the individuals with the usual cut-offs.

Bronchopulmonary dysplasia: clinical practices in five Portuguese neonatal intensive care units

With the advent of surfactant, prenatal corticosteroids (PNC) and advances in technology, the survival rate of extremely low birth weight (ELBW) infants has improved dramatically. Rates of bronchopulmonary dysplasia (BPD) vary widely among neonatal intensive care units (NICUs) and many studies using multiple interventions have shown some improvement in BPD rates. Implementing potentially better practices to reduce BPD has been an effort made over the last few decades.

AIM

To compare five Portuguese NICUs in terms of clinical practices in very low birth weight (VLBW) infants, in order to develop better practices to prevent BPD.

PATIENTS AND METHODS

256 preterm neonates, gestational age (GA) <30 weeks and/or birthweight (BW) <1250g admitted to five Portuguese NICUs (centers 1 to 5) between 1st January 2004 and 31st December 2006, were studied. VLBW infants with major malformations, grade IV intraventricular haemorrhage in the first week of life and metabolic or neuromuscular disease were excluded. BPD was defined as oxygen dependency at 36 weeks of postconceptional age. We considered a practice to be improved as clinically significant whenever a decrease greater than 10% in the prevalence of BPD adjusted for the practice, GA and BW was achieved compared to BPD prevalence adjusted only for GA and BW.

RESULTS

The overall prevalence of BPD was 12.9%. Our results revealed that PNC use should be improved in centers 4 and 5; fluid policy in center 4; oxygen therapy and sepsis prevention in centers 1 and 2. Patent ductus arteriosus (PDA) treatment should be improved in center 2.

CONCLUSION

The implementation of potentially better practices to reduce lung injury in neonates in Portuguese NICUs, according to each NICU, must be addressed to increase the prescription of PNC, to use a lower FiO2, to be careful with fluid administration in the first weeks of life and to prevent PDA and sepsis. It is necessary to follow guidelines, recommendations or protocols to improve quality in the prevention of BPD.

Screening for twin-twin transfusion syndrome at 11-14 weeks of pregnancy: the key role of ductus venosus blood flow assessment

OBJECTIVES

A discrepancy in crown-rump length (CRL) and/or nuchal translucency thickness (NT) between monochorionic twins has been found to be associated with an increased risk of twin-twin transfusion syndrome (TTTS). As one of the most plausible mechanisms for increased NT is hemodynamic imbalance and cardiac dysfunction, indirectly manifested by abnormal blood flow in the ductus venosus (DV), we aimed to clarify the role of DV blood flow assessment in identifying those monochorionic twins more prone to develop TTTS.

METHODS

We present 99 cases of monochorionic diamniotic twin pregnancies in which CRL, NT and DV blood flow were evaluated at 11-14 weeks' gestation.

RESULTS

Discrepant values of CRL were not predictive of TTTS development. Intertwin NT discrepancy >or= 0.6 mm had a sensitivity of 50.0% and a specificity of 92.0%. The presence of at least one abnormal blood flow waveform in the DV was associated with a relative risk for developing TTTS of 11.86 (95% CI, 3.05-57.45), with a sensitivity of 75.0% and a specificity of 92.0%. The combination of abnormal DV blood flow with NT discrepancy >or= 0.6 mm yielded a relative risk for the development of TTTS of 21 (95% CI, 5.47-98.33).

CONCLUSIONS

Both intertwin discrepancy in NT and abnormal flow in the DV in monochorionic twins may represent early manifestations of hemodynamic imbalance between donor and recipient. In these pregnancies, in addition to NT measurement at 11-14 weeks, the Doppler assessment of DV blood flow significantly increases the performance of screening for those at risk of developing TTTS.

Development of a tool for the assessment of calcium and vitamin D intakes in clinical settings

The study aim was to develop a tool (software and ruler) to assess the dietary calcium and vitamin D intakes in Portugal, and evaluate the usefulness of non-dietary variables as intake predictors. Our findings indicated that is possible to estimate both using three and six food items, respectively, and non-dietary predictors.

INTRODUCTION

The study aim was to develop a tool to assess the dietary calcium and vitamin D intakes in Portugal, and evaluate the usefulness of non-dietary variables as predictors.

METHODS

Trained interviewers collected information of 2,414 adults of Porto, Portugal, using a structured questionnaire and a validated semi-quantitative food frequency questionnaire (FFQ). Food items with the highest contribution to the total intake and non-dietary predictors (gender, age and body mass index (BMI)) were selected for the tool. Different statistical approaches were used to predict the intake. A Bland-Altman plot compared the predictions from the tool and the full FFQ.

RESULTS

The items selected to predict intake were milk (38%), cheese (12%), yogurt (10%) and gender for calcium and oily fish (39%), canned fish (9%), white fish (7%), eggs (5%), red meat (5%), age and BMI for vitamin D. The Bland-Altman plot showed that the mean differences were 0.0 (limits of agreement = [-220.67; 220.77]) mg/day and 0.0 (limits of agreement = [-1.03; 1.05]) microg/day, respectively for calcium and vitamin D.

CONCLUSION

The equations estimated by the best statistical model to predict the calcium and vitamin D intake allowed for the design of a software and a circular ruler useful in clinical settings.

Congenital Diaphragmatic Hernia. The Post-neonatal period. Part II

AIM

The aim of the study was to review our experience in the management of newborns with congenital diaphragmatic hernia (CDH).

METHODS

A retrospective study including all infants with CDH at the Hospital de São João, a center that does not provide ECMO support, for the period from 1997 to 2006. Since 2003, a new treatment protocol has been used.

RESULTS

There were 61 newborns (30 male/31 female) with a birth weight of 2800 g (880 - 3770), and a gestational age of 38 weeks (28 - 41); 46 (75 %) were inborn and 42 (69 %) had a prenatal diagnosis of CDH. There were 2 (3 %) chromosomal anomalies, 3 (5 %) with other congenital anomalies and 1 (2 %) with nonimmune hydrops fetalis. The diaphragmatic defect was left sided in 55 (90 %) cases. Corrective surgery was performed in 43 (70 %) patients. New therapies were used: HFOV 13 % (n = 8); inhaled nitric oxide 13 % (n = 8); and sildenafil 7 % (n = 4). We found that systemic arterial hypotension (p = 0.001), the severity of pulmonary hypertension (p = 0.001), prenatal diagnosis (p = 0.006), birth weight (p = 0.022), female gender (p = 0.029), inborn birth (p = 0.030), arterial pH < 7.35 at admission (p = 0.030), right-sided defect (p = 0.033) and pneumothorax (p = 0.033) to be predictive of mortality. The overall survival rate was 43 % (n = 26), and since 2003 this rate has improved to 61 % for term neonates without other congenital or chromosomal anomalies.

CONCLUSIONS

Our survival rate for infants with CDH has improved over the last ten years, and this improvement is associated with the use of new therapies such as HFOV, inhaled nitric oxide and sildenafil.

Congenital diaphragmatic hernia - the neonatal period (part I)

AIM

The aim of the study was to review our experience in the management of newborns with congenital diaphragmatic hernia (CDH).

METHODS

A retrospective study including all infants with CDH at the Hospital de São João, a center that does not provide ECMO support, for the period from 1997 to 2006. Since 2003, a new treatment protocol has been used.

RESULTS

There were 61 newborns (30 male/31 female) with a birth weight of 2800 g (880 - 3770), and a gestational age of 38 weeks (28 - 41); 46 (75 %) were inborn and 42 (69 %) had a prenatal diagnosis of CDH. There were 2 (3 %) chromosomal anomalies, 3 (5 %) with other congenital anomalies and 1 (2 %) with nonimmune hydrops fetalis. The diaphragmatic defect was left sided in 55 (90 %) cases. Corrective surgery was performed in 43 (70 %) patients. New therapies were used: HFOV 13 % (n = 8); inhaled nitric oxide 13 % (n = 8); and sildenafil 7 % (n = 4). We found that systemic arterial hypotension (p = 0.001), the severity of pulmonary hypertension (p = 0.001), prenatal diagnosis (p = 0.006), birth weight (p = 0.022), female gender (p = 0.029), inborn birth (p = 0.030), arterial pH < 7.35 at admission (p = 0.030), right-sided defect (p = 0.033) and pneumothorax (p = 0.033) to be predictive of mortality. The overall survival rate was 43 % (n = 26), and since 2003 this rate has improved to 61 % for term neonates without other congenital or chromosomal anomalies.

CONCLUSIONS

Our survival rate for infants with CDH has improved over the last ten years, and this improvement is associated with the use of new therapies such as HFOV, inhaled nitric oxide and sildenafil.

Combined Factor V Leiden (R506Q) and prothrombin G20210A genotyping in young patients presenting with deep venous thrombosis

Objective: To evaluate the association between the Factor V Leiden (FV R506Q) and prothrombin gene (FII G20210A) mutations and deep venous thrombosis (DVT) in young people.

Methods: Blood samples were drawn from 199 subjects: 100 healthy controls and 99 unselected patients, with an objectively documented first episode of DVT under 40 years old. DNA analysis was performed using the polymerase chain reaction.

Results: The mean age in the patient cohort was 27 years (range 16–40) and 68 (68.7%) were women. Patient prevalences were 20.6% and 10.1% for FV R506Q and FII G20210A, respectively. In the control group, carrier frequencies were 2% and 5%, respectively. We found an increased overall relative risk of DVT with statistical significance for FV R506Q carriers (OR: 12.8; 95% CI: 2.9–56.7; P < 0.001), but not for FII G20210A mutation (OR: 2.1; 95% CI: 0.7–6.5; P = 0.19).

Conclusions: Our results suggest a possible increase in DVT risk for the young G20210A allele carriers, which can be more expressed in the presence of a circumstantial risk factor. There is extremely strong evidence that the Factor V Leiden mutation is an important risk factor in the development of a first episode of DVT in young people.

Genetic Polymorphisms and Risk of Recurrent Deep Venous Thrombosis in Young People: Prospective Cohort Study

OBJECTIVE

To determine the incidence of deep venous thrombosis (DVT) recurrence in young people, and its association with some genetic polymorphisms (FV G1691A, FII G20210A, MTHFR C677T, PAI-1 4G/5G).

DESIGN

Prospective cohort study.

METHODS

A database was established prospectively to follow-up a cohort of unselected patients who had had a first episode of objectively proven DVT under the age of 40 years. All patients had DNA analysis for heritable thrombophilia. We excluded patients with deficiency of antithrombin, protein C or protein S, malignant disease, antiphospholipid syndrome, or a requirement for long-term antithrombotic treatment. The end-point was objective evidence of symptomatic DVT recurrence.

RESULTS

Eighty-seven patients were enrolled in the study. Mean duration of follow-up was 4.07 years. At 2 years, the cumulative recurrence rate was 19.3%. The risk of risk was not related to presence or absence of laboratory evidence of genetic polymorphisms: FV G1619A (HR 1.26 [95%CI: 0.64-2.46]; p = 0.51), FII G20210A (HR 0.81 [95%CI: 0.35-1.89]; p = 0.62), MTHFR C677T (HR 1.26 [95%CI: 0.56-2.81]; p = 0.58), PAI-1 4G/5G (0.84 [95%CI: 0.35-2.05]; p = 0.71).

CONCLUSION

In this study, the risk of recurrent deep venous thrombosis in young people was not related with the presence of FV G1691A, FII G20210A, MTHFR C677T or PAI-1 4G/5G polymorphisms.

Antibody mediated rejection in pig-to-nonhuman primate xenotransplantation models

Antibody-mediated mechanisms are central to the rejection that occurs when pig organs are transplanted into primates. In this article, the histopathological features of the humoral rejection process in these species combinations, namely hyperacute rejection and acute humoral xenograft rejection, will be illustrated. The profile of the natural and elicited antibodies involved will also be discussed. It has now been demonstrated that the natural immune response to a porcine xenograft is primarily directed to Galalpha1-3Gal (alphaGal) specificities, whilst the elicited immune response is directed to both alphaGal and non-alphaGal antigens. The principal characteristics of anti-alphaGal, anti-non-alphaGal and polyreactive antibodies will be described, together with the identification of the molecules recognised by natural and elicited xenoreactive antibodies. The role of the humoral immune response in the rejection of porcine islets in the primate is still uncertain and the current views on the subject will be discussed. Finally, a concise but comprehensive review of the different strategies that have been attempted to prevent the onset of antibody-mediated rejection is presented. These strategies encompass approaches aimed at interfering with the binding of xenoreactive antibodies with their targets, the use of conventional or novel immunosuppressants and splenectomy. It is undeniable that significant progress has been recently achieved in understanding the humoral rejection process of pig organs transplanted into primates. It is expected that a more comprehensive elucidation of the mechanisms underlying accommodation and tolerance may, in the not too distant future, further extend survival of pig organs transplanted into primates.