Donor InSight: characteristics and representativeness of a Dutch cohort study on blood and plasma donors

The association of Obesogenic Environments with Weight Status, Blood Pressure, and Blood Lipids: A Cross-Sectional Pooled Analysis across Five Cohorts

In this observational cross-sectional study, we investigated the relationship between combined obesogenic neighbourhood characteristics and various cardiovascular disease risk factors in adults, including BMI, systolic blood pressure, and blood lipids, as well as the prevalence of overweight/obesity, hypertension, and dyslipidaemia. We conducted a large-scale pooled analysis, comprising data from five Dutch cohort studies (n = 183,871). Neighbourhood obesogenicity was defined according to the Obesogenic Built-environmental CharacterisTics (OBCT) index. The index was calculated for 1000m circular buffers around participants' home addresses. For each cohort, the association between the OBCT index and prevalence of overweight/obesity, hypertension and dyslipidaemia was analysed using robust Poisson regression models. Associations with continuous measures of BMI, systolic blood pressure, LDL-cholesterol, HDL-cholesterol, and triglycerides were analysed using linear regression. All models were adjusted for age, sex, education level and area-level socio-economic status. Cohort-specific estimates were pooled using random-effects meta-analyses. The pooled results show that a 10 point higher OBCT index score was significantly associated with a 0.17 higher BMI (95%CI: 0.10 to 0.24), a 0.01 higher LDL-cholesterol (95% CI: 0.01 to 0.02), a 0.01 lower HDL cholesterol (95% CI: -0.02 to -0.01), and non-significantly associated with a 0.36 mmHg higher systolic blood pressure (95%CI: -0.14 to 0.65). A 10 point higher OBCT index score was also associated with a higher prevalence of overweight/obesity (PR = 1.03; 95% CI: 1.02 to 1.05), obesity (PR = 1.04; 95% CI: 1.01 to 1.08) and hypertension (PR = 1.02; 95% CI: 1.00 to 1.04), but not with dyslipidaemia. This large-scale pooled analysis of five Dutch cohort studies shows that higher neighbourhood obesogenicity, as measured by the OBCT index, was associated with higher BMI, higher prevalence of overweight/obesity, obesity, and hypertension. These findings highlight the importance of considering the obesogenic environment as a potential determinant of cardiovascular health.

Equity in blood transfusion precision services

BACKGROUND

Blood collection agencies are integrating precision medicine techniques to improve and individualise blood donor and recipient outcomes. These organisations have a role to play in ensuring equitable application of precision medicine technologies for both donors and transfusion recipients. BODY: Precision medicine techniques, including molecular genetic testing and next generation sequencing, have been integrated in transfusion services to improve blood typing and matching with the aim to reduce a variety of known transfusion complications. Internationally, priorities in transfusion research have aimed to optimise services through the use of precision medicine technologies and consider alternative uses of genomic information to personalise transfusion experiences for both recipients and donors. This has included focusing on the use of genomics when matching blood products for transfusion recipients, to personalise a blood donor's donation type or frequency, and longitudinal donor research utilising blood donor biobanks.

CONCLUSION

Equity in precision services and research must be of highest importance for blood collection agencies to maintain public trust, especially when these organisations rely on volunteer donors to provide transfusion services. The investment in implementing equitable precision medicine services, including development of blood donor biobanks, has the potential to optimise and personalise services for both blood donors and transfusion recipients.

Iron status in Dutch and Finnish blood donor and general populations: A cross-cohort comparison study

BACKGROUND AND OBJECTIVES

Blood donors are at risk of developing iron deficiency (ID) (ferritin <15 μg/L, World Health Organization definition). Blood services implement different strategies to mitigate this risk. Although in Finland risk group-based iron supplementation is in place, no iron supplementation is provided in the Netherlands. We aim to describe differences in ferritin levels and ID prevalence in donor and general populations in these countries.

MATERIALS AND METHODS

Six cohorts, stratified based on sex, and for women age, in the Netherlands and Finland were used to evaluate differences in ferritin levels and ID between donor populations (Donor InSight-III and FinDonor 10,000) and general populations (Prevention of Renal and Vascular End-Stage Disease [PREVEND], FinRisk 1997 and Health 2000) and newly registered Dutch donors. Multivariable logistic regression was used to quantify associations of various explanatory factors with ID.

RESULTS

In total, 13,443 Dutch and 13,933 Finnish subjects were included. Donors, except for women aged ≤50 years old in Finland, had lower median ferritin levels compared with the general population and new donors. Dutch regular blood donors had higher or similar prevalence of ID as compared with the Dutch general population, including new donors. In contrast, Finnish donors showed similar prevalence of ID compared with the general population, except for a markedly lower prevalence in ≤50-year-old women who routinely receive iron supplements when donating.

CONCLUSION

Iron status in blood donors differs from that in the general population. The Finnish blood service donor management policy, for example, iron supplementation for risk groups, seemingly protects young female blood donors from developing ID.

Autophagy-enhancing ATG16L1 polymorphism is associated with improved clinical outcome and T-cell immunity in chronic HIV-1 infection

Chronic HIV-1 infection is characterized by T-cell dysregulation that is partly restored by antiretroviral therapy. Autophagy is a critical regulator of T-cell function. Here, we demonstrate a protective role for autophagy in HIV-1 disease pathogenesis. Targeted analysis of genetic variation in core autophagy gene ATG16L1 reveals the previously unidentified rs6861 polymorphism, which correlates functionally with enhanced autophagy and clinically with improved survival of untreated HIV-1-infected individuals. T-cells carrying ATG16L1 rs6861(TT) genotype display improved antiviral immunity, evidenced by increased proliferation, revamped immune responsiveness, and suppressed exhaustion/immunosenescence features. In-depth flow-cytometric and transcriptional profiling reveal T-helper-cell-signatures unique to rs6861(TT) individuals with enriched regulation of pro-inflammatory networks and skewing towards immunoregulatory phenotype. Therapeutic enhancement of autophagy recapitulates the rs6861(TT)-associated T-cell traits in non-carriers. These data underscore the in vivo relevance of autophagy for longer-lasting T-cell-mediated HIV-1 control, with implications towards development of host-directed antivirals targeting autophagy to restore immune function in chronic HIV-1 infection.

The social contagion of prosocial behaviour: How neighbourhood blood donations influence individual donation behaviour

Life-saving transfusions and numerous other medical treatments are enabled by a minority of people that donate blood. But why do some people repeatedly engage in such prosocial behaviour, especially when it is costly to themselves? This study examines to what extent social contagion within neighbourhoods - changing behaviour in response to the behaviour of others - affects repeated blood donation behaviour. We draw on longitudinal survey and register data from a representative sample of blood donors in the Netherlands from 2007 to 2014 (N = 15,090). Using a panel data model and an instrumental variable approach, we find that donors are positively affected by donations made by other donors living in their neighbourhood. This effect does not seem to be mediated by normative or informational social influence. Exploratory analysis further attributes this finding to social contagion within donor couples. Our study contributes to the literature on repeated blood donation behaviour, and can inform retention strategies of blood banks.

Mass spectrometry-based analysis on the impact of whole blood donation on the global plasma proteome

BACKGROUND

Biomonitoring may provide important insights into the impact of a whole blood donation for individual blood donors.

STUDY DESIGN AND METHODS

Here, we used unbiased mass spectrometry (MS)-based proteomics to assess longitudinal changes in the global plasma proteome, after a single blood donation for new and regular donors. Subsequently, we compared plasma proteomes of 76 male and female whole blood donors, that were grouped based on their ferritin and hemoglobin (Hb) levels.

RESULTS

The longitudinal analysis showed limited changes in the plasma proteomes of new and regular donors after a whole blood donation during a 180-day follow-up period, apart from a significant short-term decrease in fibronectin. No differences were observed in the plasma proteomes of donors with high versus low Hb and/or ferritin levels. Plasma proteins with the highest variation between and within donors included pregnancy zone protein, which was associated with sex, Alfa 1-antitrypsin which was associated with the allelic variation, and Immunoglobulin D. Coexpression analysis revealed clustering of proteins that are associated with platelet, red cell, and neutrophil signatures as well as with the complement system and immune responses, including a prominent correlating cluster of immunoglobulin M (IgM), immunoglobulin J chain (JCHAIN), and CD5 antigen-like (CD5L).

DISCUSSION

Overall, our proteomic approach shows that whole blood donation has a limited impact on the plasma proteins measured. Our findings suggest that plasma profiling can be successfully employed to consistently detect proteins and protein complexes that reflect the functionality and integrity of platelets, red blood cells, and immune cells in blood donors and thus highlights its potential use for donor health monitoring.

Did you donate? Talking about donations predicts compliance with solicitations for donations

Many forms of prosocial behaviour are highly institutionalized. They are facilitated by organizations that broker between donors and recipients. A highly effective tool that organizations use to elicit prosocial behaviour are solicitations for donations (e.g., of blood, time, or money). Using register and survey data on blood donations in the Netherlands, we examine to what extent compliance with these solicitations is predicted by being recruited via word of mouth (WOM) and talking about donations. Our model predicts that donors that are one unit higher on our measure of talking about donations (range = 1-4) have a 2.9 percentage points higher compliance with solicitations for donations. In addition, this association is stronger for novice donors. Our study demonstrates the social embedding of the donors' decision-making processes about compliance. For practice, our results imply that organizations may increase their contributors' communication about donations to increase the effectiveness of their solicitations.

Ferritin-guided iron supplementation in whole blood donors: optimal dosage, donor response, return and efficacy (FORTE)-a randomised controlled trial protocol

BACKGROUND

Frequent whole blood donors have an increased risk of developing iron deficiency. Iron deficiency can have detrimental health effects when left untreated. Donation intervals are commonly too short to replenish iron stores and extending these reduces donor availability. Oral iron supplementation is known to shorten iron store recovery time but may also induce gastrointestinal complaints. We aim to optimise the effectiveness of iron supplements while minimising the risks of side effects. Therefore, we will evaluate the impact of different iron supplementation protocols in terms of dosage and frequency on ferritin and haemoglobin levels, gastrointestinal side effects, iron deficiency-related symptoms and donor return compared with placebo supplementation.

METHODS

Twelve hundred whole blood donors with ferritin levels ≤30 µg/L are included into a double-blind, randomised controlled trial. Participants are randomly allocated to one of six arms, administering capsules containing 0 mg, 30 mg or 60 mg of iron, either on alternate days or daily for 56 days. At baseline and 56, 122 and 182 days of follow-up, ferritin and haemoglobin levels are measured, and compliance, donor return, dietary iron intake, gastrointestinal, iron deficiency-related symptoms and general health are assessed by questionnaire.

ETHICS AND DISSEMINATION

This study will provide a comprehensive overview of the effects of different frequencies and dosages of administration of iron supplements on iron status and health effects, thereby considering individual differences in treatment adherence and lifestyle. The outcome will provide scientific evidence to guide the debate if and how oral iron supplements may support the recovery of whole blood donors with low ferritin levels.

TRIAL REGISTRATION NUMBER

NL8590; The Dutch trial registry.

Donation-induced iron depletion is significantly associated with low hemoglobin at subsequent donations

BACKGROUND

Blood donation is associated with a loss of hemoglobin (Hb)-bound iron. Hb levels recover relatively fast by using stored iron. However, it takes more time to replenish iron stores, potentially resulting in iron deficiency.

STUDY DESIGN

Hb and ferritin levels were measured in 5056 new, first-time, and repeat whole blood donors. We investigated whether increasing numbers of donations are associated with lower ferritin levels. Furthermore, we tested whether low ferritin levels are associated with low-Hb deferral at the subsequent donation attempt by performing logistic regression adjusted for age and stratified by sex.

RESULTS

Whereas mean Hb levels are relatively stable, ferritin levels significantly decrease with increasing numbers of donations and were approximately 50% lower for donors with >50 donations compared with those with 2-10 donations. Despite the poor correlation of ferritin and Hb levels, cross-sectional, iron-deficient donors (ferritin <15 ng/ml) had 21.8 (8.5-55.6) higher odds in men, 10.1 (6.1-16.5) in premenopausal women, and 11.7 (5.2-26.4) in postmenopausal women for Hb deferral at a subsequent visit.

DISCUSSION

To conclude, repeated donations may induce iron deficiency, which corresponds with an over tenfold increased risk of having insufficiently restored Hb levels at a subsequent donation attempt. Longer donation intervals and/or higher dietary or supplemental iron intake are warranted to prevent accumulated iron depletion and subsequent low-Hb deferral in whole blood donors.

Willingness of blood donors in Australia to provide additional data and blood sample for health research

BACKGROUND

Many blood collection agencies are generating important data on donor health outcomes using large-scale blood donor cohort studies. Such studies can be very effective when donors provide access to linkage of their data to external health databases, and storage and genomic testing of their blood sample. In this study, we aimed to assess the willingness of Australian blood donors to provide additional data and blood sample for donation-related and other health research.

STUDY DESIGN AND METHODS

We invited 2017 donors to complete a survey using four methods (postal letter, postal letter and email, email only, and in-center recruitment). The survey asked for information on demographics, lifestyle behaviors, health, experience and attitude to blood donation, and willingness to give blood sample and additional data for research.

RESULTS

Response rates ranged from 23.8% for email only to 77.2% for in-center recruitment. Of those who responded (n = 827), 95.5% indicated they would be willing to provide a blood sample for donation and transfusion-related research. Of these, >90.0% were willing for their sample to be used in research involving genetic testing and other health-related topics. Also, >90.0% were willing to consent for linkage of their information to external health databases.

CONCLUSIONS

Donors surveyed reported a high willingness to participate in health research by completing surveys, allowing linkage to external datasets, and providing a blood sample. These findings provide strong support for future longitudinal research studies with Australian blood donors.

Development and validation of a universal blood donor genotyping platform: a multinational prospective study

Each year, blood transfusions save millions of lives. However, under current blood-matching practices, sensitization to non-self-antigens is an unavoidable adverse side effect of transfusion. We describe a universal donor typing platform that could be adopted by blood services worldwide to facilitate a universal extended blood-matching policy and reduce sensitization rates. This DNA-based test is capable of simultaneously typing most clinically relevant red blood cell (RBC), human platelet (HPA), and human leukocyte (HLA) antigens. Validation was performed, using samples from 7927 European, 27 South Asian, 21 East Asian, and 9 African blood donors enrolled in 2 national biobanks. We illustrated the usefulness of the platform by analyzing antibody data from patients sensitized with multiple RBC alloantibodies. Genotyping results demonstrated concordance of 99.91%, 99.97%, and 99.03% with RBC, HPA, and HLA clinically validated typing results in 89 371, 3016, and 9289 comparisons, respectively. Genotyping increased the total number of antigen typing results available from 110 980 to >1 200 000. Dense donor typing allowed identification of 2 to 6 times more compatible donors to serve 3146 patients with multiple RBC alloantibodies, providing at least 1 match for 176 individuals for whom previously no blood could be found among the same donors. This genotyping technology is already being used to type thousands of donors taking part in national genotyping studies. Extraction of dense antigen-typing data from these cohorts provides blood supply organizations with the opportunity to implement a policy of genomics-based precision matching of blood.

Genetic determinants of ferritin, haemoglobin levels and haemoglobin trajectories: results from Donor InSight

BACKGROUND AND OBJECTIVES

Blood donors might develop iron deficiency as approximately 250 mg of iron is lost with every donation. Susceptibility to iron deficiency and low haemoglobin levels differs between individuals, which might be due to genetic variation. Therefore, the aim of this study was to investigate associations between single nucleotide polymorphisms (SNPs) and haemoglobin trajectories, haemoglobin levels and ferritin levels in blood donors.

MATERIALS AND METHODS

In 2655 donors participating in the observational cohort study Donor InSight-III (2015-2017), haemoglobin and ferritin levels were measured in venous EDTA whole blood and plasma samples, respectively. Haemoglobin trajectories (stable/declining) were determined by fitting growth-mixture models on repeated pre-donation capillary haemoglobin measurements. Genotyping was done using the UK Biobank - version 2 Axiom Array. Single SNP analyses adopting an additive genetic model on imputed genetic variants were performed for haemoglobin trajectories, haemoglobin levels and ferritin levels. Conditional analyses identified independent SNPs.

RESULTS

Twelve, twenty and twenty-four independent SNPs were associated with haemoglobin trajectories, haemoglobin levels and ferritin levels respectively (P < 1 x 10^-5 ). Rs112016443 reached genome-wide significance for ferritin levels, which influences WDSUB1 expression.

CONCLUSION

Rs112016443 was genome-wide significantly associated with ferritin levels in Dutch donors. Further validation studies are needed, as well as studies towards underlying mechanisms and predicting iron deficiency using SNPs.

Whole blood donor behavior and availability after deferral: Consequences of a new ferritin monitoring policy

Background

To prevent (negative consequences of) temporary deferral due to low hemoglobin, the Dutch national blood service Sanquin introduced a ferritin monitoring policy in 2017. Ferritin is measured after the donation (as opposed to before donation for hemoglobin), and low ferritin levels lead to deferral of 6 (ferritin 15‐30 ng/mL) or 12 months (ferritin <15 ng/mL). We explored the consequences of this policy on donor behavior and availability.

Study Design and Methods

We included all Dutch whole blood donors who made a donation (attempt) between 13 November and 31 December 2017. At that point, the ferritin monitoring policy was randomly implemented in 8 of 29 regional clusters of collection centers. We extracted information from Sanquin's donor database about donors' deferrals, subsequent donation attempts, and donation cessation (up to 31 December 2019). Donors deferred for low ferritin were compared to those deferred for low hemoglobin or other reasons, as well as to donors who were not deferred.

Results

A total of 55 644 donors were included (11% deferred). For donor behavior, we found that donors deferred for low ferritin less often unsubscribed and switched to other donation types, yet also made fewer donations in the follow‐up period. For availability, we found they were less often deferred, yet they were unavailable to donate for a longer period.

Conclusion

Results suggest that the implementation of a ferritin monitoring policy may lead to a decrease in donor availability and reduced donations. However, the policy is successful in retaining more donors and reducing low hemoglobin deferrals.

Large genome-wide association study identifies three novel risk variants for restless legs syndrome

Restless legs syndrome (RLS) is a common neurological sensorimotor disorder often described as an unpleasant sensation associated with an urge to move the legs. Here we report findings from a meta-analysis of genome-wide association studies of RLS including 480,982 Caucasians (cases = 10,257) and a follow up sample of 24,977 (cases = 6,651). We confirm 19 of the 20 previously reported RLS sequence variants at 19 loci and report three novel RLS associations; rs112716420-G (OR = 1.25, P = 1.5 × 10-18), rs10068599-T (OR = 1.09, P = 6.9 × 10-10) and rs10769894-A (OR = 0.90, P = 9.4 × 10-14). At four of the 22 RLS loci, cis-eQTL analysis indicates a causal impact on gene expression. Through polygenic risk score for RLS we extended prior epidemiological findings implicating obesity, smoking and high alcohol intake as risk factors for RLS. To improve our understanding, with the purpose of seeking better treatments, more genetics studies yielding deeper insights into the disease biology are needed.

Dietary intake of heme iron is associated with ferritin and hemoglobin levels in Dutch blood donors: results from Donor InSight

Whole blood donors, especially frequently donating donors, have a risk of iron deficiency and low hemoglobin levels, which may affect their health and eligibility to donate. Lifestyle behaviors, such as dietary iron intake and physical activity, may influence iron stores and thereby hemoglobin levels. We aimed to investigate whether dietary iron intake and questionnaire-based moderate-to-vigorous physical activity were associated with hemoglobin levels, and whether ferritin levels mediated these associations. In Donor InSight-III, a Dutch cohort study of blood and plasma donors, data on heme and non-heme iron intake (mg/day), moderate-to-vigorous physical activity (10 minutes/day), hemoglobin levels (mmol/L) and ferritin levels (μg/L) were available in 2,323 donors (1,074 male). Donors with higher heme iron intakes (regression coefficients (β) in men and women: 0.160 and 0.065 mmol/L higher hemoglobin per 1 mg of heme iron, respectively) and lower non-heme iron intakes (β: -0.014 and -0.017, respectively) had higher hemoglobin levels, adjusted for relevant confounders. Ferritin levels mediated these associations (indirect effect (95% confidence interval) in men and women respectively: 0.074 (0.045; 0.111) and 0.061 (0.030; 0.096) for heme and -0.003 (-0.008;0.001) and -0.008 (-0.013;-0.003) for non-heme). Moderate-to-vigorous physical activity was negatively associated with hemoglobin levels in men only (β: -0.005), but not mediated by ferritin levels. In conclusion, higher heme and lower non-heme iron intake were associated with higher hemoglobin levels in donors, via higher ferritin levels. This indicates that donors with high heme iron intake may be more capable of maintaining iron stores to recover hemoglobin levels after blood donation.

Ensuring HLA-matched platelet support requires an ethnic diverse donor population

BACKGROUND

Patients refractory for platelet transfusions benefit from human leukocyte antigen (HLA)‐matched platelet transfusions. Differences in ethnic background of patients and donors could hamper the availability of sufficient numbers of HLA‐matched donors for all patients. We evaluated our HLA‐matched donor program and explored the role of ethnic background of patients related to the number of available donors.

METHODS

We performed a cohort study among consecutive patients who received HLA‐matched platelet concentrates in the Netherlands between 1994 and 2017. The number of available matched donors was determined per patient. Haplotypes were constructed from genotypes with computer software (PyPop). Based on haplotypes, HaploStats, an algorithm from the National Marrow Donor Program, was used to assess the most likely ethnic background for patients with 5 or fewer and 30 or more donors.

RESULTS

HLA typing was available for 19,478 donors in September 2017. A total of 1206 patients received 12,350 HLA‐matched transfusions. A median of 83 (interquartile range, 18‐266) donors were available per patient. For 95 (10.3%) patients, 5 or fewer donors were available. These patients were more likely to have an African American background, whereas patients with 30 or more donors were more often from Caucasian origin, compared with Caucasian origin for patients with 30 donors.

CONCLUSION

Adequate transfusion support could be guaranteed for most but not all refractory patients. More non‐Caucasian donors are required to ensure the availability of HLA‐matched donors for all patients in the Netherlands.

Informed consent for whole blood donation

BACKGROUND AND OBJECTIVES

It is recognized that blood transfusion services have an ethical duty to obtain informed consent from their voluntary, non-remunerated donors. This right was most recently affirmed by the 2017 revision of the International Society of Blood Transfusion (ISBT) Code of Ethics. However, the constituent elements necessary to adequately inform such consent have not been definitively established.

MATERIALS AND METHODS

This review evaluates the historical background to informed consent in medicine and as it has been applied to blood donation. The question of what information should be disclosed is then considered with regard to existing statutory requirements in both the United States and EU as well guidance from relevant international organizations. The emerging ethical issues around repurposing of donated blood for sale as recovered plasma and use in research are included in this analysis.

RESULTS

A reasonable basis is found in the literature to advocate that valid informed consent of blood donors should encompass: the donation process itself and potential adverse effects, the need for pre-donation transfusion-transmissible infection (TTI) screening, potential non-transfusion uses of derived products, requirements to obtain and store personal information, the consequences that non-disclosure of such information may have for both the donor and the recipient and reassurance as to the confidentiality of this information.

CONCLUSION

Informed consent is a key component of the duty of care between a blood service and its donor. We identify essential elements that should be present for such consent to be considered valid.

FinDonor 10 000 study: a cohort to identify iron depletion and factors affecting it in Finnish blood donors

Background and Objectives

There is increasing evidence that frequent blood donation depletes the iron stores of some blood donors. The FinDonor 10 000 study was set up to study iron status and factors affecting iron stores in Finnish blood donors. In Finland, iron supplementation for at‐risk groups has been in place since the 1980s.

Material and Methods

A total of 2584 blood donors (N = 8003 samples) were recruited into the study alongside standard donation at three donation sites in the capital region of Finland between 5/2015 and 12/2017. All participants were asked to fill out a questionnaire about their health and lifestyle. Blood samples were collected from the sample pouch of whole blood collection set, kept in cool temperature and processed centrally. Whole blood count, CRP, ferritin and sTFR were measured from the samples, and DNA was isolated for GWAS studies.

Results

Participant demographics, albeit in general similar to the general blood donor population in Finland, indicated some bias towards older and more frequent donors. Participation in the study increased median donation frequency of the donors. Analysis of the effect of time lag from the sampling to the analysis and the time of day when sample was drawn revealed small but significant time‐dependent changes.

Conclusion

The FinDonor cohort now provides us with tools to identify potential donor groups at increased risk of iron deficiency and factors explaining this risk. The increase in donation frequency during the study suggests that scientific projects can be used to increase the commitment of blood donors.

Lifestyle behaviours are not associated with haemolysis: results from Donor InSight

BACKGROUND

Lifestyle behaviours such as physical activity, sedentary behaviour and dietary habits have been shown to influence blood lipid levels, and both lifestyle and blood lipids may be associated with haemolysis during storage of blood products. We aimed to investigate whether lifestyle behaviours are associated with degree of haemolysis in red cell concentrates (RCC), and if such associations are mediated by low-density lipoprotein (LDL) cholesterol and triglyceride levels.

MATERIALS AND METHODS

Cross-sectional analyses were performed in data from 760 Dutch blood donors participating in Donor InSight, an observational cohort study. Linear regression analyses were conducted to assess associations of lifestyle behaviours with haemolysis levels in RCC 28 days after blood sampling. Lifestyle behaviours included moderate-to-vigorous physical activity and sedentary behaviour measured by accelerometry, and self-reported intake of a selection of foods potentially related to blood lipids, i.e. consumption of eggs, meat, nuts and fish. Potential mediating roles of both LDL cholesterol and triglyceride levels were investigated separately. All analyses were adjusted for relevant confounders.

RESULTS

No statistically significant nor substantial associations of any of the lifestyle behaviours with haemolysis in RCC were found, nor were there any associations between lifestyle behaviours and blood lipids. We did find consistent positive associations of LDL cholesterol and triglyceride levels with haemolysis in RCC during storage.

DISCUSSION

In this large cohort, blood lipid levels were consistently associated with haemolysis in RCC. Nonetheless, there was no evidence for an association between lifestyle behaviours and haemolysis in RCC, or for mediating effects by blood lipid levels.

Beyond Description: The Predictive Role of Affect, Memory, and Context in the Decision to Donate or Not Donate Blood

Background

Research on the recruitment and retention of blood donors has typically drawn on a homogeneous set of descriptive theories, viewing the decision to become and remain a donor as the outcome of affectively cold, planned, and rational decision-making by the individual. While this approach provides insight into how our donors think about blood donation, it is limited and has not translated into a suite of effective interventions. In this review, we set out to explore how a broader consideration of the influences on donor decision-making, in terms of affect, memory, and the context in which donation takes place, may yield benefit in the way we approach donor recruitment and retention.

Summary

Drawing on emerging research, we argue for the importance of considering the implications of both the positive and the negative emotions that donors experience and we argue for the importance of directly targeting affect in interventions to recruit nondonors. Next, we focus on the reconstructed nature of memory and the factors that influence what we remember about an event. We discuss how these processes may impact the retention of donors and the potential to intervene to enhance donors' recollections of their experiences. Finally, we discuss how our focus on the individual has led us to neglect the influence of the context in which donation takes place on donor behavior. We argue that the amassing of comprehensive large data sets detailing both the characteristics of the individuals and the context of their giving will ultimately allow for the more effective deployment of resources to improve recruitment and retention.

Key Messages

In suggesting these directions for future research, our want is to move beyond the ways in which we have traditionally described blood donation behavior with the aim of improving our theorizing about donors while improving the translational value of our research.

Blood Donation across the Life Course: The Influence of Life Events on Donor Lapse

This article examines how blood donation loyalty changes across the life course as a result of life events. Previous studies have shown that life events affect involvement in prosocial behavior, possibly as a result of loss of human and social capital. Using registry data from the blood collection agency in the Netherlands, linked to longitudinal survey data from the Donor InSight study (N = 20,560), we examined whether life events are related to blood donor lapse. Childbirth, losing a job, and starting a job increase the likelihood of donor lapse, while health-related events (i.e., blood transfusion in a family member, death of a family member) decrease the likelihood of donor lapse. Moreover, results showed how social and practical concerns explain donors' decisions to donate blood after the occurrence of life events. We discuss theoretical implications for further studies on prosocial and health-related behavior.

The association between population density and blood lipid levels in Dutch blood donors

BACKGROUND

In low and middle-income countries (LMIC), the total and LDL cholesterol and triglyceride levels of residents of urban areas are reported to be higher than those of rural areas. This may be due to differences in lifestyle behaviors between residents of urban areas and rural areas in LMIC. In this study, our aims were to (1) examine whether or not LDL cholesterol, total/HDL ratios and triglyceride levels of individuals in densely populated areas are higher than those of individuals living in less-densely populated areas in a high-income country (HIC) and (2) investigate the potential mediating roles of physical activity and sedentary behavior.

METHODS

We used cross-sectional data from 2547 Dutch blood donors that participated in Donor InSight-III. Linear regression was used to analyze the association between population density and LDL cholesterol, total/HDL cholesterol ratio and HDL cholesterol. The mediating roles of moderate-to-vigorous physical activity (MVPA) and sedentary behavior were investigated in a subsample (n = 740) for which objectively measured MVPA/sedentary behavior data was available. Multiple mediation with linear regression analyses were performed and the product-of-coefficients method was used to calculate direct and indirect effects.

RESULTS

Mean LDL cholesterol and median total cholesterol/HDL cholesterol ratio and triglyceride levels were 2.89, 3.43 and 1.29 mmol/L, respectively. Population density was not associated with LDL cholesterol [β 0.00 (- 0.01; 0.01)], log transformed total/HDL cholesterol ratio [β 1.00 (1.00; 1.00)] and triglyceride levels [β 1.00 (0.99; 1.00)]. No statistically significant direct or indirect effects were found.

CONCLUSION

Contrary to previous findings in LMIC, no evidence was found that population density is associated with blood lipid levels in blood donors in the Netherlands or that MVPA and sedentary behavior mediate this association. This may be the result of socioeconomic differences and, in part, may be due to the good health of the study population and the relatively high population density in the Netherlands. Also, compared to LMIC, differences in physical activity levels in more versus less populated areas may be less pronounced in HIC.