No association between iron status and self-reported health-related quality of life in 16,375 Danish blood donors: results from the Danish Blood Donor Study

Iron deficiency-related symptoms in non-anemic whole blood donors

INTRODUCTION

Whole blood donors are at increased risk for iron deficiency (ID). ID anemia is associated with several symptoms, such as fatigue, cognitive dysfunction, pica, and restless leg syndrome (RLS). However, it is unclear if these symptoms also occur when a donor has developed ID without anemia. This study aims to determine whether non-anemic ID (NAID) is associated with the occurrence of ID-related symptoms.

STUDY DESIGNS AND METHODS

We combined data from three studies in whole blood donors (i.e., Donor Insight-III, FIND'EM, and FORTE) to create a substantial sample size (N = 12,143). The self-reported occurrence and severity of ID-related symptoms, such as physical and mental health, fatigue, cognitive functioning, pica, and RLS, was measured using validated questionnaires. Associations were studied using logistic regression modeling with ID-related symptoms derived from the questionnaires as the dependent variable and ferritin level group (0-15 μg/L, 15-30 μg/L, and >30 μg/L) as explanatory variable.

RESULTS

After applying inclusion and exclusion criteria, 9829 donors were eligible for analysis. In the models corrected for age, body mass index, Hb level, and cohort, only fatigue was shown to be associated with ferritin levels in men, showing lower odds (OR 1.41, 95% CI 1.11-1.79) for fatigue with higher ferritin levels.

CONCLUSION

In these studies, NAID was only associated with self-reported fatigue in male donors. Although selection bias may have led to underestimated associations, ferritin measurements in donors should be primarily considered as a measure to prevent anemia, rather than to prevent or mitigate NAID-related symptoms.

Simulated effects of ferritin screening on C-reactive protein levels in recruited blood donors

BACKGROUND AND OBJECTIVES

Ferritin is commonly measured to evaluate iron stores in the body. Some countries have added or considered adding ferritin lower bounds to donor eligibility criteria. Ferritin is also elevated by inflammation. The main goal of this study is to estimate how different ferritin cut-offs would affect the proportion of donors with a C-reactive protein (CRP) level over 3 mg/L, which is the decision limit of the highest chronic cardiovascular risk.

MATERIALS AND METHODS

To simulate recruitment of new blood donors, we selected participants from two Finnish general population cohorts, namely FINRISK 1997 (n = 5369) and Health 2000 (n = 3278), that would likely fulfil the selection criteria of blood donation. We then calculated the proportion of individuals with high-sensitivity CRP values above 3 mg/L, over a range of ferritin values.

RESULTS

We found that for several ferritin cut-offs the proportion of potential donors with CRP > 3 mg/L would rise by a statistically significant amount. The trend was significant and similar for all subgroups but weaker for non-menstruating women as well as men.

CONCLUSION

Our results show that screening a population of potential blood donors with ferritin cut-offs raises the number of people with CRP > 3 mg/L within the blood donor population.

Promoting awareness of donation-related iron depletion among high risk blood donors

BACKGROUND

The potential for iron deficiency is a known blood donor health concern and suggests the need to inform donors about the potential risks of low iron levels as well as strategies to address these risks.

STUDY DESIGN AND METHODS

Frequent (n = 904) and young (n = 629) donors were randomly assigned within risk group to either a control (n = 548) or an intervention (n = 985) group. The control group answered questions at baseline and 6-month follow-up regarding their awareness of the risk of donation-related iron depletion and whether they were taking actions to address their iron status. The intervention group answered the same questions at baseline and follow-up, but after completing the baseline survey, they received information regarding their risk of iron depletion and behaviors they could adopt to mitigate this risk. Intervention group participants were also offered the opportunity to develop an action plan to help them supplement their iron intake.

RESULTS

The intervention enhanced overall awareness of donation-related iron loss (OR = 1.5, 95% CI 1.171-1.864, p = .001), with no negative impact on retention. Reported iron health behaviors (iron supplementation, speaking with a doctor) showed significant increases when action planning was paired with the educational information.

CONCLUSION

These findings suggest that it is possible to increase awareness of donation-related risk for iron depletion without negatively influencing retention, and combining education with encouragement to develop an action plan may increase the likelihood of both retention and behavioral changes to promote healthy iron levels.

Low ferritin levels appear to be associated with worsened health in male repeat blood donors

BACKGROUND AND OBJECTIVES

Frequent blood donation depletes iron stores of blood donors. Iron depletion may lead to anaemia, but the health effects of iron depletion without anaemia in healthy blood donors are not well understood. We studied in the FinDonor cohort whether worsening of self-rated health of blood donors during the study period was associated with biomarkers for iron levels or other self-reported changes in lifestyle.

MATERIALS AND METHODS

We included 1416 participants from the cohort who answered an 89-item questionnaire on their health and lifestyle during their enrolment visit and again at the end of the study. We performed multivariate logistic regression to test if blood donation-related factors affected the probability of reporting worsened health. To set these findings into a more holistic context of health, we subsequently analysed all other questionnaire items with a data-driven exploratory analysis.

RESULTS

We found that donation frequency in men and post-menopausal women and ferritin level only in men was associated negatively with worsened health between questionnaires. In the exploratory analysis, stable physical condition was the only questionnaire item that was associated negatively with worsened health in both women and men.

CONCLUSION

Our results suggest that low ferritin level is associated with worsened health even in non-anaemic repeat donors, although we find that when health is analysed more holistically, ferritin and other factors primarily related to blood donation lose their importance.

Serum ferritin level is inversely related to number of previous pregnancy losses in women with recurrent pregnancy loss

OBJECTIVE

To study whether low serum ferritin (s-ferritin) levels are associated with recurrent pregnancy loss (RPL), and whether low s-ferritin predicts the risk of another pregnancy loss or the ability to conceive.

DESIGN

Cohort study.

SETTING

Fertility clinic at a university hospital.

PATIENT(S)

Eighty-four women referred to the RPL Unit and 153 women of reproductive age with no known fertility problem. s-Ferritin levels were measured in serum samples taken before pregnancy attempt.

INTERVENTION

None.

MAIN OUTCOME MEASURE(S)

s-Ferritin levels were correlated to pregnancy history, ability to conceive, and time to conception during the first 2 years after sampling. Furthermore, s-ferritin levels were correlated to outcome of the first pregnancy after referral for RPL.

RESULT(S)

Women with RPL had lower s-ferritin than the comparison group, 39.9 μg/L versus 62.2 μg/L, and had a higher prevalence of low iron stores (s-ferritin <30 μg/L), 35.7% versus 13.7%. We found an inverse relationship between s-ferritin level and number of pregnancy losses before referral. We did not find s-ferritin level to be associated with ability to conceive or time to pregnancy in either group. Nor did s-ferritin level predict the risk of losing the first pregnancy after referral for RPL.

CONCLUSION(S)

The inverse relationship between s-ferritin levels and previous pregnancy losses suggests that low s-ferritin is associated with a more severe reproductive disturbance in women with RPL. Whether low s-ferritin is causally related to RPL and if such women could benefit from iron supplementation to achieve a live birth warrants further investigation.

Iron status and self-reported fatigue in blood donors

Fatigue is a reported symptom of iron depletion, but studies in blood donors show no conclusive link. We conducted an observational analysis of data from the STRIDE randomized trial to evaluate association of iron status with self-reported fatigue.

STUDY DESIGN AND METHODS

Three blood centers randomly assigned 692 frequent donors to education or iron supplementation treatments. Biomarkers for iron status were measured during 20 to 24 months of follow-up. A fatigue score was derived from an 11-item questionnaire at baseline and final visits, and associations between iron status and fatigue were assessed.

RESULTS

Final lab and questionnaire data were evaluable from 337 subjects. At baseline, female sex, older age, and anemia were associated with fatigue, but iron status was not. Mean (±SD) fatigue score change was 0.0 (±0.5). Mean (±SD) increase in iron stores was 1.0 (±3.5) mg/kg, but changes in body iron stores were not associated with fatigue score changes (0.01 per mg/kg; 95% CI, -0.01 to 0.02) or with fatigue (RR, 1.01; 95% CI, 0.99 to 1.04). The only factor associated with fatigue score changes was baseline fatigue (0.36; 95% CI, 0.25 to 0.48).

CONCLUSION

Among high-frequency donors, neither iron status at baseline nor changes in iron status predicted fatigue during follow-up, with improvements limited to those with higher levels of baseline fatigue. Assessment of the association between iron and fatigue in blood donors benefits from careful consideration of study design and the study population.

Examination of the relationship between iron status and cognitive function among healthy young women with and without a recent history of blood donation

BACKGROUND

With growing awareness of the prevalence of nonanemic iron deficiency among blood donors, there is a need to explore the extent of potential negative consequences. This study examined the relationship between various measures of iron status, blood donation history, and neuropsychological and psychosocial functioning in healthy young women.

STUDY DESIGN AND METHODS

Using a cross-sectional design, 160 female undergraduates completed neuropsychology tests and measures of sleep, fatigue, quality of life, and depression before providing a blood sample. Correlational analyses examined the relationship between iron status (ferritin, iron, hemoglobin, and zinc protoporphyrin) and cognitive and psychosocial functioning. Performance on these measures was also examined as a function of recent blood donation history (zero, one, more than one donation in the past year).

RESULTS

Iron status (low ferritin, iron, or hemoglobin or high zinc protoporphyrin) was not associated with poorer performance on the cognitive tasks. Further, participants who reported donating once in the previous year performed better, rather than worse, than those with no recent donation history on several measures of executive function, even when controlling for ferritin levels. Although there was some evidence of greater fatigue among those who had donated more than once in the past year, this effect was not accounted for by ferritin levels.

CONCLUSION

The present findings are consistent with prior evidence that nonanemic iron deficiency is not associated with cognitive impairment or psychosocial dysfunction in healthy young females. Because these results are based on cross-sectional evidence, further study using longitudinal research is needed to confirm these findings.

The effects of intravenous iron supplementation on fatigue and general health in non-anemic blood donors with iron deficiency: a randomized placebo-controlled superiority trial

We investigated whether intravenous iron supplementation improves fatigue and general health in non-anemic repeat adult blood donors with iron deficiency (ferritin ≤ 50 µg/L). Of 1,487 potentially eligible participants, 203 were randomly assigned to a single intravenous dose of 800 mg iron-carboxymaltose and 202 to placebo; 393 participants completed the trial. At 6 to 8 weeks after intervention, self-rated mean fatigue scores (numeric rating scale from 1-10, primary outcome) were 3.9 ± 1.8 in the iron supplementation group and 4.0 ± 2.2 in the placebo group, showing no group difference (p = 0.819). Pre-specified subgroup analyses of gender, ferritin < 25 µg/L and fatigue ≥ 4 points, as well as exploratory analyses of lower ferritin cut-offs did not reveal any between-group differences. In terms of secondary outcomes, the mean differences were 114.2 µg/L for ferritin (95% CI 103.1-125.3) and 5.7 g/L for hemoglobin (95% CI 4.3-7.2) with significantly higher values in the iron supplementation group. No group differences were observed for different measures of general well-being and other clinical and safety outcomes. Intravenous iron supplementation compared with placebo resulted in increase of ferritin and hemoglobin levels in repeat blood donors with low iron stores, yet had no effect on fatigue and general well-being.

First results of a ferritin-based blood donor deferral policy in the Netherlands

BACKGROUND

Whole blood donors are at risk of becoming iron deficient. To monitor iron stores, Sanquin implemented a new deferral policy based on ferritin levels, in addition to the traditional hemoglobin measurements.

METHODS

Ferritin levels are determined in every fifth donation, as well as in all first-time donors. Donors with ferritin levels <15 ng/mL (WHO threshold) are deferred for 12 months; those ≥15 and ≤30 ng/mL for 6 months. The first results were analyzed and are presented here.

RESULTS

The results show that 25% of women (N = 20151, 95% CI 24%-25%) and 1.6% of men (N = 10391, 95% CI 1.4%-1.8%) have ferritin levels ≤30 ng/mL at their first blood center visit. For repeat (non-first-time) donors, these proportions are higher: 53% of women (N = 28329, 95% CI 52%-54%) and 42% of men (N = 31089, 95% CI 41%-43%). After a 6-month deferral, in 88% of returning women (N = 3059, 95% CI 87%-89%) and 99% of returning men (N = 3736, 95% CI 98%-99%) ferritin levels were ≥15 ng/mL. After a 12-month deferral, in 74% of returning women (N = 486, 95% CI 70%-78%) and 95% of returning men (N = 479, 95% CI 94%-97%) ferritin levels increased to ≥15 ng/mL.

CONCLUSION

Deferral of donors whose pre-donation ferritin levels were ≤30 ng/mL might prevent donors from returning with ferritin levels <15 ng/mL. This policy is promising to mitigate effects of repeated donations on iron stores.

Iron Depletion in Adult and Teenage Blood Donors: Prevalence, Clinical Impact, and Options for Mitigation

Iron depletion is a known risk for adult blood donors, but recent studies indicate the prevalence of iron depletion is higher in teenage blood donors. Teenage donors account for more than 10% of the blood collected in the United States and are important for maintaining component availability. Evidence of harm from iron depletion has not been demonstrated, but the area would benefit from further scientific inquiry. Options to protect against iron depletion exist, but each has limitations including cost, logistics, and potential negative impact on blood supply. Blood centers should communicate with donors and make efforts to mitigate these risks.

The effect of donation activity dwarfs the effect of lifestyle, diet and targeted iron supplementation on blood donor iron stores

The iron status of blood donors is a subject of concern for blood establishments. The Finnish Red Cross Blood Service addresses iron loss in blood donors by proposing systematic iron supplementation for demographic at-risk donor groups. We measured blood count, ferritin and soluble transferrin receptor (sTfR) and acquired lifestyle and health information from 2200 blood donors of the FinDonor 10000 cohort. We used modern data analysis methods to estimate iron status and factors affecting it with a special focus on the effects of the blood service's iron supplementation policy. Low ferritin (< 15 μg/L), an indicator of low iron stores, was present in 20.6% of pre-menopausal women, 10.6% of post-menopausal women and 6% of men. Anemia co-occurred with iron deficiency more frequently in pre-menopausal women (21 out of 25 cases) than in men (3/6) or post-menopausal women (1/2). In multivariable regression analyses, lifestyle, dietary, and blood donation factors explained up to 38% of the variance in ferritin levels but only ~10% of the variance in sTfR levels. Days since previous donation were positively associated with ferritin levels in all groups while the number of donations during the past 2 years was negatively associated with ferritin levels in pre-menopausal women and men. FRCBS-provided iron supplementation was negatively associated with ferritin levels in men only. Relative importance analyses showed that donation activity accounted for most of the explained variance in ferritin levels while iron supplementation explained less than 1%. Variation in ferritin levels was not significantly associated with variation in self-reported health. Donation activity was the most important factor affecting blood donor iron levels, far ahead of e.g. red-meat consumption or iron supplementation. Importantly, self-reported health of donors with lower iron stores was not lower than self-reported health of donors with higher iron stores.

Donor Iron Deficiency Study (DIDS): protocol of a study to test whether iron deficiency in blood donors affects red blood cell recovery after transfusion

BACKGROUND

Despite fulfilling all requirements for blood donation, a large proportion of regular blood donors are iron deficient. Red blood cells (RBC) from iron-deficient donors may be particularly susceptible to damage induced by standard refrigerated storage. Herein, we present a study protocol for testing whether correcting iron deficiency in donors with iron-deficient erythropoiesis will improve the quality of their refrigerator-stored RBC.

MATERIALS AND METHODS

This is a randomised, controlled, double-blind clinical trial. Sixty healthy regular donors who meet donation standards, while exhibiting iron-deficient erythropoiesis by laboratory testing criteria, will donate a single standard RBC unit that will be leucoreduced and stored in a refrigerator under standard conditions for 40-42 days. A 51Cr-radiolabelled 24-hour RBC recovery study will be performed and then these donors will be randomised to receive, in a double-blinded fashion, either intravenous saline, as a control, or low-molecular weight iron dextran (1 g), to provide total iron repletion. Four to six months later, they will donate a second RBC unit, which will be similarly stored, and autologous 51Cr-labelled 24-hour post-transfusion RBC recovery will again be determined.

RESULTS

The primary endpoint will be the change in 24-hour post-transfusion recovery from the first to the second donation. The primary outcome will be the group mean difference in the primary endpoints between the group receiving intravenous saline and the group receiving intravenous iron dextran. Secondary outcomes will be quality of life, fatigue, and emotional health, assessed by surveys.

CONCLUSION

This study will provide definitive evidence as to whether donor iron deficiency affects the quality of the blood supply and will assess the severity of symptoms affecting iron-deficient blood donors.

Iron deficiency among blood donors: experience from the Danish Blood Donor Study and from the Copenhagen ferritin monitoring scheme

Blood components collected from blood donors are an invaluable part of modern-day medicine. A healthy blood donor population is therefore of paramount importance. The results from the Danish Blood Donor Study (DBDS) indicate that gender, number of previous donations, time since last donation and menopausal status are the strongest predictors of iron deficiency. Only little information on the health effects of iron deficiency in blood donors exits. Possibly, after a standard full blood donation, a temporarily reduced physical performance for women is observed. However, iron deficiency among blood donors is not reflected in a reduced self-perceived mental and physical health. In general, the high proportion of iron-deficient donors can be alleviated either by extending the inter-donation intervals or by guided iron supplementation. The experience from Copenhagen, the Capital Region of Denmark, is that routine ferritin measurements and iron supplementation are feasible and effective ways of reducing the proportion of donors with low haemoglobin levels.

Low-grade inflammation is negatively associated with physical Health-Related Quality of Life in healthy individuals: Results from The Danish Blood Donor Study (DBDS)

BACKGROUND

Health-Related Quality of Life (HRQL) represent individuals' subjective assessment of their mental and physical well-being, and is highly predictive of future health. C-reactive protein (CRP) is a well-established marker of inflammation. Low-grade inflammation (LGI), defined as slightly increased CRP levels, is associated with increased risk of several diseases. LGI may reflect subclinical pathology, which could affect individual's subjective health assessment. This study aimed to examine whether LGI has an independent impact on self-reported health or rather is a mediator of a confounder in a large population of healthy individuals.

METHODS

Plasma CRP levels were measured in 17,024 participants from the Danish Blood Donor Study (DBDS). All participants completed a standard questionnaire including smoking status, and the 12-item short-form health survey (SF-12), which is a widely used scale for HRQL. SF-12 is reported as a mental (MCS) and physical (PCS) score. The relationship between LGI (defined as a plasma CRP level between 3 mg/L and 10 mg/L) and MCS or PCS was explored by mediation analysis and adjusted multivariable linear regression analysis. Multiple imputation modelling was used to remedy missing values. The analyses were stratified according to sex and use of combined oral contraception (OC).

RESULTS

In the study, 1,542 (10.3%) participants had LGI. PCS was associated with LGI in all strata, i.e. women using OC: RC = -0.36 points lower PCS in participants with LGI vs no LGI, CI: -0.94 to -0.19, women not using OC: RC = -0.63, CI: -1.05 to -0.21 and men: RC = -0.76, CI: -1.10 to -0.42. But LGI had no impact on MCS. Predictors of lower PCS included obesity, current smoking, and waist circumference in all strata. Physical activity in leisure time was the only factor positively associated with PCS. Age and physical activity in leisure time was associated with increased MCS in all strata whereas current smoking was the only strong predictor of a reduction in MCS. Only a small effect of smoking on PCS was mediated through LGI.

CONCLUSION

In this population of healthy individuals, LGI had independent impact on lower self-rated physical health score in HRQL in both sexes, but was not associated with self-rated mental health score. A small and significant effect of smoking on physical health score was mediated through LGI.

Restless legs syndrome is associated with major comorbidities in a population of Danish blood donors

BACKGROUND

Restless Legs Syndrome (RLS) is characterized by uncomfortable nocturnal sensations in the legs making sedentary activities and sleep difficult, and is thus linked with psychosocial distress. Due to the symptomatology and neurobiology of RLS (disrupting brain iron and dopamine) it is likely that RLS associates with poorer health-related quality of life (HRQL) and depressive disorder. The objective of this study was to investigate the RLS-HRQL and the RLS-depressive disorder links in a generally healthy population that is not biased by medications.

METHODS

Complete data, including the Cambridge-Hopkins RLS questionnaire, the 12-item short-form standardized health survey (SF-12), the Major Depression Inventory (MDI), body mass index, smoking status, alcohol consumption, and education were available for 24,707 participants enrolled in the Danish Blood Donor Study from May 1, 2015 to February 1, 2017. Information on quality of sleep was available for all RLS cases. T-tests and multivariable logistic regression models were applied to examine the associations of RLS and MDI scores, and the physical and mental component scores (PCS and MCS) of SF-12, respectively. Analyses were conducted separately for men and women.

RESULTS

RLS associated with poorer MCS and poorer PCS. Moreover, Participants with RLS were more likely to classify with depressive disorder. Poor quality of sleep was associated with depressive disorder and poorer MCS among RLS cases, and with poorer PCS in female RLS cases.

CONCLUSION

Thus, we demonstrated that RLS is associated with a significantly lower HRQL and a higher prevalence of depressive disorder among otherwise healthy individuals.

Retrospective analysis of capillary hemoglobin recovery in nearly 1 200 000 blood donor returns

Measuring the concentration of capillary hemoglobin (cHb) is a standard procedure before blood donation. To further assess the time period needed for cHb recovery after blood donation and to have a more in-depth understanding of features of recovery, we used data-mining tools in a large, retrospective data pool containing all 1 163 524 donor returns that took place in Finland in 2010 to 2015. The results show that the average recovery times for cHb to return back to the level preceding donation were substantially longer, over 200 days in all age groups, than were the minimum allowed donation intervals. cHb recovery was especially poor in women under the age of 30 who returned to donate soon after the minimum allowed donation interval. It was of interest that frequent donors recovered substantially faster, with the average recovery times of ∼100 days in men and ∼200 days in women, than did infrequent donors, suggesting that there is a subpopulation of donors who can donate frequently without fear of iron deficiency. Return interval in fact explained only 1% of the variation in cHb recovery, which points to unknown, individual features, such as genetic or lifestyle factors, warranting further studies and suggesting that simply extending the allowed donation intervals may not suffice to improve cHb recovery. The study demonstrates that data mining of blood bank records is a powerful tool for depicting features of blood donor population.

Iron-deficient erythropoiesis in blood donors and red blood cell recovery after transfusion: initial studies with a mouse model

BACKGROUND

Most frequent red cell (RBC) donors and many first-time donors are iron deficient, but meet haemoglobin standards. However, the effects of donation-induced iron deficiency on RBC storage quality are unknown. Thus, we used a mouse model to determine if donor iron deficiency reduced post-transfusion RBC recovery.

METHODS

Weanling mice received a control diet or an iron-deficient diet. A third group receiving the iron-deficient diet was also phlebotomised weekly. This provided 3 groups of mice with different iron status: (1) iron replete, (2) mild iron deficiency with iron-deficient erythropoiesis, and (3) iron-deficiency anaemia. At ten weeks of age, blood was collected, leucoreduced, and stored at 4 ºC. After 12 days of storage, 24-hour (h) post-transfusion RBC recovery was quantified in recipients by flow cytometry.

RESULTS

Before blood collection, mean haemoglobin concentrations in the iron-replete, iron-deficient, and iron-deficiency anaemia donor mice were 16.5±0.4, 11.5±0.4, and 7.0±1.4 [g/dL± 1 standard deviation (SD)], respectively (p<0.01 for all comparisons between groups). The 24-h post-transfusion RBC recoveries in recipients receiving transfusions from these three cohorts were 77.1±13.2, 66.5±10.9, and 46.7±15.9 (% ±1 SD), respectively (p<0.05 for all comparisons between groups).

DISCUSSION

In summary, donor iron deficiency significantly reduced 24-h post-transfusion RBC recovery in recipient mice. RBCs from mice with mild iron deficiency and iron-deficient erythropoiesis, with haemoglobin levels similar to those used for human autologous blood donation, had intermediate post-transfusion RBC recovery, as compared to iron-replete donors and those with iron-deficiency anaemia. This suggests that, in addition to the effects of iron deficiency on donor health, frequent blood donation, leading to iron-deficient erythropoiesis, may also have adverse effects for transfusion recipients.

Low-Grade Inflammation Is Associated with Susceptibility to Infection in Healthy Men: Results from the Danish Blood Donor Study (DBDS)

INTRODUCTION

The aim of this study was to examine whether low-grade inflammation (LGI) is associated with a subsequently increased risk of infection.

METHODS

We included 15,754 healthy participants from the Danish Blood Donor Study, who completed a questionnaire on health-related items. LGI was defined as a C-reactive protein level between 3 and 10 mg/L. Infections were identified by ICD-10 codes in the Danish National Patient Register and ATC-codes in the Danish Prescription Register. Multivariable Cox proportional hazard analysis was used as the statistical model.

RESULTS

During 53,302 person-years of observation, 571 participants were hospitalized for infection. Similarly, during 26,125 person-years of observation, 7,276 participants filled a prescription of antimicrobials. LGI was associated with increased risk of hospital-based treatment for infection only among men (hazard ratio = 1.60, 95% confidence interval (CI): 1.10-2.34) and specifically infections were abscesses and infections of the skin and subcutaneous tissue. Similarly, LGI was associated with the overall use of antimicrobials among men, and particularly with phenoxymethylpenicillin and broad-spectrum antimicrobials for treatment of urinary tract infections. The difference between men and women was not statistically significant.

CONCLUSIONS

In a large cohort of healthy individuals, LGI was associated with an increased risk of infection among healthy male blood donors.

The association between frequency of blood donation and the occurrence of low birthweight, preterm delivery, and stillbirth: a retrospective cohort study

BACKGROUND

Women who donate blood on a regular basis are at high risk of becoming iron depleted. Iron deficiency anemia has been shown to increase the risk of low birthweight and possibly preterm birth. Therefore, there is a concern that regular blood donation by female donors might adversely impact the well-being of their offspring. This retrospective cohort study examined the association between blood donation and the occurrence of adverse pregnancy outcomes.

STUDY DESIGN AND METHODS

The study sample included 18,483 female blood donors in their childbearing years (age 18 to 45 years) who delivered during the period 2001 to 2011 in the province of Québec (Canada). The occurrence of low birthweight (<2500 g), preterm delivery (<37 weeks of gestation), and stillbirth was ascertained by linking the donor information with provincial birth and stillbirth registries.

RESULTS

There was no association between the frequency of donation in the 2-year period before pregnancy and adverse pregnancy outcomes; compared to women who did not donate during that period, those who donated three or more donations (mean, 3.9 donations) had a relative risk of 0.83 (95% confidence interval [CI], 0.65-1.06) for low birthweight, 0.91 (95% CI, 0.75-1.11) for preterm birth, and 0.62 (95% CI, 0.18-2.12) for stillbirth. These associations remained unchanged after adjusting for baseline characteristics.

CONCLUSION

Women who donate blood on a regular but moderate basis do not appear to be at higher risk of adverse pregnancy outcomes. These findings, while reassuring, will need to be replicated in different settings.