Sleep alterations and iron deficiency anemia in infancy

Association between iron deficiency anemia and sleep duration in the first year of life

OBJECTIVE

The aim of this study was to investigate the association between iron deficiency anemia and sleep duration in the first year of life.

METHODS

A total of 123 infants were investigated, with sleep being evaluated at 3, 6, and 12 months of age and anemia at birth and 6 months. The cutoff points for anemia and short sleep duration were hemoglobin <11 g/dL (at birth and/or 6 months) and <10 h (at 3, 6, and 12 months), respectively. The comparison of the average sleep time between infants with and without anemia was performed using the Student's t-test, and logistic regression models were also used to verify differences in the sleep duration (short/not short) between the groups. Linear regression analyses were conducted to determine the association between sleep duration and hemoglobin values. The analyses were adjusted for potential confounders.

RESULTS

Children with anemia were more likely to be short sleepers [odds ratio (95% confidence interval (CI)): 4.02 (1.02-15.76); p≤0.05], and for each unit increase in hemoglobin values, the sleep duration increased by 16.2 min [β (95%CI): 0.27 (0.00-0.55); p≤0.05), regardless of family income, maternal schooling, gender, and body mass index at birth.

CONCLUSIONS

Our results suggest that iron deficiency anemia is associated with short sleep duration in the first year of life and indicate the need for longitudinal investigations, with longer follow-up, to verify the impact of anemia on sleep duration at subsequent ages.

Anemia in pregnancy and sleep of 6-month-old infants: A prospective cohort study

Objective

Anemia has been reported to adversely influence sleep in infants. However, the association between anemia in pregnancy and infant sleep remains unclear. We aimed to examine the association between maternal anemia in pregnancy and sleep parameters of 6-month-old infants.

Methods

We enrolled 2,410 mother-infant pairs between 2018 and 2021 in Hefei. Data on maternal hemoglobin concentration were collected at 24–28 gestational weeks from the electronic medical records of the hospitals. Nocturnal and daytime sleep duration, number of night awakenings, nocturnal wakefulness, and sleep latency of infants aged 6 months were measured using the Brief Infant Sleep Questionnaire with five items. A restricted cubic spline model was used to examine the relationship between maternal hemoglobin concentration and infant nocturnal sleep duration after adjusting for potential confounders.

Results

In our study, 807 (33.5%) mothers had anemia during pregnancy. Compared to infants born to mothers without anemia, infants born to mothers with anemia in pregnancy had shorter nocturnal sleep duration [mean (SD), 560.29 (79.57) mins vs. 574.27 (75.36) mins] at the age of 6 months. Subgroup analysis showed consistent significant differences in nocturnal sleep duration between infant born to anemic and non-anemic mothers, except in case of stratification by preterm birth [mean difference (mins), 2.03 (95% CI, −20.01, −24.07)] and pre-pregnancy obesity [mean difference (mins), −0.85 (95% CI, −16.86, −15.16)]. A J-shaped nonlinear correlation curve was observed between maternal hemoglobin concentration and infant nocturnal sleep duration. Compared with mothers without daily iron supplementation, mothers who had daily iron supplementation had higher hemoglobin concentrations [mean (SD), 112.39 (11.33) g/L vs. 110.66 (10.65) g/L] at delivery and their infants had longer nocturnal sleep duration [mean (SD), 565.99 (82.46) mins vs. 553.66 (76.03) mins].

Conclusion

Anemia in pregnancy may have an adverse influence on the sleep of 6-mon-old infants, and the relationship between maternal hemoglobin concentration and nocturnal sleep duration is nonlinear.

Effect of Hypoxia-Ischemia on the Expression of Iron-Related Proteins in Neonatal Rat Brains

Hypoxic-ischemic white matter injury (WMI) pathogenesis in preterm infants is not well established, and iron-related proteins in the brain may play an important role in imbalanced iron metabolism. We aimed to investigate the iron-related protein changes in neonatal rats after hypoxia-ischemia (HI), clarify the role of iron-related proteins in hypoxic-ischemic WMI, and potentially provide a new target for the clinical treatment of hypoxic-ischemic WMI in preterm infants. We adopted a WMI animal model of bilateral common carotid artery electrocoagulation combined with hypoxia in neonatal 3-day-old Sprague-Dawley rats. We observed basic myelin protein (MBP) and iron-related protein expression in the brain (ferritin, transferrin receptor [TfR], and membrane iron transporter 1 [FPN1]) via Western blot and double immunofluorescence staining. The expression of MBP in the WMI group was significantly downregulated on postoperative days (PODs) 14, 28, and 56. Ferritin levels were significantly increased on PODs 3, 7, 14, and 28 and were most significant on POD 28, returning to the sham group level on POD 56. FPN1 levels were significantly increased on PODs 7, 28, and 56 and were still higher than those in the sham group on POD 56. TfR expression was significantly upregulated on PODs 1, 7, and 28 and returned to the sham group level on POD 56. Immunofluorescence staining showed that ferritin, TfR, and FPN1 were expressed in neurons, blood vessels, and oligodendrocytes in the cortex and corpus callosum on POD 28. Compared with the sham group, the immune-positive markers of three proteins in the WMI group were significantly increased. The expression of iron-related proteins in the brain (ferritin, FPN1, and TfR) showed spatiotemporal dynamic changes and may play an important role in hypoxic-ischemic WMI.

Periodic leg movements during sleep and iron status in infants with prematurity, Down syndrome and Prader-Willi syndrome

Sleep disturbances including bedtime problems and night awakenings are common during infancy. Polysomnography during the first years of life is performed mainly to rule out sleep-disordered breathing; however, sleep-related movement disorders can constitute a significant contributor to sleep disruption in this age group. Almost no studies have investigated the presence of periodic limb movements during sleep and underlying iron deficiency in infants, especially in those born preterm or with an underlying genetic syndrome. In this retrospective study we included infants 3-24 months referred for polysomnography for snoring or frequent nocturnal awakenings. All children had bloodwork (ferritin and haemoglobin) conducted within 3 months of the overnight sleep study. We studied 79 infants, including 31 (39.2%) full-term without diagnosis, 10 (12.7%) born premature, 16 (20.3%) with Down syndrome, 15 (19.0%) with Prader-Willi syndrome, and the remaining seven (8.9%) had various disorders. Compared with those with Down syndrome, Prader-Willi syndrome and full-term infants, those with prematurity showed a statistically significant elevated periodic limb movement index and lower ferritin levels than the other groups. Both ferritin (r = -0.18) and haemoglobin (r = -0.30) were negatively correlated with periodic limb movement index; however, this correlation reached statistical significance only for haemoglobin. Iron deficiency is associated with increased periodic leg movements during sleep in infants. Infants with prematurity had higher periodic limb movement index and lower ferritin levels than infants with Down syndrome, Prader-Willi syndrome or without diagnosis.

Behavioral sleep medicine-The need for harmonization of clinical best practice outcome measures in children and adolescents with intellectual or developmental disabilities and restless sleep

In behavioral medicine, sleep disorders, insomnia in particular, may be considered comorbidities and precipitating factors to intellectual or developmental disabilities (IDD). Nevertheless, sleep alterations have often been neglected in favor of daytime features and symptoms, albeit simple behavioral nighttime observations may disclose hypermotor features that characterize restless sleep. The root of most hypermotor restlessness is linked to central iron deficiency. The latter is often exacerbated by vitamin D deficiency (VDD), which interferes with both dopaminergic and serotonergic mechanisms. In this way, an imbalance affecting daytime behavior and mood is created. Several sleep-related motor disorders such as bruxism, periodic and aperiodic leg movements, Restless Legs Syndrome (RLS), and Restless Sleep Disorder (RSD) are commonly seen in Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorders (ASD). However, they are rarely diagnosed and often overlooked in affected children and adolescents. As a result, not only are these disorders not adequately addressed therapeutically, but their symptoms may be worsened by the side-effects of drugs used to contain disruptive daytime behavior, such as antipsychotics and antidepressants. In children with IDDs, obesity, inactivity and metabolic effects of antipsychotics often lead to Sleep Disordered Breathing (SDB), which is currently understood as an inflammatory state leading to "hyperactive" lethargy and further alterations of the hypoxic chain and vitamin D levels. Endorsing simple routine blood tests, including inflammatory markers such as C-reactive protein, ferritin, transferrin, and vitamin D levels, may favorably complement caregiver observations and ambulatory sleep recordings, leading to a sleep disorder diagnosis and consequent therapy. In fact, the treatment of SDB, RLS, and RSD has been copiously demonstrated to favorably impact vigilance, behavior, social competence, and academic skills in healthy and, to a greater extent, in IDD children. Thus, consulting and deliberating the root causes of functional and categorical diagnoses within a clinical framework may engender a more precise diagnosis and further benefit pediatric daytime and nighttime management of hyperactive behaviors.

Association of maternal hemoglobin levels during pregnancy with sleep and developmental problems in 1‐year‐old infants: A cohort study

Background and Aims

Maternal hemoglobin concentration during pregnancy is reported to be associated with various perinatal outcomes and may also be associated with infant development. This study aims to investigate the association between maternal hemoglobin levels during early or mid‐pregnancy and sleep and developmental problems in 1‐year‐old infants.

Methods

We used the data of 66,935 pregnant women who were participants of the Japan Environment and Children's Study, a nationwide cohort study in Japan, between 2011 and 2014. Maternal hemoglobin level was examined at recruitment (mean gestational age, 15.3 weeks; SD, 2.85 weeks; range, 6–22 weeks). Information on infant sleep and development at the age of 1 year was acquired using a questionnaire. Infant development was evaluated using the Ages and Stages Questionnaire (ASQ).

Results

The mean (SD) maternal hemoglobin level was 12.0 (1.0) g/dl. Maternal hemoglobin levels were not associated with the majority of infant sleep and developmental outcomes. In the group with maternal hemoglobin <10.0 g/dl, the risk ratio (RR) for sleep at 22:00 or later was higher than that in the reference group with 11.0 g/dl ≤ hemoglobin < 14.0 g/dl (RR 1.12, 95% confidence interval = 1.00–1.25). In the analysis with maternal hemoglobin level as a continuous variable, both high and low hemoglobin levels were associated with a higher RR of a late bedtime. In addition, a low maternal hemoglobin level was associated with a higher RR for abnormal fine motor skills in the ASQ.

Conclusion

Our results suggest that a low level of maternal hemoglobin during pregnancy is associated with late bedtime and abnormal fine motor skills in 1‐year‐old infants. Conversely, a high level of maternal hemoglobin may also be associated with the infant's late bedtime.

The Association of Self-Reported Iron and Vitamin D Levels on Sleep Quality and Pain Perception in a Subset of Saudi Population

Background and Aims

There has been a rising concern regarding the relationship of iron levels, vitamin D, and consumption of multivitamins on pain perception and sleep quality. The purpose of this study is to shed light on these connections in hopes of enhancing quality of sleep.

Methods

A cross-sectional analysis was used, and data collection was based on close-ended online questionnaire created on Survey Monkey. The survey included an operator designed questionnaire, questions from both the Brief Pain Inventory and Sleep Quality questionnaires. The targeted population was participants who were medically fit, non-pregnant Saudi citizens aged between 25 and 55 years.

Results

Prior to the COVID-19 crisis, data were collected during the months of February and March 2020, with a grand total of 3127 participants, out of which 2774 responses were included. The outcome of the research revealed that diminished levels of vitamin D, and iron had a negative impact on sleep quality. In turn, poor sleep quality had a significant pain response.

Conclusion

This study reveals the detrimental role of vitamins on sleep, and their concurrent domino effect on pain.

Relationship between Self-Reported Sleep Duration and Risk of Anemia: Data from the Korea National Health and Nutrition Examination Survey 2016-2017

The importance of sleep has been gaining more and more attention nowadays. It has been widely studied that some major health issues, such as cardiovascular diseases or mortality, are closely related to the extreme ends of sleep durations. Anemia is one of the health problems in modern society. In this study, we aimed to find a relationship between anemia occurrence and sleep duration. Data of 11,131 Korean adults aged 19 years or older were recruited from the 2016-2017 Korea National Health and Nutrition Examination Survey and analyzed in this cross-sectional study. 'Anemia' was defined in this study by hemoglobin level of <13 g/dL in men and <12 g/dL in women. Selected data were sorted into five groups by sleep duration: <5 h, 5 h ~ <6 h, 6 h ~ <8 h, 8 h ~ <9 h, and ≥9 h per day. We performed multivariate logistic regression analysis to assess the relationship between sleep duration and risk of anemia after adjusting for covariates including age, gender, family income level, education level, physical activity, cigarette smoking, and alcohol usage. Other factors were assessed in the analysis, such as depression, hypertension, diabetes, dyslipidemia, stroke, coronary artery disease, malignancy, stress level, and body mass index (BMI). We found that sleep duration of <5 h was related to high risk of anemia (odds ratio = 1.87; 95% confidence interval = 1.01-3.49, sleep duration of 6 h ~ <8 h as the reference group). Also, sleep duration of ≥9 h was related to lower risk of anemia in most premenopausal women after adjusting for covariates (odds ratio = 0.61; 95% confidence interval = 0.38-0.96, sleep duration of 6 h ~ < 8 h as the reference group). Male individuals with sleep durations of <5 h (odds ratio = 2.01; 95% confidence interval =1.05-3.84) and of ≥9 h (odds ratio = 2.48; 95% confidence interval =1.63-3.81) had a significantly higher risk of anemia without covariate adjustment. Postmenopausal women with sleep durations of ≥9 h had a significantly higher risk of anemia (odds ratio =2.02; 95% confidence interval =1.33-3.08) without adjusting for covariates. However, the associations became statistically insignificant after adjusting for age and covariates in both men and postmenopausal women. In conclusion, we found significant associations between extreme ends of sleep duration and risk of anemia in premenopausal Korean women. However, we did not observe strong associations between self-reported sleep duration and anemia risk in men or postmenopausal women.

Anemia and insomnia: a cross-sectional study and meta-analysis

Background

Several recent genome-wide association studies suggested insomnia and anemia may share some common genetic components. We thus examined whether adults with anemia had higher odds of having insomnia relative to those without anemia in a cross-sectional study and a meta-analysis.

Methods

Included in this cross-sectional study were 12,614 Chinese adults who participated in an ongoing cohort, the Kailuan Study. Anemia was defined as hemoglobin levels below 12.0 g/dL in women and 13.0 g/dL in men. Insomnia was assessed using the Chinese version of the Athens Insomnia Scale (AIS). A total AIS score ≥6 was considered insomnia. The association between anemia and insomnia was assessed using a logistic regression model, adjusting for potential confounders such as age, sex, chronic disease status, and plasma C-reactive protein concentrations. A meta-analysis was conducted using the fixed effects model to pool results from our study and three previously published cross-sectional studies on this topic in adult populations.

Results

Individuals with anemia had greater odds of having insomnia (adjusted odds ratio [OR]: 1.32; 95% confidence interval [CI]: 1.03–1.70) compared with individuals without anemia. A significant association persisted after we excluded individuals with chronic inflammation, as suggested by C-reactive protein levels >1 mg/L (adjusted OR: 1.68; 95% CI: 1.22–2.32). The meta-analysis results, including 22,134 participants, also identified a positive association between anemia and insomnia (pooled OR: 1.39; 95% CI: 1.22–1.57).

Conclusions

The presence of anemia was significantly associated with a higher likelihood of having insomnia in adults. Due to the nature of the cross-sectional study design, results should be interpreted with caution.

The effect of sleep duration on hemoglobin and hematocrit: observational and Mendelian randomization study

STUDY OBJECTIVE

Observationally sleep duration is positively associated with hemoglobin (Hgb), whether this association is causal and consistent by sex remains unclear. Here, we assessed the association of sleep duration with Hgb and hematocrit (Hct) observationally in late adolescence in a population-representative Chinese birth cohort "Children of 1997" with validation using Mendelian randomization (MR) in adults.

METHODS

In the "Children of 1997" birth cohort (recruited = 8327, included = 3144), we used multivariable linear regression to assess the adjusted associations of sleep duration (measured as time in bed) with Hgb and Hct at 17.5 years and any sex differences. Using two-sample MR, we assessed the effect of sleep duration on Hgb and Hct, based on 61 single nucleotide polymorphisms (SNPs) applied to genome-wide association studies of Hgb and Hct in adults (n = 361 194).

RESULTS

Observationally, self-reported sleep duration was positively associated with Hct (0.034 standard deviations [SDs] per hour, 95% confidence interval [CI] 0.019 to 0.049), but not with Hgb. Using MR longer sleep increased Hct (0.077 SD per hour, 95% CI 0.035 to 0.119) and Hgb (0.065 SD per hour, 95% CI 0.020 to 0.109) using Mendelian randomization pleiotropy residual sum and outlier (MR PRESSO), with more pronounced associations in men.

CONCLUSIONS

Our novel findings indicate sleep increases both Hgb and Hct, particularly in men, perhaps contributing to its restorative qualities. Potential difference by sex and the implications of these findings warrant investigation.

Determinants of ferritin response to oral iron supplementation in children with sleep movement disorders

STUDY OBJECTIVES

To identify children who respond to oral iron supplementation as evidenced by increased ferritin levels and to identify factors that correlate with improvement in ferritin levels in those who respond.

METHODS

A retrospective chart review of the PLMS/RLS/RSD database at Seattle Children's Hospital was carried out. Data collected included nocturnal polysomnography parameters, age, sex, initial and follow-up ferritin level and date of collection, and presence of restless legs syndrome (RLS), periodic limb movements of sleep (PLMS)/PLM disorder (PLMD), restless sleep disorder (RSD), obstructive sleep apnea (OSA), neurologic, psychiatric, neurodevelopmental, or medical comorbidity. Oral iron therapy was evaluated by side effects (none; constipation; bad taste/nausea), subjective outcome in symptoms (resolved, improved, no change), and adherence to therapy (poor, fair, good).

RESULTS

Seventy-seven children were included in this study of whom 42 were classified as responders (increase in ferritin of ≥10 µg/L) and 35 were nonresponders. Age and sex were not different between groups. Adherence was the only significant predictor of an increase in ferritin of ≥10 µg/L. Constipation was seen in 7.1% of responders vs. 45.8% of nonresponders. No change in symptoms was reported in 26.2% of responders vs. 71.4% in nonresponders. A significant correlation was found between treatment duration and ferritin level change in responders but not in nonresponders.

CONCLUSIONS

Side effects hinders adherence to oral iron supplementation in children. Responders to oral iron show improvement in ferritin levels and symptoms, while nonresponders show no improvement in ferritin levels despite a long-lasting treatment, at least in part of them.

Cumulative Childhood Lead Levels in Relation to Sleep During Adolescence

STUDY OBJECTIVES

Lead exposure has been linked to adverse cognitive outcomes among children, and sleep disturbances could potentially mediate these relationships. As a first step, whether childhood lead levels are linked to sleep disturbances must be ascertained. Prior studies of lead and sleep are scarce and rely on parent-reported sleep data.

METHODS

The study population included 395 participants from the Early Life Exposure in Mexico to Environmental Toxicants project, a group of sequentially enrolled birth cohorts from Mexico City. Blood lead levels measured from ages 1 to 4 years were used to calculate a cumulative measure of early childhood lead levels. Average sleep duration, sleep fragmentation, and movement index were assessed once between the ages of 9 and 18 years with wrist actigraphs worn for a continuous 7-day interval. Linear regression models were fit with average sleep duration, fragmentation, or movement as the outcome and cumulative lead levels divided into quartiles as the exposure, adjusted for age, sex, and maternal education.

RESULTS

Mean (standard deviation) age at follow-up was 13.8 (1.9) years, and 48% of participants were boys. Median (interquartile range) cumulative childhood lead level was 13.7 (10.8, 18.0) μg/dL. Patients in the highest quartile of the cumulative childhood lead group had on average 23 minutes less sleep than those in the first quartile in adolescence (95% confidence interval [7, 39]; P, trend = .02). Higher cumulative lead level was associated with higher sleep fragmentation in younger adolescents (younger than 14 years) only (P, interaction = .02).

CONCLUSIONS

Shorter sleep duration may represent an as-yet unrecognized adverse consequence of lead exposure in youth.

Serum Concentration of Hepcidin as an Indicator of Iron Reserves in Children

Background

Anemia represents a significant cause of maternal and perinatal mortality, as well as child mortality. The aim of the research was to determine the serum concentration of hepcidin in children aged 6 months to 2 years and adolescents aged 11 to 19 years which suffer from iron deficiency anemia and compare it with the serum concentration of hepcidin in the control groups, as well as to determine its connection with the parameters of the iron metabolism.

Methods

The research included 173 examinees, 89 of them suffered from iron deficiency anemia and 84 did not suffer from iron deficiency anemia (the latter represented the control group). Blood samples were collected from all study participants. The samples were analyzed for complete blood count and parameters of iron metabolism. ELISA method was used for establishing serum hepcidin levels.

Results

The research showed that the concentration of hepcidin is statistically lower in children (4.4 ng/mL) and adolescents (4.1 ng/mL) who suffer from iron deficiency anemia in comparison with the control group (14 ng/mL, 10 ng/mL, respectively). The positive correlation between serum hepcidin level and iron in the serum, ferritin, the mean corpuscular volume and transferrin saturation was confirmed, but the negative one occurred in serum hepcidin level, transferrin and reticulocytes.

Conclusions

The age of the examinees does not influence the level of serum hepcidin which makes it a more sensitive indicator of the level of iron in the body. Besides this, serum hepcidin is a reliable biological marker for the assessment of iron deficiency anemia.

Night Sleep Duration and Risk of Incident Anemia in a Chinese Population: A Prospective Cohort Study

The purpose was to study the association between sleep duration and the prevalence of anemia in Chinese people. There were 84,791 participants (men: 79.1%; women: 20.9%) aged 18–98 years in the prospective study. We divided the participants into five categories based on the individual sleep duration: ≤5 h, 6 h, 7 h(reference), 8 h, and ≥9 h. Anemia was defined based on hemoglobin <12 g/dL for men and <11 g/dL for women. The Cox proportional hazards model was used to assess the association between sleep duration and anemia. During median follow-up of 7.9 years, 2698 cases of anemia had occurred. The HRand (95% CI) of anemia (7 h as the reference group) for individuals reporting ≤5 h, 6 h, 8 h, and ≥9 h were 1.23(1.04–1.45), 1.26(1.11–1.44), 1.04(0.92–1.16) and 1.42(1.08–1.86), respectively. It showed that there was a significant interaction on the risk of anemia between sleep duration and sex in the secondary analysis (p < 0.001).The significant association between long sleepduration and anemia was found in women (HR, 2.29; 95% CI, 1.56–3.37), not in men(HR, 0.90; 95% CI, 0.60–1.34). Both short and long night sleep duration were associated with increased risk of anemia.

Association Between Non-Iron-Deficient Anemia and Insomnia Symptoms in Community-Dwelling Older Adults: The Baltimore Longitudinal Study of Aging

Background

Anemia is associated with poorer sleep in children, and clinically, anemia is linked to insomnia. However, the association between anemia and insomnia in older adults is understudied.

Methods

We examined the cross-sectional association between anemia and insomnia in 1,053 adults (71.4 ± 10.6 years) in the Baltimore Longitudinal Study of Aging. Participants were classified as nonanemic, non-iron-deficient anemic, or iron-deficient anemic based on hemoglobin, ferritin, transferrin saturation, and mean cell volume. Insomnia symptoms were evaluated by the Women's Health Initiative Insomnia Rating Scale (WHIIRS). A total score (range 0-20) was generated, and participants were also classified as having 0, 1, or 2+ symptoms.

Results

Overall, 10.5% of participants had non-iron-deficient anemia, 0.9% had iron-deficient anemia, and 88.5% had no anemia. Due to its low prevalence, the iron-deficient anemic group was dropped from analyses. In models adjusted for demographics, number of medical conditions, and Center for Epidemiologic Studies Depression Scale score, non-iron-deficient anemic individuals had significantly higher WHIIRS total scores, indicating greater insomnia severity, compared to those without anemia (predicted adjusted mean WHIIRS of 7.24 [95% confidence interval (CI): 6.40-8.08] vs 5.92 [95% CI: 5.65-6.19]). They also had twice the risk of reporting ≥2 insomnia symptoms (vs 0 symptoms; relative risk ratio = 2.20, 95% CI: 1.25-3.89).

Conclusions

Results suggest that individuals with non-iron-deficient anemia are more likely to experience insomnia symptoms than those who are nonanemic. These results may have implications for insomnia treatment or the identification of underlying frailty in individuals with sleep problems.

Sleep disorders in pediatric chronic kidney disease patients

The prevalence of sleep disorders during childhood has been estimated to range from 25 to 43 %. The aim of this review is to determine the prevalence of sleep disorders and possible associations with chronic kidney disease (CKD)-related factors and health-related quality of life (HRQOL) in children with CKD. An electronic systematic literature search for sleep disorders in children with CKD in Pubmed, Embase and the Cochrane Library Databases identified seven relevant articles for review, all of which reported an increased prevalence of sleep disorders in children with CKD. Five studies included children with CKD undergoing dialysis, and two studies included only non-dialysis patients. In all studies the presence of sleep disturbances was assessed by questionnaires; only one study compared the results of a validated questionnaire with laboratory-based polysomnography. The prevalence of any sleep disorder ranged from 77 to 85 % in dialysis patients, to 32-50 % in transplanted patients and 40-50 % in non-dialysis patients. The most commonly studied disorder was restless legs syndrome, which presented at a prevalence of 10-35 %. Three studies showed significant associations between presence of sleep disorders and HRQOL. We found consistent evidence of an increased prevalence of sleep disturbances in children with CKD, and these seemed to play a critical role in HRQOL.

Sleep Quality and Associated Factors in Older Turkish Adults With Hypertension: A Pilot Study

PURPOSE

The purpose of this study was to evaluate sleep quality and to explore its associations with participant characteristics, anemia, excessive daytime sleepiness, and physical activity in older Turkish adults with hypertension.

METHOD

This cross-sectional study included 128 adults aged 60 years or older with hypertension. Data were collected by using a personal information form, the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, and the International Physical Activity Questionnaire. Anemia was assessed by hemoglobin levels.

RESULTS

Eighty-one patients (63.3%) reported poor sleep quality. Anemia was present in 35.2% of the patients (defined as hemoglobin <13 g/dL for males and <12 g/dL for females). Female gender, the presence of anemia, and low levels of physical activity were associated with poor sleep quality. Conclusion/Implication: The majority of the participants had poor sleep quality. Better understanding of risk factors associated with poor sleep quality may contribute to more effective interventions to improve health and well-being.

An explanation of the pathophysiology of adverse neurodevelopmental outcomes in iron deficiency

Iron deficiency (ID) is a major public health problem worldwide among children aged 0-12 months. Several factors seem to contribute to the iron-deficient state in infancy, including insufficient antenatal and neonatal iron supplementation, exclusive breastfeeding, and early umbilical cord clamping after birth. The most concerning complications of ID, except for anemia, are related to altered long-term neurodevelopment. Clinical studies have shown a negative impact of ID anemia on fetal and neonatal behavior including impairments of motor maturity, autonomic response, memory/learning, and mood. ID-induced defects during infancy seem to persist later in life, even after ID treatment. The underlying mechanisms involve dysfunctional myelination, neurotransmission alterations, and altered synaptogenesis and/or dendritogenesis. The purpose of the present review is to summarize these mechanisms and to provide recommendations for future clinical research in the field.

Are children on jejunal feeds at risk of iron deficiency?

Children on exclusive jejunal feeding may be at risk of iron deficiency due to the feeds bypassing the duodenum, which is the primary site for iron absorption. We describe the biochemical and hematological features of six children on exclusive jejunal feeding who did not receive iron supplementation. At a mean (standard deviation) period of 11 (6.5) mo after commencing jejunal feeds, there was a significant reduction in both serum iron (18.5 g/L vs 9.8 g/L, P = 0.01) and transferrin saturation levels (23.1% vs 13.7%, P = 0.02), suggesting iron deficiency. However, there was no significant change in ferritin, hemoglobin and mean corpuscular volume levels post-commencement of jejunal feeds. This may be the result of small bowel adaptation in response to early iron deficiency. Larger and longer term prospective studies are required to investigate if children on jejunal feeds are at risk of developing iron deficiency.

Striking while the iron is hot: Understanding the biological and neurodevelopmental effects of iron deficiency to optimize intervention in early childhood

Prenatal and early postnatal iron deficiency (ID) is associated with long-term neurobiological alterations and disruptions in cognitive, social, and behavioral development. Early life ID is particularly detrimental as this is a period of rapid neurodevelopment. Even after iron supplementation, cognitive and social disruptions often persist in formerly iron deficient individuals. Observational studies of the acute and long-term effects of early life ID yield different results based on the timing of ID. Further, intervention studies demonstrate some improvement for certain domains but still show residual effects years later, which are dependent on the timing of ID and treatment. This review will cover the effects of ID during infancy and early childhood on brain structure and function, cognition, and behavior in relation to preclinical models of ID and sensitive periods of human brain development.

Motor activity and intra-individual variability according to sleep-wake states in preschool-aged children with iron-deficiency anemia in infancy

BACKGROUND

A chronic or acute insult may affect the regulatory processes that guide motor and behavioral performance, leading to increased intra-individual variability (IIV). Increased variability is often interpreted as an indication of regulatory dysfunction. Iron plays an important role in the regulatory processes of the nervous system and affects motor activity. To our knowledge, no study has examined the long-lasting patterns and IIV of motor activity following iron-deficiency anemia in human infants.

AIMS

This study compared 48-h motor activity and variability in preschool-aged children with or without iron-deficiency anemia (IDA) in infancy.

METHODS

Motor activity was recorded through actigraphs during two week-days in 47 4-year-old Chilean children (23 former IDA and 24 non-anemic in infancy). All were given oral iron as infants. Sleep-wake states were identified by means of automated software. The frequency of movement units per minute was determined for each waking/sleep state during the individual day and night periods; data were examined in blocks of 15 min. Analyses of mean frequency and duration and intra-individual variability were conducted using multivariate mixed models.

RESULTS

For daytime sleep, former IDA children were more active without a difference in the total duration. They also spent less time awake throughout the individual day period. Motor activity intra-individual variability was higher in former IDA children.

CONCLUSIONS

The findings suggest that IDA in infancy sets the stage for long lasting dysfunction in the neural processes regulating sleep-wake states and spontaneous motor activity patterns.

Sleep and biomarkers in the English Longitudinal Study of Ageing: associations with C-reactive protein, fibrinogen, dehydroepiandrosterone sulfate and hemoglobin

Sleep duration and quality are associated with adverse physical health outcomes. The mechanisms are not well understood, and little is known about associations with biomarkers in older population cohorts. This study assessed cross-sectional associations between self-reported sleep measures and biomarkers in a representative sample of British people aged 50 years and above. Participants were 6465 men and women aged 50-99 years from the English Longitudinal Study of Ageing (ELSA). Associations of sleep duration and sleep disturbance with C-reactive protein (CRP), fibrinogen, dehydroepiandrosterone sulfate (DHEAS) and hemoglobin were analyzed, adjusting for age, wealth, body mass index (BMI), smoking, physical activity, limiting long-standing illness and depressive symptoms. In men, long sleep duration (OR: 1.50, 1.05-2.14) and greater sleep disturbance (OR: 1.29, C.I. 1.05-1.59) were associated with raised CRP levels, while long sleep was also related to raised plasma fibrinogen (P=0.001). DHEAS levels were lower among men reporting more sleep disturbances (P=0.016), but were not related to sleep duration. Sleep duration (P=0.015) and sleep disturbance (P=0.039) were associated with lower hemoglobin levels, and anemia was more prevalent among men with disturbed sleep (OR: 1.73, C.I. 1.13-2.65). In women more disturbed sleep was associated with greater likelihood of anemia (OR: 1.59, C.I. 1.02-2.46), but there was no relationship between sleep disturbance or duration with other biomarkers. This study suggests that self-reported sleep duration and disturbance are related to biological risk factors in community-dwelling older adults, with different associations being present in men and women. A better understanding of these relationships using longitudinal cohort studies will broaden our understanding of the mechanisms relating sleep indices and ill health in advancing age.

Medical comorbidity of sleep disorders in children and adolescents

PURPOSE OF REVIEW

Sleep disorders in children and adolescents often present with various medical comorbidities. The aim of this review is to present the recent literature findings on this issue.

RECENT FINDINGS

The major medical comorbid conditions that accompany insomnia or short sleep duration in children and adolescents are obesity and metabolic syndrome, growth hormone deficiency, allergic conditions, various disorders accompanied by chronic pain, neoplasms and blood malignancies, and genetic and congenital disorders. Hypersomnia is mainly related to malignancies. Children and adolescents with obstructive sleep apnoea syndrome or sleep-disordered breathing may suffer from obesity and metabolic syndrome, polycystic ovaries, hypothyroidism, asthma, epilepsy, various ear nose throat disorders, congenital malformations or genetic conditions. Parasomnias may be comorbid with some medical conditions, but the main challenge in their evaluation is the differential diagnosis from nocturnal epileptic seizures.

SUMMARY

The co-occurrence of sleep disorders and medical conditions in childhood and adolescence is quite frequent and has an impact on general health and quality of life.

Iron deficiency anemia in infancy exerts long-term effects on the tibialis anterior motor activity during sleep in childhood

OBJECTIVES

To explore the eventual connection between iron deficiency anemia (IDA) in infancy and altered leg movements during sleep in a 10-year follow-up study in children who did or did not have IDA in infancy.

SUBJECTS AND METHODS

Polysomnographic studies were performed in 32 10-year-old children (13 females and 19 males) who had IDA in infancy and 26 peers (10 females and 16 males) who were nonanemic controls. The time structure of their polysomnographically recorded leg movements (LM) was analyzed by means of an approach particularly able to consider their quantity, periodicity, and distribution during the night.

RESULTS

All LM indexes and those related to periodic LM during sleep (PLMS) were slightly higher in the former IDA group than in the control group, but not always significant. The Periodicity index during NREM sleep was higher and was reflected by a small but significant increase in PLMS separated by 10-50s intervals. PLMS index tended to be higher in former IDA children than in controls throughout the whole night.

CONCLUSION

The association between IDA in infancy, despite iron therapy, and PLMS in childhood could lead to new research in this area. Indeed, transient infantile IDA, a common nutritional problem among human infants, may turn out to be important for understanding the mechanisms of PLMS or restless legs syndrome, which are common in adulthood.

Rethinking placental transfusion and cord clamping issues

A brief delay in clamping the umbilical cord results in a placental transfusion that supplies the infant with a major source of iron during the first few months of life. Cord circulation continues for several minutes after birth and placental transfusion results in approximately 30% more blood volume. Gravity influences the amount of placental transfusion that an infant receives. Placing the infant skin-to-skin requires a longer delay of cord clamping (DCC) than current recommendations. Uterotonics are not contraindicated with DCC. Cord milking is a safe alternative to DCC when one must cut the cord prematurely. Recent randomized controlled trials demonstrate benefits for term and preterm infants from DCC. The belief that DCC causes hyperbilirubinemia or symptomatic polycythemia is unsupported by the available research. Delay of cord clamping substantively increases iron stores in early infancy. Inadequate iron stores in infancy may have an irreversible impact on the developing brain despite oral iron supplementation. Iron deficiency in infancy can lead to neurologic issues in older children including poor school performance, decreased cognitive abilities, and behavioral problems. The management of the umbilical cord in complex situations is inconsistent between birth settings. A change in practice requires collaboration between all types of providers who attend births.

Systems genetic analysis of multivariate response to iron deficiency in mice

The aim of this study was to identify genes that influence iron regulation under varying dietary iron availability. Male and female mice from 20+ BXD recombinant inbred strains were fed iron-poor or iron-adequate diets from weaning until 4 mo of age. At death, the spleen, liver, and blood were harvested for the measurement of hemoglobin, hematocrit, total iron binding capacity, transferrin saturation, and liver, spleen and plasma iron concentration. For each measure and diet, we found large, strain-related variability. A principal-components analysis (PCA) was performed on the strain means for the seven parameters under each dietary condition for each sex, followed by quantitative trait loci (QTL) analysis on the factors. Compared with the iron-adequate diet, iron deficiency altered the factor structure of the principal components. QTL analysis, combined with PosMed (a candidate gene searching system) published gene expression data and literature citations, identified seven candidate genes, Ptprd, Mdm1, Picalm, lip1, Tcerg1, Skp2, and Frzb based on PCA factor, diet, and sex. Expression of each of these is cis-regulated, significantly correlated with the corresponding PCA factor, and previously reported to regulate iron, directly or indirectly. We propose that polymorphisms in multiple genes underlie individual differences in iron regulation, especially in response to dietary iron challenge. This research shows that iron management is a highly complex trait, influenced by multiple genes. Systems genetics analysis of iron homeostasis holds promise for developing new methods for prevention and treatment of iron deficiency anemia and related diseases.

Long-term brain and behavioral consequences of early iron deficiency

Early iron deficiency not only affects brain and behavioral function during the period of iron deficiency, it persists long after treatment. The mechanisms include long-term alterations in dopamine metabolism, myelination, and hippocampal structure and function. Recent studies have demonstrated long-term genomic changes, which suggests the regulation of brain function is fundamentally altered.