Prevalence of vitamin D deficiency in sickle cell disease: a systematic review.
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SUBMITTER: Nolan VG
PROVIDER: S-EPMC4347975 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Vitamin D deficiency (VDD), 25-OHD levels <20 ng/ml, is prevalent among patients with sickle cell disease (SCD) and is linked to acute and chronic pain and bone fracture in this population. There is limited literature regarding VDD-associated risk factors for SCD. We examined potential clinical and genomic parameters associated with VDD in 335 adults with SCD in a cross-sectional study. VDD was present in 65% of adult SCD patients, and 25-OHD levels independently and positively correlated with older age (P < 0·001) and vitamin D supplementation (P < 0·001). 25-OHD levels were higher in SCD patients over 40 years of age compared to the general African-American population. Both lower 25-OHD levels and increased pain frequency were associated with increased expression of SLC6A5 encoding glycine transporter-2 (GlyT2), a protein involved in neuronal pain pathways. Lower 25-OHD levels were also associated with increased expression of CYP3A4, and with decreased expression of GC (also termed DBP) and VDR, three genes involved in vitamin D metabolism. We conclude that vitamin D supplementation should be an almost universal feature of the care of young adults with SCD, and that further research is warranted into genomic factors that regulate vitamin D metabolism in SCD.
| S-EPMC6002929 | biostudies-literature
Project description:BackgroundVitamin D deficiency is associated with non-communicable and infectious diseases, but the vitamin D status of African populations is not well characterised. We aimed to estimate the prevalence of vitamin D deficiency in children and adults living in Africa.MethodsFor this systematic review and meta-analysis, we searched PubMed, Web of Science, Embase, African Journals Online, and African Index Medicus for studies on vitamin D prevalence, published from database inception to Aug 6, 2019, without language restrictions. We included all studies with measured serum 25-hydroxyvitamin D (25[OH]D) concentrations from healthy participants residing in Africa. We excluded case reports and case series, studies that measured 25(OH)D only after a clinical intervention, and studies with only a meeting abstract or unpublished material available. We used a standardised data extraction form to collect information from eligible studies; if the required information was not available in the published report, we requested raw data from the authors. We did a random-effects meta-analysis to obtain the pooled prevalence of vitamin D deficiency in African populations, with use of established cutoffs and mean 25(OH)D concentrations. We stratified meta-analyses by participant age group, geographical region, and residence in rural or urban areas. The study is registered with PROSPERO, number CRD42018112030.FindingsOur search identified 1692 studies, of which 129 studies with 21 474 participants from 23 African countries were included in the systematic review and 119 studies were included in the meta-analyses. The pooled prevalence of low vitamin D status was 18·46% (95% CI 10·66-27·78) with a cutoff of serum 25(OH)D concentration less than 30 nmol/L; 34·22% (26·22-43·68) for a cutoff of less than 50 nmol/L; and 59·54% (51·32-67·50) for a cutoff of less than 75 nmol/L. The overall mean 25(OH)D concentration was 67·78 nmol/L (95% CI 64·50-71·06). There was no evidence of publication bias, although heterogeneity was high (I2 ranged from 98·26% to 99·82%). Mean serum 25(OH)D concentrations were lower in populations living in northern African countries or South Africa compared with sub-Saharan Africa, in urban areas compared with rural areas, in women compared with men, and in newborn babies compared with their mothers.InterpretationThe prevalence of vitamin D deficiency is high in African populations. Public health strategies in Africa should include efforts to prevent, detect, and treat vitamin D deficiency, especially in newborn babies, women, and urban populations.FundingWellcome Trust and the DELTAS Africa Initiative.
| S-EPMC7024961 | biostudies-literature
Project description: Not available
| S-EPMC7386793 | biostudies-literature
Project description:BackgroundSickle cell disease (SCD) is an inherited autosomal recessive disorder caused by the replacement of normal haemoglobin (HbA) by mutant Hb (sickle Hb, HbS). The sickle-shaped red blood cells lead to haemolysis and vaso-occlusion. Especially in the first years of life, patients with SCD are at high risk of life-threatening complications. SCD prevalence shows large regional variations; the disease predominantly occurs in sub-Saharan Africa. We aimed to systematically assess the evidence on the benefit of newborn screening for SCD followed by an earlier treatment start.MethodsWe systematically searched bibliographic databases (MEDLINE, EMBASE, Cochrane Databases, and the Health Technology Assessment Database), trial registries, and other sources to identify systematic reviews and randomised controlled trials (RCTs) or non-randomised trials on newborn screening for SCD. The last search was in 07/2020. Two reviewers independently reviewed abstracts and full-text articles and assessed the risk of bias of the studies included. Data were extracted by one person and checked by another. As meta-analyses were not possible, a qualitative summary of results was performed.ResultsWe identified 1 eligible study with direct evidence: a Jamaican retrospective study evaluating newborn screening for SCD followed by preventive measures (prevention of infections and education of parents). The study included 500 patients with SCD (intervention group, 395; historical control group, 105). Although the results showed a high risk of bias, the difference between the intervention and the control group was very large: mortality in children decreased by a factor of about 10 in the first 5 years of life (0.02% in the intervention group vs. 0.19% in the control group, odds ratio 0.09; 95% confidence interval [0.04; 0.22], p < 0.001).ConclusionThe results are based on a single retrospective study including historical controls. However, the decrease of mortality by a factor of 10 is unlikely to be explained by bias alone. Therefore, in terms of mortality, data from this single retrospective study included in our systematic review suggest a benefit of newborn screening for SCD (followed by preventive measures) versus no newborn screening for SCD (weak certainty of conclusions).
| S-EPMC7602310 | biostudies-literature
Project description:Sickle cell disease (SCD) is an inherited monogenic disorder with high prevalence throughout sub-Saharan Africa, the Mediterranean basin, the Middle East, and India. Sources of SCD epidemiology remain scarce and fragmented. A systematic literature review (SLR) to identify peer-reviewed studies on SCD epidemiology was performed, with a search of bibliographic databases and key conference proceedings from 1 January 2010 to 25 March 2022 (congress abstracts after 2018). The SLR followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Meta-analyses, using a binomial normal random-effects model, were performed to estimate global and regional prevalence and birth prevalence. Of 1770 journal articles and 468 abstracts screened, 115 publications met the inclusion criteria. Prevalence was highest in Africa (~800/100,000), followed by the Middle East (~200/100,000) and India (~100/100,000), in contrast to ~30/100,000 in Europe. Birth prevalence was highest in Africa (~1000/100,000) and lowest in North America (~50/100,000) and Europe (~30/100,000). This SLR confirmed that sub-Saharan and North-East Africa, India, the Middle East, and the Caribbean islands are global SCD hotspots. Publications including mortality data were sparse, and no conclusions could be drawn about mortality. The identified data were limited due to gaps in the published literature for large parts of the world population; the inconsistent reporting of SCD genotypes, diagnostic criteria, and settings; and a sparsity of peer-reviewed publications from countries with assumed high prevalence. This SLR demonstrated a lack of systematic knowledge and a need to provide uniform data collection on SCD prevalence and mortality.
| S-EPMC10488271 | biostudies-literature
Project description:Background/Objectives: Sickle cell disease (SCD) impacts about 100,000 people in the US. SCD increases the risk of cholelithiasis and microvascular ischemia, which could increase the risk of acute pancreatitis (AP). Abdominal pain is a common presenting symptom of AP and sickle cell vaso-occlusive crisis. The purpose of our systematic review is to estimate the prevalence and determine the severity of AP in individuals with SCD compared to the general population. Methods: Multiple electronic databases were searched. We included studies that included children and adults (population) and addressed the association of SCD (exposure) with AP (outcome) compared to the same population without SCD (control). Two authors screened titles and abstracts independently, and data were abstracted in duplication from included studies. We registered this protocol in PROSPERO-CRD42023422397. Results: Out of 296 studies screened from multiple electronic databases, we identified 33 studies. These studies included 17 case reports, one case series, and 15 retrospective cohort studies, and 18 studies included children. Eight of the AP case reports were in patients with HbSS genotype, two with sickle beta thalassemia, and one with HbSoArab, and in six case reports, a genotype was not specified. Complications were reported in 11 cases-respiratory complication (in at least four cases), splenic complications (three cases), pancreatic pseudocyst (two cases) and death from AP (one case). Of the four AP cases in the case series, three had HbSS genotype, and two cases had complications and severe pancreatitis. AP prevalence in SCD was estimated to be 2% and 7% in two retrospective studies, but they lacked a comparison group. In retrospective studies that evaluated the etiology of AP in children, biliary disease caused mostly by SCD was present in approximately 12% and 34%, respectively. Conclusions: Data on the prevalence of AP in individuals with SCD are limited. Prospectively designed studies aiming to proactively evaluate AP in individuals with SCD who present with abdominal pain are needed to improve timely diagnosis of AP in SCD and outcomes.
| S-EPMC11355684 | biostudies-literature
Project description:The objective of this systematic review was to assess the relationship between pain (frequency/intensity/duration, impairment, coping) and emotional functioning in pediatric Sickle Cell Disease, and evaluate the state of the literature. Studies were included if they met each of the following criteria: (a) primarily pediatric sample of youth or young adults up to age 21 years with SCD, (b) examined emotional functioning including anxiety and/or depressive and/or internalizing symptoms, and/or affect, (c) examined pain intensity/frequency/duration and/or pain-related impairment and/or pain coping as it relates to emotional functioning, as defined above. Using the established guidelines for systematic reviews, we searched PsycINFO, PubMED, and CINAHL databases for studies published through June 2018. Screening resulted in 33 studies meeting inclusion criteria. Study data were extracted and evaluated for scientific merit, resulting in four studies being removed. 29 studies were included in the final synthesis. Studies provide strongest evidence of a relationship between increased pain frequency and higher depressive and anxiety symptoms. There are moderate-to-strong associations between pain-related impairment and depressive symptoms, and small-to-strong associations between pain-related impairment and anxiety. When examining pain-coping strategies, maladaptive cognitive strategies show the strongest association with emotional functioning. There is a need for more adequately powered, prospective studies based on theoretical frameworks in order to advance our understanding of the relationship between pain and emotional functioning in pediatric SCD.
| S-EPMC7018584 | biostudies-literature
Project description:Vitamin A deficiency (VAD), a leading cause of preventable childhood blindness, has been recognized as an important public health problem in many developing countries. In this study, we conducted a systematic review to identify all population-based studies of VAD and marginal VAD (MVAD) in Chinese children published from 1990 onwards. Hierarchical Bayesian meta-regressions were performed to examine the effects of age, sex, setting and year on the prevalence of VAD and MVAD, separately. The estimated prevalence was applied to the Chinese pediatric population in the year 2015 to generate prevalence estimates of VAD and MVAD for defined age groups, with 95% credible intervals (CrIs). Fifty-four studies met the inclusion criteria. The prevalence of VAD and MVAD both decreased with increasing age, and rural children had a higher prevalence of VAD and MVAD than urban children. In 2015, the prevalence of VAD was 5.16% (95% CrI: 1.95-12.64) and that of MVAD was 24.29% (95% CrI: 12.69-41.27) in Chinese children aged 12 years and under. VAD remains a public health problem in China. Efforts to reduce VAD in younger children are needed, especially for those in rural areas.
| S-EPMC5748736 | biostudies-literature
Project description:BackgroundVitamin A deficiency is a major nutritional concern in lower-income countries. The aim of this systematic review and meta-analysis was to show the magnitude of vitamin A deficiency among preschoolers in Ethiopia.ObjectiveThe present study was aimed at synthesizing qualitatively and quantitatively the existing literature on the prevalence of VAD in preschool children in Ethiopia.MethodsStudies were searched through the search engine of Google Scholar, Hinari, MEDLINE/PubMed, Cochrane Library, and Africa-Wide Information. Searching was made using the keywords/MeSH of vitamin A deficiency, xerophthalmia, night blindness, Bitot's spot, retinol, children, and Ethiopia. Data were analyzed and compared with the WHO threshold criteria to declare a public health problem. Heterogeneity among studies was assessed using a Cochran Q test and I 2 statistics. A random-effects model with 95% confidence interval was used for prevalence estimations.ResultsOf the 13 studies included in clinical analysis, 12 of them reported the prevalence of night blindness and/or Bitot's spot among preschool children in Ethiopia which was above WHO cutoff point for the public health problem 1% and 0.5%, respectively. The prevalence of night blindness significantly decreased from moderate public health problem 4.2% (95% CI: 2.8%-5.7%) in a period from 1990 to 2004 to mild public health problem 0.8% (95% CI: 0.6%-1.0%) in a period from 2005 to 2019. Furthermore, statistically insignificant reduction was observed in the prevalence of Bitot's spot in a period from 1990 to 2004, 2.2% (95% CI: 1.3%-3.2%) to 1.8% (95% CI: 1.2%-2.3%) in a period from 2005 to 2019. Among 8 studies on subclinical vitamin A deficiency, 7 of them indicated a severe public health problem (>20%). The prevalence of subclinical vitamin A deficiency decreased from 55.7% (95% CI: 39.8%-71.6%) in a period from 1990 to 2004 to 28.3% (95% CI: 9.8%-46.7%) in a period from 2005 to 2019, but not statistically significant.ConclusionsDespite the reduced proportion of night blindness and Bitot's spot, still both clinical and subclinical vitamin A deficiencies remain a public health problem in Ethiopia requiring strengthen intervention through the newly initiated health extension program.
| S-EPMC7073500 | biostudies-literature
Project description:ObjectivesThis study evaluated the prevalence rate of vaso-occlusive crisis (VOC) episodes, rates of uncomplicated and complicated VOC episodes, and the primary reasons for emergency room (ER) visits and inpatient admissions for sickle cell disease (SCD) patients.MethodsThe Medicaid Analytic extracts database was used to identify adult SCD patients using claims from 01JUL2009-31DEC2012. The date of the first observed SCD claim was designated as the index date. Patients were required to have continuous medical and pharmacy benefits for ≥6 months baseline and ≥12 months follow-up period. Patient demographics, baseline clinical characteristics, the rate of uncomplicated and complicated VOC (VOC with concomitant SCD complications) episodes, and reasons for ER visits and inpatient stays were analyzed descriptively.ResultsA total of 8,521 patients were included in the analysis, with a median age of 30 years. The average follow-up period was 2.7 years. The rate of VOC episodes anytime in the follow-up was 3.31 in person-years. During the first-year follow-up period, an average of 2.79 VOC episodes were identified per SCD patients, with 1.06 VOC episodes treated in inpatient setting and 0.90 VOC episodes in ER without admission. A total of 76,154 VOC episodes were identified during the entire follow-up period for the overall SCD patients. Most of the VOC episodes (70.3% [n = 53,523]) were uncomplicated episodes, and 29.7% were complicated episodes. Using primary diagnosis claims only, the most frequent complications during the VOC episode were infectious diseases (25.9%), fever (21.8%), and pulmonary disorders (16.2%). Among ER and hospitalizations related to VOC or SCD complication, ~85.0% had VOCs as the primary reason for admission; 15.0% had SCD complications as the primary reason.ConclusionIn summary, SCD and its related comorbidities and complications result in high acute health care utilization. In addition, VOC remains the primary reason for SCD patients' ER visits and inpatient admissions.
| S-EPMC6611562 | biostudies-literature