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Conor P Kerley

Bio: Conor P Kerley is an academic researcher from Connolly Hospital Blanchardstown. The author has contributed to research in topics: Vitamin D and neurology & vitamin D deficiency. The author has an hindex of 14, co-authored 27 publications receiving 450 citations. Previous affiliations of Conor P Kerley include University College Dublin & Dublin Institute of Technology.

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Journal ArticleDOI
TL;DR: In patients with stable COPD, the acute consumption of dietary nitrate increased serum nitrate/nitrite levels and exercise capacity and was associated with a decrease in resting blood pressure.

68 citations

Journal ArticleDOI
TL;DR: Vitamin D supplementation had no effect on the primary outcome with limited and inconsistent effects in children with ASD, suggesting a potential role for vitamin D in autism spectrum disorder.
Abstract: Objectives Data suggest a potential role for vitamin D in autism spectrum disorder (ASD). We wanted to assess the effect of vitamin D 3 supplementation compared with placebo in children with ASD. Design This was a double-blind, randomised, placebo-controlled trial. Setting A paediatric outpatient centre at high latitude over the winter season in Dublin, Ireland (53°N). Patients 42 children with ASD. Interventions 2000 IU vitamin D 3 supplementation or placebo daily for 20 weeks. Main outcome measures Assessments were completed at baseline and after 20 weeks of supplementation. The primary outcome was the stereotypic behaviour subscale from the Aberrant Behaviour Checklist (ABC). Secondary exploratory outcomes included additional subscales from the ABC, the Social Responsiveness Scale and rating on the Developmental Disabilities—Children’s Global Assessment Scale (DD-CGAS) as well as biochemical parameters of total vitamin D status (25-hydroxyvitamin D (25(OH)D)), immunity and systemic inflammation. Results 38 children completed the trial. Baseline 25(OH)D was 54.2±19.7 nmol/L. Following vitamin D 3 supplementation, there was a significant increase in 25(OH)D to 83.8 nmol/L (p=0.0016) but no effect on the primary endpoint. However, there was an improvement in self-care on DD-CGAS (p=0.02). In contrast, there was also a trend toward decreased inappropriate speech in the placebo group (p=0.08). Conclusion Vitamin D supplementation had no effect on the primary outcome with limited and inconsistent effects in children with ASD. Considering the other promising data as well as the relative safety and cheapness of vitamin D supplementation, further trials are warranted. Trial registration NCT02508922.

51 citations

Journal ArticleDOI
TL;DR: The aim of this study was to assess the effect of 15 weeks of vitamin D3 supplementation compared with placebo in Irish children with asthma.
Abstract: Background Observational and mechanistic data suggest a role for vitamin D in childhood asthma. However, subsequent interventional trials have been inconsistent. We aimed to assess the effect of 15 weeks of vitamin D3 supplementation compared with placebo (PL) in Irish children with asthma. Methods We conducted a double-blind, randomized, PL-controlled trial of vitamin D supplementation (2000 IU/day) in 44 urban, Caucasian children at high latitude. Assessments were completed at baseline and after 15 weeks of supplementation. Outcome measures were lung function, subjective asthma control and biochemical parameters of total vitamin D, allergy, immunity, airway inflammation, and systemic inflammation. Finally, parents/guardians completed a weekly diary during the trial. Results There was no significant difference in baseline 25(OH)D levels, but there was a significant increase in median 25(OH)D in the vitamin D3 group (57.5–105 nmol/l) compared with the PL group (52.5–57.5 nmol/l) (p < 0.0001). There was no significant difference between groups regarding subjective asthma control. Compared with PL, there was a significant decrease in school days missed due to asthma (1 vs. 5 days, p = 0.04) and alkaline phosphatase (−3.4 vs. +16; p = 0.037) in the vitamin D3 group, but there were no beneficial effects regarding several other secondary end-points. However, there were non-significant, advantageous changes in the PL group compared with the vitamin D3 group in subjective asthma control and lung function, particularly percentage of predicted forced expiratory volume in 1 s (+2.5 vs. −4; p = 0.06). Conclusion Vitamin D3 supplementation led to a significant increase in serum 25(OH)D and decreased school days missed (p = 0.04), but no other advantageous changes in asthma parameters compared with PL. The potential adverse effect of vitamin D deficiency on growth and the potential negative effect of high serum 25(OH)D on pulmonary function warrant further investigation.

49 citations

Journal ArticleDOI
TL;DR: Vitamin D deficiency and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma.

48 citations

Journal ArticleDOI
01 Feb 2016-Sleep
TL;DR: There is evidence that 25(OH)D and OSAS are related, but the role, if any, of replenishment has not been investigated, and widespread vitamin D deficiency and insufficiency in a Caucasian, OSAS population is observed.
Abstract: STUDY OBJECTIVES To evaluate vitamin D (25(OH)D) levels in obstructive sleep apnea syndrome (OSAS) and possible relationships to OSAS severity, sleepiness, lung function, nocturnal heart rate (HR), and body composition. We also aimed to compare the 25(OH)D status of a subset of OSAS patients compared to controls matched for important determinants of both OSAS and vitamin D deficiency (VDD). METHODS This was a cross-sectional study conducted at an urban, clinical sleep medicine outpatient center. We recruited newly diagnosed, Caucasian adults who had recently undergone nocturnal polysomnography. We compared body mass index (BMI), body composition (bioelectrical impedance analysis), neck circumference, sleepiness (Epworth Sleepiness Scale), lung function, and vitamin D status (serum 25-hydrpoxyvitamin D (25(OH)D) across OSAS severity categories and non-OSAS subjects. Next, using a case-control design, we compared measures of serum 25(OH)D from OSAS cases to non-OSAS controls who were matched for age, gender, skin pigmentation, sleepiness, season, and BMI. RESULTS 106 adults (77 male; median age = 54.5; median BMI = 34.3 kg/m(2)) resident in Dublin, Ireland (latitude 53°N) were recruited and categorized as non-OSAS or mild/moderate/severe OSAS. 98% of OSAS cases had insufficient 25(OH)D (< 75 nmol/L), including 72% with VDD (< 50 nmol/L). 25(OH)D levels decreased with OSAS severity (P = 0.003). 25(OH)D was inversely correlated with BMI, percent body fat, AHI, and nocturnal HR. Subsequent multivariate regression analysis revealed that 25(OH)D was independently associated with both AHI (P = 0.016) and nocturnal HR (P = 0.0419). Our separate case-control study revealed that 25(OH)D was significantly lower in OSAS cases than matched, non-OSAS subjects (P = 0.001). CONCLUSIONS We observed widespread vitamin D deficiency and insufficiency in a Caucasian, OSAS population. There were significant, independent, inverse relationships between 25(OH)D and AHI as well as nocturnal HR, a known cardiovascular risk factor. Further, 25(OH)D was significantly lower in OSAS cases compared to matched, non-OSAS subjects. We provide evidence that 25(OH)D and OSAS are related, but the role, if any, of replenishment has not been investigated.

47 citations


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TL;DR: This study demonstrates an association between VitD deficiency and severity/mortality of COVID-19, highlighting the need for interventional studies on VitD supplementation in SARS-CoV-2 infected individuals.
Abstract: Infection with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) poses an enormous challenge to health care systems throughout the world. Without causal treatment, identification of modifiable prognostic factors may help to improve outcomes. To explore possible associations of vitamin D (VitD) status with disease severity and survival, we studied 185 patients diagnosed with coronavirus disease 2019 (COVID-19) and treated at our center. VitD status at first presentation was assessed retrospectively using accredited laboratory methods. VitD deficiency was defined as serum total 25-hydroxyvitamin D level < 12 ng/mL (<30 nM). Primary endpoint was severe course of disease (i.e., need for invasive mechanical ventilation and/or death, IMV/D). Within a median observation period of 66 days (range 2-92), 23 patients required IMV. A total of 28 patients had IMV/D, including 16 deaths. Ninety-three (50%) patients required hospitalization (inpatient subgroup). A total of 41 (22%) patients were VitD deficient. When adjusted for age, gender, and comorbidities, VitD deficiency was associated with higher risk of IMV/D and death (HR 6.12, 95% CI 2.79-13.42, p < 0.001 and HR 14.73, 95% CI 4.16-52.19, p < 0.001, respectively). Similar correlations were observed in the inpatient subgroup. Our study demonstrates an association between VitD deficiency and severity/mortality of COVID-19, highlighting the need for interventional studies on VitD supplementation in SARS-CoV-2 infected individuals.

286 citations

Journal ArticleDOI
TL;DR: A positive association between vitamin D deficiency and the severity of the disease was observed and was identified that severe cases of COVID-19 present 64% (or 1.64; 95% CI = 1.30–2.09) moreitamin D deficiency compared with mild cases.
Abstract: There is still limited evidence regarding the influence of vitamin D in people with COVID-19. In this systematic review and meta-analysis, we analyze the association between vitamin D deficiency and COVID-19 severity, via an analysis of the prevalence of vitamin D deficiency and insufficiency in people with the disease. Five online databases-Embase, PubMed, Scopus, Web of Science, ScienceDirect and pre-print Medrevix were searched. The inclusion criteria were observational studies measuring serum vitamin D in adult and elderly subjects with COVID-19. The main outcome was the prevalence of vitamin D deficiency in severe cases of COVID-19. We carried out a meta-analysis with random effect measures. We identified 1542 articles and selected 27. Vitamin D deficiency was not associated with a higher chance of infection by COVID-19 (OR = 1.35; 95% CI = 0.80-1.88), but we identified that severe cases of COVID-19 present 64% (OR = 1.64; 95% CI = 1.30-2.09) more vitamin D deficiency compared with mild cases. A vitamin D concentration insufficiency increased hospitalization (OR = 1.81, 95% CI = 1.41-2.21) and mortality from COVID-19 (OR = 1.82, 95% CI = 1.06-2.58). We observed a positive association between vitamin D deficiency and the severity of the disease.

241 citations

Journal ArticleDOI
TL;DR: Vitamin D supplementation was safe, and it protected against ARIs overall, and incorporation of additional IPD from ongoing trials in the field has the potential to increase statistical power for analyses of secondary outcomes.
Abstract: Background Randomised controlled trials (RCTs) exploring the potential of vitamin D to prevent acute respiratory infections have yielded mixed results. Individual participant data (IPD) meta-analysis has the potential to identify factors that may explain this heterogeneity. Objectives To assess the overall effect of vitamin D supplementation on the risk of acute respiratory infections (ARIs) and to identify factors modifying this effect. Data sources MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, ClinicalTrials.gov and the International Standard Randomised Controlled Trials Number (ISRCTN) registry. Study selection Randomised, double-blind, placebo-controlled trials of supplementation with vitamin D3 or vitamin D2 of any duration having incidence of acute respiratory infection as a prespecified efficacy outcome were selected. Study appraisal Study quality was assessed using the Cochrane Collaboration Risk of Bias tool to assess sequence generation, allocation concealment, blinding of participants, personnel and outcome assessors, completeness of outcome data, evidence of selective outcome reporting and other potential threats to validity. Results We identified 25 eligible RCTs (a total of 11,321 participants, aged from 0 to 95 years). IPD were obtained for 10,933 out of 11,321 (96.6%) participants. Vitamin D supplementation reduced the risk of ARI among all participants [adjusted odds ratio (aOR) 0.88, 95% confidence interval (CI) 0.81 to 0.96; heterogeneity p < 0.001]. Subgroup analysis revealed that protective effects were seen in individuals receiving daily or weekly vitamin D without additional bolus doses (aOR 0.81, 95% CI 0.72 to 0.91), but not in those receiving one or more bolus doses (aOR 0.97, 95% CI 0.86 to 1.10; p = 0.05). Among those receiving daily or weekly vitamin D, protective effects of vitamin D were stronger in individuals with a baseline 25-hydroxyvitamin D [25(OH)D] concentration of < 25 nmol/l (aOR 0.30, 95% CI 0.17 to 0.53) than in those with a baseline 25(OH)D concentration of ≥ 25 nmol/l (aOR 0.75, 95% CI 0.60 to 0.95; p = 0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (aOR 0.98, 95% CI 0.80 to 1.20; p = 0.83). The body of evidence contributing to these analyses was assessed as being of high quality. Limitations Our study had limited power to detect the effects of vitamin D supplementation on the risk of upper versus lower respiratory infection, analysed separately. Conclusions Vitamin D supplementation was safe, and it protected against ARIs overall. Very deficient individuals and those not receiving bolus doses experienced the benefit. Incorporation of additional IPD from ongoing trials in the field has the potential to increase statistical power for analyses of secondary outcomes. Study registration This study is registered as PROSPERO CRD42014013953. Funding The National Institute for Health Research Health Technology Assessment programme.

238 citations

Journal ArticleDOI
TL;DR: Vitamin D supplementation reduced the rate of asthma exacerbation requiring treatment with systemic corticosteroids among all participants and there were no significant differences between vitamin D and placebo in the proportion of participants with at least one exacerbation or time to first exacerbation.

224 citations

Journal ArticleDOI
TL;DR: Associations between the timing and cause of early viral infections and the subsequent risk of childhood asthma were assessed in a cohort of children at high risk.
Abstract: Jackson DJ, Gangnon RE, Evans MD, et al. Am J Respir Crit Care Med. 2008;178(7):667–672 PURPOSE OF THE STUDY. Childhood asthma is often preceded by episodes of viral wheezing. Whether specific viral infections confer more risk for future development of asthma is incompletely understood. Associations between the timing and cause of early viral infections and the subsequent risk of childhood asthma were assessed in a cohort of children at high risk. STUDY POPULATION. A total of 259 children were …

192 citations