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Kenneth Bolger

Bio: Kenneth Bolger is an academic researcher from Connolly Hospital Blanchardstown. The author has contributed to research in topics: Crossover study & Vitamin D and neurology. The author has an hindex of 3, co-authored 6 publications receiving 521 citations.

Papers
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Journal ArticleDOI
TL;DR: It is suggested that obesity-associated asthma is facilitated by inflammation mediated by NLRP3, IL-1β and ILC3 cells, which is found in the bronchoalveolar lavage fluid of individuals with asthma.
Abstract: The mechanisms underlying the association between obesity and the development of asthma remain incompletely understood. Dale T. Umetsu and his colleagues report that the number of IL-17A+ type 3 innate lymphoid cells (ILCs) is increased in the lungs of mice fed a high-fat diet. Activation of the NLRP3 inflammasome in lung macrophages promotes IL-1β production and ILC development, and blockade of IL-1 signaling inhibits airway hyperreactivity in obese mice. As these ILCs are also found in the lungs of individuals with asthma, these results suggest that this pathway may be targeted in asthma.

507 citations

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
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

Journal Article
TL;DR: Acute consumption of dietary nitrate can improve exercise tolerance and lower blood pressure in COPD patients.
Abstract: Introduction: Nitric oxide (NO) is an important systemic and pulmonary arterial vasodilator. The conversion of nitrite (derived from dietary nitrate) to nitric oxide can occur independent of nitric oxide synthase in a process that is upregulated in hypoxic conditions. Since COPD patients commonly suffer hypoxaemia during exercise, we hypothesized that dietary nitrate supplementation might acutely improve exercise capacity in hypoxic COPD patients through enhanced production of nitric oxide. Aims & objectives: We wanted to compare the effect of a single drink of beetroot juice (containing 14 mmol of nitrate) on exercise capacity (incremental shuttle walk test) and arterial blood pressure (BP) in COPD patients compared to a matched placebo drink (containing less than 0.5mmol of dietary nitrate). Methods: Twelve subjects (6 male) with COPD were recruited. Plasma nitrate and BP were assessed. Oximetry and self-reported dysnoea (Borg scale) were assessed pre- and post-incremental shuttle walk test (ISWT). Subjects were then randomized to drink beetroot juice or a matched placebo and the protocol was repeated 3 hours later. After a 7-day washout period, the protocol was repeated with the crossover beverage. Results: COPD subjects who took dietary nitrate walked significantly further than when they took placebo (+23 ± 9 vs. -13 ± 5 metres; p < 0.01) and had a reduction in systolic BP (-13 ± 5 vs. 0 ± 1 mmHg; p < 0.05) Conclusion: Acute consumption of dietary nitrate can improve exercise tolerance and lower blood pressure in COPD patients.

3 citations

Journal ArticleDOI
01 Jan 2013
TL;DR: There were no significant differences in heart rate, arterial oxygen concentrations, or breathlessness at any time point, however, COPD subjects who took dietary nitrate walked significantly further than when they took placebo and had a reduction in both systolic and diastolic blood pressure.
Abstract: Nitric oxide (NO) is an important systemic and pulmonary arterial vasodilator. The conversion of nitrite (derived from dietary nitrate) to nitric oxide can occur independent of nitric oxide synthase (Lundberg & Govoni 2004) in a process that is upregulated in hypoxic conditions (Lundberg et al., 2008). Since patients with chronic obstructive pulmonary disease (COPD) commonly suffer hypoxaemia during exercise, we hypothesized that dietary nitrate supplementation might acutely improve exercise capacity in hypoxic COPD patients through enhanced production of NO. We compared the acute effect of beetroot juice (containing14 mmol of nitrate) on exercise capacity and arterial systolic blood pressure in COPD patients compared to a matched placebo drink (containing less than 0.5 mmol of dietary nitrate). Twelve subjects (6 male) with COPD were recruited. Resting blood pressure was assessed in duplicate (manual sphygmomanometer). Heart rate and arterial oxygen concentration (pulse oximetry) as well as self-reported breathlessness (Borg dyspnea scale) were assessed preand post-incremental shuttle walk test. Subjects were then randomized to drink beetroot juice or a matched placebo and the protocol was repeated 3 hours later. The 3h rest period was to allow for sufficient recovery from baseline testing and has been found to correspond with peak plasma nitrite concentrations following oral consumption of dietary nitrate (Webb et al., 2008). After a 7-day washout period, the protocol was repeated with the crossover beverage. There were no significant differences in heart rate, arterial oxygen concentrations, or breathlessness at any time point. However, COPD subjects who took dietary nitrate walked significantly further than when they took placebo ( + 23 vs. 13 metres; p<0.01) and had a reduction in both systolic blood pressure ( 13 vs. 0 mmHg; p<0.05) and diastolic blood pressure ( 3.2 vs. + 7.8 mmHg; p<0.05). Acute consumption of dietary nitrate can improve exercise tolerance and lower blood pressure in COPD patients.

1 citations


Cited by
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Journal ArticleDOI
22 May 2014-Cell
TL;DR: This Review summarizes recent insights into inflammasome biology and discusses the questions that remain in the field.

1,820 citations

Journal ArticleDOI
TL;DR: This Review highlights experimental evidence from mouse models and patient-based studies that have elucidated the effects of ILCs on the maintenance of tissue homeostasis and the consequences for health and disease.
Abstract: Research over the last 7 years has led to the formal identification of innate lymphoid cells (ILCs), increased the understanding of their tissue distribution and has established essential functions of ILCs in diverse physiological processes. These include resistance to pathogens, the regulation of autoimmune inflammation, tissue remodeling, cancer and metabolic homeostasis. Notably, many ILC functions appear to be regulated by mechanisms distinct from those of other innate and adaptive immune cells. In this Review, we focus on how group 2 ILC (ILC2) and group 3 ILC (ILC3) responses are regulated and how these cells interact with other immune and non-immune cells to mediate their functions. We highlight experimental evidence from mouse models and patient-based studies that have elucidated the effects of ILCs on the maintenance of tissue homeostasis and the consequences for health and disease.

729 citations

Journal ArticleDOI
22 May 2015-Science
TL;DR: The power of ILCs may be controlled or unleashed to regulate or enhance immune responses in disease prevention and therapy and in immunopathology, where they play an intriguing role beyond immunity.
Abstract: Innate lymphoid cells (ILCs) are a growing family of immune cells that mirror the phenotypes and functions of T cells. However, in contrast to T cells, ILCs do not express acquired antigen receptors or undergo clonal selection and expansion when stimulated. Instead, ILCs react promptly to signals from infected or injured tissues and produce an array of secreted proteins termed cytokines that direct the developing immune response into one that is adapted to the original insult. The complex cross-talk between microenvironment, ILCs, and adaptive immunity remains to be fully deciphered. Only by understanding these complex regulatory networks can the power of ILCs be controlled or unleashed in order to regulate or enhance immune responses in disease prevention and therapy.

663 citations

Journal ArticleDOI
TL;DR: This work examines the epidemiology and characteristics of obese asthma in children and adults, as well as the changes in lung function seen in each age group, and discusses the better recognized factors and mechanisms involved in disease pathogenesis.
Abstract: Obesity is a vast public health problem and both a major risk factor and disease modifier for asthma in children and adults. Obese subjects have increased asthma risk, and obese asthmatic patients have more symptoms, more frequent and severe exacerbations, reduced response to several asthma medications, and decreased quality of life. Obese asthma is a complex syndrome, including different phenotypes of disease that are just beginning to be understood. We examine the epidemiology and characteristics of this syndrome in children and adults, as well as the changes in lung function seen in each age group. We then discuss the better recognized factors and mechanisms involved in disease pathogenesis, focusing particularly on diet and nutrients, the microbiome, inflammatory and metabolic dysregulation, and the genetics/genomics of obese asthma. Finally, we describe current evidence on the effect of weight loss and mention some important future directions for research in the field.

455 citations

Journal ArticleDOI
TL;DR: How current or novel therapeutic strategies could be used to selectively modulate ILC responses and limit chronic inflammatory diseases is discussed.
Abstract: A previously unappreciated cell type of the innate immune system, termed innate lymphoid cells (ILCs), has been characterized in mice and humans and found to influence the induction, regulation and resolution of inflammation. ILCs have an important role in these processes in mouse models of infection, inflammation and tissue repair. Further, disease-association studies in defined patient populations have identified significant alterations in ILC responses, suggesting a potential role for these cell populations in human health and disease. In this review we discuss the emerging family of ILCs, the role of ILCs in inflammation, and how current or novel therapeutic strategies could be used to selectively modulate ILC responses and limit chronic inflammatory diseases.

428 citations