2012年5月30日 星期三

維他命D缺乏孩童常因中耳炎而鼓膜破洞

Vitamin D Deficiency Linked With Eardrum Perforation Risk

Nancy A. Melville



May 29, 2012 (Thessaloniki, Greece) — Although vitamin D deficiencies in children show no strong link to a greater risk for recurrent acute otitis media (RAOM), the deficiency does show a significant association with repeated tympanic membrane perforation (RTMP) related to otitis media, according to research presented here at the European Society for Paediatric Infectious Diseases (ESPID) 30th Annual Meeting.


Vitamin D has been shown in previous studies to have immunomodulatory effects, and vitamin D deficiency can increase the risk for respiratory infections.


To further explore the role of vitamin D deficiency in RAOM, a research team led by Susanna Esposito, MD, from the Department of Maternal and Pediatric Sciences at the University degli di Milano, Italy, evaluated 128 children with a documented history of RAOM.


The children (mean age of 35.7 ± 19.8 months) had blood samples with levels of 25-hydroxyvitamin D (1,25[OH]2D3) drawn 28 to 30 days after their last episode of the ear infection.


Researchers factored in the number of older siblings, pacifier use, day care attendance, and exposure to passive smoking.


The results showed vitamin D levels less than 20 ng/mL for 39 (30.5%) of the 128 patients. Levels were 20 to 30 ng/mL in 34 (26.6%) children and greater than 30 ng/mL in 55 (42.9%) children.


The association between RAOM and vitamin D level was not significant in the unadjusted or in the multivariate model; however, a separate analysis of children with RTMP showed the condition to be significantly inversely associated with level of vitamin D in the multivariate model (β = -0.002; P = .03).


The risk for RTMP was associated with a vitamin D level less than 30 ng/mL.


"Vitamin D deficiency seems to be an independent and additive risk factor for the development of RAOM with RMTP," the authors concluded. "These data suggest that in children with RAOM and RTMP, vitamin D level has to be determined and vitamin D supplementation could be considered."


Dr. Esposito said her team was motivated to evaluate the role of vitamin D in a variety of potential mechanisms that could play a role in otitis media–related eardrum perforation.


"Vitamin D rules macrophages' and dendritic cells' activities," she told Medscape Medical News. "Indeed, 1,25(OH)2D3 stops the lipopolysaccharide capacity to induce IL-1b expression, as many antimicrobial genes do."


"Vitamin D also induces expression of catelecidin and ?-defensin, which are antimicrobial peptides widely expressed in the organism, that play a key role in the innate immunity, through their chemotactic action and toxin neutralization," she explained.


"Finally, vitamin D [induces] adaptative shifts in the expression of cytokine from Th1 toward a Th2 profile. So, for this reason, we decided to evaluate whether children with recurrent AOM had lower values than healthy children."


"We demonstrated that this was true, especially in those with perforation who have the most severe episodes, so the next step is to evaluate whether supplementation with vitamin D in these children reduces episodes of perforation."


According to Petri Koponen, MD, a research with the Paediatric Research Centre at Tampere University Hospital, Finland, the findings offer an intriguing look at the role of vitamin D in otitis media.


"I do think there is some [other] evidence of immunoregulatory effects of vitamin D, so I think this was a very interesting study," said Dr. Koponen, who also presented at the meeting.


Dr. Esposito and Dr. Koponen have disclosed no relevant financial relationships.


European Society for Paediatric Infectious Diseases (ESPID) 30th Annual Meeting. Abstract #469. Presented May 22, 2012.



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