Air pollution by NO2 is associated with the risk of Bell’s palsy: A nested case-controlled study

Abstract

this study investigated the relationship of weather and air pollution with the onset of Bell's palsy. the Korean Health insurance Review and Assessment Service-national Sample cohort (HiRA-nSc) data from 2002 through 2013 were used. The 3,935 Bell's palsy patients were matched with 15,740 control participants. the meteorological data, including daily mean temperature (°c), daily mean highest temperature (°C), daily mean lowest temperature (°C), daily mean temperature difference (°C), relative humidity (%), spot atmospheric pressure (hpa), sulfur dioxide (So 2) (ppm), nitrogen dioxide (no 2) (ppm), ozone (o 3) (ppm), carbon monoxide (co) (ppm), and pM 10 (particulate matter ≤ 10 μg/m 3) for 60 days, 30 days, 14 days, 7 days, and 3 days prior to the index date were analyzed for Bell's palsy cases and controls. conditional logistic regression analysis was used to estimate the odds ratios (oRs) of the association between the meteorological data and Bell's palsy. the mean no 2 and pM 10 concentrations for 60 days were higher, while that of O 3 was lower in the Bell's palsy group than in the control group (both p < 0.001). The Bell's palsy group showed 16.63-fold higher odds of NO 2 for 60 days (0.1 ppm) than the control group (95% CI = 10.18-27.16, P < 0.001). The ORs of PM 10 , and o 3 for 60 days showed inconsistent results according to the included variables. Bell's palsy was related to high concentrations of no 2 .

Epidemiological trends of Bell's palsy treated with steroids in Korea between 2008 and 2018

“…Because we relied on information extracted from a nationwide database, we included only those patients with the diagnostic code and concurrent treatment with steroids to ascertain the diagnosis of Bell's palsy and to include only definite cases. The case definition of the present study is supported by the similar pediatric incidence in a previous study that included only definite cases of Bell's palsy, 6 the comparable incidence in earlier studies that included patients with Bell's palsy regardless of steroid use, 1‐5,9,13‐16 and the studies that used the same case definition combining diagnostic codes and steroid use in Korea 36,37 . This strict definition of Bell's palsy has limitations and strengths in terms of accurate diagnosis.…”

“…The case definition of the present study is supported by the similar pediatric incidence in a previous study that included only definite cases of Bell's palsy, 6 the comparable incidence in earlier studies that included patients with Bell's palsy regardless of steroid use, [1][2][3][4][5]9,[13][14][15][16] and the studies that used the same case definition combining diagnostic codes and steroid use in Korea. 36,37 This strict definition of Bell's palsy has limitations and strengths in terms of accurate diagnosis. The exclusion of patients No.…”

Relationship between Bell’s Palsy and Previous Statin Use: A Case/Non-Case Study

“…Bell’s palsy was classified based on its ICD-10 code (G510). Patients with Bell’s palsy with a history of two or more treatment events and those who were prescribed steroids were selected, according to our previous studies [ 26 , 27 ].…”

“…Income groups were classified into five levels. The regions of residence were divided into urban and rural areas [ 26 , 27 ].…”

“…Data on tobacco smoking, alcohol consumption, and body mass index (kg/m 2 ) groups were collected, as previously described ( Supplementary S1 description) [ 26 , 27 ]. Charlson comorbidity index (CCI) was included in the analysis [ 28 , 29 ].…”