Air pollution increases the risk of SSNHL: A nested case-control study using meteorological data and national sample cohort data

Abstract

This study aimed to evaluate the impact of weather conditions and air pollution on the onset of sudden sensorineural hearing loss (SSNHL). The Korean Health Insurance Review and Assessment Service - National Sample Cohort (HIRA-NSC) from 2002 through 2013 was used. A total of 5,200 participants with SSNHL were matched 1:4 for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia with 20,800 control participants. Meteorological data included daily mean temperature (°C), daily highest temperature (°C), daily lowest temperature (°C), daily temperature difference (°C), relative humidity (%), ambient atmospheric pressure (hPa), pressure, SO 2 (ppm), NO 2 (ppm), O 3 (ppm), CO (ppm), and PM 10 (μg/m 3 ) of a mean of 60 days, 30 days, 14 days, 7 days, and 3 days before SSNHL were analyzed. Hourly measurements were taken from 94 places to assess the temperature, humidity, and atmospheric pressure and from 273 places to determine SO 2 , NO 2 , O 3 , CO, and PM 10 . Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of meteorological data for SSNHL were analyzed using unconditional logistic regression analyses. Subgroup analyses were conducted by age and sex. The mean NO 2 and O 3 concentrations 14 days before the index date were different in the SSNHL group compared to those in the control group (P < 0.001 for NO 2 and P = 0.021 for O 3 ). The adjusted 14-day OR for NO 2 (0.1 ppm) exposure was 3.12 in the SSNHL group compared to that in the control group (95% CI = 2.16–4.49, P < 0.001). The increased odds of NO 2 exposure for 14 days in the SSNHL group persisted in the age group older than 30 years for both sexes. Other meteorological conditions did not show differences between the SSNHL and control groups. SSNHL was associated with high concentrations of NO 2.

Short and long term exposure to air pollution increases the risk of ischemic heart disease

“…Participant selection. This study was approved by the Ethics Committee of Hallym University (2017-I102) and was exempt from requiring informed consent 20 . All procedures were followed in accordance with the relevant guidelines.…”

“…All procedures were followed in accordance with the relevant guidelines. The Korean National Health Insurance Service-Health Screening Cohort (NHIS-HEALS), meteorological, and air pollution data were used (S1 description) [20][21][22] .…”

“…Participants with ischemic heart disease were selected from 514,866 patients with 497,931,549 medical claim codes (n = 2239) [20][21][22] . Among these participants, individuals were excluded if they were diagnosed with ischemic heart disease before 2004 (n = 80) to track previous exposure to meteorological factors in the last 2 years.…”

“…Among these participants, individuals were excluded if they were diagnosed with ischemic heart disease before 2004 (n = 80) to track previous exposure to meteorological factors in the last 2 years. The control group included those without a history of ischemic heart disease from 2002 through 2013 (n = 512,627) [20][21][22] . The control participants were 1:4 matched for age, sex, income, region of residence, and index date 20 .…”

“…The index date of ischemic heart disease participants was set as the time of diagnosis of ischemic heart disease [20][21][22] . Some ischemic heart disease participants were excluded because there were not enough matched control participants (n = 4).…”