Metabolic syndrome is not an independent risk factor for hearing impairment

Objective: We aimed to investigate the association between metabolic syndrome (MS) and hearing impairment (HI) using nationally representative data from Korean adults. Design, setting and participants: A total of 16,799 subjects (≥19 years old; 7,170 men and 9,629 women) who underwent pure tone audiometry testing were included in the analysis. Data were obtained from the fifth Korea National Health and Nutrition Examination Survey (2010–2012). Subjects were divided into two groups according to the presence of MS. Results: Among the subjects with MS, 47% had HI. Logistic regression analysis revealed that MS was not an independent risk factor for HI, although increased fasting plasma glucose (OR 1·4, 95% CI: 1·1–1·8) was independently associated with HI. In addition, older age, male sex, very low body mass index (≤17·5 kg/m2), lower education level, smoking history, and occupational noise exposure were independently associated with HI. For low-frequency HI, independent risk factors included older age, lower educational level, lower economic status, and very low BMI (≤17·5 kg/m2). For high-frequency HI, independent risk factors included older age, male sex, lower educational level, lower economic status, increased blood pressure, lower high-density lipoprotein cholesterol, and smoking history. Conclusions: MS itself was not an independent risk factor for HI, and, among the individual metabolic components, only increased fasting plasma glucose was independently associated with HI.