Metabolic syndrome is associated with hearing loss among a middle-aged and older Chinese population: a cross-sectional study

Background: Although the association of metabolic syndrome (MetS) and hearing loss has been evaluated, findings are controversial. This study investigated this association in a Chinese population.Methods: A cross-sectional study including a total of 18,824 middle-aged and older participants from the Dongfeng-Tongji Cohort study was conducted. Hearing loss was defined as the pure-tone average (PTA) of frequencies 0.5, 1.0, 2.0, and 4.0kHz>25 decibels hearing level (dB HL) in the better ear and graded as mild (PTA 26-40dB HL), moderate (PTA>40 to60dB HL), and severe (PTA>60dB HL). MetS was defined according to the International Diabetes Foundation (IDF) criteria of 2005. Association analysis was performed by logistic regression.Results: After adjustment for potential confounders, participants with MetS showed higher OR of hearing loss (OR, 1.11; 95% CI: 1.03-1.19). The MetS components including central obesity (OR, 1.07; 95% CI: 1.01-1.15) and hyperglycemia (OR, 1.12; 95% CI: 1.04-1.20) were also positively associated with hearing loss. Low HDL-C levels were also associated with higher OR of moderate/severe hearing loss (OR, 1.21; 95% CI: 1.07-1.36).Conclusions: The MetS, including its components central obesity, hyperglycemia, and low HDL-C levels were positively associated with hearing loss.