Mechanisms related to neuropathic or microvascular factors, inflammation, or hyperglycemia may be mediating the association of diabetes and hearing impairment, according to an American team of researchers who examined potential mediators of the reported association between diabetes and hearing impairment. "We found no evidence suggesting that our observed relationship between diabetes and hearing impairment is due to hypertension or dyslipidemia", explained the team. Data come from 1508 participants aged 40-69 years who completed audiometric testing during 1999-2004 in the National Health and Nutrition Examination Survey (NHANES). Using logistic regression, reserchers examined whether controlling for vascular or neuropathic conditions, cardiovascular risk factors, glycemia, or inflammation diminished the association between diabetes and hearing impairment. The results were published in Diabetes Care. on 22 of January 2010. They revealed that diabetes was associated with a 100% increased odds of low/mid-frequency hearing impairment and a 67% increased odds of high-frequency hearing impairment in preliminary models after controlling for age, sex, race/ethnicity, education, smoking, and occupational noise exposure. But, adjusting for peripheral neuropathy attenuated the association with low/mid-frequency hearing impairment, and adjusting for albuminuria and C-reactive protein attenuated the association with high-frequency hearing impairment. Diabetes was not associated with high-frequency hearing impairment after controlling for A1c (Hemoglobin A1c test is used as a standard tool to determine blood sugar control for patients with diabetes), but remained associated with low frequency impairment.   Source : Potential Mediators of Diabetes-Related Hearing Impairment In The U.S. Population – NHANES 1999-2004. Kathleen E Bainbridge, Yiling J Cheng, and Catherine C Cowie. Diabetes Care. published 22 January 2010, 10.2337/dc09-1193