Noise Exposure, Diabetes Mellitus and Hypertension as Predictors of Hearing Loss among Elderly Patients in Selected Teaching Hospitals in South - West, Nigeria

Abstract

Hearing loss due to advancement in age is a phenomenon which is universally accepted as one of the challenges of old age. In spite of this fact, there is a paucity of studies on predictors and patterns of hearing loss which should serve as essential basis for developing preventive measures and strategies to reduce or eliminate the causes of hearing loss among the elderly. This study, therefore, investigated noise exposure, diabetes mellitus and hypertension as predictors of hearing loss among the elderly patients in six teaching hospitals in South-West, Nigeria. The study utilized a descriptive survey design of the expost-facto type. Purposive sampling technique was used in selecting the health institutions and 469 elderly patients with hearing loss aged 65years and above were used as participants of the study. Data were collected through audiometers, audiograms, sound pressure level meter and case notes. Three research questions were answered and four hypotheses tested at the 0.05 level of significance. Data collected were analysed using descriptive statistics and multiple regression analysis. The patients possessed bilateral (92.5%), sensorineural (right ear: 65.7%; left ear: 64%), moderately-severe (right ear: 25.4%; left ear: 25.4%) and sloping (right ear: 57.1%; left ear: 54.6%) pattern of hearing loss. Noise exposure, diabetes mellitus and hypertension correlated positively with right ear hearing loss (R = 0.56; F(3, 465) = 72.05) and explained 32% of the variance in the dependent variable. The three factors also correlated positvely with left ear hearing loss (R = 0.50; F(3, 465) = 51.71) explaining 25% of the variance in the dependent variable. The contributions of the independent variables to right ear hearing loss are in the following order: noise exposure (β=0.41), diabetes mellitus (β= 0.23) and hypertension (β=0.11). For left ear hearing loss, the order is: noise exposure (β=0.36), diabetes mellitus (β= 0.27) and hypertension (β=0.02). Furthermore, noise exposure (B=18.11; t=10.33; p<0.05), diabetes mellitus (B=11.40; t=5.52; p<0.05) and hypertension (B=4.71; t=2.65; p<0.05) could predict right ear hearing loss. On the other hand, only two of the factors: noise exposure (B=15.28; t=8.56; p<0.05) and diabetes mellitus (B=13.07; t=6.21; p<0.05) could predict left ear hearing loss. History of noise exposure, diabetes mellitus and hypertension predispose elderly people to loss of hearing. Therefore, noise should be abated at the source through sound barriers, sound diffusers and sound enclosures. Personal ear protectors such as earmuffs and earplugs should be worn by people in noisy environments. In addition, lifestyle modification and routine medical checkup are advocated for the elderly patients with diabetes mellitus and hypertension.