Childhood hearing loss; a need for primary health care.

INTRODUCTION: Essential health care for children is the care of the ear. METHODS: A cross-sectional descriptive study of 155 children with hearing loss. RESULTS: A total of 155 pupils with hearing impairment and their parents were interviewed; 77(49.7%) males and 78(50.3%) females, age ranged from 6 to 15years (mean 9.11 ± 2.5 years). None of the participants had neonatal hearing screening. Parents detected the hearing loss at a mean age of 2.3 ± 1.1years. Initial care was given by community health workers and general medical practitioners, only 21 participants had otolaryngological consultation and none had audiological rehabilitation. Barriers to accessing services were financial constraints, poor awareness and non-availability of otolaryngological service for the hearing impaired in the communities. CONCLUSION: Hearing impaired children in Nigeria have poor access to ear care. There is a need to create awareness of otological services and incorporate ear-care into the primary health care.

Evaluation of serum antioxidants in age-related hearing loss.

BACKGROUND: Age-related hearing loss (ARHL) has been linked to the shift in the pro-oxidant/antioxidant ratio. Our objectives were to assess serum levels of retinol and zinc among the elderly individuals and to correlate the levels with hearing threshold. METHODS: Prospective study of apparently healthy individuals aged ≥60 years of age. Participants had complete clinical history, physical examination and pure tone average conducted. Blood samples were collected for determination of serum levels of retinol and zinc. Mann-Whitney U test was used to compare retinol and zinc values. Pearson's correlation test was used to determine the relationship between hearing threshold and serum levels of retinol and zinc. RESULTS: Among 126 elderly participants with mean age 67 ± 2.7 years; the mean pure tone average for air conduction was 29.3 ± 1.6 dBHL while the mean bone conduction was 36.5 ± 1.8 dBHL. The median values of serum retinol and zinc levels in the elderly participants who had hearing loss in the speech frequencies were 52 and 83.3 µg/L, respectively, while among participants with normal hearing threshold, values were 50 and 89.9 µg/L, respectively (p = 0.59 and 0.99, respectively). For the high frequencies, the median value of serum retinol and zinc levels among the elderly participants with normal hearing threshold was 70.3 and 99.9 µg/L, while among those with hearing loss, it was 46.9 and 83.2 µg/L, respectively (p = 0.000 and 0.005, respectively). CONCLUSION: Serum retinol and zinc levels were significantly lower among elderly with hearing loss involving the high frequencies. This is added evidence to extant literature on the possible role of antioxidants in the development of ARHL and suggests further study on the effect of antioxidants supplementation in the control of ARHL which is presently controversial and inconclusive.

Correlation between plasma levels of radical scavengers and hearing threshold among elderly subjects with age-related hearing loss.

CONCLUSION: Low plasma melatonin is significant in the development of high frequency hearing loss (HL) among the elderly. OBJECTIVE: To determine the correlation between hearing threshold and the plasma melatonin and ascorbic acid (vitamin C). METHODS: This was a cross-sectional study involving 126 apparently healthy elderly subjects, 59 males and 67 females, aged >60 years. Subjects underwent pure tone audiometry and plasma melatonin and vitamin C were assayed using high-performance liquid chromatography. RESULTS: The mean ± SD of plasma melatonin among the subjects with normal hearing (NH) (0-30 dB) and those with HL in the speech frequencies was 18.3 ± 3.6 µg/L and 16.4 ± 4.7 µg/L, respectively. In the high frequencies the values were 17.7 ± 6.2 µg/L and 13.1 ± 6.4 µg/L for NH and HL, respectively. For vitamin C, the mean ± SD among subjects with NH and those with HL in the speech frequencies were 1.2 ± 0.2 µg/L and 1.0 ± 0.1 µg/L, respectively. In the high frequencies, the values were 1.0 ± 0.2 µg/L and 0.9 ± 0.3 µg/L for NH and HL, respectively. Among subjects with high frequency HL, Spearman's correlation revealed significant correlation between increasing hearing threshold and melatonin (correlation coefficient = -0.30, p = 0.01), but not for vitamin C (correlation coefficient = -0.12, p = 0.22). Linear regression, adjusting for age, still revealed significant correlation between the melatonin (correlation coefficient = -0.03, p = 0.00) and hearing threshold in the high frequencies.

Correlation between serum immunoglobulin G and hearing threshold among elderly subjects with age-related hearing loss.

BACKGROUND AND PURPOSE: This study was based on the hypothesis that suboptimal immune response and low serum immunoglobulin G (IgG) may predispose to age-related hearing loss (ARHL), and the objective was to determine the serum levels of IgG and hearing thresholds of apparently healthy elderly subjects and assess their correlation. METHOD: This prospective study involved 126 participants ≥ 60 years old who were found to be free of any medical conditions. Pure-tone averages for both the speech (500-2,000 Hz) and high frequencies (3,000-8,000 Hz) and serum IgG levels were determined. Using 30 dB as cut-off for hearing loss, the correlation with serum IgG was assessed. RESULTS: There were 59 males and 67 females with a mean age ± SD of 67.0 ± 2.7 years. Speech frequency hearing loss was seen in 30.2%, while high-frequency hearing loss accounted for 74.6%. In the speech frequencies, the mean ± SD of serum IgG among subjects with normal hearing was 11.3 ± 3.9 g/l, while among those with hearing loss it was 8.3 ± 3.3 g/l (p = 0.01). In the high frequencies, the mean ± SD values of serum IgG among the subjects with normal hearing was 11.1 ± 2.3 g/l, while among those with hearing loss it was 8.7 ± 1.9 g/l (p = 0.01). CONCLUSION: Low serum IgG may be a contributory factor to the development of ARHL among the elderly. However, a longitudinal study involving intervention with immunoglobulin supplementation may further confirm this role.

Age-related hearing loss, vitamin B12, and folate in the elderly.

OBJECTIVE: Determine the correlation between the hearing threshold and the serum levels of vitamin B12 (cobalamin) and folic acid among elderly subjects (> 60 years) with age-related hearing loss (ARHL). STUDY DESIGN: Cross-sectional. SETTING: Community. SUBJECTS AND METHODS: Subjects included elderly who were found apparently healthy following repeated examination by physicians. The pure tone average (PTA) for the speech and high frequencies, and the serum folate and cobalamin were determined and the correlation found. RESULTS: The mean ± SD values of serum folate among the subjects with normal PTA in the speech frequencies (0-30 dB) was 412.3 nmol/L ± 17.6 nmol/L, while among those with hearing loss (HL), it was 279.1 nmol/L ± 17.2 nmol/L (P = 0.01). In the high frequencies, the mean ± SD values among the subjects with normal PTA was 426.3 nmol/L ± 17.6 nmol/L, while among those with HL, it was 279.14 nmol/L ± 171.2 nmol/L. The serum cobalamin among the subjects with normal PTA within the speech frequencies was 49.7 pmol/L ± 9.4 pmol/L, while among those with speech-frequency HL, it was 42.6 pmol/L ± 10.2 pmol/L. However, for high frequencies, the mean ± SD values among the subjects with normal PTA was 47.4 pmol/L ± 7.3 pmol/L, while among those with HL, it was 41.3 pmol/L ± 9.2 pmol/L. Spearman's correlation revealed that low folate (correlation coefficient = -0.27, P = 0.01) and cyanocobalamin (correlation coefficient = -0.35, P = 0.02) were significantly associated with increasing hearing threshold in the high frequencies. After adjusting for age, serum folate (correlation coefficient = -0.01, P = 0.01) was significant, while vitamin B12 (correlation coefficient = -0.01, P = 0.74) was not. CONCLUSION: Serum folate was significantly lower among elderly with ARHL. Trials on nutritional supplementation may substantiate the role of serum folate in ARHL.

Socio-economic status and hearing loss in chronic suppurative otitis media in Nigeria.

BACKGROUND: Hearing loss is reported in about 50% of cases of chronic suppurative otitis media (CSOM). AIM: To report the prevalence, type and severity of hearing loss in CSOM and identify risk factors. METHODS: A prospective study of hearing loss in CSOM was undertaken in University College Hospital, Ibadan, two general hospitals and two primary health care centres, all in densely populated, semi-urban areas in south-west Nigeria. Controls were selected from school children, hospital workers' children and children whose parents were visiting the hospitals, all of whom claimed that there had been no episode of otitis media in the past. An oral questionnaire was administered to all, followed by audiometry and examination of the ear, nose and throat in study children. RESULTS: There were 189 CSOM subjects and 100 controls aged between 4 and 150 months [mean (SD) 59.25 (44.55), 173 girls and 116 boys, M:F 1.5:1]. The prevalence of hearing loss in CSOM was 89/189 (47%) and was conductive in 73/89 (82%) and sensorineural (SHL) in 16/89 (18%). Of the subjects with hearing loss, 72% had had otitis media during the 1st year of life. Of the 89, 61 (69%) were of low social class, 13/37 (35%) were middle class and 15/63 (24%) upper class. The duration of CSOM ranged from 4 weeks to 12 years [mean (SD) 4 yrs (2.04)] and from 5 to 12 years in those with SHL [mean (SD) 9 yrs (6.21)]. There was significant correlation between socio-economic status and hearing loss (r=0.138, p=0.02) while no correlation was found with upper respiratory infection (r=0.054, p=0.36), age of onset (r=0.037, p=0.62) or frequency of attacks (r=-0.068, p=0.35). CONCLUSION: About one fifth of patients with CSOM have SHL. Early diagnosis and management of CSOM is imperative to improve outcome. CSOM is strongly associated with low socio-economic status.