title: Effects of chronic and acute smoking on AMLRs in older and younger listeners.
abstract: Chronic and acute smoking effects on the auditory middle latency response (AMLR) were studied in older (55-81 years) and younger (19-30 years) normal-hearing listeners. Forty healthy participants were selected for one of four groups: older smokers, older nonsmokers, younger smokers, or younger nonsmokers. Biochemical urine analyses confirmed participant categorization as smoker or nonsmoker. Click-evoked AMLRs were acquired once from nonsmokers and twice (chronic condition, acute condition) from smokers. Waveform latency (V, Na, Pa) and relative amplitude (V-Na, Na-Pa) were examined with two independent variables (age, smoking) using MANOVA. Results (n=40) revealed no chronic effect of smoking in the AMLR from smokers compared to nonsmokers. However, in both older and younger smokers (n=20), Na-Pa amplitude was significantly larger in the acute compared to the chronic smoking condition, indicating an acute smoking effect. There was no interaction of smoking and aging. This is a first study describing long-term, chronic and acute smoking effects on AMLRs in older compared to younger listeners. Results suggest that cigarette smoking is an important variable for AMLR research and clinical practice.
authors.affiliation: University of South Alabama, Mobile, Alabama 36688, USA. ramkissoon@usouthal.edu
authors.forename: Ishara
authors.initials: I
authors.lastname: Ramkissoon
authors.forename: Ron D
authors.initials: RD
authors.lastname: Chambers
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception; D003367:Cotinine / Q000652:urine; D005072:Evoked Potentials, Auditory; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D009538:Nicotine / Q000652:urine; D012907:Smoking / Q000009:adverse effects*; D013997:Time Factors; D055815:Young Adult
chemical_list: D009538:Nicotine; D003367:Cotinine