Association between Cesarean section delivery and increased risk of childhood Kawasaki disease.

AIM: Cesarean section delivery is associated with microbiota disruption and immuno-dysregulation during childhood, but the association with Kawasaki disease remains uncertain. We aimed to evaluate the association between Cesarean section and Kawasaki disease. METHODS: We examined the association between Kawasaki disease between six and eighteen months and Cesarean section within a birth cohort of 15,796 mother-infant pairs in Taiwan. The associations were assessed with Poisson regression in the study population, in the 1:2 propensity score-matched subpopulation, and compared with febrile convulsion, trauma and accidents during the same interval as negative control outcomes. RESULTS: Cesarean section was found to increase the risk of Kawasaki disease among overall population (adjusted relative risk [aRR]: 2.22, 95 % confidence interval (CI): 1.14-4.34) and the matched subpopulation (aRR: 2.29, 95 % CI: 1.14-4.68 in PS-matched subpopulation). Meanwhile, there was no association between Cesarean section and the clinic visits for febrile convulsion, trauma and accidents. CONCLUSION: In conclusion, this study identified a potential association between Cesarean section delivery and a higher risk of Kawasaki disease during six-to eighteen months of the prospective birth cohort in Taiwan.

Associations Between Infant Developmental Delays and Secondhand Smoke Exposure Modified by Maternal Prepregnancy Overweight and Obesity Status.

INTRODUCTION: Secondhand smoke exposure during pregnancy has long been associated with adverse health outcomes in children, but only a few studies have examined its effect modifiers. In this study, we applied effect modification analysis for maternal prepregnancy weight status on detrimental neurodevelopmental effect of secondhand smoke exposure during pregnancy and infancy in a nationwide representative population. AIMS AND METHODS: Term singleton mother-infant pairs with nonsmoking mothers were included for main analysis (N = 15 987) from the Taiwan Birth Cohort Study (TBCS), and were further matched with propensity score (n = 5434). We extracted secondhand smoke exposure during pregnancy and infancy, and eight neurodevelopmental milestones from the responses in the baseline visit at 6 months, and 18-month follow-up of TBCS. The associations between secondhand smoke exposure and neurodevelopmental achievement were analyzed with multivariable logistic regression and Cox model. Propensity score weighting and matching were applied for high-versus-low analysis, and relative excess risk due to interaction were used to estimate effect modification. RESULTS: Higher secondhand smoke exposure was associated with increased likelihood of delayed milestone achievement across gross motor, fine motor, language-related, and social-related domains. The associations in fine motor domains remained observable in propensity score-weighted and -matched models. We identified additive interaction with self-reported maternal overweight and obesity status before pregnancy in milestone development for walking with support, scribbling, and waving goodbye. CONCLUSIONS: Secondhand smoke exposure during pregnancy and infancy were associated with delayed neurodevelopmental milestone achievement at 18 months, and the associations were modified by maternal prepregnancy overweight and obesity status. IMPLICATIONS: The study results suggested the association between maternal secondhand smoke exposure during pregnancy and infancy and delayed fine motor and language-related milestone achievement at 18 months in multivariable, propensity score weighting, and matching populations. The results of positive effect modifications for maternal prepregnancy overweight and obesity status suggested the importance of concurrent interventions on smoke-free environment and maternal health during pregnancy.

Association between maternal shift work and infant neurodevelopmental outcomes: results from the Taiwan Birth Cohort Study with propensity-score-matching analysis.

BACKGROUND: Maternal shift work is associated with preterm delivery, small-for-gestational-age new-borns, childhood obesity and future behavioural problems. However, the adverse effects on and interactions of maternal shift work with infant neurodevelopment remain uncertain. Therefore, we examined the associations between maternal-shift-work status and infant neurodevelopmental parameters. METHODS: The Taiwan Birth Cohort Study is a nationwide birth cohort study following representatively sampled mother-infant pairs in 2005. The participants' development and exposure conditions were assessed by home interviews with structured questionnaires at 6 and 18 months of age. Propensity scores were calculated with predefined covariates for 1:1 matching. Multivariate conditional logistic regression and the Cox proportional-hazards model were used to examine the association between maternal-shift-work status and infant neurodevelopmental-milestone-achievement status. RESULTS: In this study, 5637 term singletons were included, with 2098 cases selected in the propensity-score-matched subpopulation. Persistent maternal shift work was associated with increased risks of delays in gross-motor neurodevelopmental milestones [aOR = 1.36, 95% confidence interval (CI) = 1.06-1.76 for walking steadily], fine-motor neurodevelopmental milestones (aOR = 1.39, 95% CI = 1.07-1.80 for scribbling) and social neurodevelopmental milestones (aOR = 1.35, 95% CI = 1.03-1.76 for coming when called upon). Moreover, delayed gross-motor and social development were identified in the propensity-score-matched sub-cohort. CONCLUSIONS: This study shows negative associations between maternal shift work and delayed neurodevelopmental-milestone achievement in the gross-motor, fine-motor and social domains at 18 months. Future research is necessary to elucidate the possible underlying mechanisms and long-term health effects.

Will daytime occupational noise exposures induce nighttime sleep disturbance?

BACKGROUND: Nighttime environmental noise affects sleep quality. However, the effects of daytime occupational noise remain unclear. METHODS: A quasi-experiment of 48 participants who had been employed for at least six months in two hospital cafeterias. The participants were randomly designated to be assessed on high- and low-noise workdays for 8 h or low- and high-noise workdays, separated by a washout period of 14 days. Subsequently, pure tone audiometry, autonomic nervous system (ANS) function tests, serum cortisol tests, and polysomnography were conducted. RESULTS: For the 40 participants in the study, the 8-h time-weighted average of personal noise exposed on high- and low-noise workdays was 76.8 dBA (standard deviation, SD: 6.2) and 61.0 dBA (SD: 7.1), respectively. Participants with higher personal noise exposure during the day were found to have a lower percentage of slow wave sleep (percent change of mean value: -1.287%; 95% CI: -2.602%, -0.037%) and lower sleep efficiency (-0.267%; 95% CI: -0.525%, -0.008%). In addition, after work, personal noise exposure was revealed to be related to increased serum cortisol levels (1.698%; 95% CI: 0.887%, 2.528%), and sympathetic activity as measured by low frequency/high frequency (3.000%; 95% CI: 1.294%, 4.706%) and blood pressures by cold pressor test (systolic: 5.163%; 95% CI: 2.780%, 7.537%) (diastolic: 3.109%; 95% CI: 1.604%, 4.614%). CONCLUSIONS: Daytime occupational noise exposure had sustained effects on nighttime sleep quality, specifically on slow wave sleep and sleep efficiency. These disturbances could be partially explained by post-shift elevated cortisol and ANS activity. The psychosocial and metabolic consequences of poorer sleep quality induced by occupational noise exposure warrant further investigation.

2-Naphthol Levels and Allergic Disorders in Children.

BACKGROUND: The measurement of polycyclic aromatic hydrocarbons (PAH) in ambient air is quite difficult to perform. Using urine biomarkers of PAH such as 2-naphthol is one approach to this problem. This study explored the association between urine 2-naphthol levels and allergic diseases. The associations between 2-naphthol levels and oxidative stress biomarkers for the possible disease pathogenesis were also investigated. METHOD: A total of 453 kindergarten children from the (Childhood Environment and Allergic Diseases Study) CEAS cohort with urine samples were recruited. Urine 2-naphthol levels were measured by high-performance liquid chromatography mass spectrometry (HPLC-MS/MS) and markers of oxidative stress (8OHdG) were measured by enzyme-linked immunosorbent assays (ELISA). Information on environmental risk factors and allergic diseases were also collected. The association between 2-naphthol levels, 8OHdG levels, IgE, and allergic diseases were evaluated by multivariate linear regression and logistic regression. RESULTS: Levels of 2-naphthol were positively correlated with 8OHdG levels. A one ln-unit increase in the 2-naphthol level was positively associated to 8OHdG levels (per ln-unit: ß = 100.61, p < 0.001). When dividing 2-naphthol levels into quartiles, asthma was significantly associated with 2-naphthol levels at a concentration of >1.60 ng/mL (adjusted OR: 3.14, 95% CI 1.34⁻7.35). CONCLUSION: Urine 2-naphthol levels are associated with markers of oxidative stress and the risk of allergic diseases in young children.

Household incense burning and infant gross motor development: Results from the Taiwan Birth Cohort Study.

BACKGROUND: Air pollution from biomass burning were associated with neurodevelopmental deceleration, but limited studies concerned about the effect of indoor biomass burning. Incense burning is a common household ritual practice in Taiwan, while past studies mainly focused on birth weight and allergic disease. OBJECTIVES: We aimed to find the association between incense burning exposure and children's neurodevelopment. METHODS: In Taiwan Birth Cohort Study (TBCS), a nationwide representative birth cohort study, children were assessed upon home interview with structured questionnaires upon six and eighteen months old. Multivariate logistic and Cox proportional hazard regression adjusting confounding factors were applied to explore the odds ratio (OR) and hazard ratio (HR) between household incense burning exposure and caregiver-reported neurodevelopment milestones. RESULTS: In this study, 15,310 term singletons were included, and household incense burning was associated with delay in gross motor neurodevelopment milestone, such as walking with support (Occasional incense burning: OR = 1.26, 95% confidence interval (CI): 1.08 to 1.47, HR = 1.07, 95% CI: 1.03 to 1.11; persistent incense burning: OR = 1.44, 95% CI: 1.22 to 1.69, HR = 1.11, 95% CI: 1.07 to 1.16) and walking steadily (Occasional incense burning: OR = 1.14, 95% CI: 0.98 to 1.32, HR = 1.07, 95% CI: 1.03 to 1.11, persistent incense burning: OR = 1.24, 95% CI: 1.06 to 1.45, HR = 1.09, 95% CI: 1.04 to 1.13). CONCLUSIONS: Our study suggested household incense burning exposure was associated with delay in gross motor neurodevelopmental milestones. Further research is warranted to elucidate the possible mechanism and causal relationship.

Polychlorinated biphenyls and dibenzofurans increased abnormal sperm morphology without alterations in aneuploidy: The Yucheng study.

In 1979, more than 2000 persons ingested rice oil contaminated with polychlorinated biphenyls and polychlorinated dibenzofurans; this event was called the "Yucheng accident." An increased percentage of oligospermia, reduced ability of sperm to penetrate oocytes, and reduced percentage of male offspring were reported in Yucheng men. This study examined whether the sperm sex ratio and chromosome aneuploidy are responsible for our observed findings in Yucheng men. In 1999-2000, Yucheng men and their neighborhood referents aged 37-50 years were recruited for physical examination, followed by semen analysis. The semen samples were analyzed for chromosomal aneuploidy through fluorescent in situ hybridization according to an established procedure in our laboratory. A total of 50 Yucheng men and 34 neighborhood referents volunteered to participate in the study. Although abnormal morphology was mildly increased, no differences were observed in sperm percentages, with normal numbers of chromosomes X, Y, and 8 in the two groups. The percentage of sperm with aneuploidy of the sex chromosomes or chromosome 8 and of that with diploidy did not vary between both groups. The normal X/Y sperm ratio was not different between the groups. However, among Yucheng men, 8% had a normal X/Y sperm ratio of >1.4, and no neighborhood referent showed such an elevated X/Y ratio. Chromosomal aneuploidy was not elevated in Yucheng men. The mechanisms underlying the reduced sperm capability of oocyte penetration and changed offspring sex ratio in Yucheng men remain undetermined.

Health related quality of life and polychlorinated biphenyls and dibenzofurans exposure: 30 years follow-up of Yucheng cohort.

BACKGROUND: Quality of life (QOL) can be affected by diseases, disasters, and exposure events to environmental factors. However, whether health-related QOL (HRQOL) might be adversely affected by exposure to dioxin-like chemicals 30 years ago is unknown. METHODS: We studied people who were poisoned to polychlorinated biphenyls (PCBs) and dibebenzofurans (PCDFs) due to ingestion of contaminated rice oil in 1979 in central Taiwan, and were called Yucheng (oil-disease in Chinese) people. In 2008, we conducted a survey in 1305 exposed people by mailed questionnaire, which included HRQOL by World Health Organization (WHO) quality of life-BREF (WHOQOL-BREF) Taiwanese version. A total of 240 Yucheng subjects aged 18-65 years satisfactorily completed the Questionnaire. For comparison, we obtained information from the database of 2001 National Health Survey conducted by the National Health Research Institute and Bureau of Health Promotion, Department of Health, Taiwan. Data from age-, sex-, and county-matched background individuals were extracted using 1:3 match. HRQOL among Yucheng people with/without skin manifestation and unexposed referents were compared, while adjusting for other factors by multiple regression analyzes. RESULTS: The Yucheng people had significantly reduced scores in the physical, psychological, social, and environmental domains as compared to the referents. Those with skin manifestations were more severely affected than those with no skin manifestations, suggesting a dose-related effect on QOL in exposed people. CONCLUSION: We show for the very first time that poisoning due to persistent organic pollutants PCBs and PCDFs can affect QOL 30 years after the exposure, especially among those most severely poisoned.

EMG biofeedback effectiveness to alter muscle activity pattern and scapular kinematics in subjects with and without shoulder impingement.

BACKGROUND: Muscle imbalance between serratus anterior (SA), upper trapezius (UA), middle trapezius (MT), and lower trapezius (LT) muscles has been observed in subjects with subacromial impingement syndrome (SAIS). OBJECTIVE: (1) To investigate the effect of electromyography (EMG) biofeedback training on muscle balance ratios and scapular kinematics in healthy adults and subjects with SAIS. (2) To investigate whether the effects of EMG biofeedback on muscle balance ratios are different between groups. DESIGN: Twelve healthy adults and 13 subjects with SAIS were recruited in this study. EMG was used to record the activity of scapular muscles. The ratios (UT/SA, UT/MT, and UT/LT) during exercises with/without EMG biofeedback were calculated. Scapular kinematics were recorded before and after exercises with/without EMG biofeedback. RESULTS: For the subjects with SAIS, muscle balance ratios were lower during forward flexion with EMG biofeedback than during exercise only (UT/SA: 70.3-45.2; UT/LT: 124.8-94.6). Additionally, similar results were found during side-lying external rotation (UT/MT: 58.5-36.4). For the scapular upward rotation and tipping in both groups, there were no significant differences with and without EMG biofeedback. CONCLUSION: EMG biofeedback improved the scapular muscular balance during training exercises in both groups. Further clinical trials should investigate the long-term effects of EMG biofeedback.

Haemophilus influenzae type b combination vaccines and atopic disorders: a prospective cohort study.

BACKGROUND/PURPOSE: Epidemiologic evidence for an association between vaccinations and atopy development is inconsistent. We evaluated the influence of Haemophilus influenzae type b (Hib) combination vaccines in 6-month-old infants on the prevalence of atopic disorders in 18-month-old children. METHODS: We used multistage, stratified systematic sampling to recruit 24,200 mother-newborn pairs from the Taiwan national birth registration in 2005. Vaccination status was ascertained through official vaccine cards, while risk factors for atopic disorders were gathered by questionnaires at 6 months of age. Information about development of atopic dermatitis (AD) and recurrent wheezing was collected at 18 months of age. The relationship between atopic disorders and Hib combination vaccines, diphtheria-pertussis-tetanus-Hib and oral poliomyelitis vaccines (DPT-Hib&OPV) and DPT-Hib-inactivated poliomyelitis vaccines (DPT-Hib-IPV), were estimated by multiple logistic regression. RESULTS: A total of 19,968 children completed the follow-up and participated in the study. AD was noted in 1584 (7.9%) infants while recurrent wheezing was found in 1220 (6.1%) infants. The adjusted odds ratios (ORs) (95% CI) for the development of AD in the DPT-Hib&OPV and DPT-Hib-IPV vaccination groups were given as 1.38 (1.15-1.65) and 1.49 (1.29-1.72), compared to those without Hib vaccination (DTP&OPV vaccination). However, the association between DPT-Hib&OPV and DPT-Hib-IPV vaccinations and recurrent wheezing failed to reach statistical significance. CONCLUSION: There is a potential risk for AD after receiving Hib combination vaccines. Hib vaccination is important to the public health, and therefore the observation requires further investigations.

The Taiwan Birth Panel Study: a prospective cohort study for environmentally- related child health.

BACKGROUND: The Taiwan Birth Panel Study (TBPS) is a prospective follow-up study to investigate the development of child health and disease in relation to in-utero and/or early childhood environmental exposures. The rationale behind the establishment of such a cohort includes the magnitude of potential environmental exposures, the timing of exposure window, fatal and children's susceptibility to toxicants, early exposure delayed effects, and low-level or unknown neurodevelopmental toxicants. METHODS: A total of 486 mother-infant paired was enrolled from April 2004 to January 2005 in this study. Maternal blood before delivery, placenta and umbilical cord blood at birth, and mothers' urine after delivery were collected. The follow-up was scheduled at birth, 4, 6 months, and 1, 2, 3 and 5 years. The children's blood, urine, hair, and saliva were collected at 2 years of age and children's urine was collected at 5 years of age as well. The study has been approved by the ethical committee of National Taiwan University Hospital. All the subjects signed the inform consent on entering the study and each of the follow up. RESULTS: Through this prospective birth cohort, the main health outcomes were focused on child growth, neurodevelopment, behaviour problem and atopic diseases. We investigated the main prenatal and postnatal factors including smoking, heavy metals, perfluorinated chemicals, and non-persistent pesticides under the consideration of interaction of the environment and genes. CONCLUSIONS: This cohort study bridges knowledge gaps and answers unsolved issues in the low-level, prenatal or postnatal, and multiple exposures, genetic effect modification, and the initiation and progression of "environmentally-related childhood diseases."

Chronological changes in compromised olivocochlear activity and the effect of insulin in diabetic Wistar rats.

The aims of the present study were to investigate in diabetic rats: (1) the chronological changes of compromised medial olivocochlear bundle (MOCB) activity and auditory brainstem responses (ABR) and (2) the effect of insulin on diabetes-related hearing dysfunction. Diabetes mellitus was induced by intraperitoneal injection of streptozotocin. Thirty male Wistar rats were divided into three groups: control (C), diabetes with insulin injection (DI), and diabetes without insulin injection (DM). Click-evoked ABR, distortion product otoacoustic emission (DPOAE) and the contralateral suppression (CS) of DPOAE were measured for all animals monthly. Throughout the experiment, the thresholds of click-evoked ABR did not differ among groups. Wave III was delayed and interpeak latency I-III was prolonged in the DM group at the age of 29 weeks (p < 0.05). The amplitudes of the CS of DPOAE were markedly decreased after the 25th week in the DM group, but not in the C and DI groups. Compared to the C group, the CS in the DI group was not attenuated at any frequency. Dysfunction of auditory efferent olivocochlear activity developed in diabetic rats presenting no evidence of hearing loss. The finding of a significant decrease of the CS of DPOAE could be used as an earlier indicator of diabetes-related hearing impairment than changes of ABRs. The time course of compromised MOCB is positively correlated with the duration of diabetes. Insulin could therefore protect against compromised MOCB.

GSTM1, GSTP1, prenatal smoke exposure, and atopic dermatitis.

BACKGROUND: The increase in the prevalence of atopic dermatitis (AD) is likely to involve changes in specific environmental exposures among genetically susceptible individuals. OBJECTIVE: To evaluate the effect of glutathione S-transferase (GST) genotype polymorphisms and prenatal smoke exposure on pediatric AD on the basis of the cord blood cotinine levels. METHODS: We conducted a case-control study composed of 34 children with AD and 106 non-AD controls, all of whom were selected from 483 participants in the Taiwan Birth Panel cohort study. Cord blood samples and information on perinatal factors of children were gathered at birth. At 2 years of age, information about the development of AD and environmental exposures was collected. We compared AD with non-AD children for GTM1 and GSTP1 polymorphisms stratified by the cotinine level. Multiple logistic regressions were performed to estimate the association of genotype polymorphisms and cotinine levels with AD. RESULTS: GSTM1 null and GSTP1 Ile/Ile genotypes showed a significant increase in the risk of AD (odds ratio [OR], 3.61; 95% confidence interval [CI], 1.40-9.31; and OR, 3.11; 95% CI, 1.30-7.46; respectively). In children with a cotinine level less than 0.1 ng/mL, the risk of AD increased for those carrying 2 GSTP1 Ile-105 alleles (OR, 6.63; 95% CI, 1.46-30.18). In children a with cotinine level of 0.1 ng/mL or greater, the GSTM1 null genotype was significantly related to AD (OR, 5.21; 95% CI, 1.32-20.58). CONCLUSIONS: Within groups of children, genetic polymorphisms in GSTM1 and GSTP1 may be responsible for differences in susceptibility to AD with regard to prenatal smoke exposure.

N-acetylcysteine attenuates noise-induced permanent hearing loss in diabetic rats.

The purpose of this study is to investigate whether repeated noise exposure aggravates the level of permanent noise-induced hearing loss (NIHL) in diabetic rats and whether N-acetylcysteine (NAC), a precursor of glutathione, attenuates the level of noise-induced permanent hearing loss in diabetic rats. Fifty male Wistar rats were divided into four groups: 12 non-diabetic control rats with saline injection (Control-Saline), 11 non-diabetic control rats with NAC injection (Control-NAC), 13 streptozotocin-induced diabetic rats with saline injection (Diabetes-Saline) and 14 streptozotocin-induced diabetic rats with NAC injection (Diabetes-NAC). NAC (325mg/kg) was given by intraperitoneal injection twice per day (b.i.d.) for 14 days starting 2 days before noise exposure. All rats were exposed to noise for 8hours per day for 10 consecutive days to develop noise-induced permanent hearing loss. The hearing status of all animals was evaluated with auditory brainstem responses (ABR) evoked by clicks and tone bursts. ABRs were measured before and at 1hour, 1 week, 2 weeks and 4 weeks after noise exposure. After a recovery time of 4 weeks, animals were decapitated, and the loss of hair cells was assessed microscopically. In all groups, ABR thresholds failed to return to pre-exposure values throughout the experimental period. The ABR threshold to clicks was markedly elevated in the Diabetes-Saline group (36.9+/-2.3dB SPL), less elevated in the Control-Saline and Diabetes-NAC groups and least in the Control-NAC group (19.5+/-2.0dB SPL) at 4 weeks after noise exposure. Diabetes caused increased susceptibility to noise-induced hearing loss, and NAC treatment reduced the loss in both control and diabetic rats. Cochleograms revealed no gross destruction of hair cells in the non-diabetic groups or the Diabetes-NAC group; however, a significant number of outer hair cells (OHCs) were lost in the Diabetes-Saline group. This study demonstrated that diabetics were prone to developing more severe NIHL than non-diabetics and that NAC could preserve most OHCs and attenuate the permanent noise-induced hearing loss in both groups.

Assaults against nurses of general and psychiatric hospitals in Taiwan.

PURPOSE: Nurses are at risk of occupational assaults. However, the incidence and effects have not been documented among nurses in Taiwan. We aimed to study the incidence of assaults and their effects, including quality of life and job-related stress among nurses. METHODS: A cross-sectional study was conducted to understand the incidence of work-related assaults in nurses. Job content questionnaire was used to determine the job control, psychological demands at work, and workplace support in these nurses. Quality of life was assessed by short form-36 (SF-36). RESULTS: A total of 842 nurses satisfactorily completed the questionnaire, including 375 from general hospitals and 467 from psychiatric hospitals. A total of 237 (28.1%) reported to have experienced physical and/or verbal assaults in past 6 months. Experiences of sexual assault or verbal abuse were risk factors for feeling threatened by potential attacks. Nurses who felt threatened by potential attacked scored lower in general health, mental health, and vitality by SF-36, and had higher psychological demands at work, lower job control, and lower workplace support. CONCLUSION: We conclude that nurses in general and psychiatric hospitals had high risk of assaults. Worksite assaults caused nurses to feel threatened, and such an effect was likely to cause increased job stress and decreased quality of life.

Glutathione S-transferase M1, T1, and P1 polymorphisms as susceptibility factors for noise-induced temporary threshold shift.

The generation of reactive oxygen species (ROS) is thought to be part of the mechanism underlying noise-induced hearing loss (NIHL). Glutathione is an important cellular antioxidant that limits cell damage by ROS. We aimed to determine the effect of genetic polymorphisms of glutathione S-transferase (GST) T1, GSTM1, and GSTP1, on temporary threshold shift (TTS) in 58 noise-exposed male workers from a steel factory. The pre-shift hearing impairment at high frequency (HF, average of 3, 4, and 6kHz) was 30.7dB HL (S.D.=19.3). The amount of daily noise exposure was 83.0dBA (S.D.=5.0). Noise-induced TTS at HF by pure-tone audiometry (PTA) was related to the daily noise exposure (p<0.05). Based on combinatory analysis, we found that individuals carrying all genotypes with GSTT1 null, GSTM1 null, and GSTP1 Ile(105)/Ile(105) were more susceptible to NIHL. These results suggest that pre-shift hearing impairment and daily noise exposure had impacts on TTS at HF by PTA. In addition, GST genetic polymorphisms may modify the susceptibility to noise-induced TTS.

Diabetes impairs recovery from noise-induced temporary hearing loss.

OBJECTIVES/HYPOTHESIS: The purpose of this study is to investigate whether diabetes impairs the recovery from noised-induced temporary hearing loss. METHODS: Twenty-eight male Wistar rats were divided into three groups: control, diabetes with insulin control (DI), and diabetes without insulin control (DM). Diabetes was induced by intraperitoneal injection of streptozotocin. All animals were exposed to white noise at 110 dB SPL for 8 hours. Auditory brainstem response (ABR) thresholds and distortion product otoacoustic emission (DPOAE) amplitudes were measured for all animals 1 day prior to noise exposure to obtain a baseline for hearing function, and then 1 hour, 1 day, 2 days, 4 days, 7 days, and 14 days after noise exposure. RESULTS: One hour post exposure, ABR thresholds shifted markedly, and DPOAE was reduced similarly in all groups. Both ABR thresholds and DPOAE returned to the baseline in the control group at day 1, but they were not back to the baseline in the DM group even by day 14. Compared with the control group, the ABR threshold shifts and DPOAE returned to baseline more slowly in the DI group. CONCLUSIONS: The present study suggests that diabetic patients need proper blood sugar control and probably need more effective preventive measures to preserve their hearing from the effects of noise. Laryngoscope, 2009.

Indoor environmental risk factors and seasonal variation of childhood asthma.

Seasonality of asthma may result from varying exposures. This cross-sectional study was designed to examine the relationship between indoor environmental factors and seasonal childhood asthma. Study subjects were participants from the International Study of Asthma and Allergies in Childhood (ISAAC) in 2004, a population-based surveillance, which included school children aged 6-15 yr in south Taiwan. Cases included 1725 children who experienced asthma symptoms in the past 12 months and the references consisted of 19,646 children who reportedly have no asthma history. By using a moving average and principal component analysis, asthmatic children were grouped into four asthma subtypes: winter, spring, summer/fall, and perennial. Multivariate logistic regression was used to evaluate the effect of indoor environmental factors on seasonality of childhood asthma. For all asthma prevalence, a peak occurred in the winter and a nadir appeared in summer. Contributing factors of asthma for children, regardless of seasonality, included younger age, parental atopy, maternal smoking during pregnancy, breast feeding, and perceived air pollution. After adjusted for salient risk factors, water damage was significantly associated with all subtypes of asthma. Presence of cockroaches was related to the summer/fall asthma (adjusted odds ratio [aOR] = 1.65, 95% confidence interval [CI] = 1.12-2.55). Visible mold on the walls was associated with an increased occurrence of winter and spring asthma (aOR = 1.53, 95% CI = 1.26-1.85 and aOR = 1.34, 95% CI = 1.10-1.62, respectively). Passive smoking was shown to be related to spring and summer/fall asthma. Water damage is a possible risk for childhood asthma year-round. Cockroaches and visible mold on the walls may play essential roles for seasonality of childhood asthma in Taiwan. Plausible mechanisms and allergic effects should be further determined. Elimination of these allergens is necessary to help prevent the development of asthma.