Smoking as a Risk Factor for Injury Death: A Meta-Analysis of Cohort Studies

Background.Injury and tobacco effects represent one-quarter of the global burden of disease. Understanding the causes of injury and the effects of smoking may help reduce those burdens. Some smokers have high risks of injury. We provide an initial meta-analysis of cohort associations between smoking and fatal injury.Methods.Three authors independently searched MEDLINE, and bibliographies of the pertinent studies found, for cigarette smoker-specific injury death data which allowed estimation of an appropriate relative risk (RR) and 95% confidence interval (CI). Relative risks and dose response were summarized by fixed effects and Poisson modeling, respectively.Results.Six studies covering 10 pertinent cohorts were located. Associations between smoking and injury death have been significant after adjustment or, in effect, stratification for age, race, sex, country, and, respectively, alcohol, marriage, education, and body mass; job and time period; job, alcohol, and exercise; etc. Summary-dose response trends were significantly positive (P< 0.00005). Cigarette smoking predicted summary injury death crude RRs of 1.61 (CI 1.44–1.81) vs never smokers and 1.39 (CI 1.25–1.55) vs ex-smokers.Conclusions.Smoking has significant, consistent, dose-response, often strong and independent, prospective associations with injury death, internationally.     

Responses of the cerebellar fastigial neurones to tilt

Summary The activity of units located in the rostral portion of the fastigial nucleus has been recorded in decerebrate, unanaesthetized cats in response to tilt. The responses consisted of steady variation of the discharge rates when the animal was tilted in the median plane. The majority of the units exhibited a frequency increase on ipsilateral tilt and a frequency decrease on contralateral tilt. Some units displayed an opposite type of response, while some others responded with a frequency increase on tilt in both directions. It was possible to establish a relationship between the amount of the response and the degree of tilt. Some units exhibited a dynamic response during the movement of the tilt table and the amount of this dynamic response was related to the velocity of the movement. It was not possible to demonstrate a convergence of macular input on these dynamic units. The responses did not depend on proprioceptive feed-back since they persisted after deep curarization of the animal. Since the rostro-fastigial neurones project on the dorsal ipsilateral Deiters' nucleus the existence of a cerebellar fastigial loop through which macular information may reach Deiters' nucleus has been postulated. This loop may be of relevance in the cerebellar and vestibular control of postural activities.This investigation was supported by Public Health Service Research Grant NS 07685-05 from the National Institute of Neurological Diseases and Blindness, N.I.H., Public Health Service, U.S.A. and by a Research Grant from the Consiglio Nazionale delle Ricerche, Italy.     

The interaction of cigarette smoking and chronic drug ingestion on human drug metabolism

1. Drug metabolism was assessed by the disappearance rate of antipyrine as measured in saliva. Results were expressed in terms of both clearance and half life. 2. Basal measurements of antipyrine disappearance rate were performed in seven non-smokers and six smokers. After administration of glutethimide 250 mg daily for 7 days a second measurement of antipyrine disappearance rate was made. 3. Glutethimide enhanced antipyrine metabolism in both smokers and non-smokers. The degree of change in both groups was similar. 4. A similar study was carried out with a smaller dose (125 mg) of glutethimide. There was no significant difference between smokers and non-smokers.5. The data are consistent with smoking and chronic drug ingestion having additive effects on enhancement of hepatic drug metabolism.     

Maternal coffee and alcohol consumption during pregnancy, parental smoking and risk of childhood acute leukaemia

INTRODUCTION: We investigated the role of maternal alcohol and coffee drinking and parental smoking on the risk of childhood acute leukemia in a multicenter case-control study. METHODS: The study included 280 incident cases and 288 hospitalized controls, frequency matched with the cases by age, gender and center. Data collection was completed by face-to-face standardized interviews of the case and control mothers. RESULTS: An association with maternal alcohol consumption during pregnancy was observed with acute lymphoid leukemia (ALL) (OR=2.0 [1.4-3.0]) and acute non-lymphoid leukemia (ANLL) (OR=2.6 [1.2-5.8]). Maternal coffee consumption during pregnancy was associated with childhood acute leukemia, ORs increasing in ALL with coffee consumption (OR=1.1 [0.7-1.8], OR=2.4 [1.3-4.7] and OR=3.1 [1.0-9.5], respectively, for < or =3, 4-8 and >8 cups/day). No association with maternal smoking during pregnancy or parental smoking before or after the index child's birth was observed. DISCUSSION: Our results suggest an association with maternal alcohol and coffee drinking during pregnancy and call for further investigations. Besides, the present study does not support the hypothesis of an increase in the risk of childhood leukemia related to parental smoking.     

Genetic,Anthropometric, and Lifestyle Factors Associated with IGF-1 and IGFBP-3 Levels in Hispanic and Non-Hispanic White Women

Circulating concentrations of IGF-I and IGFBP-3 are associated with risk of pre-menopausal breast cancer. Racial differences in levels of these factors have been reported, and determinants of IGF-I and IGFBP-3 levels within racial and ethnic groups are unclear. In this study we examine genetic, anthropometric, diet, and lifestyle factors that may predict serum levels of IGF-I and IGFBP-3 among Hispanic and non-Hispanic white women. A sample of healthy controls participating in the SHINE (Southwest Hormone, Insulin, Nutrition, and Exercise Study) case-control breast cancer in Arizona, Colorado, New Mexico, and Utah were included in these analyses. Subjects included 210 Hispanic and 284 non-Hispanic white women. Hispanic women had significantly lower levels of IGFBP-3 (mean=3764.3 mcg/ml) after adjusting for age, body size, physical activity, menopausal status, and dietary factors than non-Hispanic white women (mean = 4058.0 mcg/ml; p<0.01). The CC genotype of the −202 A>C polymorphism of the IGFBP3 gene was associated with lower IGFBP-3 levels in both ethnic groups. The frequency of the IGFBP3 C allele differed between Hispanic (0.65) and non-Hispanic white women (0.53), but serum levels of IGFBP-3 were lower for Hispanic women than non-Hispanic after accounting for IGFBP3 genotype. Body size indicators, vigorous physical activity, and dietary factors appeared to influence serum levels of IGF-1 and the ratio of IGF-1 to IGFBP-3 in pre-menopausal women more than in post-menopausal women. On the other hand, using aspirin/NSAIDs appeared to increase IGFBP-3 levels significantly among pre-menopausal Hispanic women. Results from this study suggest that differences in IGFBP-3 levels exist in Hispanic and non-Hispanic white women. These differences could be due to the combined effects of genetic and behavioral factors which could account for ethnic differences in the risk of breast cancer and other chronic diseases.     

Mutations in the epidermal growth factor receptor gene are linked to smoking-independent, lung adenocarcinoma

Epidermal growth factor receptor (EGFR) mutations are a potential predictor of the effectiveness of EGFR inhibitors for the treatment of lung cancer. Although EGFR mutations were reported to occur with high frequency in nonsmoking Japanese adenocarcinoma patients, the exact nature has not been fully elucidated. We examined EGFR gene mutations within exons 18-21 and their correlations to clinico-pathological factors and other genetic alterations in tumour specimens from 154 patients who underwent resection for lung cancer at Kyoto University Hospital. Epidermal growth factor receptor mutations were observed in 60 tumours (39.0%), all of which were adenocarcinoma. Among the patients with adenocarcinoma (n=108), EGFR mutations were more frequently observed in nonsmokers than former smokers or current smokers (83.0, 50.0, 15.2%, respectively), in women than men (76.3 vs 34.0%), in tumours with bronchio-alveolar component than those without bronchio-alveolar component (78.9 vs 42.9%), and in well or moderately differentiated tumours than poorly differentiated tumours (72.0, 64.4, 34.2%). No tumours with EGFR mutations had any K-ras codon 12 mutations, which were well-known smoking-related gene mutations. In conclusion, adenocarcinomas with EGFR mutation had a distinctive clinico-pathological feature unrelated to smoking. Epidermal growth factor receptor mutations may play a key role in the development of smoking-independent adenocarcinoma.     

Standardizing questionnaire items for the assessment of waterpipe tobacco use in epidemiological studies

Lessons from surveillance of the smoking epidemic show that the lack of adequate attention to standardizing measures and instruments for epidemiological studies has negatively influenced our ability to assess spatial and secular trends in smoking worldwide. Waterpipe smoking, another hazardous form of tobacco use, is gaining popularity worldwide, with societies in the Eastern Mediterranean region (EMR) being most affected. Several research groups are currently investigating the epidemiology of waterpipe smoking among various populations in the EMR. Initial evidence shows that in contrast to usage patterns observed in adult cigarette smoking, waterpipe smoking is characterized mainly by intermittent and social use. As such, many measures that have been traditionally used for the study of usage patterns and dependence among adult cigarette smokers are uninformative for waterpipe smoking. Thus, the need to develop standardized measures and terminology for assessment of the epidemiology of waterpipe smoking in different populations is of paramount importance. As the monitoring of waterpipe smoking is in its infancy, the development of consensus measures should facilitate the initiation of effective surveillance that can guide public health response to this emerging epidemic.     

Respiratory outcomes among South African coal miners at autopsy

BACKGROUND: Studies of dose-response relationships between respiratory outcomes at autopsy and coal dust exposure are limited. The Pathology Automation System (PATHAUT) database of South African miners, is one of the largest autopsy databases of occupational lung disease. This study described the prevalence of respiratory outcomes among South African coal miners at autopsy, and determined whether dose response relationships existed between emphysema and exposure. METHODS: Autopsies conducted from 1975 to 1997 on coal miners with exclusive coal mining exposure and having exposure duration information (n = 3,167) were analyzed from PATHAUT. Logistic regression was used to determine relationships between exposure and outcomes, controlling for race, smoking and age on a subset for whom smoking history was available (n = 725). RESULTS: The mean duration of exposure was 11.0 years. Most were black miners (75.3%) with significant differences in the mean ages of black and white miners (37.9 and 55.3 years, respectively). Only 22.9% of cases had information on smoking. The prevalence of silicosis, tuberculosis (TB), coal workers' pneumoconiosis (CWP), and moderate and marked emphysema were 10.7%, 5.2%, 7.3%, and 6.4%, respectively. All diseases, except TB, were associated with exposure duration. Black miners had 8.3 and 1.2 fold greater risks for TB and CWP, respectively, than white miners. White miners had an increased risk of 1.4 and 5.4 for silicosis and moderate to marked emphysema, respectively. In models unadjusted for age, and including smoking, moderate to marked emphysema was strongly associated with exposure duration (OR = 3.4; 95% CI = 1.9-5.9 for highest tercile of exposure duration). Exposure-related risk estimates were reduced when age was introduced into the model. However, age and duration of exposure were highly correlated, (r = 0.68) suggesting a dilution of the exposure effect by age. CONCLUSIONS: There were significant dose related associations of disease, including emphysema, with coal dust exposure.