Comorbidity and lifestyle, reproductive factors, and environmental exposures associated with rheumatoid arthritis.
OBJECTIVE: To evaluate the influence of lifestyle, reproduction, and some external factors on the development of rheumatoid arthritis (RA) and to describe its comorbidity. METHODS: Cases were identified retrospectively from 1980 to 1995 at the University Hospital in Linkoping, Sweden. The study comprised 422 cases and 859 randomly selected population referents. Data on possible aetiological factors and comorbidity were collected by postal questionnaire. RESULTS: The response rates were 67% among cases and 59% among referents. A decrease in the occurrence of atopic allergy was seen in the cases (odds ratio (OR) 0.6, 95% confidence interval (CI) 0.4 to 1.0). There was a positive association between RA and insulin treatment (OR 10.2, 95% CI 1.7 to 60.8) in women, and women with a short fertile period had an increased risk of RA (OR 2.5, 95% CI 1.1 to 5.4). Current and previous smoking were associated with increased risks for RA in both sexes, and in men a dose-response relationship was found with number of tobacco pack years (p for trend <0.005). The risk for RA decreased with increasing level of education in both men and women. Increased risks were seen in men born into households with private wells (OR 2.8, 95% CI 1.5 to 5.2), residentially exposed to mould (OR 4.6, 95% CI 1.1 to 20.2), or exposed to farm animals (OR 3.3, 95% CI 0.7 to 16.6). In women there were positive associations between RA and reporting a previous joint injury (OR 2.5, 95% CI 1.0 to 6.6) and prolonged exposure to hair dyes (OR 1.9, 95% CI 0.8 to 4.5). CONCLUSIONS: RA, a disease with features of T helper 1 (Th1) dominated immune response, was inversely associated with atopic allergy, a Th2 dominated condition, while there were indications of a strong positive association with Th1 related diabetes mellitus. The results support a causal relationship between smoking and RA. The level of education was inversely associated with RA, while there was a positive association between RA and certain residential factors in men and a short fertile period in women. (+info)
Incidence of asthma in female Swedish hairdressers.
OBJECTIVE: To investigate the risk of asthma in hairdressers. METHODS: The incidence of asthma was retrospectively estimated in a Swedish nationwide study including all female hairdressers certified from vocational schools from 1970 to 1995, and a stratified sample of women from the general population were referents. A postal questionnaire included questions on respiratory tract symptoms, atopy, smoking, working periods as a hairdresser, and number of specific hair treatments performed/week. Reported exposures were validated by occupational hygienists. Rate ratios of incidence (IRRs) of asthma were estimated by Poisson regression, adjusted for calendar year of observation, hay fever, smoking, and region of domicile. RESULTS: The crude incidences of asthma/1000 person-years were: 3.9 during active years as a hairdresser, 2.8 among the hairdressers when not working in the profession, and 3.1 among the referents. The corresponding IRR for being an active hairdresser compared with the referents was 1.3 (95% confidence interval (95% CI) 1.0 to 1.6). Moderate effects on risk of asthma were found both from hairdressing work (IRR=1.6 (1.1 to 2.2) among never-smokers) and from smoking (IRR=1.6 (1.2 to 2.2) among referents). However, the combined effect from hairdressing work and smoking (IRR=1.5 (1.0 to 2.1)) was less than expected (p=0.02). No effect modification by respiratory atopy was found. The hairdressers most often performing hair bleaching treatments (IRR=1.5 (0.7 to 3.0)) or using hair spray (IRR=1.4 (0.8 to 2.4)) had, compared with the most infrequent users, a slightly, but not significantly higher incidence of asthma. Exposure to persulphates in hair bleach was estimated to be 0.04-0.15 mg/m(3) during mixing of the powder. Reported average number of bleaching treatments agreed well with those performed according to a diary. CONCLUSIONS: Active hairdressing work was associated with a moderately increased incidence of asthma among lifelong non-smokers. The results are moderately supportive, but not conclusive, of associations between asthma and exposure to hair bleach or hair spray. (+info)
Permanent hair dyes and bladder cancer: risk modification by cytochrome P4501A2 and N-acetyltransferases 1 and 2.
We have previously reported permanent hair dye use to be a significant risk factor for bladder cancer in US women. We also have examined N-acetyltransferase-2 (NAT2) phenotype in relation to the hair dye-bladder cancer relationship, and found that the association is principally confined to NAT2 slow acetylators. In the present study, we assessed the possible modifying effects of a series of potential arylamine-metabolizing genotypes/phenotypes (GSTM1, GSTT1, GSTP1, NAT1, NAT2, CYP1A2) on the permanent hair dye-bladder cancer association, among female participants (159 cases, 164 controls) of the Los Angeles Bladder Cancer Study. Among NAT2 slow acetylators, exclusive permanent hair dye use was associated with a 2.9-fold increased risk of bladder cancer (95% CI = 1.2-7.5). The corresponding relative risk in NAT2 rapid acetylators was 1.3 (95% CI = 0.6-2.8). Frequency- and duration-related dose-response relationships confined to NAT2 slow acetylators were all positive and statistically significant. No such associations were noted among NAT2 rapid acetylators. Among CYP1A2 'slow' individuals, exclusive permanent hair dye use was associated with a 2.5-fold increased risk of bladder cancer (95% CI = 1.04-6.1). The corresponding risk in CYP1A2 'rapid' individuals was 1.3 (95% CI = 0.6-2.7). Frequency- and duration-related dose-response relationships confined to CYP1A2 'slow' individuals were all positive and statistically significant. No such associations were noted among CYP1A2 'rapid' individuals. Among lifelong non-smoking women, individuals exhibiting the non-NAT1*10 genotype showed a statistically significant increase in bladder cancer risk associated with exclusive permanent hair dye use (OR = 6.8, 95% CI = 1.7-27.4). The comparable OR in individuals with the NAT1*10 genotype was 1.0 (95%CI = 0.2-4.3). Similarly, all frequency- and duration-related dose-response relationships confined to individuals possessing the non-NAT1*10 genotype were positive and statistically significant. On the other hand, individuals of NAT1*10 genotype exhibited no such associations. (+info)
Hair dye use and multiple myeloma in white men.
In recent reports, multiple myeloma has been linked to use of hair coloring products containing mutagenic and carcinogenic chemicals. A population-based case-control study in Iowa of 173 White men with multiple myeloma and 650 controls obtained information on hair dye use. Risk of multiple myeloma was significantly elevated (OR = 1.9) among hair dye users and was greatest among those using hair dyes at least once a month for a year or more (OR = 4.3). These data, along with results from other studies, suggest that use of hair dyes contributes to the development of multiple myeloma. (+info)
Effects of hair dyeing on DNA damage in human lymphocytes.
Comet assays were carried out to evaluate DNA damage in human lymphocytes from 20 volunteers before and after hair dyeing. DNA damage in lymphocytes was found to be slightly higher in volunteers after hair dyeing. Tail moments before and after hair dyeing were 1.47 +/- 0.41 and 1.75 +/- 0.29 respectively (p<0.0008). DNA damage in lymphocytes showed significant difference with treatment and heating time. The tail moments after 15 min of treatment time before and after hair dyeing were 1.44 +/- 0.22 and 1.85 +/- 0.36, respectively (p=0.0004) and the corresponding tail moments in 20 min of heating time before and after were 1.37 +/- 0.15 and 1.78 +/- 0.34 (p=0.0002). In conclusion, we found that an acute exposure of hair dyes with heating caused DNA damages in peripheral lymphocytes and that this damage had significant association with treatment and heating time. (+info)
Drug-induced hepatitis due to repeated use of hair dye.
A 27-year-old Japanese man with no past history of liver disease was admitted to our hospital due to liver abnormalities. The patient was diagnosed with drug-induced hepatitis, as the three episodes of hepatitis occurred just after repeated use of hair dye. After cessation of the hair dye use, abnormal liver function tests improved to within the normal range. Although hair dyes contain various hepatotoxic compounds, hair dye is not known to cause drug-induced hepatitis. Thus, in cases of liver abnormality of unknown origin, the history of hair dye use should be investigated. (+info)
Hair-coloring product use and risk of non-Hodgkin's lymphoma: a population-based case-control study in Connecticut.
A population-based case-control study was conducted in Connecticut in 1996-2002 to test the hypothesis that lifetime hair-coloring product use increases non-Hodgkin's lymphoma risk. A total of 601 histologically confirmed incident female cases and 717 population-based controls were included in the study. An increased risk of non-Hodgkin's lymphoma was observed among women who reported use of hair-coloring products before 1980 (odds ratio = 1.3, 95% confidence interval (CI): 1.0, 1.8). The odds ratios were 2.1 (95% CI: 1.0, 4.0) for those using darker permanent hair-coloring products for more than 25 years and 1.7 (95% CI: 1.0, 2.8) for those who had more than 200 applications. Follicular type, B-cell, and low-grade lymphoma generally showed an increased risk. On the other hand, the authors found no increased risk of non-Hodgkin's lymphoma overall and by subtype of exposure and disease among women who started using hair-coloring products in 1980 or later. It is currently unknown why an increased risk of non-Hodgkin's lymphoma was found only among women who started using hair-coloring products before 1980. Further studies are warranted to show whether the observed association reflects the change in hair dye formula contents during the past two decades or indicates that recent users are still in their induction and latent periods. (+info)
Hair dye use and risk of adult acute leukemia.
Certain chemicals in hair dyes are known animal carcinogens. Darker, more permanent, and earlier dye formulations may be more carcinogenic than other dye types. For 769 adult acute leukemia cases and 623 population-based controls in a US and Canadian case-control study in 1986-1989, the authors asked separately about use of permanent and nonpermanent (semipermanent and temporary) hair dye use. Use was reported by 45% of women and 6% of men. There was a modest positive association for ever use of permanent dyes (odds ratio = 1.5, 95% confidence interval: 1.0, 2.1), which was stronger for long duration (15 or more years) of use (odds ratio = 1.8, 95% confidence interval: 1.0, 3.1). The greatest odds ratio was for 15 or more years of using hair dyes up to six times per year (odds ratio = 2.4, 95% confidence interval: 1.0, 5.8); the corresponding odds ratio for use six or more times a year was lower, suggesting the possibility of misclassification of dye type among frequent users, since nonpermanent dyes tend to be used more frequently than permanent dyes. Nonpermanent dyes were not associated with risk. Long duration of permanent dye use may have a larger impact on the risk of adult acute leukemia and other hematopoietic cancers than prior epidemiologic data suggest. (+info)