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Biomedical subjects

W Karmaus

Publications and source records attributed to W Karmaus.

At least 19 recordsLinked to original sources
PubMed1999

Pulmonary function in children of school age is related to the number of siblings in their family.

It has been suggested that the number of siblings in a family is a surrogate variable for exposure to early infections. Since there may be an association between early respiratory infections and impaired lung function in later life, the aim of this study was to elucidate the relationship between the number of siblings and pulmonary function. We analyzed pulmonary function data from 677 schoolchildren living in 431 nuclear families. Our results show that forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV(1)) expressed as a percentage of deviation from the predicted values (FVC%, FEV(1)%) increase significantly in line with the number of siblings in a family (FVC%: no sibling = reference, 1 sibling = +1.3%, 2 siblings = +1.9%, 3 siblings = +4.0%, 4 or more siblings = +5.1%; P-value for trend = 0.01; FEV(1)%: no sibling = reference, 1 sibling = +1.6%, 2 siblings = +2.0%, 3 siblings = +4.3%, 4 or more siblings = +6.5%; P-value for trend = 0.007). Pulmonary function values were no more strongly related to the number of older siblings than to the number of younger siblings (difference between the trend for older and younger siblings for FCV%: P = 0.7; FEV(1)%: P = 0.9). The association between pulmonary function and number of siblings can be explained neither by the child's atopic status, prevalence of asthma, or history of pneumonia, nor by former or current cigarette smoke exposure. This suggests that pulmonary function status of the child appears to be related to the number of siblings, and is unlikely to be explained solely by exposure to infections early in life. Our data therefore adds strength to the hypothesis that factors which cause the size of a sibship to influence a child's respiratory health have not yet been adequately explained.

Adolescent↗
PubMed1999

Regional differences in waiting time to pregnancy: pregnancy-based surveys from Denmark, France, Germany, Italy and Sweden. The European Infertility and Subfecundity Study Group.

The objective of this study was examine geographical variation in couple fecundity in Europe. The study was based upon all recently pregnant (or still pregnant) women within well-defined geographical areas in Europe (Denmark, Germany, Italy, Sweden and France) at a given time period in 1992. Altogether, 4035 women responded to a highly structured questionnaire. Highest fecundity was found in Southern Italy and Northern Sweden; lowest fecundity was seen in data from the East German centre. Approximately 16% of the study population had a waiting time of more than 12 months to become pregnant. Most of the pregnancies were planned (64%) and approximately 14% were the result of contraceptive failures. The study shows that smoking, body mass index, age and parity did not explain the differences in fecundity found between the centres. Regional differences in fecundity exist and the causes may be genetic or due to variations in behavioural and environmental exposures.

Adult↗
PubMed1999

Exposure to toluene in the printing industry is associated with subfecundity in women but not in men.

OBJECTIVE: To examine the possible influence of exposure to toluene on human fertility. METHODS: In a cross sectional study, a sample of 150 male and 90 female printing industry workers were interviewed retrospectively on reproductive experience with a modified version of the European study of infertility and subfecundity questionnaire. Exposure categories comprised job descriptions and information on exposure measurements obtained by industrial hygienists. The fecundability ratio (FR) was estimated on the basis of time to pregnancy (TTP) or periods of unprotected intercourse not leading to pregnancy (PUNP) by means of survival analysis with proportional hazard models. Confounders such as age, ethnicity, smoking, parity, pelvic inflammatory diseases, and frequency of sexual intercourse were controlled for in the analyses. RESULTS: 256 Periods of TTP or PUNP were reported by men and 174 by women. After exclusion of induced abortions, birth control failures, and periods without employment for female workers we were able to analyse 169 periods in men and 100 periods in women. Male workers who had been exposed to different concentrations of toluene and their partners did not show a reduction in fecundity. In women (39 periods occurred during exposure) fecundity was reduced (FR 0.47, 95% confidence interval (95% CI) 0.29 to 0.77). Neither, restriction to only the first period nor exclusion of PUNPs changed the results (FR 0.48, 95% CI 0.24 to 0.97). CONCLUSION: After considering possible biases, low daily exposure to toluene in women seems to be associated with reduced fecundity. This result is in accordance with other findings for organic solvents and supports both the hypotheses that (a) organic solvents could affect hormonal regulation, and that (b) organic solvents increase early fetal losses which in turn contributes to longer times of unprotected intercourse.

Adolescent↗
PubMed1999

Exposure to polychlorinated biphenyls and levels of thyroid hormones in children.

As part of an epidemiologic study on exposure to a toxic waste incineration plant we investigated whether blood concentrations of polychlorinated biphenyls (PCBs), lead, and cadmium, as well as concentration of mercury in 24-hr urine samples were associated with thyroid hormone status. As an indication of status, we determined levels of thyroid-stimulating hormone (TSH), free thyroxine (FT(4)), and free triiodothyronine (FT(3)) in children living in households where [less than/equal to] 10 cigarettes were smoked per day. Eight PCB congeners (PCBs 101, 118, 138, 153, 170, 180, 183, and 187) were measured in whole blood samples. Of these, seven congeners (PCB 101 was not detected in any sample) and the sum of all PCB congeners were analyzed as predictors for thyroid hormone status in separate linear regression models adjusted for potential confounders. In addition, the possible effects of cadmium, lead, and mercury on levels of thyroid hormones were examined. Blood concentrations and information on questionnaire data were available for 320 children 7-10 years of age. We found a statistically significant positive association between the mono-ortho congener PCB 118 and TSH as well as statistically significant negative relationships of PCBs 138, 153, 180, 183, and 187 to FT(3). There was no association for the PCB congeners and FT(4). Blood cadmium concentration was associated with increasing TSH and diminishing FT(4). Blood lead and urine concentration of mercury were of no importance to thyroid hormone levels. The results stress the need for future studies on the possible influences of PCB and cadmium exposure on thyroid hormones, particularly in children. These studies should also take neurologic development into account.

Cadmium↗
PubMed1998

Accumulation of atopic disorders within families: a sibling effect only in the offspring of atopic fathers.

BACKGROUND: Several studies have reported an association between a child's risk of atopic disorders and family size. However, the inverse association might not be the same in populations with a different genetic disposition for atopic disorders. OBJECTIVE: This longitudinal study was designed to assess risk factors of atopy. METHODS: Lifetime prevalence of asthma, hay fever and eczema of 1440 families including 3165 offspring was ascertained by means of standardized questionnaires. RESULTS: After possible confounders had been controlled for, an inverse association between atopic disorders and the number of older siblings was found only in the offspring of atopic fathers (trend for older siblings: chi2 = 13.38, degrees of freedom [d.f.] = 1, P= 0.0002; odds ratio 'no older sibling'= 2.87 (95% confidence interval 2.18-3.78); '1 older sibling' = 2.11 [1.52-2.92], '2 older siblings' = 1.29 [0.74-2.23]; '3 or more older siblings' = 0. 15 [0.02-0.981). No such relationship was found for children without a history of paternal atopy (trend for older siblings: chi2 = 1.5 1, d.f. = 1, P = 0.22; odds ratio 'no older sibling' = 1 [reference]; '1 older sibling' =0.82 [0.63-1.06]; '2 older siblings' = 0.97 [0.67-1.40]; '3 or more older siblings' = 0.64 [0.31-1.33]). The trend for older siblings in the case of paternal atopy was significantly different from the trend for older siblings without a history of paternal atopy (chi2 = 8.68, d.f. = 1, P = 0.003). The number of younger siblings was not related to child's risk of atopy (trend for younger siblings: chi2 = 0.001, d.f. = 1, P = 0.97). CONCLUSIONS: Data from this study suggest a protective effect of sibship size only in children with a history of paternal atopy and if older siblings are present. The reason for this combined effect remains unclear. Thus, further investigations are needed to interpret the biological cause of the so called 'sibling effect'.

Adult↗
PubMed1998

Cotinine excretion as a predictor of peak flow variability.

Environmental tobacco smoke (ETS) is suspected to be an important risk factor for bronchial hyperresponsiveness. In order to test the effect of ETS, we measured expiratory flow rates and urine cotinine excretion (UCE) within a narrow time window in two consecutive years. Maternal smoking habits and medical history were ascertained by standardized questionnaires. The percentage ratio of the amplitude over the mean (AVAM) of the diurnal peak flow rates of children (complete values from at least five consecutive days) was calculated as an indicator of bronchial responsiveness. The association of UCE and log10AVAM was analyzed by multiple linear regression. Complete data were available for a sample of 417 children. The median of UCE in children of parents who smoked (3.2 ng/mg and 2.9 ng/mg creatinine, Surveys 1 and 2, respectively) was higher than the median in children of nonsmoking parents (0 ng/mg in both surveys). With increasing UCE the log10AVAM rose in the first and second surveys, as well as in the longitudinal analysis (p = 0.003). This association, however, showed up only in boys (p = 0.0001) and not in girls (p = 0.31). Our data suggest that there is a need both for further analysis of the gender difference and for more support of strategies against passive smoking as far as children are concerned, since airway hyperresponsiveness is a risk factor for chronic airway impairment.

Asthma↗
PubMed1998

PCDD/PCDF indoor exposure in day-care centers and PCDD/PCDF blood concentrations of female employees.

We determined blood concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in 41 female employees with previous exposure to pentachlorophenol-based wood preservatives from 10 day-care centers in the Hamburg, Germany, area. We compared the blood concentrations with estimated age-dependent reference values and analyzed the correlation between PCDD/PCDF indoor air exposure and blood concentrations. The analyses based on the PCDD congeners 1,2,3,4,7,8-, 1,2,3,6,7,8-, and 1,2,3,7,8,9-hexaCDD (hexaCDD), 1,2,3,4,6,7,8-heptaCDD (heptaCDD), octaCDD, and the 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalents calculated according to the international NATO-CCMS model (I-TEQ). In comparison to the estimated reference values, the blood concentrations of hexaCDD and I-TEQ spread around the mean estimate. Data for octaCDD scattered in some cases distinctly above the upper confidence limit. Reference values for heptaCDD could not be estimated. The correlation between PCDD/PCDF indoor air exposure and PCDD/PCDF blood concentrations was examined by linear multiple regression analysis considering different exposure variables and taking confounders into account. Analyses were carried out with the total study group and with a restricted subgroup. Associations were shown between the PCDD/PCDF indoor air concentrations and blood concentrations for heptaCDD and for the I-TEQ, whereas hexaCDD showed no association. OctaCDD showed a negative association in the total study group and no association in the subgroup analysis. In summary, the analyses showed no clear association between PCDD/PCDF indoor air exposure in day-care centers and PCDD/PCDF blood levels of female employees previously exposed to wood preservatives. By contrast, the results consistently indicated a positive association between PCDD/PCDF blood concentrations and exposure to wood preservatives in private homes.

Adult↗
PubMed1998

[Thyroid hormone level in children in the area of a toxic waste incinerator in South Essen].

As part of an environmental epidemiological study on potential exposure to a toxic waste incineration we investigated whether children in an area with a toxic waste incinerator (TWI) have different levels of thyroid hormones than children in two comparative regions. The TWI region is situated in the Rhine valley (about 30 km across) with low mountains on both sides. Other industries such as a chemical plant are nearby, and several municipalities are located in the environment of these. One comparative area 20 km north is also industrially and agriculturally used, but has no incinerator (Rhine Valley comparison group, RVC group). South-East of the incinerator region in an area of low mountains (about 400 m high) we investigated the second comparison group (Odenwald comparison group, OWC group). Altogether 671 children from 18 municipalities participated in 1994/95 (participation 61.5%). Blood samples were taken from 341 children, aged 7 to 10 years, living in non-smoking households or in households with only light smokers. Serum levels of thyrotropin stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were analysed. In a self-administered questionnaire for the parents, which was checked during the medical examination, we gathered information on age, gender, passive smoking, consumption of fish, as well as use of wood preservatives and pesticides at home. By means of adjusted regression analysis the first step was to check whether the TWI group had means of TSH, FT4 and FT3 that differed from the OWC group and the RVC group. If differences were at least marginally significant, the second step was to analyse whether children from different municipalities had statistically different mean values and if the pattern of these municipalities fitted into the three regions. For the latter, children from a town in the Odenwald served as comparison group. The TWI group had statistically significantly (p < or = 0.05) reduced FT3 and FT4 values with a higher prevalence of FT3 values below clinical references (TWI group: 7.7%, RVC group: 3.2%, OWC group: 1.2%). Children from four out of nine TWI municipalities showed statistically significantly lower FT3 means than children from the reference town, and one of the seven municipalities from the comparative areas. The mean FT4 was significantly lower in four municipalities of the TWI area and in one of the two other areas. The mean TSH was only marginally different, mainly influenced by gender differences with boys having higher TSH levels. Comparison of the municipalities did not reveal a consistent pattern. Industrial pollution might influence the regulatory system of the pituitary thyroid axis. Reduced peripheral thyroid hormones associated with exposure to polychlorinated biphenyls (PCB) and dioxins/furans (PCDD/F) were found in previous studies. Our results suggest that children exposed to toxic waste incineration in their environment have lower thyroxine and triiodothyronine levels.

Air Pollutants↗
PubMed1997

Construction work and low back disorder. Preliminary findings of the Hamburg Construction Worker Study.

STUDY DESIGN: Cross-sectional part of a longitudinal study in 571 male construction workers. OBJECTIVES: The Hamburg construction worker study is being conducted to assess the extent of musculoskeletal disorders in construction workers and factors predisposing for or leading to musculoskeletal disorders. The purpose of this analysis is to report findings about the association between job history and low back disorder. SUMMARY OF BACKGROUND DATA: Repetitive strain in forced positions during long periods of time has been reported as a risk factor for low back disorder. Of all construction workers, bricklayers predominantly are exposed to these conditions. METHODS: Subjects were recruited mainly from a routine health check-up. A structured interview with complete job history, job related activities, and symptoms was administered, and a detailed standardized physical examination was performed. Age-adjusted prevalences of low back pain were calculated, and logistic regression models were used to estimate odds ratios and their confidence intervals for different durations of working in a specific job category and physical signs of low back disorder, adjusting for a variety of possible confounders. RESULTS: The 12 month prevalence of low back pain was highest in painters (57%), intermediate in concrete builders and bricklayers (41%), and lowest in carpenters and unskilled workers (38%). The age-adjusted odds ratio (95% confidence interval) of low back disorder for having worked longer than 10 years as a bricklayer was 2.3 (1.2-4.5). CONCLUSIONS: Working longer than 10 years as a bricklayer was associated with signs of low back disorder. No comparable associations were found for house painters, carpenters, nor concrete builders. If replicated, these findings could be used to focus preventive measures on bricklayers with a long job history.

Adult↗
PubMed1997

The internal dose of passive smoking at home depends on the size of the dwelling.

As part of a longitudinal study two urine samples (survey 1 in 1991 and survey 2 in 1992) were collected from 602 elementary school children to investigate the relationship between urinary cotinine excretion (UCE) and the daily consumption of cigarettes at home (exposure). Size of the dwelling, educational level, and maternal smoking were taken into consideration as additional predictors. The history regarding parental smoking habits and confounding variables was ascertained by standardized questionnaires completed by the parents. Cotinine was measured using gas chromatography selected ion monitoring. UCE was expressed as cotinine/creatinine (ng/mg). In children with detectable UCE in survey 1 (35%) and in survey 2 (44%) the excretion ranged between 1.5 and 24.7 ng/mg (5-95%) and between 1.2 and 25.2 ng/mg, respectively. UCE measurements in both surveys were highly correlated (r = 0.65, P = 0.0001), and 59.6% of the UCE in survey 2 can be explained in linear regression by the UCE in survey 1. Using multiple linear regression, the categorized number of cigarettes reported to be consumed at home (20 cigarettes and more: 1991, P = 0.0001; 1992, P = 0.0003) and low educational level of the parents (P = 0.011 in 1991, P = 0.04 in 1992) were positively associated with UCE, whereas the size of the dwelling turned out to be negatively associated with UCE (P = 0.12 in 1991, P = 0.001 in 1992). In small dwellings (< or = 80 m2) the effect of exposure on UCE was much more pronounced. In conclusion, a single UCE measurement provides information which is widely stable within a yearly interval and is related to passive smoke history as well as to socio-economic status and the size of the dwelling. The latter variable should be considered as an effect modifier of exposure on internal dose and should be taken into account in future studies on passive smoke exposure.

Analysis of Variance↗
PubMed1997

The performance of several indicators in detecting recall bias. European Study Group on Infertility and Subfecundity.

Self-reported exposure data are vulnerable to differential recall, which threatens the internal validity and thus the credibility of the study. When a proxy measure of the exposure of interest is available, it may be possible to check for the presence of recall bias due to misclassification of the exposure information. We present a number of indicators of recall bias for case-control studies, and we describe their behavior by means of computer simulations. The indicators are all based upon a comparison between self-reported exposure data and data on job titles grouped into exposure-specific matrices. The indicators are based upon the assumption that job titles are reported without differential misclassification for cases as well as controls. We also assume that exposure data are reported with the same accuracy by workers in different jobs. Under these assumptions, the proposed indicators will provide valuable-although not conclusive-signs of recall bias. The principles elaborated in this paper can be applied to other situations in which self-reported exposure data are used.

Bias↗
PubMed1997

Higher frequency of atopic dermatitis and decrease in viral warts among children exposed to chemicals liberated in a chemical accident in Frankfurt, Germany.

BACKGROUND: In february 1993, a major accident occurred in a chemical plant in Frankfurt, Germany, resulting in the emission of a cloud containing 10 m3 of chlorinated and azo compounds such as o-nitroanisole. An inner zone of the suburb Schwanheim was severely polluted. OBJECTIVE AND METHODS: To assess possible long-lasting effects of this environmental accident on the incidence of skin diseases, we examined a total of 511 children from the inner and outer zones of Schwanheim 18 months later and compared the findings to those obtained from a control group of 143 children from the Frankfurt area and South Hessen. For 402 children of the exposed group, information about the exposure status was available, clearly defining presence of absence in the inner zone at the time of the accident. RESULTS: We observed an overall increase in atopic dermatitis among children present during the accident with an odds ratio of 2.44 (95% CI: 1.25-4.76, p value = 0.009). The prevalence of atopic dermatitis was most marked among exposed children in the age group of 6-12 years with a peak of 22.1% compared to 9.2% in the control group and 11.7% among non-exposed children from the outer zone. All cases of atopic dermatitis were mild, however, and did not require hospital treatment. A history of atopic dermatitis was obtained in 20.3% of all children. In the inner zone, 34.2% of the present cases with atopic dermatitis had a previous history of this disease compared to 31% in the outer zone and only 16.2% in the control group. Other skin diseases, such as birthmarks, congenital skin tumours, psoriasis or acne, did not differ, except for viral warts (verrucae vulgares), which were much more frequent in the control group. CONCLUSIONS: The data suggest that acute exposure to a major chemical burden is a risk factor that contributes even after the considerable time period of 1.5 years to the exacerbation of latent and also the development of 'new' atopic dermatitis.

Accidents, Occupational↗
PubMed1996

Shift work and subfecundity: a European multicenter study. European Study Group on Infertility and Subfecundity.

Shift work has been associated with various unfavorable pregnancy outcomes (ie, pregnancy loss, spontaneous abortion, low birth weight, etc). The suggested underlying mechanism is the interference of shift work with the circadian regulation of human metabolism and, in particular, with the temporal pattern of endocrine function. To analyze the effect of shift work on fecundity, the Time of Unprotected Intercourses (TUI) has been measured in couples recruited in the European Studies on Infertility and Subfecundity, which were undertaken in seven European countries. A low (odds ratio < 2.0) but consistent excess risk of subfecundity (TUI > or = 9.4 months) has been observed both in a representative sample of the general population of women in reproductive age and in a sample of pregnant women or women who had just given birth. The excess risk was also consistently evident both in the subsample of the first pregnancies and in the subsample of the most recent pregnancies. Only the exposure of women to shift work seemed to affect a couple's fecundity; men working shift work did not modify the fecundity pattern of their own couples. No specific job title among shift workers concentrated the risk of subfecundity. No association of menstrual disorders with shift work was identified. Even though residual confounding could partly account for the results and the fact that a plausible biological explanation of the claimed effect is still lacking, data from this study are in favor of an association between shift work and prolonged waiting time to pregnancy.

Adult↗
PubMed1995

Effects of inhalative exposure to dioxins in wood preservatives on cell-mediated immunity in day-care center teachers.

The study investigated the effects of chronic inhalative low-level exposure to dioxins in day-care centers containing wood treated with preservatives on (1) the number of peripheral CD4 and CD8 cells and the CD4:CD8 ratio in peripheral blood and (2) the delayed-type hypersensitivity reaction of the skin (Multitest Méreux). The study population consisted of 221 exposed and 189 unexposed employees of day-care centers in or near Hamburg. A status of decreased skin test reagibility was operationalized as hypoergy I (score < 5 mm), hypoergy II (< or = 1 positive reaction), and anergy (no positive reaction). Taking the fading during postexposure time into account, a surrogate for the dioxin burden based on the concentration of dioxins in indoor air (measured using the 2,3,7,8-TCDD TEF followed by the Federal Republic of Germany) was modeled. No effect was found regarding the number of CD4 cells, CD8 cells, and CD4:CD8 ratio. However, some evidence for an increasing dose-response relationship between inhalative exposure to dioxins and the risk of hypoergy and anergy was found, both in the total study population and among subjects with a short postexposure time (< or = 6 months). Subjects with a short postexposure time and a dioxin burden > 0.6 pg/m3 had a significantly higher risk of hypoergy than unexposed subjects (hypoergy I: OR = 9.51, 95% CI = 1.96-42.02; hypoergy II: OR = 2.92, 95% CI = 1.14-7.5). It is concluded that a suppressive effect of inhalative exposure to dioxins in wood preservatives on human cell-mediated immunity cannot be ruled out.

Adolescent↗
PubMed1995

Sensitization to mite allergens is a risk factor for early and late onset of asthma and for persistence of asthmatic signs in children.

BACKGROUND: To describe the natural history of asthma between the ages of 7 and 10 years and to analyze risk factors for prevalences, as well as new onset of asthma-like symptoms, a longitudinal study of 1812 children was conducted. METHODS: In four surveys, each 1 year apart, four asthma-like symptoms and several hypothetical risk factors were ascertained through standardized questionnaires. Sensitization to seven common inhalant allergens was measured by skin prick testing. Exposure to mite allergens (Der p I, Der f I) was assessed by measuring the antigen concentrations in the dust of each child's mattress. Occurrence of more than one asthma-like symptom closely related to the practioner's diagnoses of bronchial asthma and recurrent wheezy bronchitis was used as the outcome variable. RESULTS: After an initial prevalence of 14.5%, new onset of symptoms in children unaffected at the beginning was reported in 7.2% during the 3 years. Of the factors explaining prevalence and persistence of asthma-like symptoms (sensitization to mite allergens and animal danders, history of hay fever and eczema, low gestational age, male gender, parental atopy), only sensitization to mite allergens (odds ratio = 2.3, 95% confidence interval = 1.1-4.7) and parental atopy (odds ratio = 2.1, 95% confidence interval = 1.2-3.7) were also significantly associated with new onset. In a relatively small number of sensitized subjects with new onset of symptoms (n = 31), mite antigen concentration did not appear to be associated with incidence of symptoms. CONCLUSION: Sensitization to mite allergens antedated the onset of asthma-like symptoms, and no strong effect of allergen exposure on clinical development could be found. Thus the primary focus should be on preventing sensitization to mite allergens by implementing avoidance measures in infancy or at early school age in order to reduce the onset of asthma at a later stage.

Allergens↗