Beth A. Mueller

Semen quality of men employed at a lead smelter.

OBJECTIVE: To evaluate the effects of recent and long term occupational lead exposure on indicators of male reproductive health. METHODS: In a cross sectional study of male employees of a lead smelter (n = 2469), blood samples were obtained from 152 workers including 119 who also provided semen samples. Semen analysis and serum concentrations of testosterone, follicle stimulating hormone, and luteinising hormone were used as indicators of reproductive health. Semen and hormone variables were examined in relation to measures of current and long term body lead burden estimated from current blood lead concentrations and historical blood lead monitoring data. RESULTS: For current blood lead concentration groups of < 15, 15-24, 25-39, > 40 micrograms/dl, the geometric mean sperm concentrations were, respectively, 79.1, 56.5, 62.7, and 44.4 million cells/ml and geometric mean total sperm counts were 186, 153, 137, and 89 million cells (P for trend 0.04). Compared with workers with blood lead concentrations less than 15 micrograms/dl, workers with current blood lead concentrations of 40 micrograms/dl or more had an increased risk of below normal sperm concentration (odds ratio (OR) 8.2, 95% confidence interval (95% CI) 1.2-57.9) and total sperm count (OR 2.6, 95% CI 0.4-15.7), based on World Health Organisation standards. Independent of current lead exposure, sperm concentration, total sperm count, and total motile sperm count were inversely related to measures of long term lead exposure. No association was found between lead exposure and measures of sperm motility, sperm morphology, or serum concentrations of reproductive hormones. CONCLUSIONS: Blood lead concentrations below the currently accepted worker protection criteria seem to adversely affect spermatogenesis.

Periconceptional multivitamin use in relation to the risk of congenital urinary tract anomalies.

To study the relation of maternal periconceptional vitamin use to the risk of a congenital urinary tract anomaly (CUTA), we conducted a case-control study using the Washington State Birth Defect Registry. We identified CUTA cases with no known chromosomal abnormality in seven counties in western Washington State occurring between January 1, 1990, and December 31, 1991. We randomly selected a sample, as controls, of all infants delivered in five large hospitals in King County who did not have a birth defect and who were born in the same year as the cases. About 55% of all infants in King County and a smaller proportion of infants in the other six counties are delivered in these five hospitals. We interviewed mothers of 118 cases and 369 controls to obtain information about their vitamin use during the pregnancy and during the year before the conception. After adjustment for maternal race, family income, county of maternal residence, and birth year, we found that women who used multivitamins during the first trimester had only 15% the risk of bearing a child with a CUTA compared with women who did not take vitamins [odds ratio (OR) = 0.15; 95% confidence interval (CI) = 0.05–0.43]. The reduction was smaller for use restricted to the second or third trimesters (OR = 0.31; 95% CI = 0.09–1.02). Among women who used vitamins during the first trimester, vitamin use before conception was not associated with any further reduction in the risk, nor did there appear to be an association with the amount or brand of vitamin used. Restricting the analysis to residents of King County did not change the results. Our results indicate that prenatal multivitamin use, particularly during the first trimester, may reduce the risk of a CUTA. Because all of the preparations taken by study participants contained many vitamins as well as folic acid, it was not possible to identify which one (or several) chemical(s) may have been responsible for the reduced risk of a CUTA.

Childbearing and survival after breast carcinoma in young women

Many young patients with breast carcinoma have not started, or completed, their desired families. How childbearing after a diagnosis of breast carcinoma affects survival is of importance to these women and their families. The authors measured relative mortality among young patients with breast carcinoma with and without births occurring after diagnosis.

Parental age and risk of childhood cancer: a pooled analysis.

Background: Few risk factors for childhood cancer are well-established. We investigated whether advancing parental age increases childhood cancer risk. Methods: We assessed the relationship between parental age and childhood cancer in a case-control study using pooled population-based data. Our pooling was based on linked cancer and birth registry records from New York, Washington, Minnesota, Texas, and California. Subjects included 17,672 cancer cases diagnosed at ages 0–14 years during 1980–2004 and 57,966 controls born during 1970–2004. Individuals with Down syndrome were excluded. Odds ratios and 95% confidence intervals were calculated by logistic regression for the association between parental age and childhood cancer after adjustment for sex, birth weight, gestational age, birth order, plurality, maternal race, birth year, and state. Results: Positive linear trends per 5-year maternal age increase were observed for childhood cancers overall (odds ratio = 1.08 [95% confidence interval = 1.06–1.10]) and 7 of the 10 most frequent diagnostic groups: leukemia (1.08 [1.05–1.11]), lymphoma (1.06 [1.01–1.12]), central nervous system tumors (1.07 [1.03–1.10]), neuroblastoma (1.09 [1.04–1.15]), Wilms’ tumor (1.16 [1.09–1.22]), bone tumors (1.10 [1.00–1.20]), and soft tissue sarcomas (1.10 [1.04–1.17]). No maternal age effect was noted for retinoblastoma, germ cell tumors, or hepatoblastoma. Paternal age was not independently associated with most childhood cancers after adjustment for maternal age. Conclusions: Our results suggest that older maternal age increases risk for most common childhood cancers. Investigation into possible mechanisms for this association is warranted.

Injuries of the Head, Face, and Neck in Relation to Ski Helmet Use

Background: The extent to which helmet use reduces the risk of injury in ski- and snowboard-related accidents is unclear. We studied the association of helmet use with injuries of the head, face, and neck among skiers and snowboarders involved in falls and collisions. Methods: We conducted a case-control study, using ski patrol injury reports for the years 2000–2005 from 3 ski resorts in the western United States. We identified all skiers and snowboarders involved in falls or collisions who received care from the ski patrol. Helmet use among persons with injuries of the head (n = 2537), face (n = 1122), or neck (n = 565) was compared with helmet use among those involved in falls and collisions who received care for injuries below the neck (n = 17,674). We calculated odds ratios for head, face, and neck injury among helmeted compared with unhelmeted persons. Results: The adjusted odds ratios were 0.85 for head injury (95% confidence interval = 0.76–0.95), 0.93 for facial injury (0.79–1.09), and 0.91 for neck injury (0.72–1.14). Conclusions: Helmets may provide some protection from head injury among skiers and snowboarders involved in falls or collisions.

The effects of alcohol intoxication on the initial treatment and hospital course of patients with acute brain injury.

The effect of alcohol intoxication at the time of injury on hospital outcome was evaluated in 520 adult patients diagnosed with brain injury who were admitted to the emergency department of Harborview Medical Center. Data were collected for each subjects status from field intervention through hospitalization. Serum alcohol levels were measured from blood drawn in the emergency room, and the subjects were stratified into two groups: intoxicated (> or = 100 mg/dL, n = 191) and nonintoxicated (< 100 mg/dL, n = 329). Compared with subjects who were not intoxicated, intoxicated patients were more likely to be intubated in the field or emergency department (relative risk [RR] = 1.3, 95% confidence interval [CI] = 1.1-1.5), require placement of an intracranial pressure bolt (RR = 1.4, 95% CI = 1.1-1.8), develop respiratory distress requiring ventilatory assistance during hospitalization (RR = 1.8, 95% CI = 1.0-3.3), or develop pneumonia (RR = 1.4, 95% CI = 0.9-2.2). The similarities in the clinical presentation of patients with acute brain injury and those who are intoxicated appear to influence prehospital care and also suggest that a more objective assessment of cerebral injury than provided by clinical diagnostic measures alone is required, thus accounting for the elevated likelihood of intracranial pressure monitoring in intoxicated trauma patients.

The association between breast carcinoma and meningioma in women

Published case reports of a possible association between meningioma and breast carcinoma are not uncommon in the literature. Four published analytic studies have addressed this suggested association specifically. Three of these studies reported significant associations, with relative risk estimates mostly between 1.5 and 2.0. The other study reported relative risk point estimates near 1.5, but confidence intervals included 1.0. The current study was a population‐based, retrospective cohort analysis that evaluated the risk of subsequent breast carcinoma in women who were diagnosed with meningioma and the risk of subsequent meningioma in women who were diagnosed with breast carcinoma.

Drug use in trauma victims

We examined the prevalence and characteristics of drug use in a large sample of fatally and nonfatally injured trauma victims. Routinely collected urine specimens from 452 emergency room patients and 160 persons autopsied at the Medical Examiners Office (MEO) were analyzed for the presence of marijuana, cocaine, opiates and benzodiazepines using EMIT enzyme immunoassays. Blood alcohol levels were also measured. Tests were positive for at least one drug in 40.3% of the ER and 18.7% of the MEO samples. Marijuana was the most commonly detected drug in both groups. Specimens were more likely to be positive in younger persons and in males, and in victims of assaults and traffic accidents. Alcohol was present in the blood in more than one third of ER and MEO samples. Only 39.8% of ER samples and 52.3% of MEO samples were negative for both alcohol and drugs.

Occupational injuries and medication use

Recent medication use of 3,394 members of the Group Health Cooperative of Puget Sound (GHC) diagnosed with an incident work-related injury was compared to that of two controls selected from the GHC membership and matched on age, gender, and Standard Industrial Classification Code of their employer. Medication use was determined from the GHC pharmacy data base. The injuries of the cases included 496 fractures or dislocations, 2,728 open wounds, crushing injuries, or superficial injuries, 176 burns, and 64 internal or intracranial injuries. The risk of injury was elevated among users of antihistamines [odds ratio (OR) = 1.5, 95% confidence interval (CI) = 1.1-1.9], antibiotics (OR = 1.2, 95% CI = 1.0-1.5), and diabetes medications (OR = 1.3, 95% CI = 0.9-1.9). The patterns of risk were similar for males and females, but varied by type of injury. No consistent associations between use of antidepressants, antianxiety medication, or narcotics and work-related injury were observed. The use of some medications, or conditions requiring medications, may contribute to the risk of a work-related injury.

Maternal infection and risk of cerebral palsy in term and preterm infants

OBJECTIVE:We tested the hypothesis that term and preterm infants exposed to maternal infection at the time of delivery are at increased risk of developing cerebral palsy (CP).STUDY DESIGN:A population-based case–control study was conducted using Washington State birth certificate data linked to hospital discharge data. Cases (688) were children ≤6 years old, singleton births, hospitalized during 1987 to 1999 with an ICD-9 diagnosis code for CP. Controls were 3068 singleton birth infants randomly selected from birth records for the same years without CP-related hospitalizations. Infection information was available only for the birth hospitalization.RESULTS:Infants of women who had any infection during their hospitalization for delivery were at increased risk of CP (odds ratio (OR) 3.1, 95% confidence interval (CI) 2.3 to 4.2). This was observed for term deliveries (OR 1.8, 95% CI 1.1 to 2.8) and preterm deliveries (OR 2.3, 95% CI 1.3 to 4.2).CONCLUSIONS:Our results suggest that maternal infection is a risk factor for CP in both term and preterm infants.