Quantifying cancer risk from exposures to medical imaging in the Risk of Pediatric and Adolescent Cancer Associated with Medical Imaging (RIC) Study: research methods and cohort profile.

PURPOSE: The Risk of Pediatric and Adolescent Cancer Associated with Medical Imaging (RIC) Study is quantifying the association between cumulative radiation exposure from fetal and/or childhood medical imaging and subsequent cancer risk. This manuscript describes the study cohorts and research methods. METHODS: The RIC Study is a longitudinal study of children in two retrospective cohorts from 6 U.S. healthcare systems and from Ontario, Canada over the period 1995-2017. The fetal-exposure cohort includes children whose mothers were enrolled in the healthcare system during their entire pregnancy and followed to age 20. The childhood-exposure cohort includes children born into the system and followed while continuously enrolled. Imaging utilization was determined using administrative data. Computed tomography (CT) parameters were collected to estimate individualized patient organ dosimetry. Organ dose libraries for average exposures were constructed for radiography, fluoroscopy, and angiography, while diagnostic radiopharmaceutical biokinetic models were applied to estimate organ doses received in nuclear medicine procedures. Cancers were ascertained from local and state/provincial cancer registry linkages. RESULTS: The fetal-exposure cohort includes 3,474,000 children among whom 6,606 cancers (2394 leukemias) were diagnosed over 37,659,582 person-years; 0.5% had in utero exposure to CT, 4.0% radiography, 0.5% fluoroscopy, 0.04% angiography, 0.2% nuclear medicine. The childhood-exposure cohort includes 3,724,632 children in whom 6,358 cancers (2,372 leukemias) were diagnosed over 36,190,027 person-years; 5.9% were exposed to CT, 61.1% radiography, 6.0% fluoroscopy, 0.4% angiography, 1.5% nuclear medicine. CONCLUSION: The RIC Study is poised to be the largest study addressing risk of childhood and adolescent cancer associated with ionizing radiation from medical imaging, estimated with individualized patient organ dosimetry.

Prevalence of diabetes and glucose intolerance in an ethnically diverse rural community of Hawaii.

BACKGROUND: We report the prevalence of diabetes in a rural, multiethnic community in Hawaii, of predominantly Asian and Native Hawaiian ancestry, by using 1997 World Health Organization diagnostic criteria applied to a two-hour oral glucose tolerance test. METHODS: This cross-sectional survey included 1452 men and nonpregnant women who were >18 years of age. Blood was drawn in the fasting and postchallenge states. Individuals under pharmacologic treatment for diabetes were excluded. Information obtained included demographics, medical history, dietary intake, physical activity, and anthropometric measurements. RESULTS: Prevalence of diabetes was approximately three-fold higher among Asian and Native Hawaiian ancestry groups than among Caucasians, even after adjusting for other risk factors. Furthermore, diabetes prevalence was similar among all non-Caucasian ethnic groups despite significant differences in body mass indices. CONCLUSIONS: These findings indicate that earlier reports of high prevalence of diagnosed diabetes among Asians and Hawaiian ethnic groups were not due to detection bias, since our study revealed similar prevalence of previously unrecognized diabetes. Furthermore, similar prevalence among these groups was observed despite significant differences in body mass indices, diet, and physical activity. This apparent paradox may reflect limitations in the measurement of these risk factors; differences in the impact of these risk factors on diabetes risk in different ethnic groups; or ethnic differences in lifestyle, biochemical, or genetic factors that were not examined in this study.

Association between angiotensin-converting enzyme gene polymorphisms and QT duration in a multiethnic population in Hawaii.

OBJECTIVES: Recent studies have suggested that heart-rate corrected QT interval (QTc) in normal populations may be influenced by genetic factors. We report findings of a study of the relationship between QTc, increased QTc (> 440 ms) and angiotensin-converting enzyme (ACE) genotype in a multiethnic, population-based study completed in rural Hawaii. METHODS: Blood samples were obtained while fasting and after an oral glucose challenge from 1452 individuals between 1997 and 2000. The clinical examination included an electrocardiogram. Medical histories, behavioral and socio-demographic information were obtained during the interview. Ethnicity was estimated by self-report. The insertion/deletion (I/D) polymorphism in intron 16 of the ACE gene was determined by polymerase chain reaction (PCR) from a random sample of 588 participants. Multiple linear and logistic regression was used to test for associations between QTc and ACE gene polymorphisms. RESULTS: The overall crude prevalence of increased QTc was 21.2%. The prevalence of increased QTc was lowest among those with ACE DD genotype, and highest among those with ACE insertion/insertion (II) genotype. The adjusted odds ratio for increased QTc was 2.29 (95% CI 1.02-5.12) and 3.61 (95% CI 1.60-8.13) for ID and II genotypes, respectively, compared to the DD genotype. The test for trend was highly significant (p < 0.001). CONCLUSIONS: The ACE insertion allele was associated with increased prevalence of prolonged QTc independent of ethnicity, age, gender, and BMI. These findings may implicate the ACE gene as an important genetic risk factor for cardiovascular disease morbidity and mortality.

Native Hawaiian Birth Weight and Infant Mortality: Is Birth in Hawai'i Protective?

PURPOSE OF THE PAPER: This study provides baseline information on the characteristics of Native Hawaiian mothers and the health status of their infants, comparing residents of Hawaii with those of the continental U.S. The impact of Hawaii residence on low birth weight and infant mortality among Native Hawaiians is assessed. SUMMARY OF METHODS UTILIZED: Data from the National Center for Health Statistics 1983­1987 Linked U.S. Live Birth and Infant Death file were used to examine parental characteristics, prenatal care use and infant outcomes using chi­square and logistic regression procedures. PRINCIPAL FINDINGS: Despite a higher sociodemographic risk profile among Hawaii resident mothers, preterm birth, low and very low birth weight percentages were similar. Continental infants had significantly highter percentages of very pre­term birth and macrosomia. Mortality rates in both the neonatal and post­neonatal periods, and for SIDS and perinatal causes were elevated among continental infants. Hawaii residence had a borderline protective effect on infant mortality, wehn sociodemographic and prenatal care differences were controlled. CONCLUSIONS: This study suggests a possibly protective effect of Hawaii residence on the health of Native Hawaiian infants during the period of following employer­mandated health insurance coverage but before the initiation of "gap­group" coverage and the Native Hawaiian Health Care Systems in Hawaii. RELEVANCE TO ASIAN PACIFIC ISLANDER AMERICAN POPULATIONS. This is the first report documenting the sociodemographic and health status of the growing number of Native Hawaiian mothers and their infants residing outside of Hawaii. Expanded health insurance coverage and culturally appropriate and accessible health care may contribute to improved infant health status in Hawaii. Their absence, along with possible barriers of sociocultural isolation, may account for the poorer than expected outcomes of continental infants and predict a widening gap between them and their counterparts in Hawaii. A follow­up study of the health status of Native Hawaiian mothers and infants, and their access to appropriate care in Hawaii and thei continental U.S. is recommended.

Pregnancy outcomes among Whites and Filipinos: A paradoxical birth weight-neonatal mortality relationship.

Evidence from the Philippines suggests that, compared to Whites, infants born to Filipino women are more likely to be low birth weight. A paucity of information is available regarding birth outcomes of U.S.-born Filipinos. Using 1979-1987 Hawaii vital record data on single live births to resident mothers, this study compares the maternal characteristics and pregnancy outcomes of White and Filipino mothers, Filipino mothers were significantly more likely to be <18 years of age and single, and have lower educational attainment and less adequate utilization of prenatal care. Significantly higher percentages of very preterm, preterm, very low birth weight, low birth weight, and small for gestational age infants were found for Filipinos. The birth weight-specific neonatal mortality rates for Filipinos compared favorably to Whites except at the high end of the birth weight distribution. After taking into account maternal sociodemographic risk and prenatal care factors in a logistic regression, a significant ethnic difference in low birth weight persisted but was not found for neonatal mortality. These data may suggest that similar neonatal mortality rates among ethnic groups may be possible in the face of persistent birth weight distribution differences and add to the growing evidence that a single standard of low birth weight may be inappropriate as an universal indicator of health status risk in a multi-ethnic population. © 1993 Wiley-Liss, Inc.