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Biomedical subjects

Lucina Suarez

Publications and source records attributed to Lucina Suarez.

At least 19 recordsLinked to original sources
PubMed2007

Association of paternal age with prevalence of selected birth defects.

BACKGROUND: Unlike maternal age, the effect of paternal age on birth defect prevalence has not been well examined. We used cases from the Texas birth defect registry, born during 1996-2002, to evaluate the association of paternal age with the prevalence of selected structural birth defects. METHODS: Poisson regression was used to calculate prevalence ratios (PRs) and 95% confidence intervals (CIs) associated with paternal age for each birth defect, adjusting for maternal age, race/ethnicity, and parity. RESULTS: Relative to fathers ages 25-29 years, fathers 20-24 years of age were more likely to have offspring with gastroschisis (PR 1.47, 95% CI: 1.12-1.94), and fathers 40+ years old were less likely to have offspring with trisomy 13 (PR 0.40, 95% CI: 0.16-0.96). No association was seen between paternal age and prevalence of anencephaly and encephalocele. A selection bias was observed for the other birth defects in which cases of younger fathers were more often excluded from study. CONCLUSIONS: In studies of birth defect risk and paternal age, the source of information may affect the validity of findings.

Adult↗
PubMed2006

Match rate and positional accuracy of two geocoding methods for epidemiologic research.

PURPOSE: This study compares the match rate and positional accuracy of two geocoding methods: the popular geocoding tool in ArcGIS 9.1 and the Centrus GeoCoder for ArcGIS. METHODS: We first geocoded 11,016 Texas addresses in a case-control study using both methods and obtained the match rate of each method. We then randomly selected 200 addresses from those geocoded by using both methods and obtained geographic coordinates of the 200 addresses by using a global positioning system (GPS) device. Of the 200 addresses, 110 were case maternal residence addresses and 90 were control maternal residence addresses. These GPS-surveyed coordinates were used as the "true" coordinates to calculate positional errors of geocoded locations. We used Wilcoxon signed rank test to evaluate whether differences in positional errors from the two methods were statistically significantly different from zero. In addition, we calculated the sensitivity and specificity of the two methods for classifying maternal addresses within 1500 m of toxic release inventory facilities when distance is used as a proxy of exposure. RESULTS: The match rate of the Centrus GeoCoder was more than 10% greater than that of the geocoding tool in ArcGIS 9.1. Positional errors with the Centrus GeoCoder were less than those of the geocoding tool in ArcGIS 9.1, and this difference was statistically significant. Sensitivity and specificity of the two methods are similar. CONCLUSIONS: Centrus GeoCoder for ArcGIS for geocoding gives greater match rates than the geocoding tool in ArcGIS 9.1. Although the Centrus GeoCoder has better positional accuracy, both methods give similar results in classifying maternal addresses within 1500 m of toxic release inventory facilities when distance is used as a proxy of exposure.

Databases as Topic↗
PubMed2006

Folic acid awareness and supplementation among Texas women of childbearing age.

OBJECTIVE: Neural tube defects (NTDs) affect about seven of every 10,000 deliveries in Texas. To reduce the risk for NTDs, women are encouraged to supplement with 400 mcg folic acid daily during their reproductive years. This study examines folic acid awareness, knowledge, and supplementation practices among women of childbearing age (WCBA), including residents of Texas-Mexico border as well as women of Hispanic origin/ethnicity, populations that have NTD rates up to three times higher than the national average. METHODS: We conducted a statewide multistage sample telephone survey among Texas women of childbearing age in 2001. In total 1,196 women age 18 to 44 were interviewed. RESULTS: About 78% of WCBA knew about folic acid, 28% knew that folic acid prevents birth defects, and 25% knew to take folic acid before pregnancy. The prevalence of daily folic acid supplementation among all women of childbearing age was 33%. Education was the strongest predictor of folic acid awareness followed by race/ethnicity and age. Significant predictors of daily folic acid supplementation were education and ethnicity. CONCLUSIONS: Our findings suggest the need for more emphases on strategies to improve the level of folic acid supplementation among low educated women, and race ethnic minority populations.

Adolescent↗
PubMed2006

GIS-EpiLink: a spatial search tool for linking environmental and health data.

One inherent characteristic of both environmental data and health data is that they have a location component. This characteristic makes Geographic Information Systems (GIS) an ideal and sometimes indispensable tool for analyzing environmental and health data. Indeed, the past decade witnessed significant efforts in developing GIS tools for supporting epidemiologic research. Despite these efforts, the availability of accessible GIS tools that can be easily used by epidemiologists to link environmental and health data has remained a problem. We present a simple spatial search tool--GIS-EpiLink--that can be used to link environmental and health data when distance between an environmental site and the location of the maternal address of a case or control is used as a proxy for exposure. The tool was used in a research project and it successfully provided the necessary data for epidemiological analyses. This tool should be very useful to epidemiologists in environmental health research.

Environmental Exposure↗
PubMed2006

Maternal residential proximity to waste sites and industrial facilities and oral clefts in offspring.

OBJECTIVE: This study examined the association between oral clefts and maternal residential proximity to waste sites or industries. METHODS: In a case-control study, maternal residences at birth of 1781 births with oral clefts and 4368 comparison births were related to locations of waste sites and industrial facilities in Texas through geographic information systems. RESULTS: Compared with women who lived farther, women who lived within a mile of these sites or facilities were not more likely to have offspring with oral clefts. Among women > or =35 years, oral clefts in offspring were associated with living within a mile of industrial facilities (odds ratio [OR] = 2.4, 95% confidence interval [CI] = 1.3-4.2), especially smelters (OR = 15.0, 95% CI = 2.8-151). CONCLUSION: These findings suggest that maternal residential proximity to industries might be associated with oral clefts in births to older mothers.

Case-Control Studies↗
PubMed2006

Exposure to fumonisins and the occurrence of neural tube defects along the Texas-Mexico border.

Along the Texas-Mexico border, the prevalence of neural tube defects (NTDs) among Mexican-American women doubled during 1990-1991. The human outbreak began during the same crop year as epizootics attributed to exposure to fumonisin, a mycotoxin that often contaminates corn. Because Mexican Americans in Texas consume large quantities of corn, primarily in the form of tortillas, they may be exposed to high levels of fumonisins. We examined whether or not maternal exposure to fumonisins increases the risk of NTDs in offspring using a population-based case-control study. We estimated fumonisin exposure from a postpartum sphinganine:sphingosine (sa:so) ratio, a biomarker for fumonisin exposure measured in maternal serum, and from maternal recall of periconceptional corn tortilla intake. After adjusting for confounders, moderate (301-400) compared with low (< or = 100) consumption of tortillas during the first trimester was associated with increased odds ratios (ORs) of having an NTD-affected pregnancy (OR = 2.4; 95% confidence interval, 1.1-5.3). No increased risks were observed at intakes higher than 400 tortillas (OR = 0.8 for 401-800, OR = 1.0 for > 800). Based on the postpartum sa:so ratio, increasing levels of fumonisin exposure were associated with increasing ORs for NTD occurrences, except for the highest exposure category (sa:so > 0.35). Our findings suggest that fumonisin exposure increases the risk of NTD, proportionate to dose, up to a threshold level, at which point fetal death may be more likely to occur. These results also call for population studies that can more directly measure individual fumonisin intakes and assess effects on the developing embryo.

Adolescent↗
PubMed2005

Maternal exposure to arsenic, cadmium, lead, and mercury and neural tube defects in offspring.

Arsenic, cadmium, lead, and mercury are neurotoxins, and some studies suggest that these elements might also be teratogens. Using a case-control study design, we investigated the relation between exposure to these heavy metals and neural tube defects (NTDs) in offspring of Mexican-American women living in 1 of the 14 Texas counties bordering Mexico. A total of 184 case-women with NTD-affected pregnancies and 225 control-women with normal live births were interviewed about their environmental and occupational exposures during the periconceptional period. Biologic samples for blood lead and urinary arsenic, cadmium, and mercury were also obtained for a subset of these women. Overall, the median levels of these biomarkers for heavy metal exposure did not differ significantly (P > 0.05) between case- and control-women. However, among women in the highest income group, case-women were nine times more likely (95% confidence interval (CI) 1.4-57) than control-women to have a urinary mercury 5.62 microg/L. Case-women were 4.2 times more likely (95% CI 1.1-16) to report burning treated wood during the periconceptional period than control-women. Elevated odds ratios (ORs) were observed for maternal and paternal occupational exposures to arsenic and mercury, but the 95% CIs were consistent with unity. The 95% CIs of the ORs were also consistent with unity for higher levels of arsenic, cadmium, lead, and mercury in drinking water and among women who lived within 2 miles at the time of conception to industrial facilities with reported emissions of any of these heavy metals. Our findings suggest that maternal exposures to arsenic, cadmium, or lead are probably not significant risk factors for NTDs in offspring. However, the elevated urinary mercury levels found in this population and exposures to the combustion of treated wood may warrant further investigation.

Adult↗
PubMed2005

A national agenda for Latino cancer prevention and control.

Although cancer is a leading cause of morbidity and premature death among Latinos, there is limited knowledge of cancer-related issues and priorities of greatest significance to the Latino population, the largest minority group in the nation. This information is vital in helping to guide Latino cancer research, training, and awareness efforts at national, regional, and local levels. To help identify cancer issues of greatest relevance to Latinos, Redes En Accion, The National Hispanic/Latino Cancer Network, a major network among the National Cancer Institute's Special Populations Networks, conducted a survey of 624 key opinion leaders from around the country. Respondents were asked to rank the three cancer sites most important to Latinos in their region and the five issues of greatest significance for this population's cancer prevention and control. Recommendations were prioritized for three specific areas: 1) research, 2) training and/or professional education, and 3) awareness and/or public education. Among cancers, breast carcinoma was ranked number one, followed in order by cervical and lung carcinomas. The issues of greatest significance to Latinos were 1) access to cancer screening and care, 2) tobacco use, 3) patient-doctor communication, 4) nutrition, and 5) risk communication. This survey solicited information from scientists, health care professionals, leaders of government agencies, professional and community-based organizations, and other stakeholders in Latino health. The results laid the foundation for a national Redes En Accion Latino cancer agenda, thus providing a useful tool for individuals and organizations engaged in cancer prevention and control efforts among the Hispanic-Latino population.

Adult↗
PubMed2005

Iron status indicators in women with prior neural tube defect-affected pregnancies.

OBJECTIVES: Iron deficiency is the most common nutrient deficiency in pregnant women and has been linked to negative impacts on the fetus. We describe the association of various iron-deficiency indices with risk of neural tube defect (NTD) among a high-risk Mexican-American population. METHODS: The study included 158 case-women (NTD-affected pregnancies) and 189 control-women (normal births) who were residents of the 14 Texas-Mexico border counties and delivered or terminated pregnancies during 1995-2000. In-person interviews and laboratory assays provided data. RESULTS: Case-women had higher odds of having minimal or no iron stores (serum ferritin <30 microg/L) compared to control-women (OR = 1.8, 95% CI = 1.0-3.3). The risk effect was not explained by low folate or B12 or other risk factors. CONCLUSION: Low serum ferritin may reflect the additive effect of multiple long-term factors, many of them related to poverty such as poor quality diet, lack of supplementation, and frequent pregnancies. Interpartum care is indicated in this population.

Adult↗
PubMed2005

Implementation and outcomes of recommended folic acid supplementation in Mexican-American women with prior neural tube defect-affected pregnancies.

BACKGROUND: Upon discovering an NTD incidence rate of 27/10,000 in a Texas border county, the Texas Department of Health initiated folic acid intervention for prevention of recurrent NTDs in this predominantly Mexican-American population. This paper describes compliance of this population with USPHS folic acid recommendations and the impact of supplementation on pregnancy outcomes. METHODS: Based upon information from active surveillance, field teams personally contacted women having NTD-affected pregnancies to enroll them in FA intervention. Enrollees were provided FA at home visits at 3-month intervals throughout the project. RESULTS: Of 405 women identified with NTD-affected pregnancies, 299 (73.8%) enrolled in the intervention. One hundred ninety-three pregnancies occurred among 138 women. FA supplementation of 0.4 mg/day or more occurred during the last month preconception in 161 (83.4%) of the 193 pregnancies. No NTDs were detected in the 130 livebirths to women who received supplementation nor were NTDs detected in the 23 supplemented women who experienced pregnancy loss. CONCLUSIONS: Supplementation was successful in preventing recurrent NTDs in Mexican-American women.

Adult↗
PubMed2004

Prevalence of craniorachischisis in a Texas-Mexico border population.

BACKGROUND: The most severe neural tube defect (NTD), craniorachischisis, is characterized by anencephaly confluent with spina bifida open from the cervical to the lumbar region. We describe the prevalence of craniorachischisis among the Texas-Mexico border population during the period 1993-1999. METHODS: An active surveillance system identified all clinically apparent NTD-affected fetuses and infants born to mothers residing and delivering in any of the 14 Texas-Mexico border counties. Craniorachischisis cases included live-born, stillborn, and therapeutic abortions. RESULTS: A total of 16 craniorachischisis cases were identified for a total prevalence of 0.51 per 10,000 live births (Mexican American prevalence, 0.52 per 10,000) and a prevalence of 0.28 per 10,000 live births for cases of 20 weeks gestation or greater. CONCLUSIONS: The prevalence of craniorachischisis was higher than that reported in Atlanta (0.1 per 10,000 live births), but much lower than that reported in Northern China (10.7 per 10,000 births). In this high NTD prevalence region, it is possible that a multiplicity of risk factors, mostly related to poverty, contribute to a high prevalence of craniorachischisis.

Black or African American↗
PubMed2004

The effect of fever, febrile illnesses, and heat exposures on the risk of neural tube defects in a Texas-Mexico border population.

BACKGROUND: Hyperthermia produces neural tube defects (NTDs) in a variety of animal species. Elevated maternal body temperatures may also place the developing human embryo at risk. We examined the relation between maternal hyperthermia and the development of NTDs in a high-risk Mexican-American population. METHODS: Case-women were Mexican-American women with NTD-affected pregnancies who resided and delivered in any of the 14 Texas counties bordering Mexico, during 1995-2000. Control-women were randomly selected from study area residents delivering normal live births, frequency-matched to cases by hospital and year. Information on maternal fevers, febrile illnesses, exposures to heat generated from external sources, and hyperthermia-inducing activities was gathered through in-person interviews, conducted about six weeks postpartum. RESULTS: The risk effect (OR) associated with maternal fever in the first trimester, compared to no fever, was 2.9 (95% CI, 1.5-5.7). Women taking fever-reducing medications showed a lower risk effect (OR, 2.4; 95% CI, 1.0-5.6) than those who did not (OR, 3.8; 95% CI, 1.4-10.9). First-trimester maternal exposures to heat devices such as hot tubs, saunas, or electric blankets were associated with an OR of 3.6 (95% CI, 1.1-15.9). Small insignificant effects were observed for activities such as cooking in a hot kitchen (OR, 1.6; 95% CI, 1.0-2.6) and working or exercising in the sun (OR, 1.4; 95% CI, 0.9-2.2). CONCLUSIONS: Maternal hyperthermia increases the risk for NTD-affected offspring. Women intending to become pregnant should avoid intense heat exposures, carefully monitor and manage their febrile illnesses, and routinely consume folic acid supplements.

Adult↗
PubMed2004

Promoter haplotype combinations for the human PDGFRA gene are associated with risk of neural tube defects.

Recent animal studies suggested that deregulated expression of the platelet-derived growth factor receptor alpha (PDGFRalpha) may contribute to the failure of normal neural tube closure (NTC). There is also suggestive evidence that the promoter haplotype of the PDGFRA is associated with genetic susceptibility in human neural tube defects (NTDs). The purpose of our study was to investigate the association between promoter haplotype combinations of the human PDGFRA gene and risk for NTDs in a Hispanic population from the Texas-Mexico border region. This population has a considerably higher prevalence of NTDs (16/10,000 live births) than that generally reported in the United States (8-10/10,000 live births). In the present study, NTDs were defined as spina bifida or anencephaly. The haplotype of PDGFRA gene promoter was determined by direct DNA sequence analysis. Two novel haplotypes, H2epsilon and H1beta, were found. We observed significant differences among variable haplotype groups from in vitro transient transfection studies in U2-OS osteosarcoma cell and two other cell lines (HeLa cell and MCF7 cell). Result from our case-control study demonstrated that the frequencies of haplotypes with low transcription activity were significantly higher in NTD mothers than that observed in control mothers (odds ratio=2.2, 95% CI=1.0-4.6). Infants with at least one low activity allele showed slightly higher risk (odds ratio=1.5, 95%=0.8-3.1). Our study suggests that the reduced transcriptional activity of PDGFRA gene could increase the risk of having an NTD-affected pregnancy.

Adult↗
PubMed2004

Cancer risk factors among men of diverse Hispanic or Latino origins.

BACKGROUND: Personal health behaviors play a fundamental role in premature cancer morbidity and mortality. However, routine risk factor data on Latino groups are lacking. Knowledge of cancer risk prevalence by ethnoregional groups is particularly important for development of effective prevention and control strategies. METHODS: Using the diverse populations and sites involved in the National Hispanic Leadership Initiative on Cancer (NHLIC): En Acción, this paper examines prevalence of six cancer risk factors among Mexican, Puerto Rican, Cuban, and Central American adult males in eight U.S. cities. Data were collected through two telephone surveys. The 1993-1994 sample consisted of 4170 males (2041 <40 years and 2120 > or =40 years). The 1997-1998 sample consisted of 4486 males (2286 <40 years and 2200 > or =40 years). RESULTS: Clear differences exist in risk factor prevalence among Latino subgroups. Overall, riskiest behaviors were found among Mexican American men in Texas, more of whom smoked, engaged in acute alcohol drinking, and had poorer diets and higher obesity levels than other Latino men. CONCLUSIONS: Root causes of these ethnoregional differences are likely due to both economic and cultural factors. Cancer prevention and control strategies and programs should be tailored to address specific needs of each population group.

Adult↗
PubMed2004

Dietary nitrites and nitrates, nitrosatable drugs, and neural tube defects.

BACKGROUND: Amine-containing (nitrosatable) drugs can react with nitrite to form N-nitroso compounds, some of which are teratogenic. Data are lacking on whether dietary intake of nitrates and nitrites modifies the association between maternal nitrosatable drug exposure and neural tube defects (NTDs) in offspring. METHODS: We examined nitrosatable drug exposure and NTD-affected pregnancies in relation to dietary nitrite and total nitrite intake in a case-control study of Mexican American women. We interviewed 184 women with NTD-affected pregnancies and 225 women with normal live births, including questions on periconceptional drug exposures and dietary intake. For 110 study participants, nitrate was also measured in the usual source of drinking water. RESULTS: Women who reported taking drugs classified as nitrosatable were 2.7 times more likely to have an NTD-affected pregnancy than women without this exposure (95% confidence interval [CI] = 1.4-5.3). The effect of nitrosatable drugs was observed only in women with higher intakes of dietary nitrite and total nitrite (dietary nitrite + 5% dietary nitrate). Women within the highest tertile (greater than 10.5 mg/day) of total nitrite were 7.5 times more likely to have an NTD-affected pregnancy if they took nitrosatable drugs (95% CI = 1.8-45.4). The association between nitrosatable drug exposure and NTDs was also stronger in women whose water nitrate levels were higher. CONCLUSIONS: Findings suggest that effects of nitrosatable drug exposure on risk for neural tube defects in offspring could depend on the amounts of dietary nitrite and total nitrite intake.

Adolescent↗
PubMed2003

Diarrhea: a new risk factor for neural tube defects?

BACKGROUND: Neural tube defects (NTDs) affect approximately 4000 US pregnancies annually. Folic acid supplementation taken before conception protects against the occurrence of NTDs. Adequate levels of vitamin B12 also appear to play a significant role. Gastrointestinal disturbances, such as those caused by diarrhea, might negatively affect the availability of these vitamins, thereby increasing the risk of these birth defects. METHODS: To determine whether periconceptional diarrhea increases the risk of NTD-affected pregnancies, a population-based case-control study was conducted in the 14 Texas-Mexico border counties. Information on diarrhea and other risk factors was ascertained by in-person interview. Study subjects were Mexican-American women who resided and delivered in any border county during 1995-2000. Case women, identified through active surveillance, had liveborn or stillborn infants or fetuses diagnosed with anencephalus, spina bifida, or encephalocele. Control women were randomly selected from women delivering normal live births in study area health facilities. RESULTS: One or more episodes of periconceptional diarrhea were associated with increased risk of NTD-affected pregnancies compared to no episodes of diarrhea (OR = 3.7, 95% CI = 1.8-7.6). This association was independent of fever, obesity, maternal age, maternal birthplace, income, prior unproductive pregnancy, and dietary plus multivitamin folate intake, known risk factors for NTDs. CONCLUSIONS: Confirmation of this new risk factor might have public health implications due to the feasibility of modifying exposure.

Adult↗
PubMed2003

Maternal serum B12 levels and risk for neural tube defects in a Texas-Mexico border population.

PURPOSE: Neural tube defects (NTDs) are common birth defects that can be prevented with folate fortification and supplementation. Studies suggest that other nutrients may also be essential to neural tube closure and have a potential role in risk reduction, with vitamin B(12) mentioned most often. We determined the effect of maternal serum B(12) levels, measured postpartum, on the risk of NTDs among a high risk Mexican American population. METHODS: The case-control study included 157 Mexican American women with NTD-affected pregnancies and 186 Mexican American women with normal pregnancies, who were residents of Texas-Mexico border counties and delivered during 1995 to 2000. RESULTS: Compared with women in the highest vitamin B(12) quintile, women in the lowest quintile showed a strong risk effect (odds ratio (OR) = 3.0, confidence interval (CI): 1.4, 6.3); while those in the 2nd and 3rd quintiles showed moderate risk effects (OR = 1.6, CI = 0.7, 3.6 and OR = 1.7, CI = 0.8, 3.8, respectively). Adjusting for obesity, vitamin supplements, dietary folate, dietary B(12), red blood cell folate, and other covariates did not materially change these estimates. CONCLUSIONS: Insufficient levels of serum B(12), which are not normally indicative of a classical vitamin B(12) deficiency nor stem from an inadequate diet, may be an important etiologic factor for NTDs in this population.

Adult↗