Regional disparity of HIV incidence and prevalence among men who have sex with men.

BACKGROUND: HIV incidence can be estimated with cross-sectional studies using clinical, serological, and molecular data. Worldwide, HIV incidence data in only men who have sex with men (MSM) are scarce and principally focus on those with healthcare or under treatment. However, better estimates can be obtained through studies with national representativeness. The objective was to estimate the prevalence, incidence, and factors associated with acquiring HIV in a national sample of MSM who attend meeting places, considering geographical regions. METHODS: A nationally representative survey of MSM attending meeting places was performed in Mexico. Participants answered a questionnaire, and a dried blood spot (DBS) was collected. Samples were classified as recent infections using an algorithm with HIV status, antiretroviral therapy, and the result of BED-EIA assay. Parameters were analysed considering regions and demographic and sexual behaviour characteristics. RESULTS: The national HIV prevalence was 17.4% with regional differences; the highest prevalence (20.7%) was found in Mexico City, and the lowest prevalence was found in the West region (11.5%). The incidence was 9.4 per 100 p/y, with regional values from 6.2 to 13.2 for the Northeast and the Centre regions, respectively. Age, age at sexual debut, low wealth index, and rewarded sex were associated with HIV prevalence. Centre region, use of private clinics as health services, and having sex exclusively with men were associated with recent HIV infections. CONCLUSIONS: The incidence and prevalence showed regional differences, suggesting a difference in the dynamics of HIV transmission; some regions have a greater case accumulation, and others have a greater rate of new infections. Understanding this dynamic will allow developing health programs focused on HIV prevention or treating people already living with HIV.

Overweight and obesity status from the prenatal period to adolescence and its association with non-alcoholic fatty liver disease in young adults: cohort study.

OBJECTIVE: To examine the associations of maternal and child overweight status across multiple time-points with liver fat content in the offspring during young adulthood. DESIGN: Cohort study. SETTING: ELEMENT Cohort in Mexico City. POPULATION: Pregnant women with singleton births (n = 97). METHODS: We quantified hepatic triglyceride content (liver fat content) by proton magnetic resonance spectroscopy (1H MRS) and conventional T2-weighted MRIs (3T scanner) in 97 young adults from the ELEMENT birth cohort in Mexico City. Historical records of the cohort were used as a source of pregnancy, and childhood and adolescence anthropometric information, overweight and obesity (OWOB) were defined. Adjusted structural equation models were run to identify the association between OWOB in different life stages with liver fat content (log-transformed) in young adulthood. MAIN OUTCOME: Maternal OWOB at the time of delivery was directly and indirectly associated with the liver fat content in the offspring at young adulthood. RESULTS: Seventeen percent of the participants were classified as having NAFLD. We found a strong association of OWOB between all periods assessed. Maternal OWOB at time of delivery (ß = 1.97, 95% CI 1.28-3.05), and OWOB status in the offspring at young adulthood (ß = 3.17, 95% CI 2.10-4.77) were directly associated with the liver fat content in the offspring. Also, maternal OWOB was indirectly associated with liver fat content through offspring OWOB status. CONCLUSION: We found that maternal OWOB status is related to fatty liver content in the offspring as young adults, even after taking into account OWOB status and lifestyle factors in the offspring. TWEETABLE ABSTRACT: There was an association between pre-pregnancy overweight and the development of NAFLD in adult offspring.

Diabetes is associated with a higher risk of mortality among women in a middle-income country: Results form the Mexican Teacher's cohort study.

AIMS: In Mexico City, the mortality rate among patients with diabetes appears to be four times that of people without diabetes. Our study aimed to refine analyses of the impact of diabetes on mortality in a large cohort of women from different areas in Mexico with healthcare insurance. METHODS: Our study followed 111,299 women with comprehensive healthcare coverage from the Mexican Teachers' Cohort. After a median follow-up of 7.8years, 5514 (5%) prevalent self-reported diabetes cases and 4023 incident cases were identified, while deaths were identified through employers' databases and next-of-kin reports, with dates and causes of death for 1121 women obtained from mortality databases. Hazard ratios (HRs) for total and cause-specific mortality were estimated by Cox regression models, using follow-up time as the time scale and allowing for time-variable diabetes status after adjusting for age, socioeconomic status, use of health services, and anthropometric and lifestyle variables. RESULTS: In multivariable-adjusted models, the HR for all-cause mortality was 3.28 (95% CI: 2.86-3.75) in women with vs. without diabetes. The impact of diabetes on mortality was higher in rural vs. urban areas (HR: 4.72 vs. 2.98, respectively). HRs were 1.57 and 23.44 for cancer and renal disease mortality, respectively. CONCLUSION: In women with healthcare coverage in Mexico, the magnitude of the association between diabetes and all-cause mortality was higher than that observed in high-income countries, but less than what has previously been reported for Mexico. Such elevated mortality suggests a lack of adequate access to quality diabetes care in the population despite comprehensive healthcare coverage.

Early introduction and cumulative consumption of sugar-sweetened beverages during the pre-school period and risk of obesity at 8-14 years of age.

BACKGROUND: Consumption of sugar-sweetened beverages (SSB) has been associated with risk of obesity, but little evidence exists to evaluate if age of introduction and cumulative SSB consumption increases risk in children. OBJECTIVES: The objective of the study was to estimate the relationship between age of introduction and cumulative SSB consumption with risk of obesity in 227 Mexican children. METHODS: SSB intake was measured every 6 months; age of introduction and cumulative consumption during the pre-school period were calculated. Height, weight, waist circumference, SSB intake and other relevant variables were measured at age 8-14 years and obesity defined using standard criteria. RESULTS: All participants were introduced to SSB before age 24 months and most (73%) before 12 months. Early SSB introduction (≤12 months) was not significantly associated with increased odds of obesity (odds ratio [OR] = 2.00, 95% confidence interval [CI]: 0.87, 4.59). However, children in the highest tertile of cumulative SSB consumption, compared with the lowest, had almost three times the odds of general (OR = 2.99, 95% CI: 1.27, 7.00) and abdominal (OR = 2.70, 95% CI: 1.03, 7.03) obesity at age 8-14 years. CONCLUSIONS: High SSB consumption increased the likelihood of obesity in 8-14-year-old children. Our results suggest that SSB intake should be delayed and excessive SSB consumption in pre-school period should be avoided.

Price elasticity of the demand for sugar sweetened beverages and soft drinks in Mexico.

A large and growing body of scientific evidence demonstrates that sugar drinks are harmful to health. Intake of sugar-sweetened beverages (SSB) is a risk factor for obesity and type 2 diabetes. Mexico has one of the largest per capita consumption of soft drinks worldwide and high rates of obesity and diabetes. Fiscal approaches such as taxation have been recommended as a public health policy to reduce SSB consumption. We estimated an almost ideal demand system with linear approximation for beverages and high-energy food by simultaneous equations and derived the own and cross price elasticities for soft drinks and for all SSB (soft drinks, fruit juices, fruit drinks, flavored water and energy drinks). Models were stratified by income quintile and marginality index at the municipality level. Price elasticity for soft drinks was -1.06 and -1.16 for SSB, i.e., a 10% price increase was associated with a decrease in quantity consumed of soft drinks by 10.6% and 11.6% for SSB. A price increase in soft drinks is associated with larger quantity consumed of water, milk, snacks and sugar and a decrease in the consumption of other SSB, candies and traditional snacks. The same was found for SSB except that an increase in price of SSB was associated with a decrease in snacks. Higher elasticities were found among households living in rural areas (for soft drinks), in more marginalized areas and with lower income. Implementation of a tax to soft drinks or to SSB could decrease consumption particularly among the poor. Substitutions and complementarities with other food and beverages should be evaluated to assess the potential impact on total calories consumed.

Drug resistance in Mexico: results from the National Survey on Drug-Resistant Tuberculosis.

OBJECTIVE: To present estimations obtained from a population-level survey conducted in Mexico of prevalence rates of mono-, poly- and multidrug-resistant strains among newly diagnosed cases of pulmonary tuberculosis (TB), as well as the main factors associated with multidrug resistance (combined resistance to isoniazid and rifampicin). DESIGN: Study data came from the National Survey on TB Drug Resistance (ENTB-2008), a nationally representative survey conducted during 2008-2009 in nine states with a stratified cluster sampling design. Samples were obtained for all newly diagnosed cases of pulmonary TB in selected sites. Drug susceptibility testing (DST) was performed for anti-tuberculosis drugs. RESULTS: DST results were obtained for 75% of the cases. Of these, 82.2% (95%CI 79.5-84.7) were susceptible to all drugs. The prevalence of multidrug-resistant TB (MDR-TB) was estimated at 2.8% (95%CI 1.9-4.0). MDR-TB was associated with previous treatment (OR 3.3, 95%CI 1.1-9.4). CONCLUSIONS: The prevalence of drug resistance is relatively low in Mexico. ENTB-2008 can be used as a baseline for future follow-up of drug resistance.

Eficacia y seguridad del tratamiento antibiótico domiciliario endovenoso en pacientes con patología infecciosa procedentes del servicio de urgencias / Safety and efficacy of home intravenous antibiotic therapy for patients referred by the hospital emergency department

Objetivo: Analizar la eficacia y seguridad del tratamiento antibiótico domiciliario endovenoso (TADE) en infecciones de pacientes procedentes del servicio de urgencias. Método: Estudio prospectivo de los pacientes ingresados para TADE en la unidad de hospitalización a domicilio (HaD) del Hospital de Sabadell entre enero del 2008 a junio del 2011. Se comparan dos grupos: pacientes derivados desde urgencias frente a pacientes procedentes de otros dispositivos asistenciales. Las variables analizadas fueron edad, sexo, estancia media, índice de Barthel, vía y forma de administración del antibiótico, tipo de infección, microorganismo aislado, antibiótico utilizado, índices de reingreso precoz y tardío y complicaciones médicas y asociadas al acceso venoso. El TAD Ese autoadministró por parte del cuidador y/o el paciente mediante dispositivos de infusión elastoméricos. Resultados: Se reclutaron 409 pacientes que generaron 492 episodios de TADE, 92 (..) (AU)

Objective: To analyze the safety and efficacy of home intravenous antibiotic therapy (HIVAT) for patients with infections discharged from the emergency department and referred to the home hospital program. Methods: Prospective study of patients referred to the home hospital program of Hospital de Sabadell for HIVAT between January 2008 and June 2011. We compared 2 groups: patients referred by the emergency department and patients referred by any other department or service. Variables analyzed included age, sex, mean stay in the program, Barthel index, route and method for administering the antibiotic, type of infection, microorganism isolated, antibiotic prescribed, early and late readmission rates, and complications (medical and those associated with venous access). HIVAT was self-administered by the patient (or home caregiver) through an elastomeric infusion device. Results: We studied 409 patients and 492 courses of HIVAT; 92 patients were referred by the emergency department and400 came from other care units. Emergency patients were older, had greater functional impairment, a shorter stay in the (..) (AU)

Protocolo de actuación ante el maltrato infantil y situaciones de riesgo en el ámbito sanitario en la provincia de Salamanca / Action protocol when there is child battering and situations of risk in the health care setting in the province of Salamanca (Spain)

El maltrato infantil en sus diversas formas de manifestaciónes un problema que afecta a la infancia en el mundo entero y los pediatras, como responsables de la salud integral del niño, debemos estar concienciados de la importancia de intervenir en nuestro entorno para identificar situaciones de riesgo y aprovechar todos los recursos sociosanitarios para la implementación de medidas preventivas adecuadas. Se ha elaborado un protocolo con el fin de facilitarla atención adecuada de estos niños en la provincia de Salamanca (AU)

Child battering in its different manifestation forms is a problem that affects young children worldwide. The pediatricians, who are responsible for the integral health of the child, should be aware of the importance of intervening within their setting in order to identify risk situations and to take advantage of the social-health care resources for the establishment of adequate preventive measures. A protocol has been elaborated in order to facilitate adequate care for these children in the providence of Salamanca (AU)

The impact of taxation on tobacco consumption in Mexico.

BACKGROUND: The price of cigarettes to consumers in Mexico, and Latin America in general, remains low in comparison with other regions of the world. In Mexico, taxes represented 59% of the total price of cigarettes in 2006, compared to 75% or more in many high-income countries. The feasibility of raising taxes on cigarettes in Mexico--to both discourage consumption and increase revenues--is an important policy question. METHODS: Using household survey data, we undertake a pooled cross-sectional analysis of the demand for cigarettes in Mexico. We use a two-part model to estimate the price elasticity of cigarettes. This model controls for the selection effect that arises from the fact that the impact of price on the decision to smoke or not is estimated using all households in the dataset. RESULTS: The results indicate that price is a significant factor in household decisions concerning smoking and the number of cigarettes smoked. Holding other factors constant, our simulations show that a 10% increase in the cigarette tax in Mexico--calculated as a percentage of the price--yields a 12.4% increase in the price to the consumer, a 6.4% decrease in consumption of cigarettes and a 15.7% increase in the revenue yielded by the tax. CONCLUSION: In Mexico, there are strong arguments for increasing cigarette taxes. Revenue raised could be used to further prevent tobacco consumption and to finance current funding shortages for the treatment of diseases related to smoking.

GSTM1 and GSTP1 and respiratory health in asthmatic children exposed to ozone.

Acute exposure to ozone has been related to a wide spectrum of health effects in susceptible individuals. Genetic factors may influence interindividual variation in ozone response. The current authors investigated the relationships between common polymorphisms in two genes involved in response to oxidative stress, i.e. glutathione S-transferases M1 (GSTM1) and P1 (GSTP1), and both respiratory symptoms and lung function in response to ozone among childhood asthmatics. A total of 151 asthmatic children, who were participants in a randomised controlled trial of antioxidant vitamin supplementation in Mexico City, were studied. Children were genotyped using PCR methods and followed from October 1998-April 2000. Increases in reported breathing difficulty were associated with ozone exposure in children with GSTM1 null (8%, 95% confidence interval (CI) 1-15%, per 20-ppb increase in 1-h maximum daily average over 7 days) or GSTP1 Valine/Valine (Val/Val) genotypes (14%, 95% CI 5-25%). In children with both GSTM1 null and GSTP1 Val/Val genotypes, the increase in breathing difficulty associated with a 20-ppb increase in ozone exposure was even greater (21%, 95% CI 5-39%). GSTP1 genotypes were not significantly associated with ozone-related lung function changes. In conclusion, asthmatic children with glutathione S-transferase M1 null and glutathione S-transferase P1 Valine/Valine genotypes appear more susceptible to developing respiratory symptoms related to ozone exposure.

Building capacity for tobacco control research and policy.

The Fogarty International Center (FIC) initiative, "International Tobacco and Health Research Capacity Building Program" represents an important step in US government funding for global tobacco control. Low- and middle-income countries of the world face a rising threat to public health from the rapidly escalating epidemic of tobacco use. Many are now parties to the Framework Convention on Tobacco Control (FCTC) and capacity development to meet FCTC provisions. One initial grant provided through the FIC was to the Institute for Global Tobacco Control (IGTC) at the Johns Hopkins Bloomberg School of Public Health (JHSPH) to support capacity building and research programmes in China, Brazil, and Mexico. The initiative's capacity building effort focused on: (1) building the evidence base for tobacco control, (2) expanding the infrastructure of each country to deliver tobacco control, and (3) developing the next generation of leaders as well as encouraging networking throughout the country and with neighbouring countries. This paper describes the approach taken and the research foci, as well some of the main outcomes and some identified challenges posed by the effort. Individual research papers are in progress to provide more in-depth reporting of study results.

Human papillomavirus in men: comparison of different genital sites.

OBJECTIVE: To elucidate which anatomical sites need to be sampled to detect human papillomavirus (HPV) infection in the lower male genital tract. METHOD: In an HPV survey of Mexican soldiers (median age 24 years; range 16-50 years), a cell sample from 2 cm deep into the distal urethra (group 1; n = 168 men), or 0.5 cm deep into the meatus urethralis (group 2; n = 414 men) was collected, along with a sample from the external genitalia. The different samples were tested for 27 HPV types using a polymerase chain reaction based strip assay. RESULTS: HPV DNA was detected more frequently in external genitalia samples (46.4%) than in the urethra (20.8%) or meatus samples (12.1%). Lack of samples from the urethra or meatus would have led to 5.1% and 1.5% false HPV negative results, respectively. The most frequently detected high risk HPV types (HPV 59, 52, 51, and 16) were similar in different sites, whereas low risk types were found rarely in urethra samples. CONCLUSIONS: The addition of cell samples from the meatus to those from external genitalia contributed negligibly to the evaluation of the prevalence of HPV in men. HPV detection was slightly improved by the addition of urethra samples, but the gain may not justify the discomfort of the procedure in large epidemiological studies.

Dietary factors and endometrial cancer risk. Results of a case-control study in Mexico.

Daily diet factors that could potentially be related to endometrial cancer (EC) in Mexico are still unknown. This study aims to evaluate the association between EC and Mexican dietary factors. A case-control study in Mexico City was conducted during 1995-1997 in a social security hospital, using 85 incident cases of EC and 629 controls. A validated questionnaire with 116 items about the frequency and type of food intake was used. The analysis of nutrients was performed using the residual method, adjusting by predictor variables through logistic regression methods. In addition, partitional models estimated total caloric intake for other sources. We found no association between EC risk and consumption of animal or vegetable proteins, saturated, monounsaturated, or polyunsaturated fat, although high intake of nutrients such as lactose (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.21-1.01, P for trend = 0.004), vitamin D (OR, 0.38; 95% CI, 0.18-0.82, P= 0.003), and calcium (OR, 0.39; 95% CI, 0.17-0.89, P= 0.02) were inversely associated with EC. Our results suggest that dietary vitamin D and calcium play an important role in the development of EC, although the mechanisms postulated should be explained with additional studies with large populations.

Genetic polymorphism of GSTM1 and antioxidant supplementation influence lung function in relation to ozone exposure in asthmatic children in Mexico City.

BACKGROUND: We recently reported that antioxidant supplementation with vitamins C and E mitigated ozone related decline in forced expiratory flow (FEF(25-75)) in 158 asthmatic children in an area with high ozone exposure in Mexico City. METHODS: A study was undertaken to determine whether deletion of glutathione S-transferase M1 (GSTM1 null genotype), a gene involved in response to oxidative stress, influences ozone related decline in FEF(25-75) and the benefit of antioxidant supplementation. RESULTS: GSTM1 null children receiving placebo had significant ozone related decrements in FEF(25-75) (percentage change per 50 ppb of ozone 2.9 (95% CI -5.2 to -0.6), p=0.01); GSTM1 positive children did not. Conversely, the effect of antioxidants was stronger in children with the GSTM1 null genotype. CONCLUSIONS: Asthmatic children with a genetic deficiency of GSTM1 may be more susceptible to the deleterious effects of ozone on the small airways and might derive greater benefit from antioxidant supplementation.

Perceptions of nurses with regard to doctor-patient communication.

The objective of this study was to evaluate nurses' perceptions of communication between doctors and patients with cancer, AIDS and rheumatoid arthritis. A cross-sectional study was conducted with 741 nurses in 12 hospitals. Nurses received a self-questionnaire that included questions on personal value and attitudes. The answers were used in constructing affective variables (religious beliefs, attitude towards death, paternalism). The prevalence of explicit communication in 'nurse perception of doctor-patient communication' in the case of cancer was 4.5%, with AIDS 30%, and with rheumatoid arthritis 41.8%. When the value of communication was evaluated, it became evident that the likelihood of a nurse perceiving explicit communication in reference to a diagnosis of cancer was 6.5 time greater when communication was considered to be of greater value (CI 95% 2.6-6.6). For nurses who accept the possibility of death, the likelihood of perceiving explicit communication in the case of AIDs was 7.4 times greater than for nurses who deny this possibility (CI 95% 3.7-14.7), and when nurses displayed a deeply religious attitude, the likelihood of perceiving explicit communication was 80% greater than for nurses without this attitude (CI 95% 1.1-2.9). Nurses participate actively in the process of attending to patients with cancer and other disabling illnesses. Thus, there is a need for health professionals who provide compassionate attention, which will improve the various interrelationships between nurses and patients.

Indirect lead exposure among children of radiator repair workers.

BACKGROUND: Secondary exposure to lead has been identified as a public health problem since the late 1940s; we investigate the risk of lead exposure among families of radiator repair workers. METHODS: A sample of the wives and children, aged 6 months to 6 years (exposed children) (n = 19), of radiator repair workers and a sample of children whose parents were not occupationally exposed to lead (non-exposed children) (n = 29) were matched for age and residence; their geometric mean blood lead levels are compared. Blood samples were obtained by the finger stick method and environmental dust samples by the wipe method; both were analyzed using a portable anodic stripping voltameter. RESULTS: Dust lead levels were significantly higher in the houses of exposed children (143.8 vs. 3.9 microg/g; P < 0.01). In crude analyses, the highest lead levels were observed among children whose fathers worked in home-based workshops (22.4 microg/dl)(n = 6). Children whose fathers worked in an external workshop (n = 13) also had high levels (14.2 microg/dl) (P < 0.01), while blood lead levels in non-exposed children were significantly lower (5.6 microg/dl)(P < 0.01). The observed differences remained significant after adjustment for age and gender. CONCLUSIONS: This study confirms that children of radiator repair workers are at increased risk of lead exposure and public health interventions are needed to protect them.

Acceptability of a human papillomavirus (HPV) trial vaccine among mothers of adolescents in Cuernavaca, Mexico.

BACKGROUND: A scenario that must be considered when testing prophylactic human papillomavirus (HPV) vaccines in teenagers is the parents' acceptability of their daughters' participation in the study. METHODS: A survey was carried out in a random sample of 880 women between the ages of 15 and 49 years in the metropolitan area of Cuernavaca, Mexico. These women were interviewed to obtain information concerning their knowledge of risk factors for cervical cancer and their perception of the usefulness of vaccines. Afterward, they were provided with information on the main risk factors for cervical cancer and the future availability of a human papillomavirus (HPV) vaccine to prevent cervical cancer. Finally, we explored, with parents, the possible acceptability of an HPV vaccine for their teenaged daughters. The degree of acceptability and its association with a series of sociodemographic and reproductive factors were assessed. RESULTS: The respondents had little knowledge regarding the etiology of cervical cancer. Only 1.9% said that the principal risk factor was infection with HPV; however, 84.2% were aware of the usefulness of vaccines and 83.6% of the women indicated that they would allow their daughters to participate in a trial to evaluate the effectiveness of an HPV vaccine that helps prevent cervical cancer. The main factor associated with the acceptance of a possible vaccine against HPV was the knowledge of the usefulness of vaccines [odds ratio (OR) = 6.5, 95% confidence interval (CI) 5.2-8.2]. Likewise, a history of two or more sexual partners (OR = 2.2, 95% CI 1.3-3.6) increased acceptability. Acceptance was not associated with the number of live births (never vs. ever OR = 0.9, 95% CI 0.3-2.1). There were 525 women with children over the age of 10 years (59.6%); prevalence of acceptability among these women was 80.1%, not statistically different from the remainder of the sample (p >0.05). CONCLUSIONS: Acceptance of a potential HPV vaccine was high in this sample of Mexican women. Initiation of HPV vaccine clinical trials and immunization campaigns that target school children and/or teenagers who are not sexually active should include educational programs aimed at mothers of these individuals. Knowledge of the benefits of a preventive vaccine as well as the etiology and risk factors of cervical cancer should be emphasized.

Interrelations of lead levels in bone, venous blood, and umbilical cord blood with exogenous lead exposure through maternal plasma lead in peripartum women.

Recent research has raised the possibility that fetal lead exposure is not estimated adequately by measuring lead content in maternal whole blood lead because of the variable partitioning of lead in whole blood between plasma and red blood cells. Lead in maternal plasma may derive in large part from maternal bone lead stores. In this study we aimed to estimate the contribution of maternal whole blood lead, maternal bone lead levels, and environmental lead to umbilical cord blood lead levels (as a measure of fetal lead exposure). In the model, we assumed that lead from all of these sources reaches the fetus through the maternal plasma lead pathway. In 1994-1995, we recruited 615 pregnant women for a study of lead exposure and reproductive outcomes in Mexico City. We gathered maternal and umbilical cord blood samples within 12 hr of each infant's delivery and measured maternal lead levels in cortical bone and trabecular bone by a K-X-ray fluorescence (K-XRF) instrument within 1 month after delivery. We administered a questionnaire to assess use of lead-glazed ceramics (LGC) to cook food and we obtained data on regional air lead levels during the 2 months before delivery. We used structural equation models (SEMs) to estimate plasma lead as the unmeasured (latent) variable and to quantify the interrelations of plasma lead, the other lead biomarkers, and environmental lead exposure. In the SEM analysis, a model that allowed plasma lead to vary freely from whole blood lead explained the variance of cord blood lead (as reflected by a total model R(2); R(2) = 0.79) better than did a model without plasma lead (r(2) = 0.67). Cortical bone lead, trabecular bone lead, use of LGC, and mean air lead level contributed significantly to plasma lead. The exchange of lead between plasma and red blood cells was mostly in the direction of plasma to cells. According to the final model, an increase in trabecular bone lead and cortical bone lead was associated with increases in cord blood lead of 0.65 and 0.25 microg/dL, respectively. An increase of 0.1 microg/m(3) in air lead was associated with an increase in the mean level of fetal cord blood lead by 0.67 microg/dL. With one additional day of LCG use per week in the peripartum period, the mean fetal blood lead level increased by 0.27 microg/dL. Our analyses suggested that maternal plasma lead varies independently from maternal whole blood lead and that the greatest influences on maternal plasma lead are maternal bone lead stores, air lead exposures, and recent cooking with LGC. The contributions from endogenous (bone) and exogenous (environmental) sources were relatively equal. Measurement of plasma and bone lead may be important in accurately assessing fetal lead exposure and its major sources, particularly if exogenous exposures decline.

Effect of maternal lead burden on infant weight and weight gain at one month of age among breastfed infants.

INTRODUCTION: Transfer of lead from bone to the bloodstream increases during lactation. However, the effect of maternal lead burden on growth in breastfed newborns is still unknown. This study examined early postnatal growth in a cohort of healthy breastfed newborns in relation to maternal bone lead burden. METHODS: Lead levels were measured among 329 mother-infant pairs in umbilical cord blood at birth and in maternal and infant venous blood at 1 month postpartum. Maternal evaluations at 1 month postpartum included lead measures in blood and bone (measured in the tibia and the patella). Blood lead was determined by graphite furnace atomic absorption spectrophotometry. Bone lead was measured by (109)Cd Kx-radiograph fluorescence instrument. The primary endpoints were attained weight 1 month of age, and weight gain from birth to 1 month of age, which were analyzed in relation to lead biomarkers and relevant covariates by linear regression models. RESULTS: Infants studied had an average weight gain of 33.1 g/day (standard deviation [SD] = 11.6). Mean infant (at 1 month of age) and maternal blood lead levels were 5.6 microg/dL (SD = 3.0) and 9.7 microg/dL (SD = 4.1), respectively. Mean maternal bone lead levels were 10.1 microg of lead/g (SD = 10.3) and 15.29 microg of lead/g (SD = 15.2) of bone mineral for tibia and patella, respectively. Infant blood lead levels were inversely associated with weight gain, with an estimated decline of 15.1 g per microg/dL of blood lead. Children who were exclusively breastfed had significantly higher weight gains; however, this gain decreased significantly with increasing levels of patella lead. The multivariate regression analysis predicted a 3.6-g decrease in weight at 1 month of age per microg of lead per gram bone mineral increase in maternal patella lead levels. CONCLUSIONS: Maternal lead burden is negatively associated to infant attained weight at 1 month of age and to postnatal weight gain from birth to 1 month of age. Additional studies are needed to better understand this source of exposure and to develop interventions to minimize its impact.