Safe Listening at Venues and Events with Amplified Music - United States, 2022.

Nearly one in four (24.4%) U.S. adults aged 20-69 years show evidence of noise-induced hearing loss (1). Among those reporting exposure to noise outside of work, 19.9% showed possible noise-induced hearing loss. Exposure to non-job-related noise can be substantial (2). Loud music from personal listening devices and entertainment venues might place more than 1 billion teenagers and young adults at risk for hearing loss worldwide (3). Early noise exposure might increase the risk for age-related hearing loss later in life (4). CDC analyzed data from the 2022 FallStyles survey (conducted by Porter Novelli via the Ipsos' KnowledgePanel) on U.S. adult perceptions regarding preventing hearing loss from amplified music at venues or events. More than one half of U.S. adults agreed with one or more of the following protective actions: limiting sound levels, posting warning signs, and using hearing protection when music at such events reaches potentially hazardous levels. Hearing and other health professionals can make use of existing materials available from the World Health Organization (WHO), CDC, and other professional organizations to raise awareness about noise risks and promote protective behaviors.

Survey of Teen Noise Exposure and Efforts to Protect Hearing at School - United States, 2020.

Noise-induced hearing loss (NIHL) is a substantial, often unrecognized, health problem. Various learning environments and activities in school settings are loud. Researchers have reported the prevalence of NIHL among U.S. adolescents ranging between 12.8% and 17.5%, suggesting that one in every six to eight middle and high school students (aged 12-19 years) has measurable hearing loss likely resulting from excessive noise exposure (1). Evidence suggests that even mild levels of hearing loss negatively affect auditory perception and cognitive skills.* CDC analyzed data from a sample of 817 youths aged 12-17 years who responded to the web-based YouthStyles survey in 2020. The survey measured the frequency of exposure to loud noise in school settings, the provision of hearing protection devices (HPDs) during exposure, and whether prevention techniques were part of their educational curriculum. Approximately three in four teenage students reported being exposed to loud sound at school, and nearly one half (46.5%) of respondents reported exposure to loud sounds at school on a regular basis. A majority of students (85.9%) reported that their school did not provide HPDs during classes or activities where they were exposed to loud sounds, and seven out of 10 reported they were never taught how to protect their hearing. Increasing youth's awareness about the adverse health effects of excessive noise exposure and simple preventive measures to reduce risk can help prevent or reduce NIHL. Health care providers and educators have resources and tools available to prevent NIHL among school-aged children. Increased efforts are needed to promote prevention.

Perfluoroalkyl substances and anthropomorphic measures in children (ages 3-11 years), NHANES 2013-2014.

BACKGROUND: Perfluoroalkyl acids (PFAAs) are man-made compounds that are persistent in the environment and highly bioaccumulative in the body. Humans are exposed to a mixture of these substances, and the effects of these mixtures may be different than the effects noted for individual compounds. Prenatal exposure to PFAAs has been associated with decreased birth weight. The objective of the present study is to evaluate concurrent serum PFAA levels, as single compounds and as mixtures, in relation to anthropomorphic measures in children. METHODS: Using multivariate linear regression, we evaluated the association between single or PFAA mixtures and with height-for-age (HAZ), weight-for-age (WAZ), and BMI (BMIZ) z-scores in children (ages 3-11 years) participants of the National Health and Nutrition Examination Survey (NHANES) 2013-2014. Analyses were also stratified by sex. The PFAA mixture was based on relative potency factors express in terms of PFOA equivalency (CmixRPFi) or as molar sum of the PFAA congeners (∑molPFAA). RESULTS: There was a statistically significant association of PFHxS and PFOS with decreased HAZ in boys. The significantly decreased HAZ in boys was also found when the PFAAs were analyzed as mixtures: CmixRPFi (ß = -0.33; 95%CI: 0.63, -0.04) or ΣmolPFAAs (ß = -0.30; 95%CI: 0.56, -0.04). In boys, PFHxS was also associated with decreased WAZ and BMIZ. The only statistically significant association found in girls was between decreased HAZ and PFHxS. CONCLUSIONS: We found sex differences in the association between concurrent serum PFAA levels and anthropomorphic measures in children 3-11 years old. PFAA levels, as single congeners or as mixture concentrations were associated with decreased height-for-age z-score in boys.

Age and sex differences in hearing loss association with depressive symptoms: analyses of NHANES 2011-2012.

BACKGROUND: Depression is a common and significant health problem. Hearing loss is the third most common chronic physical condition in the USA and might be a factor in depression. To determine whether hearing loss is associated with depressive symptoms in US adults ages 20-69 years. METHODS: National Health and Nutrition Examination Survey (NHANES) data (2011-2012) were used to assess the potential relationship between hearing loss and depression, in adults (20-69 years) who answered the Patient Health Questionnaire (PHQ-9) depression screening module, with pure tone audiometry measurements, and complete information on the co-variates data (n = 3316). The degree of speech-frequency hearing loss (SFHL) and high-frequency hearing loss (HFHL) were defined as slight/mild hearing loss ⩾26-40 dB; moderate/worse hearing loss ⩾41 dB by pure tone audiometry examination. RESULTS: Moderate/worse HFHL was statistically significantly associated with depressive symptoms (OR 1.54, 95% CL 1.04-2.27) when the analyses were conducted among all participants. Further stratification by gender and age groups found that moderate/worse HFHL (OR 3.85, 95% CL 1.39-10.65) and moderate/worse SFHL (OR 5.75, 95% CL 1.46-22.71) were associated with depressive symptoms in women ages 52-69 years. CONCLUSIONS: Moderate/worse speech frequency and HFHL are associated with depression in women ages 52-69 years, independent of other risk factors. Hearing screenings are likely to reduce delays in diagnosis and provide early opportunities for noise prevention counseling and access to hearing aids. Health professionals should be aware of depressive signs and symptoms in patients with hearing loss.

Use of Personal Hearing Protection Devices at Loud Athletic or Entertainment Events Among Adults - United States, 2018.

Tens of millions of U.S. residents have a range of adverse health outcomes caused by noise exposure (1). During 2011-2012, 21 million U.S. adults who reported no exposure to loud or very loud noise at work exhibited hearing damage suggestive of noise-induced hearing loss (2). In addition to the known risk for hearing damage, nonauditory adverse health outcomes and health risks from excessive environmental sound exposure can include effects on the cardiovascular system, metabolism, blood pressure, body weight, cognition, sleep, mental health, quality of life, and overall well-being (1,3,4). CDC analyzed a representative sample of the U.S. adult population (aged ≥18 years) from a 2018 national marketing survey (50 states and the District of Columbia) that included questions about use of hearing protection devices (HPDs) (e.g., ear plugs or ear muffs) during recreational exposure to loud athletic and entertainment events; approximately 8% of respondents reported consistent use of an HPD at these types of events. Among those adults more likely to wear an HPD, 63.8% had at least some college education, and 49.1% had higher income levels. Women and older adults were significantly less likely to use HPDs. These findings suggest a need to strengthen a public health focus on the adverse health effects of excessive noise exposure at home and in recreational settings as well as a need for continued efforts to raise public awareness about the protective value of HPDs.

Vital Signs: Noise-Induced Hearing Loss Among Adults - United States 2011-2012.

INTRODUCTION: The 2016 National Academies of Sciences report "Hearing Health Care for Adults: Priorities for Improving Access and Affordability" included a call to action for government agencies to strengthen efforts to collect, analyze, and disseminate population-based data on hearing loss in adults. METHODS: CDC analyzed the most recent available data collected both by questionnaire and audiometric tests of adult participants aged 20-69 years in the 2011-2012 National Health and Nutrition Examination Survey (NHANES) to determine the presence of audiometric notches indicative of noise-induced hearing loss. Prevalence of both unilateral and bilateral audiometric notches and their association with sociodemographics and self-reported exposure to loud noise were calculated. RESULTS: Nearly one in four adults (24%) had audiometric notches, suggesting a high prevalence of noise-induced hearing loss. The prevalence of notches was higher among males. Almost one in four U.S. adults who reported excellent or good hearing had audiometric notches (5.5% bilateral and 18.0% unilateral). Among participants who reported exposure to loud noise at work, almost one third had a notch. CONCLUSIONS AND IMPLICATIONS FOR PUBLIC HEALTH PRACTICE: Noise-induced hearing loss is a significant, often unrecognized health problem among U.S. adults. Discussions between patients and personal health care providers about hearing loss symptoms, tests, and ways to protect hearing might help with early diagnosis of hearing loss and provide opportunities to prevent harmful noise exposures. Avoiding prolonged exposure to loud environments and using personal hearing protection devices can prevent noise-induced hearing loss.

Antimony and sleep-related disorders: NHANES 2005-2008.

BACKGROUND: Antimony is used as a flame-retardant in textiles and plastics, in semiconductors, pewter, and as pigments in paints, lacquers, glass and pottery. Subacute or chronic antimony poisoning has been reported to cause sleeplessness. The prevalence of short sleep duration (<7h/night) has been reported to be 37.1% in the general US population, and obstructive sleep apnea (OSA) affects 12-28 million US adults. Insufficient sleep and OSA have been linked to the development of several chronic conditions including diabetes, cardiovascular disease, obesity and depression, conditions that pose serious public health threats. OBJECTIVE: To investigate whether there is an association between antimony exposure and sleep-related disorders in the US adult population using the National Health and Nutrition Examination Survey (NHANES) 2005-2008. METHODS: We performed multivariate logistic regression to analyze the association of urinary antimony with several sleep disorders, including insufficient sleep and OSA, in adult (ages 20 years and older) participants of NHANES 2005-2008 (n=2654). RESULT: We found that participants with higher urinary antimony levels had higher odds to experience insufficient sleep (≤6h/night) (OR 1.73; 95%CI; 1.04, 2.91) as well as higher odds to have increased sleep onset latency (>30min/night). Furthermore, we found that higher urinary antimony levels in participants were associated with OSA (OR 1.57; 95%CI; 1.05, 2.34), sleep problems, and day-time sleepiness. CONCLUSION: In this study, we found that urinary antimony was associated with higher odds to have insufficient sleep and OSA. Because of the public health implications of sleep disorders, further studies, especially a prospective cohort study, are warranted to evaluate the association between antimony exposure and sleep-related disorders.

Urinary antimony and leukocyte telomere length: An analysis of NHANES 1999-2002.

Telomeres are repetitive DNA sequences (TTAGGG) at the end of chromosomes. Cells with critically short telomeres enter replicative senescence and apoptosis. Several in vitro studies report that antimony causes cell apoptosis in human leukocyte cell lines. The goal of this analysis was to investigate whether there is an association between antimony exposure and leukocyte telomere length (LTL) among US adults aged 20 and older based on the National Health and Nutrition Examination Survey (NHANES) 1999-2002. We used multivariate linear regression to analyze the association of urinary antimony with LTL. LTL was log-natural transformed and the results were re-transformed and presented as percent differences. After adjustment for potential confounders, individuals in the 3rd and 4th quartiles of urinary antimony had statistically significantly shorter LTL (-4.78%, 95% CI: -8.42,-0.90; and -6.11%, 95% CI: -11.04,-1.00, respectively) compared to the lowest referent quartile, with evidence of a dose-response relationship (p-value for trend =0.03). Shorter LTL with antimony was driven by middle aged (40-59 years) and older (60-85 years) adult groups. The association may be biologically plausible because of reported oxidative stress and apoptosis effects of antimony on blood cells, effects known to shorten telomere length.

Acrolein metabolites, diabetes and insulin resistance.

Acrolein is a dietary and environmental pollutant that has been associated in vitro to dysregulate glucose transport. We investigated the association of urinary acrolein metabolites N-acetyl-S-(3-hydroxypropyl)-l-cysteine (3-HPMA) and N-acetyl-S-(carboxyethyl)-l-cysteine (CEMA) and their molar sum (∑acrolein) with diabetes using data from investigated 2027 adults who participated in the 2005-2006 National Health and Nutrition Examination Survey (NHANES). After excluding participants taking insulin or other diabetes medication we, further, investigated the association of the compounds with insulin resistance (n=850), as a categorical outcome expressed by the homeostatic model assessment (HOMA-IR>2.6). As secondary analyses, we investigated the association of the compounds with HOMA-IR, HOMA-ß, fasting insulin and fasting plasma glucose. The analyses were performed using urinary creatinine as independent variable in the models, and, as sensitivity analyses, the compounds were used as creatinine corrected variables. Diabetes as well as insulin resistance (defined as HOMA-IR>2.6) were positively associated with the 3-HPMA, CEMA and ∑Acrolein with evidence of a dose-response relationship (p<0.05). The highest 3rd and 4th quartiles of CEMA compared to the lowest quartile were significantly associated with higher HOMA-IR, HOMA-ß and fasting insulin with a dose-response relationship. The highest 3rd quartile of 3-HPMA and ∑Acrolein were positively and significantly associated with HOMA-IR, HOMA-ß and fasting insulin. These results suggest a need of further studies to fully understand the implications of acrolein with type 2 diabetes and insulin.

A simple procedure for estimating pseudo risk ratios from exposure to non-carcinogenic chemical mixtures.

Non-cancer risk assessment traditionally assumes a threshold of effect, below which there is a negligible risk of an adverse effect. The Agency for Toxic Substances and Disease Registry derives health-based guidance values known as Minimal Risk Levels (MRLs) as estimates of the toxicity threshold for non-carcinogens. Although the definition of an MRL, as well as EPA reference dose values (RfD and RfC), is a level that corresponds to "negligible risk," they represent daily exposure doses or concentrations, not risks. We present a new approach to calculate the risk at exposure to specific doses for chemical mixtures, the assumption in this approach is to assign de minimis risk at the MRL. The assigned risk enables the estimation of parameters in an exponential model, providing a complete dose-response curve for each compound from the chosen point of departure to zero. We estimated parameters for 27 chemicals. The value of k, which determines the shape of the dose-response curve, was moderately insensitive to the choice of the risk at the MRL. The approach presented here allows for the calculation of a risk from a single substance or the combined risk from multiple chemical exposures in a community. The methodology is applicable from point of departure data derived from quantal data, such as data from benchmark dose analyses or from data that can be transformed into probabilities, such as lowest-observed-adverse-effect level. The individual risks are used to calculate risk ratios that can facilitate comparison and cost-benefit analyses of environmental contamination control strategies.

Cynomolgus and pigtail macaque IgG subclasses: characterization of IGHG genes and computational analysis of IgG/Fc receptor binding affinity.

Macaques are the most widely used experimental nonhuman primate (NHP) species. Rhesus (Macaca mulatta, Macmul), cynomolgus (Macaca fascicularis, Macfas), and pigtail (Macaca nemestrina, Macnem) macaques continue to be popular models for vaccine and infectious diseases research, especially HIV infection and AIDS, and for the development of antibody-based therapeutic strategies. Increased understanding of the immune system of these species is necessary for their optimal use as models of human infections and intervention. In the past few years, the antibody/Fc receptor system has been characterized in a stepwise manner in these species. We have continued this characterization by identifying the four IG heavy gamma (IGHG) genes of Macfas and Macnem in this study. Our results show that these genes share a high degree of similarity with those from other NHP species, while presenting consistent differences when compared to human IGHG genes. Furthermore, comparison of Macfas IGHG genes with those described in other studies suggests the existence of polymorphism. Using sequence- and structure-based computational tools, we performed in silico analysis on multiple polymorphic Macfas IgG and their interactions with human IgG Fc receptors (FcγR), thus predicting that Macfas IGHG polymorphisms influence IgG protein stability and/or binding affinity towards FcγR. The presence of macaque IGHG polymorphisms and macaque/human amino acid changes at locations potentially involved in antibody functional properties indicate the need for cautious design and data interpretation of studies in these models, possibly requiring the characterization of antibody/Fc receptor interactions at the individual level.

Association of urinary phenols with increased body weight measures and obesity in children and adolescents.

OBJECTIVE: To examine the association of urinary levels of the environmental phenol pesticides 2,5-dichlorophenol, 2,4-dichlorophenol, and triclosan with body weight outcomes in children and adolescent participants in the National Health and Nutrition Examination Survey 2007-2010. STUDY DESIGN: We performed multivariate linear and multinomial logistic regressions to analyze the association of body mass index (BMI) z-score, waist circumference (WC), and obesity with urinary pesticide concentration in children and adolescents. RESULTS: After adjustment for covariates, we found a statistically significant positive association (P < .05) between both 2,5-dichlorophenol and 2,4-dichlorophenol with BMI z-score, WC, and obesity in children and adolescents. After stratification by age, the significant associations remained only in adolescents (ages 12-19). No associations were found between triclosan and any of the body weight outcomes. CONCLUSIONS: We found an association between dichlorophenols and increased body weight measures (BMI z-score, WC, and obesity) in adolescents. However, further studies, such as a longitudinal study, are needed to confirm and elucidate on our findings.

Hearing Loss and Urinary trans,trans-Muconic Acid (t,t-MA) in 6- to 19-Year-Old Participants of NHANES 2017-March 2020.

Hearing loss (HL) is associated with poorer language development and school performance. Ototoxic substances such as metals and solvents, including benzene, are a risk factor associated with HL. This study examines potential associations between the benzene metabolite trans,trans-muconic acid (t,t-MA) and HL in youth of the National Health and Nutrition Examination Survey (NHANES). Logistic regression calculated adjusted odds ratio (aOR) associations between HL and urinary t,t-MA quartiles, natural-log transformed, and doubled urinary t,t-MA. Hearing threshold pure-tone average (PTA) at speech frequencies (SF) 0.5, 1, 2, and 4 kHz and high frequencies (HF) 3, 4, and 6 kHz were analyzed for slight HL (PTA > 15 dB) and mild HL (PTA > 20 dB). Urinary t,t-MA was statistically significantly associated with both slight SF and HF HL. For each doubling of t,t-MA there were increased odds of having slight SFHL (aOR = 1.42; 95% CI: 1.05, 1.92), slight HFHL (aOR = 1.31; 95% CI: 1.03, 1.66), mild SFHL (aOR = 1.60; 95% CI: 1.10, 2.32), and mild HFHL (aOR = 1.45; 95% CI: 1.03, 2.04). To our knowledge, this is the first population-based report of an association between SFHL, HFHL, and the benzene metabolite t,t-MA in youth 6 to 19 years old.

Blood lead level association with lower body weight in NHANES 1999-2006.

BACKGROUND: Lead exposure is associated with low birth-weight. The objective of this study is to determine whether lead exposure is associated with lower body weight in children, adolescents and adults. METHODS: We analyzed data from NHANES 1999-2006 for participants aged ≥3 using multiple logistic and multivariate linear regression. Using age- and sex-standardized BMI Z-scores, overweight and obese children (ages 3-19) were classified by BMI ≥85 th and ≥95 th percentiles, respectively. The adult population (age ≥20) was classified as overweight and obese with BMI measures of 25-29.9 and ≥30, respectively. Blood lead level (BLL) was categorized by weighted quartiles. RESULTS: Multivariate linear regressions revealed a lower BMI Z-score in children and adolescents when the highest lead quartile was compared to the lowest lead quartile (ß (SE)=-0.33 (0.07), p<0.001), and a decreased BMI in adults (ß (SE)=-2.58 (0.25), p<0.001). Multiple logistic analyses in children and adolescents found a negative association between BLL and the percentage of obese and overweight with BLL in the highest quartile compared to the lowest quartile (OR=0.42, 95% CI: 0.30-0.59; and OR=0.67, 95% CI: 0.52-0.88, respectively). Adults in the highest lead quartile were less likely to be obese (OR=0.42, 95% CI: 0.35-0.50) compared to those in the lowest lead quartile. Further analyses with blood lead as restricted cubic splines, confirmed the dose-relationship between blood lead and body weight outcomes. CONCLUSIONS: BLLs are associated with lower body mass index and obesity in children, adolescents and adults.

DDT/DDE and breast cancer: a meta-analysis.

The biological basis for investigating dichlorodiphenyltrichloroethane (DDT) exposure and breast cancer risk stems from in vitro and animal studies indicating that DDT has estrogenic properties. The objective of this study was to update a meta-analysis from 2004 which found no association between dichlorodiphenyldichloroethylene (DDE) and breast cancer. We searched PubMed and Web of Science for studies published through June 2012 assessing DDT/DDE exposure and breast cancer. Summary Odds Ratios (ORs) with 95% confidence intervals (CIs) were calculated for the prevalence of breast cancer in the highest versus the lowest exposed groups for DDT and DDE. Difference of means of exposure for cases versus controls was analyzed for DDT and DDE. From the 500 studies screened, 46 were included in the meta-analysis. Slightly elevated, but not statistically significant summary ORs were found for DDE (1.05; 95% CI: 0.93-1.18) and DDT (1.02; 95% CI: 0.92-1.13). Lipid adjusted difference of means analysis found a significantly higher DDE concentration in cases versus controls (11.30 ng/g lipid; p=0.01). No other difference of means analysis found significant relationships. The existing information does not support the hypothesis that exposure to DDT/DDE increases the risk of breast cancer in humans.

Characterization and allelic polymorphisms of rhesus macaque (Macaca mulatta) IgG Fc receptor genes.

Macaque models are invaluable for AIDS research. Indeed, initial development of HIV-1 vaccines relies heavily on simian immunodeficiency virus-infected rhesus macaques. Neutralizing antibodies, a major component of anti-HIV protective responses, ultimately interact with Fc receptors on phagocytic and natural killer cells to eliminate the pathogen. Despite the major role that Fc receptors play in protective responses, there is very limited information available on these molecules in rhesus macaques. Therefore, in this study, rhesus macaque CD32 (FcγRII) and CD64 (FcγRI) homologues were genetically characterized. In addition, presence of CD16 (FcγRIII), CD32, and CD64 allelic polymorphisms were determined in a group of nine animals. Results from this study show that the predicted structures of macaque CD32 and CD64 are highly similar to their human counterparts. Macaque and human CD32 and CD64 extracellular domains are 88-90% and 94-95% homologous, respectively. Although all cysteines are conserved between the two species, macaque CD32 exhibits two additional N-linked glycosylation sites, whereas CD64 lacks three of them when compared to humans. Five CD32, three CD64, and three CD16 distinct allelic sequences were indentified in the nine animals examined, indicating a relatively high level of polymorphism in macaque Fcγ receptors. Together, these results validate rhesus macaques as models for vaccine development and antibody responses, while at the same time, underscoring the need to take into account the high degree of genetic heterogeneity present in this species when designing experimental protocols.

Association of low-level blood lead and blood pressure in NHANES 1999-2006.

This study investigated whether low blood-lead levels (≤10 µg/dL) were associated with blood pressure (BP) outcomes. The authors analyzed data from National Health and Nutrition Examination Survey 1999-2006 and participants aged 20 years or older. Outcome variables were systolic and diastolic BP measurements, pulse pressure, and hypertension status. Multivariable linear and logistic regressions stratified by race/ethnicity and gender were performed. Blood lead levels (BLL) were significantly correlated with higher systolic BP among black men and women, but not white or Mexican-American participants. BLLs were significantly associated with higher diastolic BPs among white men and women and black men, whereas, a negative association was observed in Mexican-American men that had, also, a wider pulse pressure. Black men in the 90th percentile of blood lead distribution (BLL≥3.50 µg/dL) compared to black men in the 10th percentile of blood lead distribution (BLL≤0.7 µg/dL) had a significant increase of risk of having hypertension (adjusted POR=2.69; 95% CI: 1.08-6.72). In addition, blood cadmium was significantly associated with hypertension and systolic and diastolic blood. This study found that, despite the continuous decline in blood lead in the U.S. population, lead exposure disparities among race and gender still exist.

The impact of CYP2E1 genetic variability on risk assessment of VOC mixtures.

Humans are simultaneously exposed to multiple chemicals in the environment. Many of the chemicals use the same enzymes in their metabolic pathways. Competitive inhibition may occur as one of the possible interactions between the xenobiotics in human body. For example, many volatile organic compounds (VOCs) are metabolized using P450 enzymes, specifically CYP2E1. Inheritable gene alterations may result in changes of function of the enzymes in different human subpopulations. Variations in quantity and/or quality of particular isoenzymes may cause differences in the metabolism of VOCs. These variations may cause higher sensitivity in certain populations. Using examples of three different mixtures, this review paper outlines the variances in CYP2E1 isoenzymes, effect of exposure to such mixtures on sensitive populations, and approaches to mixtures risk assessment.

Limited evolution of human immunodeficiency virus type 1 in the thymus of a perinatally infected child.

BACKGROUND: Involvement of the thymus during human immunodeficiency virus (HIV) infection may impair production of naive lymphocytes leading to more rapid depletion, but the characteristics of primary strains in the thymus are not well studied because of the unavailability of tissue in living individuals. METHODS: We studied the characteristics of HIV type 1 (HIV-1) in a 5-year old perinatally infected child with thymitis and compared the genomic sequences of the HIV-1 C2-V5 region of the env gene in the thymic tissue and peripheral blood. RESULTS: The thymus harbored predominantly viral sequences close to the founder HIV-1 variant that circulated in the blood at 2 and 3 months of age, whereas the peripheral blood virus at 5 years of age had evolved extensively. Viral sequences from circulating CD8(+) T cells at 5 years of age phylogenetically clustered with those from the thymic tissue. CONCLUSIONS: These results indicate the existence of a distinct thymic viral reservoir and suggest that circulating CD8(+) T cells were infected in the thymus, presumably at the CD4(+)CD8(+) thymocyte stage. They also demonstrate that not all thymic HIV infections will necessarily lead to severe thymic dysfunction. The characteristics of the virus strain seeding the thymus may dictate the rate of disease progression.

Perfluoroalkyl acids, hyperuricemia and gout in adults: Analyses of NHANES 2009-2014.

BACKGROUND: Previous studies have reported a positive association of perfluoralkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), with hyperuricemia. The objective of the study is to investigate whether there is an association between concurrent serum levels of several PFAAs and gout, serum uric acid (SUA) or hyperuricemia in the U.S. adult population as represented by the National Health and Nutrition Examination Survey (NHANES) 2009-2014 sample (n = 4917). The PFAAs investigated include PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorohexane sulfonic acid (PFHxS) and PFOS. METHODS: This cross-sectional study used multivariate logistic regressions to analyze the association of single PFAAs with hyperuricemia and self-reported gout; the association with SUA was analyzed by multivariate linear regression. Analyses were adjusted for race/ethnicity, age, sex, education, alcohol consumption, smoking, serum cotinine, BMI, diabetes, hypertension, chronic kidney disease, and SUA (for gout only). RESULTS: Higher quartile values of serum PFOA and PFHxS were associated with increased odds of self-reported gout. There was a positive association of SUA with increased levels of PFOA, PFNA, PFOS, PFHxS and PFDA. Higher quartile values of PFOA, PFNA, and PFHxS were associated with higher odds of hyperuricemia. CONCLUSIONS: In this population-based cross-sectional analysis, we found an association between selected PFAAs and self-reported gout. We also confirmed previous reports of an association between several PFAAs and hyperuricemia. Our study suggests that exposure to PFAAs may be a risk factor for hyperuricemia and gout.