Publications by authors named "Michael D Mcclean"

Introduction: The relations between coffee and tea consumption and head and neck cancer (HNC) incidence are unclear. With increasing global HNC burden, this study aims to examine the association between coffee, tea, and HNC.

Methods: A pooled analysis of 9548 HNC cases and 15,783 controls from 14 individual-level case-control studies was conducted from the International Head and Neck Cancer Epidemiology consortium.

View Article and Find Full Text PDF
Article Synopsis
  • * A study identified a strong link between Native American ancestry and an increased risk of MeN, while certain genetic variants were found to significantly reduce the odds of developing the disease.
  • * Findings suggest that genetic differences in sensitivity to heat and dehydration contribute to the prevalence of kidney disease in these workers, highlighting both environmental and genetic factors.
View Article and Find Full Text PDF

Background And Objectives: Obstructive sleep apnea (SA) is common in older men and a contributor to negative cognitive, psychiatric, and brain health outcomes. Little is known about SA in those who played contact sports and are at increased risk of neurodegenerative disease(s) and other neuropathologies associated with repetitive head impacts (RHI). In this study, we investigated the frequency of diagnosed and witnessed SA and its contribution to clinical symptoms and tau pathology using PET imaging among male former college and former professional American football players.

View Article and Find Full Text PDF

Background And Objectives: Recent data link exposure to repetitive head impacts (RHIs) from American football with increased white matter hyperintensity (WMH) burden. WMH might have unique characteristics in the context of RHI beyond vascular risk and normal aging processes. We evaluated biological correlates of WMH in former American football players, including markers of amyloid, tau, inflammation, axonal injury, neurodegeneration, and vascular health.

View Article and Find Full Text PDF
Article Synopsis
  • - The study investigates tau pathology in chronic traumatic encephalopathy (CTE) using tau PET imaging from 218 participants, including former professional and college football players, and a control group of individuals without head impact exposure.
  • - Elevated tau levels were found in former football players compared to controls, especially in older players over 60 with cumulative head impact exposure, but PET imaging didn't effectively distinguish between individuals with and without traumatic encephalopathy syndrome.
  • - The authors emphasize the need for further research to better understand the link between tau pathology and chronic traumatic brain injuries, as current findings only partially clarify these relationships.
View Article and Find Full Text PDF

Background: Exposure to repetitive head impacts (RHI) in American football players can lead to cognitive impairment and dementia due to neurodegenerative disease, particularly chronic traumatic encephalopathy (CTE). The pathognomonic lesion of CTE consists of perivascular aggregates of hyper-phosphorylated tau in neurons at the depths of cortical sulci. However, it is unclear whether exposure to RHI accelerates amyloid-β (Aβ) plaque formation and increases the risk for Alzheimer's disease (AD).

View Article and Find Full Text PDF
Article Synopsis
  • Chronic traumatic encephalopathy (CTE) is a brain disease that can happen from repeated hits to the head, especially in football players.
  • Researchers made a special tool called a position exposure matrix (PEM) to estimate how much head impact different players experience based on their position and level of play.
  • The study found that how long players participate in football and the total strength of their head impacts are closely related to CTE, suggesting that stronger and more repeated hits to the head are more likely to cause this brain disease.
View Article and Find Full Text PDF

Background: There is growing attention on occupational heat stress in Central America, as workers in this region are affected by a unique form of chronic kidney disease. Previous studies have examined wet bulb globe temperatures and estimated metabolic rates to assess heat stress, but there are limited data characterizing heat strain among these workers.

Objective: The aims were to characterize heat stress and heat strain and examine whether job task, break duration, hydration practices, and kidney function were associated with heat strain.

View Article and Find Full Text PDF

Background: Patterns of cognitive impairment in former American football players are uncertain because objective neuropsychological data are lacking. This study characterized the neuropsychological test performance of former college and professional football players.

Methods: One hundred seventy male former football players (n=111 professional, n=59 college; 45-74 years) completed a neuropsychological test battery.

View Article and Find Full Text PDF

Introduction: The presentation, risk factors, and etiologies of white matter hyperintensities (WMH) in people exposed to repetitive head impacts are unknown. We examined the burden and distribution of WMH, and their association with years of play, age of first exposure, and clinical function in former American football players.

Methods: A total of 149 former football players and 53 asymptomatic unexposed participants (all men, 45-74 years) completed fluid-attenuated inversion recovery magnetic resonance imaging, neuropsychological testing, and self-report neuropsychiatric measures.

View Article and Find Full Text PDF
Article Synopsis
  • Chronic kidney disease of unknown etiology (CKDu) has a high mortality rate among sugarcane workers on the Pacific coast of Central America, prompting the Mesoamerican Nephropathy Occupational Study (MANOS) to investigate its prevalence.
  • The study recruited 569 workers from multiple industries, collecting baseline data on health and kidney function through questionnaires and biological samples to determine CKD prevalence.
  • Findings revealed a 7.4% baseline prevalence of CKD, with the highest rates in Salvadoran sugarcane workers (14.1%), indicating significant kidney health issues in the region despite attempts to exclude pre-existing conditions.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the relationship between DNA methylation-derived systemic inflammation (mdSI) indices and oropharyngeal cancer risk and survival rates.
  • Higher levels of the methylation-derived neutrophil-to-lymphocyte ratio (mdNLR) indicate an increased risk of developing oropharyngeal squamous cell carcinoma (OPSCC), while higher levels of methylation-derived lymphocyte-to-monocyte ratio (mdLMR) are linked to better survival outcomes.
  • The findings suggest that mdLMR could serve as an independent prognostic factor for OPSCC, emphasizing the importance of mdSI indices in understanding cancer risks and outcomes.
View Article and Find Full Text PDF
Article Synopsis
  • Chronic traumatic encephalopathy (CTE) is a serious brain disease caused by repeated head impacts and can only be diagnosed after death; the DIAGNOSE CTE Research Project aims to develop diagnostic methods for this condition.
  • Funded by the National Institute of Neurological Disorders and Stroke, the project includes 240 male participants, focusing on former football players and asymptomatic individuals, to study various risk factors and biomarkers related to CTE.
  • The research involves extensive evaluations such as neurological exams, brain imaging, and biological sample collection, with a focus on refining clinical criteria and sharing data with the broader research community.
View Article and Find Full Text PDF

Unlabelled: Uterine leiomyomata (UL) are hormone-responsive benign neoplasms. Brominated flame retardants and organochlorine pesticides (OCPs) can disrupt hormones involved in UL etiology.

Methods: The Study of Environmental, Lifestyle, and Fibroids is a Detroit-area prospective cohort of 1693 Black women 23-35 years of age.

View Article and Find Full Text PDF

Background: Uterine leiomyomata, or fibroids, are hormone-dependent neoplasms of the myometrium that can cause severe gynecologic morbidity. In previous studies, incidence of these lesions has been positively associated with exposure to polychlorinated biphenyls (PCBs), a class of persistent endocrine-disrupting chemicals. However, previous studies have been retrospective in design and none has used ultrasound to reduce disease misclassification.

View Article and Find Full Text PDF

Background: Phthalates are endocrine-disrupting chemicals that are widely present in consumer products. In the United States, Black women are more highly exposed to phthalates than other racial/ethnic groups, yet information on predictors of phthalate exposure among Black women is limited.

Objective: We evaluated the association of demographics, lifestyle, reproductive history, and personal care product use with urinary concentrations of phthalate and phthalate alternative metabolites, using cross-sectional data from a study of 754 Black women from Detroit, Michigan (2010-2012).

View Article and Find Full Text PDF

Background: An epidemic of CKD in Central America predominantly affects males working in certain industries, including sugarcane. Urinary tract infections are commonly diagnosed among men in Nicaragua, who often receive antibiotics and nonsteroidal anti-inflammatory drugs for urinary symptoms.

Methods: We followed 251 male Nicaraguan sugarcane workers in seven job tasks over one harvest and measured urine dipstick parameters, kidney injury biomarkers, and eGFR.

View Article and Find Full Text PDF

Metals are suspected contributors of autoimmune disease among indigenous Americans. However, the association between metals exposure and biomarkers of autoimmunity is under-studied. In Nicaragua, environmental exposure to metals is also largely unexamined with regard to autoimmunity.

View Article and Find Full Text PDF
Article Synopsis
  • - The study investigates how exposure to multiple per- and polyfluoroalkyl substances (PFAS) during early pregnancy affects thyroid function in both mothers and their newborns, emphasizing the importance of thyroid hormones for growth and development.
  • - It involved 726 mothers and 465 neonates, where researchers measured various PFAS and thyroid hormones using advanced statistical techniques to analyze individual and combined effects of PFAS exposure.
  • - Results indicated that higher PFAS levels were linked to lower maternal Free T Index (FTI) and neonatal thyroid hormone levels, particularly affecting male infants, while certain PFAS like MeFOSAA and PFHxS had the most significant impacts.
View Article and Find Full Text PDF

Background: Polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls (PBBs) are brominated flame retardant chemicals detectable in the environment and U.S. population, and are associated with adverse health outcomes over the life course.

View Article and Find Full Text PDF

Objective: Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to contact and collision sports, including American football. We hypothesized a dose-response relationship between duration of football played and CTE risk and severity.

Methods: In a convenience sample of 266 deceased American football players from the Veterans Affairs-Boston University-Concussion Legacy Foundation and Framingham Heart Study Brain Banks, we estimated the association of years of football played with CTE pathological status and severity.

View Article and Find Full Text PDF
Article Synopsis
  • Asbestos is a group of mineral compounds known to cause serious respiratory diseases such as mesothelioma and lung cancer, and has also been linked to laryngeal and pharyngeal squamous cell carcinoma (SCC).
  • This study aimed to provide stronger evidence of asbestos's role in these cancers by analyzing tissue samples from patients with occupational asbestos exposure.
  • The findings revealed chrysotile asbestos fibers in the tissues of 3 out of 6 patients with laryngeal SCC who had asbestos exposure, supporting the idea that asbestos exposure is a significant risk factor for these types of cancers.
View Article and Find Full Text PDF

Importance: Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repetitive head impacts, including those from US football, that presents with cognitive and neuropsychiatric disturbances that can progress to dementia. Pathways to dementia in CTE are unclear and likely involve tau and nontau pathologic conditions.

Objective: To investigate the association of white matter rarefaction and cerebrovascular disease with dementia in deceased men older than 40 years who played football and had CTE.

View Article and Find Full Text PDF

Rationale & Objective: In Central America, there is a high prevalence of chronic kidney disease (CKD) of nontraditional etiology often observed among agricultural workers. Few studies have assessed CKD prevalence among workers in nonagricultural occupations, which was the objective of this investigation.

Study Design: Prospective cohort study.

View Article and Find Full Text PDF

We performed a cross-sectional analysis to identify correlates of urinary concentrations of seven phenols (bisphenols A, F, and S; 2,4-dichlorophenol; 2,5-dichlorophenol; benzophenone-3; triclosan), triclocarban, and four parabens (butyl, ethyl, methyl, and propyl). We analyzed baseline data from 766 participants in the Study of Environment, Lifestyle, and Fibroids, a prospective cohort study of 1693 Black women aged 23-34 years residing in Detroit, Michigan (2010-2012). We collected data on demographic, behavioral, and anthropometric factors via telephone interviews, clinic visits, and self-administered questionnaires.

View Article and Find Full Text PDF