The association between obesity, other cardiovascular risk factors, and cognitive function in a Canadian First Nations population was investigated using a cross‐sectional design. Eligible individuals were aged ≥18 years, without a history of stroke, nonpregnant, with First Nations status, and who had undergone cognitive function assessment by the Clock Drawing Test (CDT) and Trail Making Test Parts A and B. Parts A and B were combined into an Executive Function Score (TMT‐exec). Hypertension, a previous history of cardiovascular disease, dyslipidemia, metabolic syndrome, insulin resistance, and the presence and duration of diabetes were examined in addition to obesity. In the case of TMT‐exec only, obese individuals were at an approximately fourfold increased risk for lowered cognitive performance compared to those who were not obese in multivariable models (odds ratio (OR): 3.77, 95% confidence interval (CI): 1.46–9.72) whereas there was no effect for overweight individuals compared to those with a normal weight in unadjusted analysis. Those having an increased waist circumference also had 5 times the risk compared to those without an increased waist circumference (OR: 5.41, 95% CI: 1.83–15.99). Adjusted for age, sex, and insulin resistance, individuals having the metabolic syndrome were at an approximately fourfold increased risk compared to those without the metabolic syndrome (OR: 3.67, 95% CI: 1.34–10.07). No other cardiovascular risk factors were associated. Obesity and metabolic syndrome were associated with lowered cognitive performance. These results highlight the importance of studying the health effects of obesity beyond traditional disease endpoints, even in a relatively youthful population.

raumatic brain injury (TBI) is a leading cause of death and disability worldwide. It is a very serious and often overlooked health care issue. Victims are often young, and survivors of TBI often live with devastating consequences, including temporary or permanent impairments, partial or total functional disability, psychosocial maladjustments and associated economic burdens. 1 Even mild injuries can have long-term consequences. 2 An examination of coroners' files in Ontario showed that approximately half of all workplace fatalities involved a brain injury. 3 In a study by Kim et al. 4 based on severe injuries identified from the Ontario Trauma Registry, it was found that hospitalizations involving workrelated traumatic brain injuries increased by 12.4% from 1993 to 2001. Information obtained from the Workplace Safety and Insurance Board (WSIB) of Ontario revealed that the number of occupational TBI claims has nearly doubled over a span of eight years. 5 Previous studies have examined severe/fatal 3,4 or mild cases separately. 6 To date, no recent study has investigated occupational TBI across levels of severity. Because of the number of negative repercussions associated with occupational TBI and the apparent rise in its occurrence, a comprehensive examination of occupational TBI across levels of severity is needed in the Canadian context. Additionally, men continue to represent the majority of fatal and seriously injured, 3,4 therefore we hypothesize that men will display a more detrimental profile of occupational TBIs than women. Thus the objectives of this study were to provide an overview of occupational TBIs that includes factors associated with the injury, the implication being that the results may assist in better targeting the prevention of work-related TBI, such as through sex-specific prevention. METHODSA case series design was used to examine all WSIB claims with an injury date in the year 2004 and categorized by the WSIB as either "intracranial injury" or "concussion". All fatalities categorized as "traumatic" were also examined, for evidence of traumatic brain injury. The WSIB data are based on approximately 70% of the total Ontario workforce and were abstracted using a form that drew upon Haddon's Matrix. 7 In total, just over 1,500 non-fatal claim files were examined. Of those claims, 1,006 qualified as TBIs. Only claims with a confirmed

Breast cancers classified by estrogen receptor (ER) and/or progesterone receptor (PR) expression have different clinical, pathologic, and molecular features. We examined existing evidence from the epidemiologic literature as to whether breast cancers stratified by hormone receptor status are also etiologically distinct diseases. Despite limited statistical power and nonstandardized receptor assays, in aggregate, the critically evaluated studies (n = 31) suggest that the etiology of hormone receptor–defined breast cancers may be heterogeneous. Reproduction-related exposures tended to be associated with increased risk of ER-positive but not ER-negative tumors. Nulliparity and delayed childbearing were more consistently associated with increased cancer risk for ER-positive than ER-negative tumors, and early menarche was more consistently associated with ER-positive/PR-positive than ER-negative/PR-negative tumors. Postmenopausal obesity was also more consistently associated with increased risk of hormone receptor–positive than hormone receptor–negative tumors, possibly reflecting increased estrogen synthesis in adipose stores and greater bioavailability. Published data are insufficient to suggest that exogenous estrogen use (oral contraceptives or hormone replacement therapy) increase risk of hormone-sensitive tumors. Risks associated with breast-feeding, alcohol consumption, cigarette smoking, family history of breast cancer, or premenopausal obesity did not differ by receptor status. Large population-based studies of determinants of hormone receptor–defined breast cancers defined using state-of-the-art quantitative immunostaining methods are needed to clarify the role of ER/PR expression in breast cancer etiology.