J. Dorn

Exercise, occupational activity, and risk of endometrial cancer

We conducted a case-control study in western New York state among 232 women with newly-diagnosed endometrial cancer and 631 controls selected from the community. Physical activity was measured by participation in vigorous exercise and walking at four time periods: at age 16, and at 20, 10, and 2 years before the interview and by occupational activity based on a detailed lifetime history. Women who did a moderate amount of vigorous exercise at age 16 and at 20 years before the interview were at reduced risk as compared with those who reported no activity, with odds ratios (OR) (95% confidence intervals) of 0.51 (0.31-0.83) and 0.50 (0.29-0.89), respectively. However, there was no evidence of declining risk with greater amount of activity. At later times, 10 years and 2 years before the interview, being in the highest group with regard to vigorous activity was associated with a slightly but nor significant lower risk as compared with women who reported no activity; the adjusted OR were 0.72 (0.43-1.19) and 0.67 (0.42-1.09), respectively. Being in the highest category of miles walked at age 16 (i.e., > or = 15 miles per week) was associated with a slightly reduced risk as compared with not walking at all (OR 0.64 (0.26-1.16)), whereas the number of miles walked at other times was not related to reduced risk. Occupational physical activity was not related to the risk of endometrial cancer. Overall, these results indicate that physical activity at levels prevalent in this population has at most a modest relationship to reduced risk of endometrial cancer.

Oxidative stress and glucose levels in a population‐based sample

Objectives  To examine the relationship between markers of oxidative status and glucose on a population basis.

Adiposity, Muscle, and Physical Activity: Predictors of Perturbations in Heart Rate Variability

This study examines cross‐sectional associations of indices of adiposity, lean body mass, and physical activity, with heart rate variability (HRV), a marker for parasympathetic cardiac vagal control.

Tissue factor gene polymorphisms and haplotypes and the risk of ischemic vascular events: four studies and a meta-analysis.

Summary  Objective: The exposure of tissue factor (TF) to blood flow is the initial step in the coagulation process and plays an important role in thrombogenesis. We investigated the role of genetic polymorphisms and haplotypes of the TF gene in the risk of ischemic vascular disease. Methods: Four hundred and twenty‐two Italian patients with juvenile myocardial infarction (MI) and 434 controls, 808 US cases with MI and 1005 controls, 267 Italian cases with juvenile ischemic stroke and 209 controls and 148 German cases with juvenile ischemic stroke and 191 controls were studied. rs1361600, rs3917629 (rs3354 in the US population), rs1324214 and rs3917639 Tag single nucleotide polymorphisms were genotyped. Additionally, a meta‐analysis of all previous studies on TF loci and the risk of ischemic coronary disease (ICD) was performed. Results: After multivariable analysis none of the SNPs, major SNP haplotypes or haplotype‐pairs showed any consistent association with MI. Pooled meta‐analysis of six studies also suggested that TF polymorphisms are not associated with CHD. A significant, independent association between SNP rs1324214 (C/T) and juvenile stroke was found in Italian and German populations (OR for TT homozygotes = 0.47, 95% CI 0.24–0.92, in combined analysis). Pooled analysis also showed a significant association for haplotype H3 (OR = 0.76, 95% CI 0.57–1.00) and haplotype‐pair H3–H3 (OR = 0.43, 95% CI 0.20–0.92). Conclusions: TF genetic variations were associated with the risk of ischemic stroke at young age, but did not affect ischemic coronary disease.

Haplotypes and haplotype-pairs of IL-1 beta and IL-6 genes and risk of non fatal myocardial infarction in the Western New York Acute MI Study

Haplotypes and haplotype-pairs of IL-1 beta and IL-6 genes and risk of non fatal myocardial infarction in the Western New York Acute MI Study -

Estimation of the maximum flow-mediated brachial artery response using local regression methods

We consider methods for estimating the maximum from a sequence of measurements of flow-mediated diameter of the brachial artery. Flow-mediated vasodilation (FMD) is represented using the maximum change from a baseline diameter measurement after the release of a blood pressure cuff that has been inflated to reduce flow in the brachial artery. The influence of the measurement error on the maximum diameter from raw data can lead to overestimation of the average maximum change from the baseline for a sample of individuals. Nonparametric regression models provide a potential means for dealing with this problem. When using this approach, it is necessary to make a judicious choice of regression methods and smoothing parameters to avoid overestimation or underestimation of FMD. This study presents results from simulation studies using kernel-based local linear regression methods that characterize the relationship between the measurement error, smoothing and bias in estimates of FMD. Comparisons between fixed or constant smoothing and automated smoothing parameter selection using the generalized cross validation (GCV) statistic are made, and it is shown that GCV-optimized smoothing may over-smooth or under-smooth depending on the heart rate, measurement error and measurement frequency. We also present an example using measured data from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) pilot study. In this example, smoothing resulted in lower estimates of FMD and there was no clear evidence of an optimal smoothing level. The choice to use smoothing and the appropriate smoothing level to use may depend on the application.