Rena S. Day

Dietary Mutagen Exposure and Risk of Pancreatic Cancer

To investigate the association between dietary exposure to food mutagens and risk of pancreatic cancer, we conducted a hospital-based case-control study at the University of Texas M. D. Anderson Cancer Center during June 2002 to May 2006. A total of 626 cases and 530 noncancer controls were frequency matched for race, sex and age (±5 years). Dietary exposure information was collected via personal interview using a meat preparation questionnaire. A significantly greater portion of the cases than controls showed a preference to well-done pork, bacon, grilled chicken, and pan-fried chicken, but not to hamburger and steak. Cases had a higher daily intake of food mutagens and mutagenicity activity (revertants per gram of daily meat intake) than controls did. The daily intakes of 2-amino-3,4,8-trimethylimidazo[4,5−f]quinoxaline (DiMeIQx) and benzo(a)pyrene (BaP), as well as the mutagenic activity, were significant predictors for pancreatic cancer (P = 0.008, 0.031, and 0.029, respectively) with adjustment of other confounders. A significant trend of elevated cancer risk with increasing DiMeIQx intake was observed in quintile analysis (Ptrend = 0.024). A higher intake of dietary mutagens (those in the two top quintiles) was associated with a 2-fold increased risk of pancreatic cancer among those without a family history of cancer but not among those with a family history of cancer. A possible synergistic effect of dietary mutagen exposure and smoking was observed among individuals with the highest level of exposure (top 10%) to PhIP and BaP, Pinteraction = 0.09 and 0.099, respectively. These data support the hypothesis that dietary mutagen exposure alone and in interaction with other factors contribute to the development of pancreatic cancer. (Cancer Epidemiol Biomarkers Prev 2007;16(4):655–61)

Interaction of the cytochrome P4501A2, SULT1A1 and NAT gene polymorphisms with smoking and dietary mutagen intake in modification of the risk of pancreatic cancer

Aromatic amines, N-nitroso compounds and heterocyclic amines are suspected human pancreatic carcinogens. Cytochrome P450 (CYP) 1A2, N-acetyltransferase (NAT) 1, NAT2 and sulfotransferase (SULT) are enzymes involved in the metabolism of these carcinogens. To test the hypothesis that genetic variations in carcinogen metabolism modify the risk of pancreatic cancer (PC), we investigated the effect of single-nucleotide polymorphisms (SNPs) of the CYP1A2, NAT1, NAT2 and SULT1A1 gene on modification of the risk of PC in a hospital-based study of 755 patients with pancreatic adenocarcinoma and 636 healthy frequency-matched controls. Smoking and dietary mutagen exposure information was collected by personal interviews. Genotypes were determined using the polymerase chain reaction–restriction fragment length polymorphism and Taqman methods. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional multivariate logistic regression analysis. We observed no significant main effects of any of these genes on the risk of PC. The CYP1A2 and NAT1 but not SULT1A1 and NAT2 genotypes showed significant interactions with heavy smoking in women not men. In contrast, a significant interaction between NAT1 genotype and dietary mutagen intake on modifying the risk of PC were observed among men but not women. The OR (95% CI) of PC was 2.23 (1.33–3.72) and 2.54 (1.51–4.25) for men having the NAT1*10 and a higher intake of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and benzo[a]pyrene, respectively, compared with individuals having no NAT1*10 or a lower intake of these dietary mutagens. These data suggest the existence of gender-specific susceptibility to tobacco carcinogen and dietary mutagen exposure in PC.

Physician weight recommendations for overweight and obese firefighters, United States, 2011-2012.

Introduction National guidelines state that health care professionals (HCPs) should advise patients on the importance of maintaining a healthy weight. Firefighters have high rates of obesity, and cardiovascular events are the leading cause of line-of-duty deaths in firefighters. This study assessed the association of age and body mass index (BMI) with HCP weight recommendations among male firefighters. Methods We used data on self-reported HCP weight recommendations and measured BMI from a 2011–2012 national sample of male firefighters (N = 1,002). HCP recommendations were recorded as no advice, maintain, gain, or lose weight, and BMI was categorized as normal (<25.0 kg/m2), overweight (25.0–29.9 kg/m2), class I obese (30.0–34.9 kg/m2), and class II or III obese (≥35.0 kg/m2). We used multinomial logistic regression to estimate the odds of receiving weight advice by age and BMI categories. Results Most firefighters (96%) reported visiting an HCP in the past year. Most (69%) firefighters and 48% of class I to III obese firefighters reported receiving no weight advice. Higher BMI predicted HCP advice to lose weight (odds ratio class I obese vs normal weight: 12.98; 95% confidence interval: 5.38–31.34). Younger firefighters were less likely to receive weight loss advice than older firefighters, except among those who were class II or III obese. Conclusions HCPs are important sources of health information for firefighters. Overweight and obese firefighters, particularly those who are younger, do not consistently receive HCP advice to lose weight. This marks a missed opportunity to prevent further weight gain and reduce obesity-related health outcomes.

Accuracy of self-reported weight, height and BMI in US firefighters.

BACKGROUND Obesity is of increasing concern especially among firefighters. Bias in self-reported body weight, height and body mass index (BMI) has received a great deal of attention given its importance in epidemiological field research on obesity. AIMS To determine the validity of self-reported weight, height and BMI and identify potential sources of bias in a national sample of US firefighters. METHODS Self-reported and measured weight and height (and BMI derived from them) were assessed in a national sample of 1001 career male firefighters in the USA and errors in self-reported data were determined. RESULTS There were 1001 participants. Self-reported weight, height and BMI were significantly correlated with their respective measured counterparts, i.e. measured weight (r = 0.990; P < 0.001), height (r = 0.961; P < 0.001) and BMI (r = 0.976; P < 0.001). The overall mean difference and standard deviation between self-reported weight, height and BMI were 1.3±2.0kg, 0.94±1.9cm and 0.09±0.9kg/m(2), respectively, for male firefighters. BMI-based weight status (P < 0.001) was the most consistent factor associated with bias in self-reported BMI, weight and height, with heavier firefighters more likely to underestimate their weight and overestimate their height, resulting in underestimated BMIs. Therefore, using self-reported BMI would have resulted in overestimating the prevalence of obesity (BMI ≥ 30.0) by 1.8%, but underestimating the prevalence of more serious levels of obesity (Class II and III) by 1.2%. CONCLUSIONS Self-reported weight and height (and the resulting BMI) were highly correlated with measured values. A primary and consistent source of error in self-reported weight, height and BMI based on those indices was BMI-based weight status.

Adiposity predicts self-reported frequency of poor health days among male firefighters.

Objective: Quantify the association between adiposity and frequency of self-reported poor health days among male firefighters. Methods: Measures were taken for body mass index, waist circumference, and percentage of body fat. Firefighters self-reported the outcome of the number of poor health days in the past 30 days. Zero-inflated negative binomial models and fractional polynomial plots were used to determine the impact of adiposity on the frequency of self-reported poor health days. Results: Body mass index (rate ratio [RR]: 1.037; 95% confidence interval [CI]: 1.003 to 1.073), waist circumference (RR: 1.012; 95% CI: 0.999 to 1.030), and percentage of body fat (RR: 1.021; 95% CI: 0.999 to 1.041) were associated with self-reported poor health days. Conclusions: Adiposity is positively associated with frequency of self-reported poor health days among male firefighters. Future efforts to improve health among firefighters should emphasize reductions in adiposity.

Prevalence and Correlates of Late Initiation of Smokeless Tobacco in US firefighters

Introduction Prevalence rates of smokeless tobacco (SLT) use and late initiation among firefighters (ie, starting use as an adult after joining the fire service) are remarkably high, 10.5% and 26.0%, respectively. The purpose of this study is to examine characteristics associated with late SLT initiation in a sample comprised of male career firefighters from two large cohort studies. Methods We examined correlates of late SLT initiation in a secondary analysis of data combining the baseline evaluations of two published firefighter health studies with 1474 male career firefighters in the United States. Results Fourteen percent of participants were current SLT users. Among this group, the unadjusted rate of firefighters who initiated SLT use after joining the fire service was 15.9%, while the age-standardized rate was 38.2%; this is substantially higher than the national adjusted late initiation rate among adult males (0.8%). In addition, firefighters demonstrated higher rates of late SLT initiation (15.9% unadjusted; 18.4% age-standardized) when compared to males in the military overall (13.8%). Conclusions The exceptionally high prevalence of SLT use overall and late initiation in the fire service suggest that joining the fire service in the United States is a risk factor for SLT use. There is a need to develop interventions aimed at reducing SLT use in the fire service that are specifically tailored for this occupational group. Implications The high prevalence of late SLT initiation (ie, starting use as an adult after joining the fire service) among firefighters should be addressed by both researchers and fire service organizations given the significant health risks associated with SLT and its impact on occupational readiness. There is a need for developing intervention programs aimed at reducing SLT use in the fire service. Interventions would need to be specifically tailored for this occupational group and their unique culture, given that joining the fire service appears to be a risk factor for SLT initiation among firefighters who did not use tobacco prior to joining the fire service.