Dorothee M. Baur

Type 2 diabetes mellitus and medications for type 2 diabetes mellitus are associated with risk for and mortality from cancer in a German primary care cohort.

There is growing evidence that patients with type 2 diabetes mellitus have increased cancer risk. We examined the association between diabetes, cancer, and cancer-related mortality and hypothesized that insulin sensitizers lower cancer-related mortality. Participants in the Diabetes Cardiovascular Risk and Evaluation: Targets and Essential Data for Commitment of Treatment study, a nationwide cross-sectional and prospective epidemiological study, were recruited from German primary care practices. In the cross-sectional study, subjects with type 2 diabetes mellitus had a higher prevalence of malignancies (66/1308, 5.1%) compared to nondiabetic subjects (185/6211, 3.0%) (odds ratio, 1.64; 95% confidence interval, 1.12-2.41) before and after adjustment for age, sex, hemoglobin A(1c), smoking status, and body mass index. Patients on metformin had a lower prevalence of malignancies, comparable with that among nondiabetic patients, whereas those on any other oral combination treatment had a 2-fold higher risk for malignancies even after adjusting for possible confounders; inclusion of metformin in these regimens decreased the prevalence of malignancies. In the prospective analyses, diabetic patients in general and diabetic patients treated with insulin (either as monotherapy or in combination with other treatments) had a 2- and 4-fold, respectively, higher mortality rate than nondiabetic patients, even after adjustment for potential confounders (incidence of cancer deaths in patients with type 2 diabetes mellitus [2.6%] vs the incidence of cancer deaths in patients without type 2 diabetes mellitus [1.2%]). Our results suggest that diabetes and medications for diabetes, with the exception of the insulin sensitizer metformin, increase cancer risk and mortality.

Sudden Cardiac Death Among Firefighters £45 Years of Age in the United States *

Sudden cardiac death (SCD) is the leading cause of death in firefighters. Although on-duty SCD usually occurs in older victims almost exclusively because of coronary heart disease, no studies have examined causation across the career span. In the present retrospective case-control study, cases of SCD in young (aged ≤45 years) firefighters from the National Institute for Occupational Safety and Health fatality investigations (n = 87) were compared with 2 age- and gender-matched control groups: occupationally active firefighters (n = 915) and noncardiac traumatic firefighter fatalities (n = 56). Of the SCD cases, 63% were obese and 67% had a coronary heart disease-related cause of death. The SCD victims had much heavier hearts (522 ± 102 g) than noncardiac fatality controls (400 ± 91 g, p <0.001). Cardiomegaly (heart weight >450 g) was found in 66% of the SCD victims and conveyed a fivefold increase (95% confidence interval [CI] 1.93 to 12.4) in SCD risk. Furthermore, hypertension, including cases with left ventricular hypertrophy, increased SCD risk by 12-fold (95% CI 6.23 to 22.3) after multivariate adjustment. A history of cardiovascular disease and smoking were also independently associated with elevated SCD risk (odds ratio 6.89, 95% CI 2.87 to 16.5; and odds ratio 3.53, 95% CI 1.87 to 6.65, respectively). In conclusion, SCD in young firefighters is primarily related to preventable lifestyle factors. Obesity entry standards, smoking bans, and improved screening and/or wellness program are potential strategies to reduce SCD in younger firefighters.

Cardiorespiratory fitness predicts cardiovascular risk profiles in career firefighters.

Objective: Evaluate the association between cardiovascular disease (CVD) risk factors and cardiorespiratory fitness (CRF) in firefighters. Methods: Cross-sectional study of 968 male career firefighters. Cardiorespiratory fitness was measured by maximal exercise tolerance tests. Cardiovascular disease risk parameters included body composition, resting vital signs, and metabolic profiles. Group comparisons were performed using &khgr;2 test, analysis of variance, and general linear regression with/without adjustment for age and body mass index (BMI). Results: Higher metabolic equivalents categories were significantly associated with lower diastolic blood pressure, body fat, triglycerides, low-density lipoprotein cholesterol and total/high-density cholesterol ratio, and higher high-density lipoprotein (P ⩽ 0.0272, age and BMI adjusted). Conclusions: Increasing CRF has beneficial independent effects on CVD risk factor profiles among firefighters. Higher CRF was beneficial regardless of BMI; nevertheless, increasing BMI had strong independent unfavorable effects. Firefighters should be encouraged to increase their CRF to decrease their future risk of CVD.

Metabolic syndrome is inversely related to cardiorespiratory fitness in male career firefighters.

Abstract Baur, DM, Christophi, CA, and Kales, SN. Metabolic syndrome is inversely related to cardiorespiratory fitness in male career firefighters. J Strength Cond Res 26(9): 2331–2337, 2012—Cardiovascular disease (CVD) accounts for 45% of on-duty fatalities among firefighters, occurring primarily in firefighters with excess CVD risk factors in patterns resembling the metabolic syndrome (MetSyn). Additionally, firefighters have a high prevalence of obesity and sedentary behavior suggesting that MetSyn is also common. Therefore, we assessed the prevalence of MetSyn in firefighters and its association with cardiorespiratory fitness (CRF) in a cross-sectional study of 957 male career firefighters. The CRF was measured by maximal exercise tolerance testing (standard metabolic equivalent [METS]). The MetSyn was defined according to modified criteria from the Joint Scientific Statement. Group differences were compared using &khgr;2-test and logistic regression. The prevalence of MetSyn was 28.3%. Firefighters in the lowest fitness category (METS ⩽ 10) had a nearly 10-fold higher prevalence of MetSyn (51.2%) compared with colleagues in the highest fitness category (METS > 14) (MetSyn prevalence 5.2%) (p value < 0.0001, adjusted for age). In multivariate regression models, every 1-unit increase in METS decreased the odds of having the MetSyn by 31% (odds ratio 0.69 [95% confidence interval 0.63–0.76] [age adjusted]), whereas age had no significant effect after adjusting for CRF. We found a high prevalence of the MetSyn in this group of career emergency responders expected to be more active, fit, and relatively younger than the general population. Moreover, there is a highly significant inverse, dose-response association with CRF. Firefighters should be given strong incentives to improve their fitness, which would decrease prevalent MetSyn, a likely precursor of on-duty CVD events and contributor to CVD burden in this population.

Weight- perception in male career firefighters and its association with cardiovascular risk factors

BackgroundThe prevalence of obesity has reached epidemic proportions worldwide, and is also increasing among public safety professionals like firefighters who are expected to be fit and more active. The present study evaluates the associations among Body Mass Index (BMI), weight perception and cardiovascular risk factors in 768 male career firefighters from two Midwestern states in the United States.MethodsA physical examination was performed and fasting blood samples were taken. Cardio-respiratory fitness (CRF) was determined from symptom- limited maximal treadmill exercise testing with electrocardiogram (ECG) monitoring and estimation of oxygen consumption (metabolic equivalents, METS) using the Bruce protocol. A health and lifestyle questionnaire was administered with standardized written instructions for completion. Self-reports of weight perception were extracted from responses to the completed multiple choice questionnaire. Baseline characteristics were described using the mean (standard deviation) for continuous variables and frequency for categorical variables. Group comparisons were calculated using analysis of variance (ANOVA). Linear models and logistic regression models were used to adjust for possible confounders. Logistic regression analyses were used to calculate the odds ratios of underestimating one’s weight category.ResultsA high proportion of overweight and obese male career firefighters underestimate their weight categories (68%). The risk of underestimating one’s weight category increased by 24% with each additional unit of increasing BMI after adjustment for age and CRF. When divided into six groups based on combinations of measured BMI category and weight perception, there were significant differences among the groups for most cardiovascular risk factors. After adjustment for age and BMI, these differences remained statistically significant for CRF, amount of weekly exercise, prevalence of Metabolic Syndrome (MetSyn), body fat percentage and cholesterol measurements.ConclusionA high proportion of overweight and obese male career firefighters underestimate their measured BMI categories. As a result, they are unlikely to fully appreciate the negative health consequences of their excess weight. The results of this study emphasize the importance of objectively measuring BMI and then informing patients of their actual weight status and the associated disease risks.

Age-Related Decline in Cardiorespiratory Fitness among Career Firefighters: Modification by Physical Activity and Adiposity

Firefighting is a very hazardous occupation, and strenuous fire duties require high levels of physical fitness. In the general adult population, cardiorespiratory fitness (CRF) declines with aging. We sought to investigate the effect of increasing age on CRF in male career firefighters as well as the modifying effects of physical activity and adiposity. We cross-sectionally examined 804 male career firefighters from two Midwestern states. CRF was determined from symptom-limited maximal treadmill exercise testing in metabolic equivalents (METS) following the Bruce protocol. Physical activity self-reports were extracted from responses to a health and lifestyle questionnaire. We found as expected that CRF declines with advancing age; however, the decline is greatly attenuated among leaner firefighters who report more physical activity. Furthermore, in a linear regression model including age, BMI, and variables describing physical activity behaviors, we could predict CRF (R2 = 0.6286). The total weekly duration of aerobic exercise as well as the duration of weight lifting sessions both had significant impacts on age-related decline. We conclude that firefighters are more likely to maintain the high levels of CRF needed to safely perform their duties if they engage in frequent exercise and maintain healthy weights.

Association of Sleep Habits With Accidents and Near Misses in United States Transportation Operators

Objective: To explore sleep risk factors and their association with adverse events in transportation operators. Methods: Self-reported sleep-related behaviors were analyzed in transportation operators (drivers, pilots, and rail operators) aged 26 to 78 years who completed the National Sleep Foundations 2012 “Planes, Trains, Automobiles, and Sleep” survey. Regression analyses were used to assess the associations of various sleep-related variables with the combined outcome of self-reported accidents and near misses. Results: Age- and body mass–adjusted predictors of accidents/near misses included an accident while commuting (odds ratio [OR] = 4.6; confidence interval [CI], 2.1 to 9.8), driving drowsy (OR = 4.1; CI, 2.5 to 6.7), and Sheehan Disability Scale score greater than 15 (OR = 3.5; CI, 2.2 to 5.5). Sleeping more than 7 hours nightly was protective for accident/near misses (OR = 0.6; CI, 0.4 to 0.9). Conclusion: Recognized risk factors for poor sleep or excessive daytime sleepiness were significantly associated with self-reported near misses and/or accidents in transportation operators.

Low fitness is associated with exercise abnormalities among asymptomatic firefighters

BACKGROUND Low cardiorespiratory fitness (CRF) has been repeatedly linked to cardiovascular morbidity and mortality, while higher CRF levels are protective. This relationship is likely to be highly relevant in firefighters, who have increased risk of cardiovascular disease (CVD) mortality during strenuous emergencies, which can require prolonged periods of near-maximal heart rates (HR) and high workloads. Abnormalities during maximal stress testing could mark future CVD risk during strenuous duties. AIMS To determine if low CRF among asymptomatic firefighters is associated with higher risk of electrocardiographic (ECG) and autonomic abnormalities during maximal exercise stress testing and recovery. METHODS Male career firefighters completed a maximal stress test exercising to volitional exhaustion (mean maximal age-predicted HR achieved 98%, standard deviation (SD) = 6.5). CRF was measured as maximal metabolic equivalents (METS) achieved. Abnormal exercise tests included the following: abnormal HR recovery; chronotropic insufficiency; exaggerated blood pressure response; and ECG abnormalities. The relationship of CRF to stress testing abnormalities was analysed using peak METS categories and peak METS as a continuous variable after adjusting for age, body mass index (BMI) and metabolic syndrome (MetSyn). RESULTS There were 1149 study participants. CRF was inversely associated with the risk of both ECG and autonomic exercise testing abnormalities before and after adjustment for age, BMI and MetSyn. CONCLUSIONS Firefighters with lower CRF are significantly more prone to exhibit abnormal stress test parameters, which may indicate higher future risk of cardiovascular events. As such, firefighters with low CRF (≤ 12 METS) should receive cardiovascular risk reduction, including efforts to improve their CRF.

Long-term follow-up after endoscopic stent therapy for benign biliary strictures.

Background and Aims: Endoscopic therapy holds an important role in the management of benign biliary strictures. This study compares the long-term outcome of stenting therapy depending on the underlying cause of the stricture. Methods: In a retrospective cohort study, 228 patients with benign biliary strictures were identified using an endoscopic database, hospital charts, and cholangiograms between January 1992 and December 2008. Long-term follow-up was evaluated with cholangiograms, transabdominal ultrasound, laboratory parameters, and physical examination. The median follow-up period was 44.7 months. Results: Endoscopic management showed best long-term results in patients with stone-associated biliary stricture. In this subgroup, endoscopic therapy could be successfully completed in 92% (71/77) of the patients. Patients with postoperative biliary stricture had good outcome in 83% (53/64) of cases. Idiopathic strictures presented a successful outcome in 58% (15/26). Biliary strictures caused by chronic pancreatitis had a significantly poorer outcome compared with strictures of other origin. Therapeutic success of endoscopic therapy could only be observed in 31% of patients (19/61). Conclusions: Long-term outcome of endoscopic therapy for benign strictures was significantly dependent on the underlying cause of the stricture. In particular, patients with biliary strictures due to chronic pancreatitis benefit least from endoscopic therapy, whereas patients with stone-associated strictures had the highest therapeutic success rate.

Duty-related risk of sudden cardiac death among young US firefighters.

BACKGROUND Little is known regarding duty-related risks for sudden cardiac death (SCD) among young firefighters. AIMS To investigate duty-related SCD among US firefighters aged 45 or younger. METHODS We collected data on duty-related SCD from the US Fire Administration (USFA) and the US National Institute for Occupational Safety and Health (NIOSH). Two physicians independently reviewed each record. The proportions of time spent by firefighters performing specific duties were estimated from a municipal department, 17 large metropolitan departments and a national database. We estimated the duty-specific relative risks (RRs) and 95% confidence intervals (95% CI) of SCD relative to non-emergency duties based on the observed deaths and the expected average proportions of time per duty. RESULTS The USFA recorded 205 age-eligible on-duty SCDs between 1996 and 2012; 86 (42%) of these deaths and one additional SCD were investigated by NIOSH (total n = 206). NIOSH was more likely (P < 0.001) to report on SCD associated with physical training (69% of cases were investigated) and fire suppression (57%). Compared with non-emergency duties, the risk of SCD was increased for fire suppression (RR 22.1, 95% CI 14.8-32.9), alarm response (RR 2.6, 95% CI 1.5-4.6), alarm return (RR 4.1, 95% CI 2.7-6.2) and physical training (RR 4.8, 95% CI 3.2-7.2). RRs for SCD were higher among firefighters with a pre-existing history of a cardiac condition. All 16 SCDs associated with alarm response occurred among volunteer firefighters. CONCLUSIONS The performance of strenuous emergency duties is strongly associated with an increased risk of SCD among young firefighters, particularly among those with a history of cardiovascular disease.