Intra-Tour Variation of Firefighter Sleep Duration and Sleep-Wake Cycle within the 24/48 and 48/96 Shift Schedules.

OBJECTIVE: The purpose of this paper is to investigate intra-tour variation in total sleep time (TST) and sleep-wake cycle among US firefighters working the 24 hours on and 48 hours off shift schedule (24/48) and the 48 hours on and 96 hours off shift schedule (48/96). METHODS: Twenty-four firefighters were recruited for this sleep study and were evaluated over 18 days during a 24/48 shift schedule and again 6 months after firefighters transitioned to a 48/96 shift schedule. The primary outcome variables included TST, measured by actigraphy, and sleep-wake cycle (in-bed time and sleep offset) using the Emergency Services Sleep Diary. RESULTS: Firefighters experienced intra-tour variations in TST and sleep offset. The least TST occurred at home prior to starting shift on the 24/48 and 48/96 schedules (5.80 hours and 5.66 hours, respectively). The second least TST occurred the night preceding shift end (5.84 hours and 5.81 hours, respectively). In contrast to in-bed time, sleep offset varied throughout the schedule and was found to correlate with TST. In addition, shift start/end time appears to be responsible for advanced sleep offset. CONCLUSION: Results indicate that firefighters' sleep is complex and should not be reduced to singular averages. In both schedules, firefighters arrived at work with insufficient sleep, received insufficient sleep while on shift, and would commute home with insufficient sleep. These findings can inform future firefighter sleep research by accounting for intra-tour variations.

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.

Accuracy of body mass index-defined overweight in fire fighters.

BACKGROUND: Overweight, obesity and weight gain are significant problems in the U.S. fire service. While classification of obesity using body mass index (BMI) has demonstrated accuracy and low rates of false positives when compared with body fat percentage (BF%)-based standards, no studies have examined the accuracy of BMI-based overweight and normal weight status with other comparable body composition indices. AIMS: To compare overweight and normal weight BMI categories with BF% standards from the American Council on Exercise and analogous waist circumference (WC) categories and to examine rates and types of misclassification in fire fighters. METHODS: Data were collected from 11 randomly selected career fire departments in the International Association of Fire Chief's Missouri Valley Region. Demographics, occupational history, and body composition indices (weight, BF% and WC) were obtained from male career fire fighters who were categorized as normal weight or overweight based on BMI. RESULTS: There were 293 participants of whom 92 had normal BMI. There were low rates of false positives (12%) and moderate rates of false negatives (22%) when comparing BMI categories to the compar able BF% categories. However, using WC as the standard resulted in very high rates of false positives (63%) and very low rates of false negatives (5%). CONCLUSIONS: BMI-based overweight status was associated with significant errors in classification depending on the standard to which it was compared.

A national qualitative study of tobacco use among career firefighters and department health personnel.

INTRODUCTION: Firefighters currently have substantially lower smoking rates than similar occupational groups and the general U.S. population. In contrast, firefighters have very high rates of smokeless tobacco (SLT). The reasons for this paradox have not been explored; thus, the current study examined firefighters' perspectives on tobacco use. METHODS: Key informant interviews and focus groups were conducted in a national, cross-sectional purposively sampled group of 332 career firefighters. RESULTS: Firefighters suggested several reasons for the decline in smoking in the fire service including changes in the fire service culture, concerns about the impact of smoking on their ability to perform their job, regulations aimed at reducing smoking in departments, and the costs of smoking. In contrast, they felt that the greater use of SLT was primarily due to increasing restrictions on smoking. CONCLUSIONS: The primary reasons cited for decreased smoking rates by firefighters in our study were policy implementation at the state and local levels that prohibit tobacco use as a condition of employment and related presumption laws. However, reasons beyond policy mandates such as witnessing the end results of tobacco use, fitness, greater education about the negative health effects of smoking, and awareness about increased risk of exposure to toxic products of combustions also were noted. The primary reason cited for increased SLT use was the greater restrictions on smoking.

Alcohol use among firefighters in the Central United States.

BACKGROUND: Although the US National Fire Service is concerned about alcohol use among firefighters, little research has been conducted on the topic. AIMS: To survey alcohol use patterns among career and volunteer firefighters. METHODS: Data were from a population-based cohort study of male firefighters conducted in randomly selected career and volunteer departments. Data were collected from 2008 to 2010. RESULTS: There were 656 participants from 11 career and volunteer 13 departments included in the study with a response rate of 97%. Career firefighters drank approximately 10 days per month (just about half of their off duty days) and drank relatively heavily on those days. Fifty-eight per cent of career and 40% of volunteer firefighters averaged three or more drinks and similar percentages reported binge drinking on the days they consumed alcohol. In general, firefighters who drank but did not binge drink tended to have the best health outcomes, while those who binge drank typically were at highest risk of negative health outcomes. Nine per cent of career and 10% of volunteer firefighters who drank self-reported driving while intoxicated in the previous 30 days. CONCLUSIONS: Given the high rates of heavy and binge drinking, local and nationally coordinated efforts to increase the surveillance of drinking behaviour among firefighters and the development of targeted prevention interventions are critically needed.

Prevalence of overweight and obesity in Thai population: results of the National Thai Food Consumption Survey.

Overweight and obesity are considered a serious health problem in Thailand. This study examined the prevalence of overweight and obesity in a nationally representative sample of Thai children and adults based on international standards. A cross-sectional population survey of 16,596 Thais aged 3 years and over was conducted. Heights and weights were obtained using standardized methods. Estimates of the overweight and obesity prevalence in children, adolescents, and adults were computed. The prevalence of overweight and obesity among children and adolescents aged 3 to 18 years was 7.6% and 9.0%, respectively, and was higher among boys than girls. Among adults, using the the Regional Office for the Western Pacific (WPRO) standard, 17.1% of adults were classified as overweight [body mass index (BMI) 23.0-24.9 kg/m²], 19.0% as class I obesity (BMI 25.0-29.9 kg/m²), and 4.8% as class II obesity (BMI ≥ 30.0 kg/m²). Using the World Health Organization (WHO) definition, 19.0% were overweight (BMI 25-29.9 kg/m²), 4.0% class I obesity (BMI 30.0-34.9 kg/m²), 0.8% class II obesity (BMI 35.0-39.9 kg/m²), and 0.1% class III obesity (BMI ≥ 40.0 kg/m²). There was a vast difference in obesity prevalence between the WHO and the WPRO criteria. Obesity prevalence when using the WPRO definition (23.8%) was almost five times greater than when defined with the WHO standard (4.9%). The present study found a high prevalence of overweight and obesity in nationally representative sample of the Thai population. Higher rates of overweight and obesity prevalence were computed using the WPRO standard when compared to the WHO standard.

Genome-wide association analyses suggested a novel mechanism for smoking behavior regulated by IL15.

Cigarette smoking is the leading preventable cause of death in the United States. Although smoking behavior has a significant genetic determination, the specific genes and associated mechanisms underlying the smoking behavior are largely unknown. Here, we carried out a genome-wide association study on smoking behavior in 840 Caucasians, including 417 males and 423 females, in which we examined approximately 380,000 single nucleotide polymorphisms (SNPs). We found that a cluster of nine SNPs upstream from the IL15 gene were associated with smoking status in males, with the most significant SNP, rs4956302, achieving a P-value (8.80 x 10(-8)) of genome-wide significance. Another SNP, rs17354547 that is highly conserved across multiple species achieved a P-value of 5.65 x 10(-5). These two SNPs, together with two additional SNPs (rs1402812 and rs4956396) were selected from the above nine SNPs for replication in an African-American sample containing 1251 subjects, including 412 males and 839 females. The SNP rs17354547 was replicated successfully in the male subgroup of the replication sample; it was associated with smoking quantity (SQ), the Heaviness of Smoking Index (HSI) and the Fagerstrom Test for Nicotine Dependence (FTND), with P-values of 0.031, 0.0046 and 0.019, respectively. In addition, a haplotype formed by rs17354547, rs1402812 and rs4956396 was also associated with SQ, HSI and FTND, achieving P-values of 0.039, 0.0093 and 0.0093, respectively. To further confirm our findings, we carried out an in silico replication study of the nine SNPs in a Framingham Heart Study sample containing 7623 Caucasians from 1731 families, among which, 3491 subjects were males and 4132 were females. Again, the male-specific association with smoking status was observed, for which seven of the nine SNPs achieved significant P-values (P<0.05) and two achieved marginally significant P-values (P<0.10) in males. Several of the nine SNPs, including the highly conserved one across species, rs17354547, are located at potential transcription factor binding sites, suggesting transcription regulation as a possible function for these SNPs. Through this function, the SNPs may modulate the gene expression of IL15, a key cytokine regulating immune function. As the immune system has long been recognized to influence drug addiction behavior, our association findings suggest a novel mechanism for smoking addiction involving immune modulation through the IL15 pathway.

Effectiveness of Medifast supplements combined with obesity pharmacotherapy: a clinical program evaluation.

PURPOSE: To evaluate the long-term impact of Medifast meal-replacement supplements (MMRS) combined with appetite suppressant medication (ASM) among participants who received 52 weeks of treatment. METHODS: We conducted a systematic program evaluation of weight loss data from a medically-supervised weight control program combining the use of MMRS and ASM. Data were obtained and analyzed from 1,351 patient (BMI> or =25) medical charts who had participated for at least 12 weeks of treatment. Outcomes included weight loss (kg) and percent weight loss from baseline and at 12, 24, and 52 weeks. Both completers and intention-to-treat analyses were conducted. Completers' (i.e., those with complete data for 52 weeks) outcomes were evaluated after stratification for reported adherence to the MMRS and ASM. RESULTS: Participants who completed 52 weeks of treatment experienced substantial weight losses at 12 (-9.4+/-5.7 kg), 24 (-12.0+/-8.1 kg), and 52 weeks (-12.4+/-9.2 kg) and all measures were significantly different from baseline weight (p<0.001 for all contrasts) for both true completers (n=324) and for ITT analysis (n=1,351). Fifty percent of patients remained in the program at 24 weeks and nearly 25% were still participating at one year. CONCLUSIONS: This weight loss program using a combination of MMRS and ASM produced significant and sustained weight losses at 52 weeks. Results were better than those typically reported for obesity pharmacotherapy in both short- and long-term studies and also better than those reported for partial meal replacement programs. Program retention at one year was similar to that reported in many controlled drug trials and better than most commercial programs reported in the literature.

Veterans' views on military tobacco use and tobacco control policy.

National military and veteran service organizations (MVSOs) have the potential to be advocates for stronger military tobacco control. This study consisted of qualitative analysis of interviews with 5 MVSO leaders (or their designees) and 6 focus groups conducted with veterans, to explore the opinions of MVSO leaders and veterans about military tobacco use and tobacco control policy, and to assess their current knowledge, attitudes, and likelihood of engaging with civilian tobacco control. Themes discussed include the impact of tobacco use on the military mission and on veterans; the possibility of stronger military tobacco control policies; and the idea that such policies would affect the rights of military personnel. Participants considered whether tobacco use impacts the military mission in the most literal sense (e.g., giving away patrol locations), ignoring larger scale effects on long term health and costs. While familiar with tobacco's impacts on veterans' health, MVSO leaders did not endorse stronger policies, although some veterans did. Participants were largely unaware of the impact of tobacco use on military readiness. Establishment of better alliances among MVSOs and civilian public health groups for mutual education about tobacco's many negative effects on the military's mission may be necessary to achieve a tobacco-free military.

Tobacco use among medical professionals in Kerala, India: the need for enhanced tobacco cessation and control efforts.

In developing nations where reductions in tobacco use have not been realized, it is critical that health professionals be encouraged to abstain from tobacco use. Data on tobacco use among health professionals in India are limited. We conducted cross-sectional surveys among 110 male medical school faculty (MSF), 229 physicians (67% male), 1130 medical students (46% male), and 73 female nursing students. Information on tobacco use and quit attempts was collected using structured questionnaires. Among the male respondents, current smokers were 15.1% of MSF, 13.1% of physicians, and 14.1% of medical students. Among current smokers, 42% of MSF and physicians and 51% of medical students had not attempted quitting in the last year. However, one third of MSF and physicians and 16% of medical students had attempted to quit at least 4 times. This is one of the first studies among health care professionals in India. Our findings show that a substantial proportion of physicians and medical students in Kerala continue to smoke. Smoking cessation programs are warranted in medical schools in Kerala. An initiative is presently underway by the authors to incorporate tobacco education into the medical school curriculum.

Does metabolic syndrome mitigate weight loss in overweight Mexican American women treated for 1-year with orlistat and lifestyle modification?

AIMS: To investigate the effects of a pharmacotherapy (orlistat) plus lifestyle management (OLM) intervention on weight loss in Mexican American women with and without metabolic syndrome (MS). METHODS: One hundred and seven female participants aged 21-65 years and of Mexican origin were randomized to either OLM or a wait-list control group (WLC) for one year. The lifestyle interventions were tailored to exhibit features of the Mexican culture. Within each group, subjects with MS were compared to those without MS to assess whether its presence mitigates weight loss. Risk factors for MS also were assessed. RESULTS: Participants with MS in the OLM group experienced significant decreases in weight and body mass index (BMI) as compared to participants without MS. Participants with MS in the OLM group and who completed the study lost 9.3+/-7.5 kg (20.5+/-16.5 lb) as compared to participants with MS in the WLC group, who only lost 0.2+/-3.1 kg (0.4+/-6.8 lb). Further, participants with MS in the OLM group who completed the study experienced a 3.1+/-3.9 kg/m2 decrease in BMI whereas participants with MS in the WLC group only experienced a 0.1+/-1.2 kg/m2 decrease in BMI. No changes in other MS risk factors were significant. CONCLUSIONS: Patients with MS experienced significant weight loss and decreases in BMI as a result of a lifestyle and pharmacotherapy intervention.

A longitudinal analysis of the impact of dietary intake and physical activity on weight change in adults.

The current investigation is a longitudinal analysis of the relationship between dietary intake, physical activity, and body weight change in adult men (n = 142) and women (n = 152). Measures of dietary intake, physical activity, and cigarette and alcohol consumption were obtained for 3 y. Results indicated a different pattern of predictors of weight change for men vs women. For women a high dietary energy and fat intake as well as increases in total energy intake were related to higher weight gain and increases in work activity levels were related to decreased weight gain. For men weight gain was predicted by increases in dietary fat intake. Sex differences are discussed as a possible moderator variable in the energy balance equation.

Effects of obesity, social interactions, and physical environment on physical activity in preschoolers.

Examined demographic, environmental, and parent-child interactional correlates of physical activity in a group of 222 preschoolers. Activity levels were assessed with a system that quantified directly observed physical activity in the natural environment. Using regression-modeling procedures, results revealed a significant relationship between (a) child's relative weight, parental weight status, and percentage of time spent outdoors (environment) and (b) children's activity levels. Parental obesity was associated with lower levels of physical activity in children, childhood relative weight was associated with slightly higher levels of physical activity, and more outdoor activity was associated with higher activity levels. Parental participation in children's activities also significantly interacted with levels of parental obesity in predicting activity levels. Those children with a 50% risk for obesity (as defined by both, one, or neither parent being overweight) had small changes in activity across levels of parent-child interaction, whereas those at higher risk for obesity responded with increased activity as parent-child interactions increased. Results are discussed, and the implications of these findings for future intervention efforts are examined.

The relationship between smoking and body weight in a population of young military personnel.

Evidence indicates that middle-aged smokers weigh less than nonsmokers and that smoking cessation reliably produces weight gain, but recent studies have questioned the weight control "benefits" of smoking in younger populations (the time that people typically initiate smoking). The relationship between smoking and body weight was evaluated in all U.S. Air Force Basic Military Training recruits during a 1-year period (n = 32,144). Those who smoked prior to Basic Military Training (n = 10,440) were compared to never smokers or experimental smokers. Results indicated that regular-current smoking had no relationship to body weight in women (p > .05) and a very small effect in men (p < .05). Ethnicity, education, income, and duration and intensity of smoking did not affect the relationship between smoking and body weight. It was concluded that smoking has no effects on the body weights of young women and minimal effects in young men.

Efficacy of forced smoking cessation and an adjunctive behavioral treatment on long-term smoking rates.

This study evaluated the efficacy of a 6-week forced ban on smoking and brief behavioral counseling on long-term smoking rates. Participants were active-duty enrollees in U.S. Air Force basic military training over a 1-year period (N = 25,996). All participants were under a 6-week ban from tobacco products, and 75% were randomized to a brief smoking cessation intervention, with the other 25% randomized to a control condition. At 1-year follow-up, 18% of smokers were abstinent; women, ethnic minorities, and those intending to stay quit at baseline were more likely to be abstinent. Among smokers not planning to remain abstinent at baseline, those receiving the intervention were 1.73 times more likely to be abstinent. Over time, substantial smoking initiation occurred among nonsmokers (8% of never smokers, 26% of experimental smokers, and 43% of ex-smokers). Forced cessation is associated with good levels of long-term cessation, and brief behavioral interventions enhance cessation in certain subgroups.

Relationship between psychosocial functioning and body fat in preschool children: a longitudinal investigation.

This study examined whether preschool children differed on measures of psychosocial functioning both cross-sectionally and longitudinally. One hundred and thirty-two children who varied in levels of body fat participated in the study along with their natural parents. Results indicated that the children did not differ in levels of self-esteem and family functioning as a function of their body fat. Prospectively, physical self-esteem weakly (but significantly) correlated with body fat at 1 and 2 years, and father's perception of family functioning predicted body fat at 1 year only. Results suggested that childhood obesity may not develop as a result of psychosocial factors.

Genetic bottlenecks, perceived racism, and hypertension risk among African Americans and first-generation African immigrants.

The complexity of factors influencing the development of hypertension (HTN) in African Americans has given rise to theories suggesting that genetic changes occurred due to selection pressures/genetic bottleneck effects (ie, constriction of existing genetic variability) over the course of the slave trade. Ninety-nine US-born and 86 African-born health professionals were compared in a cross-sectional survey examining genetic and psychosocial predictors of HTN. We examined the distributions of three genetic loci (G-protein, AGT-235, and ACE I/D) that have been associated with increased HTN risk. There were no significant differences between US-born African Americans and African-born immigrants in the studied genetic loci or biological variables (eg, plasma renin and angiotensin converting enzyme activity), except that the AGT-235 homozygous T genotype was somewhat more frequent among African-born participants than US-born African Americans. Only age, body mass index, and birthplace consistently demonstrated associations with HTN status. Thus, there was no evidence of a genetic bottleneck in the loci studied, ie, that US-born African Americans have different genotype distributions that increase their risk for HTN. In fact, some of the genotypic distributions evidenced lower frequencies of HTN-related alleles among US-born African Americans, providing evidence of European admixture. The consistent finding that birthplace (ie, US vs Africa) was associated with HTN, even though it was not always significant, suggests potential and unmeasured cultural, lifestyle, and environmental differences between African immigrants and US-born African Americans that are protective against HTN.

Predictors of milk consumption in a population of 17- to 35-year-old military personnel.

OBJECTIVE: The purpose of this investigation was to survey an entire population of Air Force recruits (N = 32,144) regarding milk consumption and demographic and health-related factors that may predict milk consumption. DESIGN: All subjects were required to fill out a 53-item health survey at the start of basic military training. SUBJECTS/SETTING: All recruits who entered the US Air Force from August 1995 to August 1996 participated in this study (N = 32,144). STATISTICAL ANALYSES PERFORMED: Potential correlates of milk intake were analyzed using Spearman rank order correlations and multiple linear regression. Variables were removed if they did not make a meaningful contribution to variance in milk intake. Because of skewed distributions, several variables were dichotomized (e.g., age: 17 to 24 vs 25 to 35 years). RESULTS: In terms of milk consumption, 51.7% of the respondents reported intake of fewer than 1 serving per day; only 17.9% reported intake of 3 servings or more per day. Milk intake was positively associated with body weight and fruit/vegetable intake and negatively associated with age, education level, reported milk-related gastric distress, physical activity level, dieting frequency, and concern about weight. Gender (women reported lower intake) and ethnicity (minorities reported lower intake) were independently related to milk consumption. Of all respondents, 16.1% reported themselves to have milk-related gastric distress, but rates varied depending on age, gender, and ethnicity (ranging from 10.2% for younger non-Hispanic white men to 60.4% for older Asian men). APPLICATIONS/CONCLUSIONS: Despite the efforts of large, costly campaigns designed to increase milk consumption, self-reported milk consumption in young adults is extremely low. Given the importance of dairy products as a major source of calcium in the American diet, dietetics practitioners should assess milk consumption among young adults to ensure sufficient calcium intake to maximize peak bone mass in this group.

Echocardiographic assessment of patients receiving long-term treatment with anorexiant medications.

OBJECTIVE: To describe the prevalence and evaluate the risk of echocardiogram-determined valvulopathy in patients who received fenfluramine and phentermine in an effort to lose weight, in comparison with normal control subjects. METHODS: A historical cohort study was conducted in a clinical obesity-management practice. A total of 164 patients (88% women) who were treated with fenfluramine-phentermine for weight loss had echocardiographic evaluations. A subsample was cross-validated. RESULTS: The prevalence of mild or greater aortic regurgitation was 18.3%, and the prevalence of moderate or greater mitral regurgitation was 3.7%. The prevalences of mild or greater tricuspid and pulmonary valve regurgitation, valve thickening, and pulmonary hypertension were 23.2%, 5.5%, 10.4%, and 6.7%, respectively. No significant increases in risk were found for moderate or greater regurgitation of any valve. Patients had at least a 3-fold risk for mild or greater aortic regurgitation (standardized morbidity ratio [SMR] = 3.03; 95% confidence interval [CI] = 2.05 to 4.33) and a 2-fold risk for tricuspid regurgitation (SMR = 2.24; 95% CI = 1.58 to 3.06) in comparison with normal healthy adults. Age and duration of drug therapy predicted increased risk for aortic regurgitation. Four patients who had moderate or greater aortic regurgitation had taken the fenfluramine-phentermine combination continuously for 454, 615, 645, and 984 days. CONCLUSION: Use of serotonergic anorexiant medications may increase risk for mild or greater aortic and tricuspid regurgitation, although selection bias and obesity as causes of the association cannot be ruled out. Age and duration of drug therapy were predictors of aortic valvulopathy. Population-based studies are needed to confirm these preliminary findings.

Preliminary development of the Children's Physical Self-Concept Scale.

The development of a healthy eating style and physical fitness regimen in adolescence or adulthood might be contingent on physical self-concept in childhood. Most available measures of physical self-concept are inappropriate for use with 1st and 2nd grade children, so the present study developed, piloted, and partially validated the 27-item Children's Physical Self-Concept Scale (CPSS), which assesses Global physical self-concept and subscales of Physical Performance, Physical Appearance, and Weight Control behaviors in children 6 to 11 years of age. The test exhibits adequate test-retest reliability and internal consistency. A comparison of 316 normal and overweight children indicated that normal-weight children obtained higher Global physical self-concept scores and higher subscale scores. In addition, the CPSS distinguished test groups of diabetic, overweight, and normal-weight children in a contrasted-groups analysis.