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.

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.

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.

Obesity and incident injury among career firefighters in the central United States.

OBJECTIVE: Firefighting is a dangerous profession with high injury rates, particularly musculoskeletal (MS), but limited longitudinal data is available to examine predictors of MS injuries in this population. DESIGN AND METHODS: The relationship between personal individual, nonoccupational factors (e.g., demographic characteristics, body composition, fitness, and health behaviors) and incident injury and incident MS injury in a prospective cohort of 347 firefighters from the central United States was examined. RESULTS: Baseline weight status was a significant predictor of incident MS injury, with obese (BMI ≥ 30 kg m(-2)) firefighters 5.2 times more likely (95% CI = 1.1-23.4) to experience a MS injury than their normal weight (BMI = 18.5-24.9 kg m(-2)) colleagues over the course of the study. Similarly, firefighters who were obese based on WC (>102.0 cm) were almost three times as likely (OR = 2.8, 95% CI = 1.2-6.4) to have a MS injury at follow-up. CONCLUSIONS: Findings highlight the importance of focusing on firefighters' body composition, nutrition and fitness as a means of decreasing risk for injury.

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.

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.

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.

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.

Evaluation of a primary care-oriented brief counselling intervention for obesity with and without orlistat.

OBJECTIVE: There is a significant need for an obesity treatment model suitable for the primary care environment. We examined the effectiveness of a brief counselling intervention alone, in combination with orlistat, and drug-alone in a 12-month randomized-clinical trial at a medical school obesity centre. METHODS: Participants (N = 250) with body mass index (BMI) >or=27 were randomized. Changes in body weight, lipids, blood pressure and serum glucose were examined. Drug adherence and attendance were also evaluated. RESULTS: Completers analysis was conducted on 136 participants with data at baseline, 6 and 12 months and intention-to-treat analyses (ITT) for the total sample. Amongst completers, participants in the drug only (P = 0.012) and drug + brief counselling (P = 0.001) groups lost more weight (mean +/- SD: -3.8 +/- 5.8 kg and -4.8 +/- 4.4 kg, respectively) than participants in the brief counselling only group at 6 months (-1.7 +/- 3.3 kg), but there were no significant group differences at 12 months. ITT model results were similar to completers at 6 months and remained significant at 12 months, but the weight losses were more modest (<3 kg) for both groups receiving orlistat. For brief counselling alone, participants gained weight (1.7 +/- 4.2 kg). Cardiovascular disease (CVD) parameter changes were negligible. CONCLUSIONS: Pharmacotherapy alone or combined with brief counselling resulted in modest weight losses that had minimal impact on cardiovascular parameters, but were greater than brief counselling alone. Whilst brief interventions and primary pharmacotherapy have been suggested as viable treatments for implementation in primary care settings, our study suggests that such minimal interventions provide minimal benefits.

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.

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.

Weight loss with meal replacement and meal replacement plus snacks: a randomized trial.

OBJECTIVE: To evaluate whether snacking would improve weight loss and weight maintenance in overweight individuals within the context of a structured meal replacement (MR) weight loss program. DESIGN: A prospective 24 week, 2 (snacking vs nonsnacking) x 2 (MR vs meal replacement augmented with snacks (MRPS)) randomized trial. Participants were instructed to limit their total daily intake to 1200 (women) or 1500 (men) kcals. Those receiving the MR program were instructed not to snack while those in the MRPS program were told to snack three times per day. SUBJECTS: A total of 100 participants were block-randomized, based on prestudy snacking status (high vs low), to receive a standard meal replacement program (MR) or MRPS. MEASUREMENTS: Weight, height, blood pressure, lipid fractions, glucose, and insulin were assessed at the baseline, 12-, and 24 weeks. RESULTS: Completers analysis at 24 weeks demonstrated a significant time effect (F(1,46)=44.6, P<0.001), indicating that all participants lost significant amounts of weight regardless of group assignment. An intention-to-treat model resulted in similar results. By week 24, the average weight loss across groups was 4.6 kg. There also were significant improvements across all groups among completers for systolic blood pressure (P=0.047), cholesterol (P=0.001), LDL (P=0.001), glucose (P=0.004), and insulin (P=0.001) at week 12, and glucose (P=0.001) and insulin at week 24 (P=0.003). CONCLUSIONS: Our results suggest that a participant's preferences for snacking did not affect their response to treatment. Snackers and nonsnackers responded equally well whether they received a standard meal replacement program or one augmented with snacks.

Weight loss in obese Mexican Americans treated for 1-year with orlistat and lifestyle modification.

OBJECTIVE: To evaluate the effectiveness of a culturally appropriate lifestyle intervention combined with orlistat in producing weight loss with obese Mexican-American women. SUBJECTS: Mexican-American women (N=108), aged 21-65 y, with a body mass index (BMI) > or =27 kg/m(2) were randomized to 1 y of treatment with orlistat and a culturally tailored lifestyle modification intervention (OLM; n=56) or a wait-list control group (WLC; n=52). DESIGN: A randomized, controlled, open-label 12-month study. Orlistat was dosed at 120 mg, three times per day. The OLM intervention included behavior modification, a low-fat (< or =30% of total daily calories) diet, and moderate physical activity (> or =150 min/week). MEASUREMENT: Primary outcomes included changes in body weight (kg), BMI, waist circumference, blood pressure, glucose, and lipids. RESULTS: A total of 72 (37 OLM, 35 WLC) and 66 participants (32 OLM, 34 WLC) completed the 6- and 12-month follow-ups, respectively. Repeated-measures ANOVA demonstrated a significant time x treatment interaction (Wilks' lambda=12.61; P<0.001), indicating that OLM-treated patients achieved significant weight loss relative to the WLC group during the study (mean percentage weight loss+/-s.e.m.; -8.1%+/-1.2 vs -1.6%+/-0.7 at 6 months and -8.8%+/-1.5 vs -0.2%+/-1.0 at 12 months, respectively). OLM-treated patients also experienced significant reductions in waist circumference, low-density-lipoprotein, and total cholesterol. CONCLUSIONS: This study demonstrates the effectiveness of an intervention combining orlistat and lifestyle modification with Mexican-American women, a population with substantial risk for obesity.

Physical activity does not mitigate G-protein-related genetic risk for obesity in individuals of African descent.

The G-protein beta3 subunit 825 TT genotype has been associated with obesity and hypertension. We examined the interaction between the G-protein TT genotype, physical activity and body mass index (BMI) in a cross-sectional study of African immigrants and African Americans. The genotype frequencies were 6.3% CC, 37.7% CT, and 56% TT. After adjusting for potential confounders, BMI was found to be significantly higher in the sedentary than in the physically active participants (p=0.045). There was no statistically significant effect for genotype (p=0.215) or the interaction between genotype and the level of physical activity (p=0.219). However, the individuals with the CC or CT genotype who were physically active had substantially lower BMIs (M+/-SE) (i.e., 25.74+/-2.02) than any of the other groups: sedentary CC + CT (30.58+/-1.03), sedentary TT (30.65+/-1.00) or active TT (29.43+/-1.65). Because of the low statistical power of this study, further research is needed to confirm these findings and to explore potential gene-environment/lifestyle interactions.

Pharmacotherapy for obesity: a quantitative analysis of four decades of published randomized clinical trials.

AIM: This article provides the first comprehensive meta-analysis of randomized clinical trials of medications for obesity. METHOD: Based on stringent inclusionary criteria, a total of 108 studies were included in the final database. Outcomes are presented for comparisons of single and combination drugs to placebo and for comparisons of medications to one another. RESULT: Overall, the medications studied produced medium effect sizes. Four drugs produced large effect sizes (ie d>0.80; amphetamine, benzphetamine, fenfluramine and sibutramine). The placebo-subtracted weight losses for single drugs vs placebo included in the meta-analysis never exceeded 4.0 kg. No drug, or class of drugs, demonstrated clear superiority as an obesity medication. Effects of methodological factors are also presented along with suggestions for future research.

Lifestyle treatments in randomized clinical trials of pharmacotherapies for obesity.

OBJECTIVE: This meta-analysis evaluated the types of lifestyle treatments used in published obesity drug studies and assessed their contribution to weight losses associated with pharmacological interventions. RESEARCH METHODS AND PROCEDURES: Randomized, placebo-controlled, double-blind clinical trials of anti-obesity agents that are/were Food and Drug Administration-approved for the treatment of obesity (both prescription and over-the-counter), and drugs that are Food and Drug Administration-approved and are used off-label for obesity were included. Studies were located by computer searches of databases (e.g., Medline, PsychInfo) and reviewing tables of content/reference sections of journals, abstracts, previous reviews, past empirical studies, relevant book chapters, and recent issues of journals that regularly publish obesity research. In addition, a number of individuals who regularly publish in the obesity literature were asked to provide personal lists of obesity-drug studies. Based on the above criteria, a total of 108 randomized clinical trials were located. RESULTS: Balanced-deficit diets, low-calorie diets, and self-monitoring were the most used lifestyle treatments in published obesity studies. They were incorporated into 40.7%, 25%, and 23.1% of pharmacotherapy studies, respectively. Physical activity and other behavioral or psychotherapeutic interventions rarely were used. A substantial portion of weight loss experienced by patients was attributable to both "placebo effects" and to the lifestyle treatments. DISCUSSION: Obesity-pharmacotherapy trials do not use lifestyle treatments with the frequency expected based on the official positions of most professional organizations concerned with the comprehensive management of obesity.

Evaluation of a culturally appropriate intervention to increase physical activity.

OBJECTIVE: To evaluate a culturally appropriate intervention to increase activity in overweight Mexican American women. METHODS: Participants were randomly assigned to a physical activity program or wait-list control. RESULTS: Treated participants were not more active than controls at 6 or 12 months. In addition, we found no significant differences in the proportion of individuals who met an objective criterion for physical activity from baseline to 6 months in the treatment or control groups. CONCLUSION: The intervention did not increase physical activity in this population. Differences in baseline activity and contamination of the control group may partially account for the outcome.

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.