Megan Jehn

Results of the Diet, Exercise, and Weight Loss Intervention Trial (DEW-IT)

National guidelines for the prevention and treatment of hypertension recommend sodium reduction, weight loss, the Dietary Approach to Stop Hypertension (DASH) diet, and regular aerobic exercise. However, no trial has assessed the efficacy of simultaneously implementing all of these recommendations. The objective of this study was to determine the effects on blood pressure and other cardiovascular disease risk factors of a comprehensive lifestyle intervention. We conducted a randomized controlled trial of 44 hypertensive, overweight adults on a single blood pressure medication. Participants were randomized to a lifestyle or control group. For 9 weeks, the lifestyle group was fed a hypocaloric version of the DASH diet that provided 100 mmol/d of sodium. This group also participated in a supervised, moderate-intensity exercise program 3 times per week. The control group received no intervention. Outcomes were ambulatory blood pressure, serum lipids, weight, and fitness. At the end of the intervention, mean weight loss in the lifestyle group, net of control, was 4.9 kilograms. In the lifestyle group mean net reductions in 24-hour ambulatory systolic and diastolic blood pressures were 9.5 mm Hg (P<0.001) and 5.3 mm Hg (P<0.002), respectively. Corresponding changes in daytime systolic and diastolic blood pressures were 12.1 mm Hg (P<0.001) and 6.6 mm Hg (P<0.001). The lifestyle group experienced mean reductions in total cholesterol (-25 mg/dL, P<0.001), low-density lipoprotein cholesterol (-18 mg/dL, P=0.005), high-density lipoprotein cholesterol (-5 mg/dL, P<0.001), net of control. In conclusion, among hypertensive overweight adults already on antihypertensive medication, a comprehensive lifestyle intervention can substantially lower blood pressure and improve blood pressure control.

The effect of ambient temperature and barometric pressure on ambulatory blood pressure variability

BACKGROUND The effect of ambient temperature on cardiovascular disease has previously been studied. Less known are the effects of climate on blood pressure (BP) regulation, specifically, the role of temperature on BP variability. METHODS We investigated the effect of temperature and barometric pressure on ambulatory BP variability in 333 men and women with above-optimal BP or stage 1 hypertension participating in the Dietary Approaches to Stop Hypertension (DASH) multicenter feeding trial. Each subject consumed the same diet for 3 weeks. Daytime, nighttime, and 24-h BP were recorded by ambulatory BP monitoring (ABPM). Climatologic data were obtained from local meteorologic centers. RESULTS After adjustment for body mass index (BMI), age, sex, baseline clinic systolic BP, and clinical center, systolic BP variability was inversely associated with 24-h temperature (P =.005) and daytime temperature (P =.006). There was no observed association between BP variability and barometric pressure. There was a significant trend of increasing nighttime systolic BP and diastolic BP with increasing temperature, but these results did not persist after adjustment for confounding variables. CONCLUSIONS During periods of cold weather, an increase in BP variability may complicate the diagnosis and management of hypertension and may contribute to the high cardiovascular mortality observed in the winter.

Racial Differences in Diurnal Blood Pressure and Heart Rate Patterns: Results From the Dietary Approaches to Stop Hypertension (DASH) Trial

BACKGROUND Several studies have suggested that blacks, on average, have a blunted decline in nocturnal blood pressure (BP) as compared with nonblacks. It is unknown whether differences in traditional determinants of BP, specifically diet and obesity, account for observed differences in diurnal patterns. METHODS We conducted an analysis of the Dietary Approaches to Stop Hypertension (DASH) trial that enrolled adults with prehypertension or stage 1 hypertension. At the end of a 3-week run-in period, ambulatory BP monitoring data were obtained on 333 participants, all of whom ate the same diet. Mean ambulatory daytime (6 am-11 pm) and nighttime (11 pm-6 am) systolic BP, diastolic BP, and heart rate (HR) were measured. Dipping was defined as a nighttime drop of less than 10% from mean daytime values. RESULTS Office BP was similar in blacks and nonblacks, as were 24-hour and daytime BP and HR. However, blacks demonstrated a statistically significant, blunted nocturnal decline in BP and HR. Blacks were significantly more likely than nonblacks to have systolic nondipping (44.9% vs 26.7%, P = .001), diastolic nondipping (20.9% vs 11.6%, P = .03), and HR nondipping (40.9% vs 19.9%, P < .001). These differences persisted after adjustment for site, sex, age, body mass index, alcohol intake, physical activity, office BP (or HR), education, and income. CONCLUSION Blacks with similar office BP, and who consumed the same diet as nonblacks, had a blunted nocturnal decline in systolic BP, diastolic BP, and HR, even after factors that influence BP were controlled for.

Prevalence of Overweight among Baltimore City Schoolchildren and its Associations with Nutrition and Physical Activity

Objective: To determine the prevalence of overweight and at‐risk‐for‐overweight in schoolchildren from Baltimore City.

Health status among urban African American women: associations among well-being, perceived stress, and demographic factors.

The purpose of this study was to evaluate the associations among health status, well-being, and perceived stress in a sample of urban African American women. African American women (n=128) (Mean ± SD, 49.3 ± 10.5) from Baltimore, Maryland, enrolled in a church-based physical activity randomized trial were included in the analysis. Health status was assessed from the SF-36. Well-being, perceived stress, and demographics were also determined from self-report. Results indicated that the sample reported favorable health status, well-being, and stress levels compared to mean levels reported in the literature. Spearman rank-order correlations indicated that perceived stress score negatively correlated with most health status dimensions and well-being in the present, past, and future. Multiple regression analyses, adjusting for potential demographic confounders, indicated that higher perceived stress was associated with lower health status and well-being. If these results are confirmed in prospective investigations, they suggest that interventions designed to reduce stress may impact health status and future morbidity and mortality.

Community knowledge, risk perception, and preparedness for the 2009 influenza A/H1N1 pandemic.

OBJECTIVE To examine public knowledge, perceptions, and preparedness for the 2009 influenza A/H1N1 pandemic. DESIGN We conducted a telephone survey of selected households in Arizona during the month of October 2009. RESULTS Among the 727 households interviewed, one-third (34%) were not aware that the terms swine flu and H1N1 refer to the same virus. Many believed that it is more difficult to contract 2009 H1N1 (27%) than seasonal influenza (14%). About three-quarters of respondents perceived the H1N1 situation as urgent (76%), but only about one-third of those surveyed believed a family member would get sick with H1N1 within a year (35%). Approximately half (53%) of those surveyed intended to get the H1N1 influenza vaccine. Family doctors, television news, and local public health officials were the most trusted sources for H1N1 information. CONCLUSIONS The survey highlighted a number of important misconceptions about H1N1 knowledge, treatment options and transmissibility. Increased efforts should be made to understand how messages are transmitted and received in the community during a pandemic to improve risk communication plans moving forward.

A pandemic influenza simulation model for preparedness planning

Pandemic influenza continues to be a national and international public health concern that has received significant attention recently with the recent swine flu outbreak worldwide. Many countries have developed and updated their preparedness plans for pandemic influenza. School closure has been recommended as one of the best ways to protect children and indeed all susceptible individuals in a community during a possible disease outbreak. In this paper, we present a geospatial and temporal disease spread model for pandemic influenza affecting multiple communities. School closure, one of the social distancing policies, is investigated in this paper with several questions such as: at what level should schools be closed, for how long should they be kept closed, and how should be the re-opening decisions made. These questions are considered in terms of minimizing: the total infection cases, total mortalities, and the impact on educational services to school children.

New high blood pressure guidelines create new at-risk classification: changes in blood pressure classification by JNC 7.

High blood pressure has become increasingly prevalent and is an important risk factor for cardiovascular disease. The Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) has redefined normal blood pressure as less than 120/80 mm Hg and created a new blood pressure category called “prehypertension” for those with a systolic BP of 120 to 139 mm Hg or a diastolic BP of 80 to 89 mm Hg. This new blood pressure category was created to identify adults considered to be at risk for developing hypertension and to alert both patients and healthcare providers of the importance of adopting lifestyle changes. Recognition of prehypertension provides important opportunities to prevent hypertension and cardiovascular disease.

A New Method of Exercising Pandemic Preparedness Through an Interactive Simulation and Visualization

As seen in the spring 2009 A/H1N1 influenza outbreak, influenza pandemics can have profound social, legal and economic effects. This experience has also made the importance of public health preparedness exercises more evident. Universities face unique challenges with respect to pandemic preparedness due to their dense student populations, location within the larger community and frequent student/faculty international travel. Depending on the social structure of the community, different mitigation strategies should be applied for decreasing the severity and transmissibility of the disease. To this end, Arizona State University has developed a simulation model and tabletop exercise that facilitates decision-maker interactions around emergency-response scenarios. This simulation gives policy makers the ability to see the real-time impact of their decisions. Therefore, tabletop exercises with computer simulations are developed to practice these decisions, which can possibly give opportunities for practicing better policy implementations. This paper introduces a new method of designing and performing table-top exercises for pandemic influenza via state-of-the-art technologies including system visualization and group decision making with a supporting simulation model. The presented exercise methodology can increase readiness for a pandemic through the support of computer and information technologies and the survey results that we include in this paper certainly support this result. The video scenarios and the computer simulation model make the exercise appear very compelling and real, which makes this presented method of exercising different than the other table-top exercises in the literature. Finally, designing a pandemic preparedness exercise with supporting technologies can help identifying the communication gaps between responsible authorities and advance the table-top exercising methodology.

A simulation model for policy decision analysis: A case of pandemic influenza on a university campus

Pandemic influenza preparedness plans strongly focus on efficient mitigation strategies including social distancing, logistics and medical response. These strategies are formed by multiple decision makers before a pandemic outbreak and during the pandemic in local communities, states and nation-wide. In this paper, we model the spread of pandemic influenza in a local community, a university, and evaluate the mitigation policies. Since the development of an appropriate vaccine requires a significant amount of time and available antiviral quantities can only cover a relatively small proportion of the population, university decision makers will first focus on non-pharmaceutical interventions. These interventions include social distancing and isolation. The disease spread is modelled as differential equations-based compartmental model. The system is simulated for multiple non-pharmaceutical interventions such as social distancing including suspending university operations, evacuating dorms and isolation of infected individuals on campus. Although the model is built based on the preparedness plan of one of the biggest universities in the world, Arizona State University, it can easily be generalized for other colleges and universities. The policies and the decisions are tested by several simulation runs and evaluations of the mitigation strategies are presented in the paper.