Recent Research in Nutrition & Physical Activity
Addressing Health Literacy and Numeracy to Prevent Childhood Obesity
Addressing The Role of Nutrition Education & Health Literacy in Diabetes Care
Dietary Antioxidants and Incidence of Adult-onset Asthma
Effects of Brassica Intake or Indole-3-Carbinol (I3C) Supplements on PSA among Men with Biochemical Failure
Iron as a Nutritional Modifier of Antiretroviral Treatment Complications in HIV/AIDS
Multi-Center Cohort Study of ACL Reconstruction Outcomes
Obesity Prevention in Youth Using Dental Settings
Weight Gain Prevention in Hispanic Girls
Addressing Health Literacy and Numeracy to Prevent Childhood Obesity
In 2003, Surgeon General Richard Carmona stated that low health literacy was "one of the largest contributors to our nation´s epidemic of overweight and obesity." This assertion is supported by recent studies which have found that low health literacy or numeracy is associated with poorer caregiver breastfeeding knowledge, incorrect mixing of infant formula, difficulty understanding food labels and portion sizes, and higher Body Mass Index (BMI) in adults and children. Of particular concern is the impact of the obesity epidemic on our youngest children. Over 26 percent of preschool children are now overweight (BMI>85 percent) or obese (BMI>95 percent) (based on 2007 HHS/CDC Expert panel definitions). Rates of obesity in preschool children have doubled over the past decade, with the highest increases among low income and minority children-- the same communities most affected by low health literacy. To date, clinical efforts to prevent or treat childhood obesity have had limited efficacy. Efforts need to start early, because children who are overweight by age two are five times as likely to become overweight adolescents, and subsequently at higher risk for obesity-related complications, including early-onset Type-2 Diabetes and cardiovascular disease. No published clinical studies have rigorously addressed obesity prevention prior to age 2 with a specific low-literacy and numeracy focus. Addressing caregiver health literacy in early childhood is an innovative strategy to promote healthy nutrition and activity among these families and prevent unhealthy weight gain across the child´s life, which would have great public health significance by preventing both child and adult chronic illness. The proposed study is a multi-site randomized, controlled trial to assess the efficacy of a low- literacy/numeracy-oriented intervention designed to promote healthy family lifestyles and to prevent early childhood obesity. The intervention will be delivered through pediatric resident physicians in primary care settings in under-resourced communities. Four academic medical centers will be randomized: Vanderbilt University, the University of Miami, the University of North Carolina at Chapel Hill, and New York University. Two centers will receive the intervention while the other two centers will receive an active control. At each site, a cohort of 250 English- or Spanish-speaking caregiver-child dyads will be enrolled and followed from the child´s 4-6 month well-child visit through the 24-month well-child visit. The intervention will include a low- literacy-oriented toolkit for pediatric residents to use with families and clear health communication training for the pediatric residents. At control sites, pediatric residents will provide "usual care" with respect to lifestyle counseling, but they will also receive an injury-prevention education program to act as an attention control. The primary hypotheses are that the intervention will improve family dietary and physical activity behaviors and that it will reduce the rate of childhood overweight (BMI > 85 percent) at age 24 months. Funded by the National Institute of Child Health and Human Development Investigators: Russell L. Rothman, M.D. (PI); Bettina Beech, Dr.P.H., M.P.H.; Shari Barkin, M.D.; Sunil Kripalani, M.D. M.S.; Lisa Rawn, M.S.; Ayumi Shintani, Ph.D., M.P.H.; Shonna Yin, M.D., M.S.
Addressing The Role of Nutrition Education & Health Literacy in Diabetes Care
Medical Nutrition therapy (MNT) is essential for self-management of type 2 diabetes(T2DM). However, there have been few rigorous studies evaluating the role of different educational approaches to MNT, such as education that focuses on carbohydrate counting vs. plate method. Understanding the strengths and weaknesses of different approaches to MNT education could help educators to optimize the education they provide. Choosing a particular nutrition education approach may be particularly important for educating patients with low literacy or numeracy (math skills). Over 90 million Americans have low literacy or numeracy, and research has demonstrated that low literacy or numeracy is independently associated with worse diabetes knowledge, poorer understanding of nutrition labels, worse self-efficacy, and worse glycemic control. We propose a randomized trial to better evaluate: (1) the importance of nutrition education from a certified diabetes educator(CDE), (2) the similarities and differences between different nutrition education approaches, and (3) the unique role of health literacy and numeracy in patient’s response to nutrition education. 150 patients with T2DM will be randomized to: (1) “Usual care” from a primary care provider (PCP) plus 3 control visits with a health educator providing non-nutrition oriented diabetes education, (2) “Usual care” from a PCP plus 3 visits with an RD CDE focusing on carbohydrate counting, or (3) “Usual care” from a PCP plus 3 visits with an RD CDE focusing on a modified plate method. Patient will be followed for 6 months and outcomes will include: A1C, Weight/BMI, lipids, dietary behaviors, diabetes self-care activities, self-efficacy, and treatment satisfaction. Funded by the American Association of Diabetes Educators Investigators: Russell L. Rothman, M.D. (PI); Ken Wallston, Ph.D.; Kathleen Wolff, M.S.N., A.P.R.N., B.C.-A.D.M.; Becky Gregory, R.D., L.D.N., C.D.E.; Dianne Davis, R.D., L.D.N., C.D.E.
Dietary Antioxidants and Incidence of Adult-onset Asthma
The objectives of this application are to study the association of dietary and serum antioxidants and oxidative stress on adult-onset asthma incidence among a cohort of 75,000 women. We hypothesize that dietary antioxidants play a role in the development of asthma, particularly in persons with a family history of atopic disease. Questions related to dietary antioxidant intake that this application aims to address are whether dietary and serum antioxidants protect against development of adult-onset asthma, whether persons with atopic disease have higher indices of oxidative stress, and whether those with a genetic susceptibility to be atopic are protected by higher intake of dietary antioxidants. To examine these hypotheses, we will utilize an existing large prospective cohort, the Shanghai Women’s Health Study (SWHS), which tracks detailed information on dietary intake and environmental factors as they relate to cancer incidence and other chronic diseases. This prospective cohort study is being conducted among approximately 75,000 female residents of Shanghai, China between the ages of 35 and 69, where there is marked heterogeneity in dietary intake and 97 percent of the cohort are non-smokers. Measurements of free radicals will be made in baseline urine samples using an assay for isoprostanes, recently described lipid peroxidation products, to determine if there is a correlation between adult-onset asthma and increased markers of lipid peroxidation. Isoprostanes are considered the most accurate marker of oxidative stress currently available. Measurements of serum antioxidants will be made using baseline serum samples. We propose in this project: (1) an incidence study to determine the association between dietary antioxidants and incident asthma, and (2) a nested case control study examining (a) the correlation between a urinary measure of oxidative stress and incident asthma, and (b) the relationship between serum antioxidants and incident asthma. This series of studies, with the combination of three measures of antioxidant exposure and oxidant stress, are designed to uncover antioxidant-specific effects in the development of asthma. Funded by the National Institute of Allergy and Infectious Diseases Investigators: Tina V. Hartert, M.D., M.P.H. (PI)
Effects of Brassica Intake or Indole-3-Carbinol (I3C) Supplements on PSA among Men with Biochemical Failure
There is considerable basic science research to suggest that isothiocyanates (ITC) or several indole analogs (e.g., indole-3carbinol (I3C)) slow cellular proliferation, re-instate apoptotic action, and reduce colon tumor incidence. Humans are exposed to these agents primarily through consuming Brassica vegetables (e.g., broccoli), but it is unknown if greater Brassica consumed could affect colon cancer risk. We propose a short-term pilot dietary intervention to investigate the effects of greater Brassica consumption on markers colon cancer progression. Twenty adenoma patients will participate in a randomized controlled cross-over trial. Recruitment, intervention, and lab protocols have been developed through other on-going studies, improving the cost-efficiency of this pilot project. The intervention-arm of the trial is based on a model developed for the Women’s Health Initiative, and provides social support and information to help participants incorporate these vegetables into their daily diet. Biomarkers measured from rectal biopsies will include Bcl-2 (inhibits apoptosis), Bak and Bax (promote apoptosis), Mib-1 (marker of cellular proliferation), and p21 (marker of cellular differentiation). Multiple 24-hour dietary recalls will measure each participant’s adherence to the intervention. Dietary adherence will be measured further by urinary ITC level (combined with GST enzyme genotype), a unique and specific biomarker of Brassica vegetable intake. Using mixed-model repeated-measures ANOVA, we will compare molecular marker expression when participants consume Brassica vegetables to when these same participants consume an over-the-counter fiber and vitamin supplement. This pilot study will provide the needed estimates of variance in biomarker response to the dietary change for sample size calculations for future applications. Previously, we found that healthy people were able to increase the consumption of these vegetables with minimal social and instructional support, and we used those pilot data to gain funding for a larger randomized trial enrolling breast cancer survivors. Since Brassica vegetables are widely available, inexpensive, and consumed without harm, a change in molecular marker expression consistent with reduced proliferation and enhanced differentiation and apoptosis would suggest further research to evaluate the application of Brassica consumption to reduce colon cancer risk. Funded by the National Cancer Institute Investigators: Jay H. Fowke, M.P.H., Ph.D. (PI); Sam Chang, M.D.; Saundra Motley, R.N.
Iron as a Nutritional Modifier of Antiretroviral Treatment Complications in HIV/AIDS
Access to highly active anti-retroviral drug therapy has markedly reduced morbidity and mortality associated with the acquired immunodeficiency syndrome (AIDS). Although the incidence of most of the neurological complications of HIV infection has declined dramatically with the use of these drug regimens, peripheral neuropathy (PN), a devastating complication of nucleoside reverse transcriptase inhibitor (NRTI) therapy, is increasingly common among persons living with HIV/AIDS. The precise mechanisms of nerve damage in PN are unclear, but important factors include: nerve inflammation caused by HIV-infected macrophages, drug-induced mitochondrial abnormalities leading to oxidative stress, and poor nutrition. Iron metabolism is abnormal in HIV infection, but the role of iron, a micronutrient critical for mitochondrial and neuronal function, has not been directly explored in HIV-associated PN. A common variant in the hemochromatosis (HFE) gene, C282Y, causes increased dietary iron absorption and defects in cellular iron transport and immunity. Expression of the HFE-encoded iron-transport protein on macrophages has been shown to decrease as result of HIV-1 infection. We previously used clinical data and stored DNA from a large, prospective cohort study conducted by the AIDS Clinical Trials Group (ACTG) to make the seminal observation that HFE C282Y may protect against the development of PN and other inflammatory complications of NRTI therapy in HIV/AIDS. Since this iron-loading variant is protective against PN, and iron deficiency is endemic in many populations devastated by HIV/AIDS, it is critical to define the mechanism underlying this protective effect in order to benefit patients globally. The goals of this study are therefore to use cryopreserved serum samples in the same HIV cohort to determine 1) if reduced PN in HFE C282Y carriers is due to increased body iron stores, 2) if time to onset of PN during NRTI therapy is related to systemic iron stores before starting treatment, 3) if a statistical model incorporating iron stores, early changes in iron levels during NRTI therapy; HFE genotype, and high-risk mitochondrial DNA variants can be developed to predict the development of PN. Conventional regression as well as newer statistical modeling tools will be used. These studies will generate critical preliminary data for an R01 grant application to fund in-depth mechanistic studies that we hope will ultimately enable clinicians to reduce the incidence of this debilitating complication of HIV/AIDS treatment. Funded by the National Heart Lung and Blood Institute Investigators: Asha Kallianpur, M.D., M.P.H.(PI); David Haas, M.D.; Todd Hulgan, M.D., M.P.H.; Wanqing Wen, M.D.; Jeffrey Canter, M.D., M.P.H.; Marylyn Ritchie, Ph.D.
Multi-Center Cohort Study of ACL Reconstruction Outcomes
Physical activity and fitness is one of the focus areas of Healthy People 2010, and sports participation is increasing. In accord, the number of ACL injuries and subsequent ACL reconstructions is increasing at an estimated annual cost of 2 billion dollars. Available evidence shows that ACL reconstructions have been successful in restoring preoperative function at two years, but these studies have utilized non-validated outcome measures, often lack long-term follow-up, and have left risk factors for poor outcome, graft failure, and additional surgical procedures ill defined. Design: A multi-center observational cohort study involving an established Multi-center Orthopaedic Outcomes Network (MOON) will be utilized. The purpose of the proposed mentored research is to test the hypothesis that objective predictors recorded at the time of ACL reconstruction are associated with validated outcome instruments and arthritis (Aim 1), and additional surgical procedures and graft failure (Aim 2). The ACL is the most frequently injured ligament in the body, and disruption of this important stabilizer leads to giving way episodes that cause further injury to the knee. ACL reconstruction restores stability to the knee, however, it is unclear if surgery prevents later arthritis of the knee. Identifying factors associated with quality of life and arthritis is critical because arthritis, particularly in young adults, is a major public health concern. Funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases Investigators: Warren R. Dunn, M.D., M.P.H. (PI)
Obesity Prevention in Youth Using Dental Settings
The prevalence of obesity among children in the United States increased 130% between 1970 and 2000. Current estimates indicate that 15.3% of 6 to11 year olds and 15.5% of 12 to 19 year olds are overweight, with even higher rates (23%) among African American and Hispanic adolescents. Control of obesity among youth will require multiple interventions society-wide in order to provide cumulative and synergistic effects that can result in sustained health practices. One step in this approach is to encourage clinicians of all specialties to provide appropriate health promotion advice and counseling to their patients during routine office visits. Dentists and dental hygienists are in a unique position to provide such advice in the context of routine dental care. This seems particularly promising in light of the role of sugar consumption in both dental caries and weight gain. Further, consistent exposure to food advertising, particularly during television viewing, can lead to increased consumption of sugar-sweetened beverages and snacks among children and adolescents. Effective behavioral interventions are needed to reduce these behaviors, and dental offices offer an excellent channel in which to conduct such interventions. The objective of this research is to develop and test the feasibility of a dental office intervention to reduce the consumption of sugar-sweetened beverages and snacks and TV viewing among youth ages 9 to 14. We believe these changes will decrease the risk of dental caries, excessive caloric intake leading to weight gain, and exposure to TV advertisements and messages that encourage the consumption of sugar-sweetened beverages and snacks. The specific aims of this project are to use formative assessment methods including focus groups with youth 9 to14 years of age, parents, and dental professionals (dentists and dental hygienists) to obtain feedback regarding the proposed intervention materials and recruitment and retention strategies. We will then use intervention development methods to develop a repeated contact counseling intervention with dentists and dental hygienists based on Social Cognitive Theory (SCT) and modeled after successful tobacco control interventions conducted in dental offices. Funded by the National Institute of Dental and Craniofacial Research Investigators: Bettina Beech, M.P.H., Dr.P.H. (PI); Ayumi Shintani, M.P.H., Ph.D.; Heidi Silver, M.S., Ph.D.
Weight Gain Prevention in Hispanic Girls
Over the past 30 years obesity has reached epidemic proportions in the United States (Ogden et al, 2006). While this epidemic affects all socioeconomic levels, certain racial/ethnic groups such as Hispanics are disproportionately affected by obesity and diabetes. The age of onset of excess obesity in Hispanic females, formerly young adulthood, is now younger. Childhood obesity poses intermediate and long-term health risks, including: type 2 diabetes, hyperlipidemia, elevated blood pressure and metabolic syndrome. Although biological factors may influence a child´s risk for becoming overweight, the home environment has been shown to be a predisposing and reinforcing contextual factor for unhealthy eating and exercise behaviors. Since parents are the primary transmitters of Hispanic cultural practices and significantly influence their children´s diet and physical activity behaviors from preschool through high school, family-based weight-gain prevention interventions are likely to b. effective. The goal of this implementation study is to contribute to the reduction of racial/ethnic disparities in obesity and risk of type 2 diabetes by tailoring a successful childhood obesity, prevention program originally developed for African American girls, to implement and evaluate with preadolescent Hispanic girls. Funded by the State of Tennessee Investigators: Bettina Beech, M.P.H., Dr.P.H.(PI); Shari Barkin, M.D., M.P.H.; Thomas Cook, B.S.N., M.S.N., F.N.P, Ph.D.; Roger Zoorob, M.D., M.P.H.