Jeffrey A. Katula

One-Year Results of a Community-Based Translation of the Diabetes Prevention Program Healthy-Living Partnerships to Prevent Diabetes (HELP PD) Project

OBJECTIVE Although the Diabetes Prevention Program (DPP) and the Finnish Diabetes Prevention Study (FDPS) demonstrated that weight loss from lifestyle change reduces type 2 diabetes incidence in patients with prediabetes, the translation into community settings has been difficult. The objective of this study is to report the first-year results of a community-based translation of the DPP lifestyle weight loss (LWL) intervention on fasting glucose, insulin resistance, and adiposity. RESEARCH DESIGN AND METHODS We randomly assigned 301 overweight and obese volunteers (BMI 25–40 kg/m2) with fasting blood glucose values between 95 and 125 mg/dL to a group-based translation of the DPP LWL intervention administered through a diabetes education program (DEP) and delivered by community health workers (CHWs) or to an enhanced usual-care condition. CHWs were volunteers with well-controlled type 2 diabetes. A total of 42.5% of participants were male, mean age was 57.9 years, 26% were of a race/ethnicity other than white, and 80% reported having an education beyond high school. The primary outcome is mean fasting glucose over 12 months of follow-up, adjusting for baseline glucose. RESULTS Compared with usual-care participants, LWL intervention participants experienced significantly greater decreases in blood glucose (−4.3 vs. −0.4 mg/dL; P < 0.001), insulin (−6.5 vs. −2.7 μU/mL; P < 0.001), homeostasis model assessment of insulin resistance (−1.9 vs. −0.8; P < 0.001), weight (−7.1 vs. −1.4 kg; P < 0.001), BMI (−2.1 vs. −0.3 kg/m2; P < 0.001), and waist circumference (−5.9 vs. −0.8 cm; P < 0.001). CONCLUSIONS This translation of the DPP intervention conducted in community settings, administered through a DEP, and delivered by CHWs holds great promise for the prevention of diabetes by significantly decreasing glucose, insulin, and adiposity.

Using Network Science to Evaluate Exercise-Associated Brain Changes in Older Adults

Literature has shown that exercise is beneficial for cognitive function in older adults and that aerobic fitness is associated with increased hippocampal tissue and blood volumes. The current study used novel network science methods to shed light on the neurophysiological implications of exercise-induced changes in the hippocampus of older adults. Participants represented a volunteer subgroup of older adults that were part of either the exercise training (ET) or healthy aging educational control (HAC) treatment arms from the Seniors Health and Activity Research Program Pilot (SHARP-P) trial. Following the 4-month interventions, MRI measures of resting brain blood flow and connectivity were performed. The ET groups hippocampal cerebral blood flow (CBF) exhibited statistically significant increases compared to the HAC group. Novel whole-brain network connectivity analyses showed greater connectivity in the hippocampi of the ET participants compared to HAC. Furthermore, the hippocampus was consistently shown to be within the same network neighborhood (module) as the anterior cingulate cortex only within the ET group. Thus, within the ET group, the hippocampus and anterior cingulate were highly interconnected and localized to the same network neighborhood. This project shows the power of network science to investigate potential mechanisms for exercise-induced benefits to the brain in older adults. We show a link between neurological network features and CBF, and it is possible that this alteration of functional brain networks may lead to the known improvement in cognitive function among older adults following exercise.

The Lifestyle Interventions and Independence for Elders Study: Design and Methods

Background. As the number of older adults in the United States rises, maintaining functional independence among older Americans has emerged as a major clinical and public health priority. Older people who lose mobility are less likely to remain in the community; demonstrate higher rates of morbidity, mortality, and hospitalizations; and experience a poorer quality of life. Several studies have shown that regular physical activity improves functional limitations and intermediate functional outcomes, but definitive evidence showing that major mobility disability can be prevented is lacking. A Phase 3 randomized controlled trial is needed to fill this evidence gap. Methods. The Lifestyle Interventions and Independence for Elders (LIFE) Study is a Phase 3 multicenter randomized controlled trial designed to compare a supervised moderate-intensity physical activity program with a successful aging health education program in 1,600 sedentary older persons followed for an average of 2.7 years. Results. LIFEs primary outcome is major mobility disability, defined as the inability to walk 400 m. Secondary outcomes include cognitive function, serious fall injuries, persistent mobility disability, the combined outcome of major mobility disability or death, disability in activities of daily living, and cost-effectiveness. Conclusions. Results of this study are expected to have important public health implications for the large and growing population of older sedentary men and women.

Enhancing quality of life in older adults: A comparison of muscular strength and power training

BackgroundAlthough progressive resistance strength training (ST) has been found to improve various measures of physical functioning in older adults, the benefit to quality of life is unclear. Additionally, recent evidence suggests that high velocity power training (PT) may be more beneficial for physical functioning than ST, but it is not known whether this type of training impacts quality of life. The purpose of this study was to compare changes in multiple measures of quality of life resulting from ST vs. PT in older adults. A no exercise group was also included as control comparison condition.MethodsForty-five older adults (M age = 74.8 years; SD = 5.7) were randomly assigned to either a) PT, b) ST, or c) control group (no exercise). Measures of self-efficacy (SE), satisfaction with physical function (SPF), and the Satisfaction with Life Scale (SWL) were assessed at baseline and following training. The resistance training conditions met 3 times per week for 12 weeks at an intensity of 70% 1 repetition maximum.ResultsA series of ANCOVAs comparing between group differences in change and controlling for baseline values revealed significant group differences in all three measures: SE (F(2,31) = 9.77; p < .001); SPF (F(2,32) = 3.36; p = .047); SWL (F(2,31) = 4.76; p = .016). Follow up analyses indicated that the PT group reported significantly more change in SE, SPF, and SWL than the control group whereas the ST group reported greater change than the control group only in SE.ConclusionThese pilot data indicate that high velocity power training may influence multiple levels of quality of life over and above the benefits gained through traditional strength training.

The Healthy Living Partnerships to Prevent Diabetes Study: 2-Year Outcomes of a Randomized Controlled Trial

BACKGROUND Since the Diabetes Prevention Project (DPP) demonstrated that lifestyle weight-loss interventions can reduce the incidence of diabetes by 58%, several studies have translated the DPP methods to public health-friendly contexts. Although these studies have demonstrated short-term effects, no study to date has examined the impact of a translated DPP intervention on blood glucose and adiposity beyond 12 months of follow-up. PURPOSE To examine the impact of a 24-month, community-based diabetes prevention program on fasting blood glucose, insulin, insulin resistance as well as body weight, waist circumference, and BMI in the second year of follow-up. DESIGN An RCT comparing a 24-month lifestyle weight-loss program (LWL) to an enhanced usual care condition (UCC) in participants with prediabetes (fasting blood glucose=95-125 mg/dL). Data were collected in 2007-2011; analyses were conducted in 2011-2012. SETTING/PARTICIPANTS 301 participants with prediabetes were randomized; 261 completed the study. The intervention was held in community-based sites. INTERVENTION The LWL program was led by community health workers and sought to induce 7% weight loss at 6 months that would be maintained over time through decreased caloric intake and increased physical activity. The UCC received two visits with a registered dietitian and a monthly newsletter. MAIN OUTCOME MEASURES The main measures were fasting blood glucose, insulin, insulin resistance, body weight, waist circumference, and BMI. RESULTS Intent-to-treat analyses of between-group differences in the average of 18- and 24-month measures of outcomes (controlling for baseline values) revealed that the LWL participants experienced greater decreases in fasting glucose (-4.35 mg/dL); insulin (-3.01 μU/ml); insulin resistance (-0.97); body weight (-4.19 kg); waist circumference (-3.23 cm); and BMI (-1.40), all p-values <0.01. CONCLUSIONS A diabetes prevention program administered through an existing community-based system and delivered by community health workers is effective at inducing significant long-term reductions in metabolic indicators and adiposity.

Effects of Tai Chi Chuan on Insulin and Cytokine Levels in a Randomized Controlled Pilot Study on Breast Cancer Survivors

BACKGROUND Tai Chi Chuan (TCC) is an integrative medicine mind-body practice with a physical activity component that has positive effects on aerobic capacity, muscular strength, and quality of life among cancer survivors, similar to the effects elicited by other modes of moderate-intensity exercise. Inflammatory cytokines and insulin and insulin-related signaling molecules may contribute to weight gain and affect cancer recurrence rates and survival; exercise can curb cancer- and treatment-related weight gain, increase survival, and reduce levels of insulin and inflammatory cytokines. Despite knowing the beneficial effects of conventional exercise interventions on these mediators, little is known about the physiologic effects of TCC on these pathways in breast cancer survivors. METHODS We assessed the effects of a 12-week, moderately intense, TCC intervention (n = 9) compared with a non-physical activity control (n = 10) consisting of psychosocial support therapy (PST), on levels of insulin, insulin-like growth factor (IGF)-1, insulin growth factor-like binding protein (IGFBP)-1, IGFBP-3, and cytokines interleukin (IL)-6, IL-2, and interferon (IFN)-γ in breast cancer survivors. RESULTS Levels of insulin are significantly different in TCC and PST groups; levels remained stable in the TCC group but increased in the PST control group (P = .099). Bivariate analysis revealed novel and significant correlations (all r > 0.45, all P ≤ .05) of both decreased fat mass and increased fat-free mass with increased IL-6 and decreased IL-2 levels. CONCLUSIONS This pilot study shows that TCC may be associated with maintenance of insulin levels and changes in cytokine levels that may be important for maintenance of lean body mass in breast cancer survivors.

Lifestyle Interventions and Independence for Elders Pilot Study: Recruitment and Baseline Characteristics

OBJECTIVES: To describe several recruitment parameters derived from the Lifestyle Interventions and Independence for Elders pilot (LIFE‐P) study for use in a full‐scale trial of mobility disability prevention.

Healthy Living Partnerships to Prevent Diabetes (HELP PD): Design and Methods

Although the Diabetes Prevention Program (DPP) developed a lifestyle weight loss intervention that has been demonstrated to prevent type 2 diabetes in high-risk individuals, it has yet to be widely adopted at the community level. The Healthy Living Partnership to Prevent Diabetes study (HELP PD) was designed to translate the DPP approach for use in community settings as a cost-effective intervention led by Community Health Workers (CHWs) and administered through a Diabetes Care Center (DCC). Approximately 300 overweight and obese (BMI 25-40 kg/m(2)) individuals with prediabetes (fasting blood glucose 95-124 mg/dl) were randomly assigned to either a lifestyle weight loss intervention (LW) or an enhanced usual care comparison condition (UC). The goal of LW is >or=7% weight loss achieved through increases in physical activity (180 min/wk) and decreases in caloric intake (approximately 1500 kcal/day). The intervention consists of CHW-led group-mediated cognitive behavioral meetings that occur weekly for 6 months and monthly thereafter for 18 months. UC consists of 2 individual meetings with a registered dietitian and a monthly newsletter. The primary outcome is change in fasting blood glucose. Secondary outcomes include cardiovascular risk factors, health-related quality of life, and social cognitive variables. Outcomes are masked and are collected every 6 months. The cost-effectiveness of the program will also be assessed. A community-based program that is administered through local DCCs and that harnesses the experience of community members (CHWs) may be a promising strategy for the widespread dissemination of interventions effective at preventing type 2 diabetes in high risk individuals.

Relationship Between Physical Functioning and Physical Activity in the Lifestyle Interventions and Independence for Elders Pilot

OBJECTIVES: To determine whether participation in usual moderate‐intensity or more‐vigorous physical activity (MVPA) is associated with physical function performance and to identify sociodemographic, psychosocial, and disease‐related covariates that may also compromise physical function performance.

Self-Reported Napping and Duration and Quality of Sleep in the Lifestyle Interventions and Independence for Elders Pilot Study

OBJECTIVES: To determine the prevalence of self‐reported napping and its association with subjective nighttime sleep duration and quality, as measured according to sleep‐onset latency and sleep efficiency.