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Summary Reports

The following is a list of the Summary Reports for some of our most recent studies. Please select from the options below.

 

Activity Counseling Trial (ACT) - Summary Report

 The Activity Counseling Trial (ACT) was a randomized clinical trial to evaluate the efficacy of two primary care, practice-based physical activity behavioral interventions. Approximately 810 sedentary men and women 35-75 years of age were enrolled in the study, including substantial minority representation. Each participant received two years of intervention and follow-up. Participants were enrolled over a period of 15 months.

The three study groups, simultaneously implemented at three clinical centers (located in California, Texas and Tennessee) consisted of the same initial physician assessment and advice. Participants assigned to the two intervention groups also received varying levels of practice-based intervention. The interventions were based on behavior change theory, but they differed in the amount of resourced required for implementation. The three study groups are as follows:

GROUP A: STANDARD CARE

This group was provided physician assessment and advice and written materials. It did not offer behavioral counseling.

GROUP B: STAFF ASSISTANCE

This intervention was a subset of the Staff-Counseling Intervention and required fewer resources and less staff time. A guiding principle in developing this intervention was for it to be feasible for delivery in a wide variety of primary care settings without requiring staff support. The intervention employed brief in-person counseling video, interactive mail, referral to community resources, and occasional telephone contact.

GROUP C: STAFF COUNSELING

This intervention was designed to be an optimal intervention that could be delivered in a primary care setting. It required substantial staff involvement and employed on-site interpersonal counseling, regular telephone follow-up counseling, in-clinic follow-up counseling, written and visual materials, interactive mail, onsite classes, and referral to community resources.

There were two primary study outcomes: (1) maximal oxygen uptake (VO2max) (L•min-1) measured treadmill test using a standardized protocol, and (2) kilocalories expended in physical activity (kcal•kg-1•min-1) measured by standardized and validated self-report instrument, the seven-day physical activity recall. To determine the relative efficacy of the interventions, comparison between groups for mean changes in the outcome measures will be performed. All analyses will be done separately for men and women. Change from baseline to two years was the primary outcome analysis. Short-term effects were examined by change from baseline to six months. Secondary outcomes related to cardiovascular disease risk included plasma lipids/lipoproteins (e.g., triglycerides and HDL), blood pressure, body composition (body mass index, skinfolds, waist-to-hip ratio), plasma insulin, fibrinogen, dietary intake, smoking, heart rate variability, cost-effectiveness, and psychosocial factors. Subgroup analyses were also conducted.

 

Project ACTIVE - Summary Report

Project Active was a four-year, randomized controlled trial funded by the National Institutes of Health. In this study, we proposed to evaluate the short- and long-term effectiveness of two different exercise interventions in promoting change in physical activity patterns and physical fitness levels. The primary research hypothesis tested was that a lifestyle exercise intervention, in which physical activity was increased by integration of increase energy expenditure into daily activities, resulted in higher levels of physical activity and fitness at two years compared with a more traditional exercise intervention.

 

Depression Outcomes Study of Exercise (DOSE) - Summary Report

The DOSE project incorporated two types of studies in the examination of exercise and its effect on depression.

In Phase I, an epidemiological study was conducted using data from the Aerobics Center Longitudinal Study (ACLS). In Phase II, a randomized controlled clinical trial (RCT) was used to assess the effectiveness of exercise as a treatment for depression. Two related questions were examined: What is the dose-response relation between physical activity or fitness and symptoms of depression and psychological well being in a healthy population? And what is the efficacy of exercise as a treatment for mild to moderate major depressive disorder (MDD) in participants diagnosed with these levels of major depression? The primary research hypotheses to be tested were: (1) there are dose-response relations between exercise and depressive symptoms and psychological well-being; and (2) exercise is an efficacious treatment for mild to moderate MDD. For the first hypothesis, data was used from the Aerobics Center Longitudinal Study (ACLS), a large database that includes validated measures of physical fitness, physical activity and standardized measures of depression (CES-D) and general well being (GWB). This subset of ACLS data includes information from clinic visits (n=8,345) and mail-back surveys (n=13,627 in 1990 and n= 13,329 in 1995).

This data will be analyzed and the results will be reported regarding the first question and hypothesis. The second phase, a RCT study, examined the efficacy and dose-response relation of exercise in treating mild to moderate depression in young to middle-aged adults (20-45 years old).

 

Lifestyle Nutrition Study (LNS) - Summary Report

The Lifestyle Nutrition Study (LNS) was a study conducted from October 2001-April 2002 in which we tested a curriculum that focused on teaching adults lifestyle skills for improving the quality of their diet. Ninety-eight participants were randomly assigned to one of three groups: 1) Weekly meeting group (WM) that met face-to-face with other participants and two facilitators for six months; 2) Correspondent group (CR) that received the intervention materials by mail and email; 3) Usual care group (UC) that received a nutrition book for six months then received the correspondent intervention for the next six months. A Modified Healthy Eating Index (MHEI) score was obtained for each participant at baseline and at six months. The MHEI is a composite score of overall diet quality and was based on food records kept by participants.

The WM group significantly improved their MHEI score from baseline and compared to the other two groups. The CR also showed a slightly increased score and the UC group had a slightly decreased score. These results showed that the lifestyle approach, especially delivered via small group meetings, was effective in improving total diet quality. A peer-reviewed paper describing the study was published in the Journal of Nutrition Education and Behavior in January 2004.

After we proved the LNS was effective, we developed a program called Healthy Eating Every Day to disseminate the curriculum materials so others could benefit from it. The entire program, including a support website and online learning guide, is available from our dissemination partner, Human Kinetics at www.activeliving.info.

PUBLICATION:
Carpenter RA, Finley C, Barlow CE. Pilot test of a behavioral skill building intervention to improve diet quality. Journal of Nutrition Education and Behavior. 2004;26:20-26.

 

PRIME - Summary Report

Project Prime (Physically Ready for Invigorating Movement Everyday) was a four-year, randomized controlled trial funded by the National Institutes of Health. This study was designed to enhance the development and evaluation of using a lifestyle approach for increasing physical activity in initially sedentary men and women over two years, and was compared to a standard care intervention (YMCA membership). Our previous study, Project Active, compared a traditional structured exercise intervention (delivered at a state-of-the-art fitness center) with a new public health oriented approach to increasing physical activity (a lifestyle physical activity intervention delivered via behavioral group processing). Six-month and 24-month results show similar increases in physical activity and improvements in clinical variables such as blood pressure and body composition in both intervention groups.

Project Prime further refined the lifestyle intervention by comparing the effectiveness of two different lifestyle intervention approaches. Specifically, the original group meeting lifestyle approach (Group) was compared against an approach based on mail and telephone contact (Correspondent). The Group intervention was called PRIME G and the Correspondent intervention PRIME C. Both of these were compared to a standard care control condition, PRIME SC.

The primary research hypothesis to be tested was that the Correspondent lifestyle intervention would be as effective in increasing physical activity and endurance fitness in initially healthy sedentary men and women as the more intensive Group meeting lifestyle approach.

The secondary hypotheses to be tested was: (a) there would be significant and comparable improvements in secondary outcome variables (functional health status, lipids, lipoproteins, serum total cholesterol level, triglyceride concentrations, HDL cholesterol, percent body fat, blood pressure, estimated survival gain, general well-being, exercise self-efficacy/confidence, social support, stages of physical activity behavior change, processes of physical activity behavior change, decision making for physical activity, health-related quality of life, and depression) for both PRIME C and G when compared to PRIME SC; and (b) there would be a significantly greater difference in incremental cost per unit of increase in physical activity, endurance fitness, and all other secondary outcome measures, with the cost-effectiveness being greater in the PRIME C than the PRIME G intervention.

 

Vitamins and Supplements - Summary Report

CRP is an acronym for C-reactive protein which is a protein produced by the liver and found in the blood. CRP is a marker for systemic inflammation, which may occur due to injury, infection, or fever. Because elevated CRP levels are associated with an increased risk for cardiovascular disease and diabetes, we sought to determine whether multivitamin supplementation reduces CRP levels in our Cooper Complete® Study.

We measured the effects of six vitamins, namely C, E, B6, B12, folate, and beta carotene, within a 24-ingredient multivitamin/mineral formula, the Cooper Complete® Vitamin, and found both vitamin B6 and vitamin C significantly reduced CRP levels compared with those participants who took a placebo. More specifically, we found following multivitamin supplementation, the prevalence of patients with a high risk C-reactive protein level (>3.0 mg/L) reduced from 30% to 14%. The average change in the patients’ CRP levels over the course of six months was 0.70 mg/L. The greatest reduction in CRP levels was seen in patients whom initially had elevated CRP levels. As such, use of a commercially available multivitamin was found to significantly reduce C-reactive protein levels.

Table 1. Prevalence of Patients with High Risk C-Reactive Protein Level (>3.0 mg/L)

We demonstrated two further benefits from six months of multivitamin supplementation. First, we showed that six months of supplementation significantly increased plasma vitamin levels, namely vitamin C, beta carotene, vitamin E, folic acid, vitamin B6 and vitamin B12, as further evidenced below in Table 2.

Table 2. Change in Plasma Vitamin Concentration Following Six Months of Multivitamin Supplementation

Second, we found a significant reduction in LDL (Low-Density Lipoprotein, “bad cholesterol”) oxidation and in homocysteine levels which are risk factors associated with cardiovascular disease. To this end, we found an 14.6% reduction in LDL oxidation rate, which may be attributed to vitamin E, vitamin C, and lycopene. A reduction in LDL oxidation rate is significant because oxidation, or the addition of oxygen to low-density lipoproteins, contributes to atherosclerosis and may ultimately lead to further progression of heart disease. Further, we found a 17.2% reduction in circulating homocysteine levels. Homocysteine is an amino acid found in the blood, and elevated levels are linked to heart disease, atherosclerosis (“hardening” of the arteries), stroke, colon cancer and Alzheimer’s disease. It has been shown that homocysteine levels are strongly influenced by dietary intake and genetic factors, and through our research, we found that a multi-ingredient vitamin formula, which particularly includes folic acid and vitamin B12, favorably influences homocysteine levels in blood.
Our findings in our Cooper Complete® Study show the favorable effects on homocysteine and CRP levels in the blood as well as the anti-oxidant properties of complex multivitamin supplementation.