Background: Obesity and being overweight are associated with many comorbid conditions, and are major contributing factors to cardiovascular disease (CVD). The increased proportion of overweight and obese individuals in Western societies over the past few decades has been attributed largely to behaviors including sedentary lifestyle and dietary excess. While genetics and aging may increase the risk of obesity and being overweight, individual, social, and environmental factors may play a significant role in the development of CVD risk factors among women. Women are at an increased risk during perimenopause when hormones change and metabolism slows. African American (AA) women are particularly at a high risk. Objectives and Aims: Incorporating the behavioral principles identified in a review of literature, a study was conducted to determine the feasibility and potential efficacy of a 10-week weight-loss program, and to determine whether adopting healthy behaviors by focusing on creating a structured healthy environment, will improve clinical outcomes and reduce risk factors of CVD among AA women ages 35-75 compared to randomized active, control group; barriers, facilitators and lessons learned are presented. The first aim (Aim 1) of the dissertation was to describe the results of a literature review that explored current research that focused on modification of behaviors of diet and physical activity, to identify short-term outcome measures that would be appropriate, feasible, and achievable for weight-loss intervention in primary care for midlife women to reduce risks and improve their cardiovascular health. A second aim (Aim 2) was to determine if it is feasible to operationalize and successfully implement a cohesive weight-loss program, and to foster enduring adoption of healthy nutrition and physical activity behaviors. A third aim (Aim 3) of this study was to determine the effect size of the program by employing additional structured content that targets the external social/environmental aspects of their life. Another aim (Aim4) was to determine if, when operationalized in the context of a 10-week behavioral weight-loss program, the structured content would result in greater changes in weight and selected secondary bio-behavioral outcomes among AA women 35-75 years old compared to a group receiving unstructured, individual-focused/peer discussions. Lastly, another aim (Aim 5) was to evaluate satisfaction with the program and identify subjectively perceived challenges and facilitators in participation and meeting goals of the weight-loss intervention in this AA community. Methods: Twenty-three AA women from one AA church of two campuses were recruited into a quasi-experimental randomized controlled trial that was conducted to achieve the objective and aims. Twenty-two women completed the study of the 10-week bio-behavioral weight loss program which had common dietary and physical activity content as well as separate time for structured discussion (experimental treatment group, n=11) and unstructured discussion (control group, n=11). Bio-behavioral outcomes included: adopting behavior to increase and/or meet goals of nutritional intake; adopting behavior to increase and/or meet goals of physical activity; and improving fasting blood sugar (FBS), systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), weight, hip circumference (HC), waist circumference (WC), and waist-to-hip ratio (WHR). Challenges, facilitators and satisfaction were also assessed via a short self-administered survey with both open-ended and non-open-ended questions. Both parametric and non-parametric statistics were used to describe baseline characteristics and results and to test for within and between group differences in outcomes, and changes from pre- to post when groups were combined, and to examine correlations of selected variables. Effect sizes of the intervention for the primary and selected secondary outcome variables were calculated and expressed with Cohen’s d statistics. Results: The study described in this dissertation was informed by the review of literature (Chapter 2), and generated empirical findings (Chapter 3). Lessons learned and recommendations for future research (Chapter 4). Empirical results by aim are described: Aim 1: A combination of vigorous exercise and a modified diet approach appears to be the best obesity management strategy. If confirmed in larger studies, it may be an effective non-pharmacological approach for the reduction of risk factors in the prevention and treatment of CVD. Aim 2: The results of this study showed that it was feasible, and standard behavioral strategies were well - received, but not consistently applied by participants to attain desired weight loss. However, despite good attendance (5.9± 2.5 (p=0.62) days for experimental group, and 5.5±1.7 days (p >.05) for active, control group), and because of a number of challenges encountered during the study, it is impossible to measure adoption of enduring healthy nutrition and physical activity behaviors. Aim 3: The estimated effect size for change in SBP was small (0.2), and small-to-moderate (0.3) for change in weight; however, for change in DBP it was moderate (0.5), suggesting that the addition of a structured group intervention component could potentially yield a clinically significant effect on blood pressure and other variables. However, large-scale studies are needed to test this hypothesis. Aim 4: The primary outcome measure was weight. Statistical analysis demonstrated that even though there appeared to be a small difference in weight loss between the experimental and active, control groups (2.16±5.2 lbs. vs. 0.40±6.4 lbs.), it was not statistically significant (p=0.49) due to high variability. When groups were combined, the average weight loss for the 22 women was 1.28±5.8 lbs., albeit not statistically different (p=0.31) from baseline. There were no significant differences between groups in any of the secondary measures. The overall change in BMI was not significant when both groups were combined (0.22±0.98, p=0.31). The SBP reduction for the groups when combined was 4.95±14.51 mm/Hg, which was also not statistically significant (p=0.12). However, participants in the combined analysis were found to have statistically significant DBP improvement (6.45±9.71 mm/Hg decrease, p= 0.005). Analyses showed statistically significant decrease in HC when the intervention groups were combined (0.7±1.4 in., p=0.03), as well as statistically significant WC reduction (pre to post) (1.34±1.6 in., p< 0.001). Importantly, there was a correlation between the number of attended meetings and weight loss. Five out of 22 participants who attended at least 8 out of 10 sessions, lost more weight (6.3 lbs on average) than their counterparts attending fewer than 8 out of 10 meetings who gained an average of 0.2 lbs (p= 0.02). Analysis showed that there was no significant difference in the baseline weight of participants who attended the meetings 8 or more times versus less than 8 times (p=0.82). Aim 5: Satisfaction with the program was excellent. All participants responded positively to the satisfaction questionnaire (100%), except for one participant in structured group (10%) and 2 in unstructured group (20%) who found it difficult to fit meetings into their schedule. Conclusion: The study was judged overall to be feasible, and standard behavioral strategies were well- received, but not consistently applied by participants to attain desired weight loss. No statistically significant differences were observed between groups, so the groups were combined to examine overall outcomes. In combined analyses, DBP, HC and WC showed statistically significant improvements. The structured versus unstructured discussion approach as implemented in this study is a novel approach. If further developed and tested, this type of program has the potential to be a valuable non-pharmacological approach to facilitate weight loss and weight management. This study adds to the existing literature on obesity management among AA women. Efforts to implement the protocol successfully could lead to better patient outcomes and improved quality of life for AA women. Recommendations: Several recommendations can be made for the design of future weight-loss studies. Setting realistic goals and expectations and reviewing them throughout the study are important to maintain self-efficacy of participants. In future research, this could be measured and tracked to confirm. A change in time for conducting a study from summer when everybody is busy with other activities and taking care of children and grandchildren who are out of school, to the fall when people are ready to return to more structured routine, might yield more favorable results, including even better attendance. In future studies, it is recommended that make-up sessions be planned or other forms of content delivery (e.g., email, text messaging, and posting information on designated websites). Mid-week phone follow-up, more peer-to-peer interaction, and determination of readiness to change prior to the study enrollment and selecting only those with readiness to change could also be helpful in increasing attendance, anticipating that such participants would make an explicit commitment to the intervention schedule which would improve attendance, engagement in the protocol and improve outcomes. If possible, a “run-in” period in which women attend and perform study activities could be implemented to exclude women who do not adhere to minimal protocol requirements. This may ensure that women are recruited who are truly ready to change their lifestyle and behavior, and who may utilize study resources more fruitfully.
University of Minnesota Ph.D. dissertation.August 2015. Major: Nursing. Advisor: Ruth Lindquist. 1 computer file (PDF); xiii, 127 pages.
Feasibility Study of Behavioral Weight-Loss Program for African-American Women Aged 35-75 Years.
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