Steven T. Johnson

Metabolic Risk Varies According to Waist Circumference Measurement Site in Overweight Boys and Girls

OBJECTIVES To compare waist circumference (WC) values measured at 4 commonly recommended sites and examine the relationships between WC sites and markers of metabolic risk in a sample of overweight boys and girls referred for weight management. STUDY DESIGN Overweight (mean body mass index percentile, 98.7; SD, 1.0) children and adolescents (n = 73; 41 girls, 32 boys; mean age, 12.5 years; SD, 2.6 years) had WC measured at 4 sites: iliac crest (WC1), narrowest waist (WC2), midpoint between the floating rib and iliac crest (WC3), and umbilicus (WC4). Height, weight, fasting insulin level, glucose level, cholesterol level, and systolic and diastolic blood pressure were also measured. RESULTS Overall, WC1 (108.5 cm; SD, 16.3 cm) was greater than WC2 (97.4 cm; SD, 13.6 cm; P < .003), and WC2 was smaller than WC3 (104.3 cm; SD, 15.3 cm; P = .02) and WC4 (108.7 cm; SD, 16.2 cm; P < .0003). With logistic regression, WC2 and WC3 were revealed to be more consistently associated with metabolic syndrome by using 3 different definitions. CONCLUSION In our sample, we observed differences in 4 commonly recommended WC measurement sites and found that all sites were not equivalently associated with metabolic risk. Our findings provide preliminary support suggesting that WC measured at the narrowest waist and midpoint between the floating rib and iliac crest may represent the measurement sites most closely associated with metabolic risk in overweight boys and girls.

Metformin and Exercise in Type 2 Diabetes: Examining treatment modality interactions

OBJECTIVE To determine the effect of metformin on the acute metabolic response to submaximal exercise, the effect of exercise on plasma metformin concentrations, and the interaction between metformin and exercise on the subsequent response to a standardized meal. RESEARCH DESIGN AND METHODS Ten participants with type 2 diabetes were recruited for this randomized crossover study. Metformin or placebo was given for 28 days, followed by the alternate condition for 28 days. On the last 2 days of each condition, participants were assessed during a nonexercise and a subsequent exercise day. Exercise took place in the morning and involved a total of 35 min performed at three different submaximal intensities. RESULTS Metformin increased heart rate and plasma lactate during exercise (both P ≤ 0.01) but lowered respiratory exchange ratio (P = 0.03) without affecting total energy expenditure, which suggests increased fat oxidation. Metformin plasma concentrations were greater at several, but not all, time points on the exercise day compared with the nonexercise day. The glycemic response to a standardized meal was reduced by metformin, but the reduction was attenuated when exercise was added (metformin × exercise interaction, P = 0.05). Glucagon levels were highest in the combined exercise and metformin condition. CONCLUSIONS This study reveals several ways by which metformin and exercise therapies can affect each other. By increasing heart rate, metformin could lead to the prescription of lower exercise workloads. Furthermore, under the tested conditions, exercise interfered with the glucose-lowering effect of metformin.

Improved cardiovascular health following a progressive walking and dietary intervention for type 2 diabetes

Aim: To examine the impact of two different lifestyle programmes on cardiovascular health and glycaemic control among people with type 2 diabetes.

Understanding Physical Activity Intentions and Behavior in Postmenopausal Women: An Application of the Theory of Planned Behavior

BackgroundIn the present paper, we report the social cognitive correlates of physical activity (PA) intentions in postmenopausal women using the two-component theory of planned behavior (TPB) framework.PurposeThe primary objective of the present study was to investigate the utility of the TPB in understanding PA behavior in postmenopausal women.MethodPostmenopausal women (N = 297) residing in Southern Alberta, Canada completed a mailed questionnaire that assessed self-reported PA and TPB constructs.ResultsData indicated that 67% of postmenopausal women intended to engage in PA behavior consistent with the public health PA guidelines. Multiple regression analysis suggested that the TPB model explained 44% of the variance in PA intentions with instrumental attitude (β = 0.33), affective attitude (β = 0.29), descriptive norm (β = 0.19), and self-efficacy (β = 0.24) making significant contributions to PA intentions. Postmenopausal women meeting PA guidelines reported higher scores across all TPB variables when compared to women not meeting PA guidelines. Unique behavioral, normative, and control beliefs were also elicited.ConclusionThe two-component TPB framework appears to be a useful model for understanding PA intentions and behavior in postmenopausal women. These data can be used in the development and establishment of PA behavior intervention and health promotion materials designed to facilitate PA intentions and behavior in postmenopausal women.

Physical activity and health-related quality of life among older men: an examination of current physical activity recommendations.

OBJECTIVE To determine differences in health-related quality of life (HRQoL) between older men achieving versus not achieving American College of Sports Medicine (ACSM) and the United States Department of Health and Human Services recommendations (USDHHS) physical activity (PA) recommendations. METHOD Older-aged men (≥ 55 years) completed a mailed survey that assessed self-reported PA and HRQoL. Data were collected between September and October of 2010. RESULTS 387 older men (Mean age=65) completed the survey. Under half (48%) reported achieving the ACSM recommendation while 64% reported achieving the USDHHS recommendation. Older men achieving the ACSM recommendation reported significantly higher scores in physical health (Δ=3.5, p<0.001), mental health (Δ=4.4, p<0.001), and global health (Δ=4.3, p<0.001) component scores compared to those not achieving the recommendation. Those achieving the higher dose recommended by the USDHHS (≥ 300 min per week of moderate-intensity activity) reported significantly higher scores on the PHC (Δ=2.1, p=0.029) and GHC (Δ=2.3, p=0.027) scales compared to those achieving the USDHHS base recommendation (150-299.9 min per week of moderate-intensity activity). CONCLUSIONS Self-reported PA was significantly and positively associated with higher HRQoL scores among older men. Associations were stronger for those achieving a higher volume of PA.

Quality of life and psychosocial health in postmenopausal women achieving public health guidelines for physical activity.

Objective: The aim of this study was to determine if there are differences in health-related quality of life (HRQoL) and psychosocial health between postmenopausal women who meet public health physical activity (PA) guidelines versus those who do not (ie, self-report) and those women who achieve at least 7,500 steps · day−1 versus those who do not (ie, via objective monitor). Methods: Postmenopausal women (n = 297) residing in Southern Alberta, Canada, completed a mailed questionnaire that assessed self-reported PA, HRQoL, and psychosocial health outcomes. Total daily steps were assessed with a pedometer via a 3-day step monitoring period. Results: Of the postmenopausal women, 43.1% were meeting public health PA guidelines. A significant multivariate model (Wilks &lgr; = 0.968, F2,294 = 4.918, P = 0.008) indicated that women achieving public health PA guidelines reported higher HRQoL on both the physical (mean difference [Mdiff] = 2.4, P = 0.008, d [effect size] = 0.31) and mental (Mdiff = 2.3, P = 0.011, d = 0.30) component scales of the RAND-12 compared with women not achieving PA guidelines. Furthermore, women achieving at least 7,500 steps · day−1 indicated significantly higher scores on the physical component scale (Mdiff = 4.33, P < 0.001, d = 0.56) than did women achieving fewer than 7,500 pedometer steps · day−1. Conclusions: These findings lend support for the health benefits of achieving public health PA guidelines in postmenopause and further the rationale for developing, evaluating, and implementing strategically designed PA behavior change programs for postmenopausal women.

Peer Telephone Counseling for Adults With Type 2 Diabetes Mellitus A Case-Study Approach to Inform the Design, Development, and Evaluation of Programs Targeting Physical Activity

Purpose The purpose of this case study was to determine the feasibility of peer-led telephone counseling for people with type 2 diabetes mellitus related to physical activity (PA) and to establish preliminary efficacy of peer-led telephone counseling for eliciting recommended changes in PA-related cognitions and behaviors for adults with type 2 diabetes mellitus. Methods A total of 8 adults (5 males and 3 females, aged 59.5 (6.5) years) with type 2 diabetes mellitus completed quantitative self-report measures of aerobic-based PA, resistance training (RT), along with metrics from social cognitive theory (SCT) before and after a 12-week intervention. Qualitative data from weekly peer-led telephone sessions were collected by a peer counselor and subsequently organized into themes and analyzed using a mixed-methods, collective case-study approach. Results PA behaviors remained relatively constant over the 12-week intervention. Self-efficacy for RT improved ( z = -2.03; P = .04). From the peer counselor’s perspective, identifiable inhibitors to PA, which included low self-efficacy and disease condition limitations, were successfully translated into enablers/motivators. Perceived health benefits were frequently reported by the peer counselor as motivators for the participants over the study period. Participants believed peer counseling by telephone influenced their decision to continue to participate in PA. Conclusion Theory-based, peer-led telephone counseling shows some promise for increasing receptiveness to PA, but had little effect on improving behavior for most participants. Further studies will be necessary to determine the effectiveness and the sustainability of this approach.

Population-Based Estimates of Physical Activity for Adults with Type 2 Diabetes: A Cautionary Tale of Potential Confounding by Weight Status

At a population level, the method used to determine those meeting physical activity guidelines has important implications, as estimating “sufficient” physical activity might be confounded by weight status. The objective of this study was to test the difference between three methods in estimating the prevalence of “sufficient activity” among Canadian adults with type 2 diabetes in a large population sample (N = 1614) while considering the role of weight status as a potential confounder. Our results revealed that estimates of physical activity levels vary by BMI categories, depending on the methods examined. Although physical activity levels were lower in the obese, their energy expenditure estimates were not different from those who were overweight or of a healthy weight. The implications of these findings are that biased estimates of physical activity at a population level may result in inappropriate classification of adults with type 2 diabetes as “sufficiently active” and that the inclusion of body weight in estimating physical activity prevalence should be approached with caution.

Applying the RE-AIM framework to the Alberta's Caring for Diabetes Project: a protocol for a comprehensive evaluation of primary care quality improvement interventions

Introduction Diabetes represents a major public health and health system burden. As part of the Albertas Caring for Diabetes (ABCD) Project, two quality-improvement interventions are being piloted in four Primary Care Networks in Alberta. Gaps between health research, policy and practice have been documented and the need to evaluate the impact of public health interventions in real-world settings to inform decision-making and clinical practice is paramount. In this article, we describe the application of the RE-AIM framework to evaluate the interventions beyond effectiveness. Methods and analysis Two quality-improvement interventions were implemented, based on previously proven effective models of care and are directed at improving the physical and mental health of patients with type-2 diabetes. Our goal is to adapt and apply the RE-AIM framework, using a mixed-methods approach, to understand the impact of the interventions to inform policy and clinical decision-making. We present the proposed measures, data sources and data management and analysis strategies used to evaluate the interventions by RE-AIM dimension. Ethics and dissemination Ethics approval for the ABCD Project has been granted from the Health Research Ethics Board (HREB #PRO00012663) at the University of Alberta. The RE-AIM framework will be used to structure our dissemination activities by dimension. Results It will be presented at relevant conferences and prepared for publication in peer-reviewed journals. Various products, such as presentations, briefing reports and webinars, will be developed to inform key stakeholders of the findings. Presentation of findings by RE-AIM dimension will facilitate discussion regarding the public health impact of the two interventions within the primary care context of Alberta and lessons learned to be used in programme planning and care delivery for patients with type-2 diabetes. It will also promote the application of evaluation models to better assess the impact of community-based primary healthcare interventions through our dissemination activities.

In search of quality evidence for lifestyle management and glycemic control in children and adolescents with type 2 diabetes: A systematic review

BackgroundOur purpose was to evaluate the impact of lifestyle behavior modification on glycemic control among children and youth with clinically defined Type 2 Diabetes (T2D).MethodsWe conducted a systematic review of studies (randomized trials, quasi-experimental studies) evaluating lifestyle (diet and/or physical activity) modification and glycemic control (HbA1c). Our data sources included bibliographic databases (EMBASE, CINAHL®, Cochrane Library, Medline®, PASCAL, PsycINFO®, and Sociological Abstracts), manual reference search, and contact with study authors. Two reviewers independently selected studies that included any intervention targeting diet and/or physical activity alone or in combination as a means to reduce HbA1c in children and youth under the age of 18 with T2D.ResultsOur search strategy generated 4,572 citations. The majority of citations were not relevant to the study objective. One study met inclusion criteria. In this retrospective study, morbidly obese youth with T2D were treated with a very low carbohydrate diet. This single study received a quality index score of < 11, indicating poor study quality and thus limiting confidence in the studys conclusions.ConclusionsThere is no high quality evidence to suggest lifestyle modification improves either short- or long-term glycemic control in children and youth with T2D. Additional research is clearly warranted to define optimal lifestyle behaviour strategies for young people with T2D.