Daniel P. Beavers

Effects of intensive diet and exercise on knee joint loads, inflammation, and clinical outcomes among overweight and obese adults with knee osteoarthritis: the IDEA randomized clinical trial.

IMPORTANCE Knee osteoarthritis (OA), a common cause of chronic pain and disability, has biomechanical and inflammatory origins and is exacerbated by obesity. OBJECTIVE To determine whether a ≥10% reduction in body weight induced by diet, with or without exercise, would improve mechanistic and clinical outcomes more than exercise alone. DESIGN, SETTING, AND PARTICIPANTS Single-blind, 18-month, randomized clinical trial at Wake Forest University between July 2006 and April 2011. The diet and exercise interventions were center-based with options for the exercise groups to transition to a home-based program. Participants were 454 overweight and obese older community-dwelling adults (age ≥55 years with body mass index of 27-41) with pain and radiographic knee OA. INTERVENTIONS Intensive diet-induced weight loss plus exercise, intensive diet-induced weight loss, or exercise. MAIN OUTCOMES AND MEASURES Mechanistic primary outcomes: knee joint compressive force and plasma IL-6 levels; secondary clinical outcomes: self-reported pain (range, 0-20), function (range, 0-68), mobility, and health-related quality of life (range, 0-100). RESULTS Three hundred ninety-nine participants (88%) completed the study. Mean weight loss for diet + exercise participants was 10.6 kg (11.4%); for the diet group, 8.9 kg (9.5%); and for the exercise group, 1.8 kg (2.0%). After 18 months, knee compressive forces were lower in diet participants (mean, 2487 N; 95% CI, 2393 to 2581) compared with exercise participants (2687 N; 95% CI, 2590 to 2784, pairwise difference [Δ](exercise vs diet )= 200 N; 95% CI, 55 to 345; P = .007). Concentrations of IL-6 were lower in diet + exercise (2.7 pg/mL; 95% CI, 2.5 to 3.0) and diet participants (2.7 pg/mL; 95% CI, 2.4 to 3.0) compared with exercise participants (3.1 pg/mL; 95% CI, 2.9 to 3.4; Δ(exercise vs diet + exercise) = 0.39 pg/mL; 95% CI, -0.03 to 0.81; P = .007; Δ(exercise vs diet )= 0.43 pg/mL; 95% CI, 0.01 to 0.85, P = .006). The diet + exercise group had less pain (3.6; 95% CI, 3.2 to 4.1) and better function (14.1; 95% CI, 12.6 to 15.6) than both the diet group (4.8; 95% CI, 4.3 to 5.2) and exercise group (4.7; 95% CI, 4.2 to 5.1, Δ(exercise vs diet + exercise) = 1.02; 95% CI, 0.33 to 1.71; P(pain) = .004; 18.4; 95% CI, 16.9 to 19.9; Δ(exercise vs diet + exercise), 4.29; 95% CI, 2.07 to 6.50; P(function )< .001). The diet + exercise group (44.7; 95% CI, 43.4 to 46.0) also had better physical health-related quality of life scores than the exercise group (41.9; 95% CI, 40.5 to 43.2; Δ(exercise vs diet + exercise) = -2.81; 95% CI, -4.76 to -0.86; P = .005). CONCLUSIONS AND RELEVANCE Among overweight and obese adults with knee OA, after 18 months, participants in the diet + exercise and diet groups had more weight loss and greater reductions in IL-6 levels than those in the exercise group; those in the diet group had greater reductions in knee compressive force than those in the exercise group. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00381290.

Effectiveness of Lifestyle Interventions for Individuals With Severe Obesity and Type 2 Diabetes Results from the Look AHEAD trial

OBJECTIVE Rates of severe obesity (BMI ≥40 kg/m2) are on the rise, and effective treatment options are needed. We examined the effect of an intensive lifestyle intervention (ILI) on weight loss, cardiovascular disease (CVD) risk, and program adherence in participants with type 2 diabetes who were severely obese compared with overweight (BMI 25 to <30 kg/m2), class I (BMI 30 to <35 kg/m2), and class II (BMI 35 to <40 kg/m2) obese participants. RESEARCH DESIGN AND METHODS Participants in the Action for Health in Diabetes (Look AHEAD) trial were randomly assigned to ILI or diabetes support and education (DSE). DSE participants received a less intense educational intervention, whereas ILI participants received an intensive behavioral treatment to increase physical activity (PA) and reduce caloric intake. This article focuses on the 2,503 ILI participants (age 58.6 ± 6.8 years). RESULTS At 1 year, severely obese participants in the ILI group lost −9.04 ± 7.6% of initial body weight, which was significantly greater (P < 0.05) than ILI participants who were overweight (−7.43 ± 5.6%) and comparable to class I (−8.72 ± 6.4%) and class II obese (−8.64 ± 7.4%) participants. All BMI groups had comparable improvements in fitness, PA, LDL cholesterol, triglycerides, blood pressure, fasting glucose, and HbA1c at 1 year. ILI treatment session attendance was excellent and did not differ among weight categories (severe obese 80% vs. others 83%; P = 0.43). CONCLUSIONS Severely obese participants in the ILI group had similar adherence, percentage of weight loss, and improvement in CVD risk compared with less obese participants. Behavioral weight loss programs should be considered an effective option for this population.

Associations between body composition and gait-speed decline: results from the Health, Aging, and Body Composition study

BACKGROUND In older adults, every 0.1-m/s slower gait speed is associated with a 12% higher mortality. However, little research has identified risk factors for gait-speed decline. OBJECTIVE We assessed the association between several measures of body composition and age-related decline in gait speed. DESIGN Data were from 2306 older adults who were participating in the Health, Aging, and Body Composition cohort and were followed for 4 y (50% women; 38% black). Usual walking speed (m/s) over 20 m was measured in years 2 through 6, and the baseline and changes in several measures of body composition were included in mixed-effects models. RESULTS Gait speed declined by 0.06 ± 0.00 m/s over the 4-y period. Baseline thigh intermuscular fat predicted the annual gait-speed decline (±SE) in both men and women (-0.01 ± 0.00 and -0.02 ± 0.00 m/s per 0.57 cm(2), respectively; P < 0.01). In men, but not in women, this relation was independent of total body adiposity. In longitudinal analyses, changes in thigh intermuscular fat and total thigh muscle were the only body-composition measures that predicted gait-speed decline in men and women combined. When modeled together, every 5.75-cm(2) increase in thigh intermuscular fat was associated with a 0.01 ± 0.00-m/s decrease in gait speed, whereas every 16.92-cm(2) decrease in thigh muscle was associated with a 0.01 ± 0.00-m/s decrease in gait speed. CONCLUSIONS High and increasing thigh intermuscular fat are important predictors of gait-speed decline, implying that fat infiltration into muscle contributes to a loss of mobility with age. Conversely, a decreasing thigh muscle area is also predictive of a decline in gait speed.

Psychosocial Burden and Glycemic Control During the First 6 Years of Diabetes: Results From the SEARCH for Diabetes in Youth Study

PURPOSE To evaluate the psychosocial burden of adolescents with diabetes, determine the trajectory of psychosocial burden, and examine the interdependent relationships between psychosocial burden and glycemic control across the first 6 years of diabetes. METHODS Data from SEARCH for Diabetes in Youth, an observational study of U.S. children diagnosed with diabetes before the age of 20, were collected during study visits conducted at baseline and then at 12, 24, and 60 months after baseline. Blood was drawn, clinical and demographic information was collected, and psychosocial burden was evaluated using standardized depression and generic and diabetes-specific health-related quality of life (QOL) surveys. RESULTS Among the 1,307 adolescents (mean age, 14.1±2.5 years) with baseline data, 1,026 had type 1 diabetes and 281 had type 2 diabetes. For those with a 60-month follow-up visit, glycated hemoglobin (A1c) values rose 1.5% from baseline (type 1, 7.7%-9.3% and type 2, 7.3%-8.8%). Adolescents with type 2 diabetes reported more depression and poorer QOL than adolescents with type 1 diabetes. For each diabetes type, there were similar baseline risk factors for higher A1c values: longer diabetes duration, ethnic minority status, and declining diabetes QOL (p < .05). However, youth with type 2 diabetes had higher A1c values with increasing generic QOL, an unexpected finding. Younger adolescents with type 1 diabetes had higher A1c values at the end of the study. CONCLUSIONS Significant deterioration in glycemic control marks the first 6 years of diabetes for adolescents. Psychosocial burden, particularly poor diabetes-specific QOL, is a contributor to suboptimal glycemic outcomes.

The long-term effectiveness of a lifestyle intervention in severely obese individuals.

OBJECTIVE Severe obesity (body mass index [BMI] ≥40 kg/m(2)) is a serious public health concern. Although bariatric surgery is an efficacious treatment approach, it is limited in reach; thus, nonsurgical treatment alternatives are needed. We examined the 4-year effects of an intensive lifestyle intervention on body weight and cardiovascular disease risk factors among severely obese, compared with overweight (25 ≤BMI <30), class I (30 ≤BMI <35), and class II obese (35 ≤BMI <40) participants. METHODS There were 5145 individuals with type 2 diabetes (45-76 years, BMI ≥25 kg/m(2)) randomized to an intensive lifestyle intervention or diabetes support and education. The lifestyle intervention group received a behavioral weight loss program that included group and individual meetings, a ≥10% weight loss goal, calorie restriction, and increased physical activity. Diabetes support and education received a less intense educational intervention. Four-year changes in body weight and cardiovascular disease risk factors were assessed. RESULTS Across BMI categories, 4-year changes in body weight were significantly greater in lifestyle participants compared with diabetes support and education (Ps <.05). At year 4, severely obese lifestyle participants lost 4.9%±8.5%, which was similar to class I (4.8%±7.2%) and class II obese participants (4.4%±7.6%), and significantly greater than overweight participants (3.4%±7.0%; P <.05). Four-year changes in low-density-lipoprotein cholesterol, triglycerides, diastolic blood pressure, HbA(1c), and blood glucose were similar across BMI categories in lifestyle participants; however, the severely obese had less favorable improvements in high-density-lipoprotein cholesterol (3.1±0.4 mg/dL) and systolic blood pressure (-1.4±0.7 mm Hg) compared with the less obese (Ps <.05). CONCLUSION Lifestyle interventions can result in important long-term weight losses and improvements in cardiovascular disease risk factors among a significant proportion of severely obese individuals.

Nine-year effects of 3.7 years of intensive glycemic control on cardiovascular outcomes

OBJECTIVE In the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, ∼4 years of intensive versus standard glycemic control in participants with type 2 diabetes and other cardiovascular risk factors had a neutral effect on the composite cardiovascular outcome, increased cardiovascular and total mortality, and reduced nonfatal myocardial infarction. Effects of the intervention during prolonged follow-up were analyzed. RESEARCH DESIGN AND METHODS All surviving ACCORD participants were invited to participate in the ACCORD Follow-on (ACCORDION) study, during which participants were treated according to their health care provider’s judgment. Cardiovascular and other health-related outcomes were prospectively collected and analyzed using an intention-to-treat approach according to the group to which participants were originally allocated. RESULTS A total of 8,601 people, representing 98% of those who did not suffer a primary outcome or death during the ACCORD trial, were monitored for a median of 8.8 years and a mean of 7.7 years from randomization. Intensive glucose lowering for a mean of 3.7 years had a neutral long-term effect on the primary composite outcome (nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death), death from any cause, and an expanded composite outcome that included all-cause death. Moreover, the risk of cardiovascular mortality noted during the active phase (hazard ratio 1.49; 95% CI 1.19, 1.87; P < 0.0001) decreased (HR 1.20; 95% CI 1.03, 1.39; P = 0.02). CONCLUSIONS In high-risk people with type 2 diabetes monitored for 9 years, a mean of 3.7 years of intensive glycemic control had a neutral effect on death and nonfatal cardiovascular events but increased cardiovascular-related death.

Exposure to isoflavone-containing soy products and endothelial function: A Bayesian meta-analysis of randomized controlled trials

BACKGROUND AND AIMS To determine whether and to what degree exposure to isoflavone-containing soy products affects EF. Endothelial dysfunction has been identified as an independent coronary heart disease risk factor and a strong predictor of long-term cardiovascular morbidity and mortality. Data on the effects of exposure to isoflavone-containing soy products on EF are conflicting. METHODS AND RESULTS A comprehensive literature search was conducted using the PUBMED database (National Library of Medicine, Bethesda, MD) inclusively through August 21, 2009 on RCTs using the keywords: soy, isoflavone, phytoestrogen, EF, flow mediated vasodilation, and FMD. A Bayesian meta-analysis was conducted to provide a comprehensive account of the effect of isoflavone-containing soy products on EF, as measured by FMD. A total of 17 RCTs were selected as having sufficient data for study inclusion. The overall mean absolute change in FMD (95% Bayesian CI) for isoflavone-containing soy product interventions was 1.15% (-0.52, 2.75). When the effects of separate interventions were considered, the treatment effect for isolated isoflavones was 1.98% (0.07, 3.97) compared to 0.72% (-1.39, 2.90) for isoflavone-containing soy protein. The models were not improved when considering study-specific effects such as cuff measurement location, prescribed dietary modification, and impaired baseline FMD. CONCLUSIONS Cumulative evidence from the RCTs included in this meta-analysis indicates that exposure to soy isoflavones can modestly, but significantly, improve EF as measured by FMD. Therefore, exposure to isoflavone supplements may beneficially influence vascular health.

Plasma nitrate and nitrite are increased by a high-nitrate supplement but not by high-nitrate foods in older adults

Little is known about the effect of dietary nitrate on the nitrate/nitrite/nitric oxide cycle in older adults. We examined the effect of a 3-day control diet vs high-nitrate diet, with and without a high-nitrate supplement (beetroot juice), on plasma nitrate and nitrite kinetics and blood pressure using a randomized 4-period crossover controlled design. We hypothesized that the high-nitrate diet would show higher levels of plasma nitrate/nitrite and lower blood pressure compared with the control diet, which would be potentiated by the supplement. Participants were 8 normotensive older men and women (5 female, 3 male, 72.5 ± 4.7 years old) with no overt disease or medications that affect nitric oxide metabolism. Plasma nitrate and nitrite levels and blood pressure were measured before and hourly for 3 hours after each meal. The mean daily changes in plasma nitrate and nitrite were significantly different from baseline for both control diet + supplement (P < .001 and P = .017 for nitrate and nitrite, respectively) and high-nitrate diet + supplement (P = .001 and P = .002), but not for control diet (P = .713 and P = .741) or high-nitrate diet (P = .852 and P = .500). Blood pressure decreased from the morning baseline measure to the three 2-hour postmeal follow-up time points for all treatments, but there was no main effect for treatment. In healthy older adults, a high-nitrate supplement consumed at breakfast elevated plasma nitrate and nitrite levels throughout the day. This observation may have practical utility for the timing of intake of a nitrate supplement with physical activity for older adults with vascular dysfunction.

Effect of an 18-month physical activity and weight loss intervention on body composition in overweight and obese older adults

Our primary objective was to determine the long‐term effects of physical activity (PA) and weight loss (WL) on body composition in overweight/obese older adults. Secondarily, the association between change in body mass and composition on change in several cardiometabolic risk factors and mobility was evaluated.

Effects of total and regional fat loss on plasma CRP and IL-6 in overweight and obese, older adults with knee osteoarthritis.

OBJECTIVE To describe associations between total and regional body fat mass loss and reduction of systemic levels of inflammation (C-reactive protein (CRP) and interleukin-6 (IL-6)) in obese, older adults with osteoarthritis (OA), undergoing intentional weight loss. DESIGN Data come from a single-blind, 18-month, randomized controlled trial in adults (age: 65.6 ± 6.2; Body mass index (BMI): 33.6 ± 3.7) with knee OA. Participants were randomized to diet-induced weight loss plus exercise (D + E; n = 150), diet-induced weight loss-only (D; n = 149), or exercise-only (E; n = 151). Total body and region-specific (abdomen and thigh) fat mass were measured at baseline and 18 months. High-sensitivity CRP and IL-6 were measured at baseline, six and 18 months. Intervention effects were assessed using mixed models and associations between inflammation and adiposity were compared using logistic and mixed linear regression models. RESULTS Intentional total body fat mass reduction was associated with significant reductions in log-adjusted CRP (β = 0.06 (95% CI = 0.04, 0.08) mg/L) and IL-6 (β = 0.02 (95% CI = 0.01, 0.04) pg/mL). Loss of abdominal fat volume was also associated with reduced inflammation, independent of total body fat mass; although models containing measures of total adiposity yielded the best fit. The odds of achieving clinically desirable levels of CRP (<3.0 mg/L) and IL-6 (<2.5 pg/mL) were 3.8 (95% CI = 1.6, 8.9) and 2.2 (95% CI = 1.1, 4.6), respectively, with 5% total weight and fat mass loss. CONCLUSIONS Achievement of clinically desirable levels of CRP and IL-6 more than double with intentional 5% loss of total body weight and fat mass. Global, rather than regional, measures of adiposity are better predictors of change in inflammatory burden. CLINICAL TRIAL REGISTRATION NUMBER NCT00381290.