Impact of perioperative chemotherapy on survival in patients with advanced primary urethral cancer: results of the international collaboration on primary urethral carcinoma

BACKGROUND

To investigate the impact of perioperative chemo(radio)therapy in advanced primary urethral carcinoma (PUC).

PATIENTS AND METHODS

A series of 124 patients (86 men, 38 women) were diagnosed with and underwent surgery for PUC in 10 referral centers between 1993 and 2012. Kaplan-Meier analysis with log-rank testing was used to investigate the impact of perioperative chemo(radio)therapy on overall survival (OS). The median follow-up was 21 months (mean: 32 months; interquartile range: 5-48).

RESULTS

Neoadjuvant chemotherapy (NAC), neoadjuvant chemoradiotherapy (N-CRT) plus adjuvant chemotherapy (ACH), and ACH was delivered in 12 (31%), 6 (15%) and 21 (54%) of these patients, respectively. Receipt of NAC/N-CRT was associated with clinically node-positive disease (cN+; P = 0.033) and lower utilization of cystectomy at surgery (P = 0.015). The objective response rate to NAC and N-CRT was 25% and 33%, respectively. The 3-year OS for patients with objective response to neoadjuvant treatment (complete/partial response) was 100% and 58.3% for those with stable or progressive disease (P = 0.30). Of the 26 patients staged ≥cT3 and/or cN+ disease, 16 (62%) received perioperative chemo(radio)therapy and 10 upfront surgery without perioperative chemotherapy (38%). The 3-year OS for this locally advanced subset of patients (≥cT3 and/or cN+) who received NAC (N = 5), N-CRT (N = 3), surgery-only (N = 10) and surgery plus ACH (N = 8) was 100%, 100%, 50% and 20%, respectively (P = 0.016). Among these 26 patients, receipt of neoadjuvant treatment was significantly associated with improved 3-year relapse-free survival (RFS) (P = 0.022) and OS (P = 0.022). Proximal tumor location correlated with inferior 3-year RFS and OS (P = 0.056/0.005).

CONCLUSION

In this series, patients who received NAC/N-CRT for cT3 and/or cN+ PUC appeared to demonstrate improved survival compared with those who underwent upfront surgery with or without ACH.

Increased cardiovascular stiffness and impaired age-related functional status

Our objective was to determine if increased cardiovascular (CV) stiffness is associated with disability in middle-aged and older adults at risk for congestive heart failure. CV stiffness (brachial pulse pressure/left ventricular stroke volume indexed to body surface area) and total disability (the summed assessment of activities of daily living, mobility, and instrumental activities of daily living) were measured in 445 individuals. A subset of 109 randomly selected individuals also underwent physical function testing. Total disability was associated with CV stiffness (p = .01), driven by an association with mobility (p = .005), but not activities of daily living (p = .13) or instrumental activities of daily living (p = .61). After accounting for age, these correlations remained significant for men (p = .04), but not for women. CV stiffness was also associated with increased 400-m walk time (p = .02). In middle-aged and elderly men at risk for congestive heart failure, CV stiffness is associated with decreased mobility and physical function, and increased overall disability.

Mechanism of decreased sensitivity of dobutamine associated left ventricular wall motion analyses for appreciating inducible ischemia in older adults

BACKGROUND

Dobutamine associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible ischemia in individuals with increased LV wall thickness. This study was performed to better understand the mechanism of this reduced sensitivity in the elderly who often manifest increased LV wall thickness and risk factors for coronary artery disease.

METHODS

During dobutamine cardiovascular magnetic resonance (DCMR) stress testing, we assessed rate pressure product (RPP), aortic pulse wave velocity (PWV), LV myocardial oxygen demand (pressure volume area, PVA, mass, volumes, concentricity, and the presence of wall motion abnormalities (WMA) and first pass gadolinium enhanced perfusion defects (PDs) indicative of ischemia in 278 consecutively recruited individuals aged 69 ± 8 years with pre-existing or known risk factors for coronary artery disease. Each variable was assessed independently by personnel blinded to participant identifiers and analyses of other DCMR or hemodynamic variables.

RESULTS

Participants were 80% white, 90% hypertensive, 43% diabetic and 55% men. With dobutamine, 60% of the participants who exhibited PDs had no inducible WMA. Among these participants, myocardial oxygen demand was lower than that observed in those who had both wall motion and perfusion abnormalities suggestive of ischemia (p = 0.03). Relative to those with PDs and inducible WMAs, myocardial oxygen demand remained different in these individuals with PDs without an inducible WMA after accounting for LV afterload and contractility (p = 0.02 and 0.03 respectively), but not after accounting for either LV stress related end diastolic volume index (LV preload) or resting concentricity (p = 0.31-0.71).

CONCLUSIONS

During dobutamine stress testing, elderly patients experience increased LV concentricity and declines in LV preload and myocardial oxygen demand, all of which are associated with an absence of inducible LV WMAs indicative of myocardial ischemia. These findings provide insight as to why dobutamine associated wall motion analyses exhibit reduced sensitivity for identifying inducible ischemia in elderly.

TRIAL REGISTRATION

This study was registered with Clinicaltrials.gov (NCT00542503).

Abnormal stress-related measures of arterial stiffness in middle-aged and elderly men and women with impaired fasting glucose at risk for a first episode of symptomatic heart failure

Background

Abnormal resting arterial stiffness is present in middle‐aged and elderly persons with abnormalities of fasting glucose (diabetes or impaired fasting glucose) and is associated with exercise intolerance. We sought to determine whether these same persons exhibited stress‐related abnormalities of arterial stiffness.

Methods and Results

We analyzed dobutamine magnetic resonance stress imaging results from 373 consecutively recruited persons aged 55 to 85 years with normal fasting glucose, impaired fasting glucose, or diabetes who were at risk for but without symptomatic heart failure. Personnel blinded to participant identifiers measured arterial stiffness (brachial pulse pressure/left ventricular stroke volume indexed to body surface area, the aortic elastance index [brachial end‐systolic pressure/left ventricular stroke volume indexed to body surface area], and thoracic aortic distensibility) at 80% of the maximum predicted heart rate response for age. Participants averaged 69±8 years of age; 79% were white, 92% were hypertensive, and 66% were women. After accounting for hypertension, sex, coronary artery disease, smoking, medications, hypercholesterolemia, and visceral fat, we observed an effect of glycemic status for stress measures of arterial stiffness in those with diabetes and impaired fasting glucose relative to those with normal fasting glucose (P=0.002, P=0.02, and P=0.003, respectively).

Conclusion

Middle‐ and older‐aged individuals with diabetes or impaired fasting glucose have higher stress measures of arterial stiffness than those with normal fasting glucose. These data emphasize the need for future studies with larger sample sizes to determine whether stress‐related elevations in arterial stiffness are related to exercise intolerance and future episodes of heart failure experienced by those with abnormalities of fasting glucose.

Clinical Trial Registration

URL: http://clinicaltrials.gov/. Unique identifier: NCT00542503.

Effects of a community-based weight loss intervention on adipose tissue circulating factors

AIMS

Obesity is associated with metabolic dysfunctions, which may be mediated by changes in adipose tissue signaling factors. These molecules are denoted as Adipose Tissue Generated Mediators of CardioVascular Risk (ATGMCVR) here, and include leptin, adiponectin, C-reactive protein (CRP), interleukin 6 (IL-6), tumor necrosis factor alpha (TNFα), and plasminogen activator inhibitor 1 (PAI-1). This study examined the effect of a weight loss program on ATGMCVR in obese adults with prediabetes.

MATERIALS AND METHODS

Subjects were randomized to usual care (UC; n=15) or lifestyle weight loss groups (LWL; n=15). LWL was a community-based weight loss intervention to promote physical activity and healthy eating. ATGMCVR at 1-year were compared between groups by analysis of covariance; baseline value of the mediator was the covariate. Baseline means for ATGMCVR were compared between those with (n=21) and without (n=9) metabolic syndrome (MetS).

RESULTS

At baseline, subjects were 58±9 (SD) years, 70% female, with a BMI of 34±4kg/m(2). One-year weight loss (%) was 7.8±6.0% for LWL and 1.7±4.5% for UC. Group differences at 1-year were noted (adjusted means [95%CI] for UC and LWL, respectively) for adiponectin (8526.3 [7397.7, 9827]; 10,870.9 [9432.0, 12,529.3]ng/ml; p=0.02), leptin (30.4 [26.1, 35.4]; 23.7 [20.3, 27.5]ng/ml; p=0.02), IL-6 (0.4 [0.3, 0.5]; 0.2 [0.1, 0.2] pg/ml; p=0.001), and PAI-1 (50 [42.7, 58.7]; 36.2 [30.8, 42.4]pg/ml; p=0.01). No differences in baseline ATGMCVR were seen between subjects with and without MetS.

CONCLUSION

These findings suggest ATGMCVR can be improved with weight loss; larger studies are needed to determine if improvements in metabolic dysfunction are related to changes in ATGMCVR.

Longitudinal associations between sex, diabetes self-care, and health-related quality of life among youth with type 1 or type 2 diabetes mellitus

OBJECTIVE

To examine the longitudinal associations between sex, diabetes self-care, and the health-related quality of life (HRQL) of children and adolescents with type 1 or type 2 diabetes.

STUDY DESIGN

The sample included 910 participants with type 1 and 241 participants with type 2, ages 10-22 years at baseline, from the SEARCH for Diabetes in Youth Study, a longitudinal observational study. The primary outcome measure was the Pediatric Quality of Life Inventory. Repeated measures, mixed-model regression analysis was conducted with the use of data from baseline and at least one follow-up assessment, spanning approximately 4 years.

RESULTS

HRQL was greater among those with type 1 versus type 2 diabetes. Among participants with type 1, greater (better) Pediatric Quality of Life Inventory total scores over time were related to greater parent education (P = .0007), lower glycated hemoglobin values (P < .0001), and greater physical activity during the past 7 days (P = .0001). There was a significant interaction between sex and age (P < .0001); girls' HRQL remained stable or decreased over time, whereas males' HRQL increased. For participants with type 2 diabetes, there was no significant interaction by age and sex, but lower total HRQL was related to being female (P = .011) and greater body mass index z-scores (P = .014).

CONCLUSIONS

HRQL in this cohort varied by diabetes type. The interaction between sex and age for type 1 participants, coupled with poorer HRQL among female than male participants with type 2 diabetes, suggests the impacts of diabetes on HRQL differ by sex and should be considered in clinical management. Encouraging physical activity and weight control continue to be important in improving HRQL.

Outcomes of combined cardiovascular risk factor management strategies in type 2 diabetes: the ACCORD randomized trial

OBJECTIVE

To compare effects of combinations of standard and intensive treatment of glycemia and either blood pressure (BP) or lipids in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.

RESEARCH DESIGN AND METHODS

ACCORD enrolled 10,251 type 2 diabetes patients aged 40-79 years at high risk for cardiovascular disease (CVD) events. Participants were randomly assigned to hemoglobin A1c goals of <6.0% (<42 mmol/mol; intensive glycemia) or 7.0-7.9% (53-63 mmol/mol; standard glycemia) and then randomized a second time to either 1) systolic BP goals of <120 mmHg (intensive BP) or <140 mmHg (standard BP) or 2) simvastatin plus fenofibrate (intensive lipid) or simvastatin plus placebo (standard lipid). Proportional hazards models were used to assess combinations of treatment assignments on the composite primary (deaths due to CVD, nonfatal myocardial infarction [MI], and nonfatal stroke) and secondary outcomes.

RESULTS

In the BP trial, risk of the primary outcome was lower in the groups intensively treated for glycemia (hazard ratio [HR] 0.67; 95% CI 0.50-0.91), BP (HR 0.74; 95% CI 0.55-1.00), or both (HR 0.71; 95% CI 0.52-0.96) compared with combined standard BP and glycemia treatment. For secondary outcomes, MI was significantly reduced by intensive glycemia treatment and stroke by intensive BP treatment; most other HRs were neutral or favored intensive treatment groups. In the lipid trial, the general pattern of results showed no evidence of benefit of intensive regimens (whether single or combined) compared with combined standard lipid and glycemia treatment. The mortality HR was 1.33 (95% CI 1.02-1.74) in the standard lipid/intensive glycemia group compared with the standard lipid/standard glycemia group.

CONCLUSIONS

In the ACCORD BP trial, compared with combined standard treatment, intensive BP or intensive glycemia treatment alone improved major CVD outcomes, without additional benefit from combining the two. In the ACCORD lipid trial, neither intensive lipid nor glycemia treatment produced an overall benefit, but intensive glycemia treatment increased mortality.

Skeletal muscle abnormalities and exercise intolerance in older patients with heart failure and preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFPEF) is the most common form of HF in older persons. The primary chronic symptom in HFPEF is severe exercise intolerance, and its pathophysiology is poorly understood. To determine whether skeletal muscle abnormalities contribute to their severely reduced peak exercise O2 consumption (Vo2), we examined 22 older HFPEF patients (70 ± 7 yr) compared with 43 age-matched healthy control (HC) subjects using needle biopsy of the vastus lateralis muscle and cardiopulmonary exercise testing to assess muscle fiber type distribution and capillarity and peak Vo2. In HFPEF versus HC patients, peak Vo2 (14.7 ± 2.1 vs. 22.9 ± 6.6 ml·kg(-1)·min(-1), P < 0.001) and 6-min walk distance (454 ± 72 vs. 573 ± 71 m, P < 0.001) were reduced. In HFPEF versus HC patients, the percentage of type I fibers (39.0 ± 11.4% vs. 53.7 ± 12.4%, P < 0.001), type I-to-type II fiber ratio (0.72 ± 0.39 vs. 1.36 ± 0.85, P = 0.001), and capillary-to-fiber ratio (1.35 ± 0.32 vs. 2.53 ± 1.37, P = 0.006) were reduced, whereas the percentage of type II fibers was greater (61 ± 11.4% vs. 46.3 ± 12.4%, P < 0.001). In univariate analyses, the percentage of type I fibers (r = 0.39, P = 0.003), type I-to-type II fiber ratio (r = 0.33, P = 0.02), and capillary-to-fiber ratio (r = 0.59, P < 0.0001) were positively related to peak Vo2. In multivariate analyses, type I fibers and the capillary-to-fiber ratio remained significantly related to peak Vo2. We conclude that older HFPEF patients have significant abnormalities in skeletal muscle, characterized by a shift in muscle fiber type distribution with reduced type I oxidative muscle fibers and a reduced capillary-to-fiber ratio, and these may contribute to their severe exercise intolerance. This suggests potential new therapeutic targets in this difficult to treat disorder.

Chronic diuretic therapy attenuates renal BOLD magnetic resonance response to an acute furosemide stimulus

BACKGROUND

Blood Oxygen Level Dependent (BOLD) magnetic resonance (MR) is a novel imaging tool that detects changes in tissue oxygenation. Increases in renal oxygenation in response to a standard 20 mg intravenous furosemide stimulus have been evaluated to assess kidney viability in patients with renal artery stenosis (RAS). The effect of prior exposure to furosemide on the ability of BOLD MR techniques to evaluate renal function is unknown.This study tested the hypothesis that chronic loop diuretic therapy is associated with attenuated responses in renal tissue oxygenation as measured by BOLD MR with an acute 20 mg intravenous furosemide stimulus in participants undergoing evaluation for RAS.

METHODS

Thirty-eight participants referred for evaluation of RAS were recruited for this study. We examined renal cortical and medullary BOLD signal (T2*) intensities before and after a 20 mg intravenous furosemide stimulus. Additionally, we measured changes in renal artery blood flow using phase contrast techniques.

RESULTS

After controlling for covariates age, race, gender, diabetes, glomerular filtration rate, body mass index, and stenosis severity, daily oral furosemide dose was an independent, negative predictor of renal medullary T2* response (p=0.01) to a standard 20 mg intravenous furosemide stimulus. Stenosis severity and ethnicity were also significant independent predictors of changes in T2* signal intensity in response to an acute furosemide challenge. Changes in renal blood flow in response to acute furosemide administration were correlated with changes in T2* in the renal cortex (r=0.29, p=0.03) but not the medulla suggesting changes in renal medullary oxygenation were not due to reduced renal medullary blood flow.

CONCLUSIONS

Chronic furosemide therapy attenuates BOLD MR responses to an acute furosemide stimulus in patients with RAS being evaluated for renal artery revascularization procedures. Thus, patients who are chronically administered loop diuretics may need a different dosing strategy to accurately detect changes in renal oxygenation with BOLD MR in response to a furosemide stimulus.

Determinants of weight gain in the action to control cardiovascular risk in diabetes trial

OBJECTIVE

Identify determinants of weight gain in people with type 2 diabetes mellitus (T2DM) allocated to intensive versus standard glycemic control in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.

RESEARCH DESIGN AND METHODS

We studied determinants of weight gain over 2 years in 8,929 participants (4,425 intensive arm and 4,504 standard arm) with T2DM in the ACCORD trial. We used general linear models to examine the association between each baseline characteristic and weight change at the 2-year visit. We fit a linear regression of change in weight and A1C and used general linear models to examine the association between each medication at baseline and weight change at the 2-year visit, stratified by glycemia allocation.

RESULTS

There was significantly more weight gain in the intensive glycemia arm of the trial compared with the standard arm (3.0 ± 7.0 vs. 0.3 ± 6.3 kg). On multivariate analysis, younger age, male sex, Asian race, no smoking history, high A1C, baseline BMI of 25-35, high waist circumference, baseline insulin use, and baseline metformin use were independently associated with weight gain over 2 years. Reduction of A1C from baseline was consistently associated with weight gain only when baseline A1C was elevated. Medication usage accounted for <15% of the variability of weight change, with initiation of thiazolidinedione (TZD) use the most prominent factor. Intensive participants who never took insulin or a TZD had an average weight loss of 2.9 kg during the first 2 years of the trial. In contrast, intensive participants who had never previously used insulin or TZD but began this combination after enrolling in the ACCORD trial had a weight gain of 4.6-5.3 kg at 2 years.

CONCLUSIONS

Weight gain in ACCORD was greater with intensive than with standard treatment and generally associated with reduction of A1C from elevated baseline values. Initiation of TZD and/or insulin therapy was the most important medication-related factor associated with weight gain.

Conservative Sample Size Determination for Repeated Measures Analysis of Covariance

In the design of a randomized clinical trial with one pre and multiple post randomized assessments of the outcome variable, one needs to account for the repeated measures in determining the appropriate sample size. Unfortunately, one seldom has a good estimate of the variance of the outcome measure, let alone the correlations among the measurements over time. We show how sample sizes can be calculated by making conservative assumptions regarding the correlations for a variety of covariance structures. The most conservative choice for the correlation depends on the covariance structure and the number of repeated measures. In the absence of good estimates of the correlations, the sample size is often based on a two-sample t-test, making the 'ultra' conservative and unrealistic assumption that there are zero correlations between the baseline and follow-up measures while at the same time assuming there are perfect correlations between the follow-up measures. Compared to the case of taking a single measurement, substantial savings in sample size can be realized by accounting for the repeated measures, even with very conservative assumptions regarding the parameters of the assumed correlation matrix. Assuming compound symmetry, the sample size from the two-sample t-test calculation can be reduced at least 44%, 56%, and 61% for repeated measures analysis of covariance by taking 2, 3, and 4 follow-up measures, respectively. The results offer a rational basis for determining a fairly conservative, yet efficient, sample size for clinical trials with repeated measures and a baseline value.

Effect of endurance exercise training on endothelial function and arterial stiffness in older patients with heart failure and preserved ejection fraction: a randomized, controlled, single-blind trial

OBJECTIVES

The study sought to evaluate the effects of endurance exercise training (ET) on endothelial-dependent flow-mediated arterial dilation (FMD) and carotid artery stiffness, and their potential contributions to the training-related increase in peak exercise oxygen consumption (Vo2) in older patients with heart failure with preserved ejection fraction (HFPEF).

BACKGROUND

Elderly HFPEF patients have severely reduced peak Vo2, which improves with ET, however, the mechanisms of this improvement are unclear. FMD and arterial distensibility are critical components of the exercise response and are reduced with aging. However, it is unknown whether these improve with ET in elderly HFPEF or contribute to the training-related improvement in peak Vo2.

METHODS

A total of 63 HFPEF patients (age 70 ± 7 years) were randomized to 16 weeks of ET (walking, arm and leg ergometry, n = 32) or attention control (CT) (n = 31). Peak Vo2, brachial artery FMD in response to cuff ischemia, carotid artery distensibility by high-resolution ultrasound, left ventricular function, and quality of life were measured at baseline and follow-up.

RESULTS

ET increased peak Vo2 (ET: 15.8 ± 3.3 ml/kg/min vs. CT: 13.8 ± 3.1 ml/kg/min, p = 0.0001) and quality of life. However, brachial artery FMD (ET: 3.8 ± 3.0% vs. CT: 4.3 ± 3.5%, p = 0.88), and carotid arterial distensibility (ET: 0.97 ± 0.56 vs. CT: 1.07 ± 0.34 × 10(-3) mm·mm Hg(-2); p = 0.65) were unchanged. Resting left ventricular systolic and diastolic function were unchanged by ET.

CONCLUSIONS

In elderly HFPEF patients, 16 weeks of ET improved peak Vo2 without altering endothelial function or arterial stiffness. This suggests that other mechanisms, such as enhanced skeletal muscle perfusion and/or oxygen utilization, may be responsible for the ET-mediated increase in peak Vo2 in older HFPEF patients. (Prospective Aerobic Reconditioning Intervention Study [PARIS]; NCT01113840).

Cost of a group translation of the Diabetes Prevention Program: Healthy Living Partnerships to Prevent Diabetes

BACKGROUND

Although numerous studies have translated the Diabetes Prevention Program lifestyle intervention into various settings, no study to date has reported a formal cost analysis.

PURPOSE

To describe costs associated with the Healthy Living Partnerships to Prevent Diabetes (HELP PD) trial.

DESIGN

HELP PD was a 24-month RCT testing the impact of a lifestyle weight-loss intervention administered through a diabetes education program and delivered by community health workers (CHWs) on blood glucose and body weight among prediabetics.

SETTING/PARTICIPANTS

In all, 301 participants with prediabetes were randomized in Forsyth County NC. Data reported in these analyses were collected in 2007-2011 and analyzed in 2011-2012.

INTERVENTION

The lifestyle weight-loss group had a 7% weight loss goal achieved and maintained by caloric restriction and increased physical activity. The usual care group received two visits with a registered dietitian and monthly newsletters.

MAIN OUTCOME MEASURES

Measures are direct medical costs, direct nonmedical costs, and indirect costs over the 2-year study period. Research costs are excluded.

RESULTS

The direct medical cost (in 2010 dollars) to identify one participant was $16.85. Direct medical costs per capita for participants in the usual care group were $142 and $850 for lifestyle weight-loss participants. Per capita direct costs of care outside the study were $7454 for the usual care group and $5177 for the lifestyle weight-loss group. Per capita direct nonmedical costs were $12,881 for the usual care group and $13,836 for the lifestyle weight-loss group. The lifestyle weight-loss group in HELP PD cost $850 in direct medical costs for 2 years, compared to $2631 in direct medical costs for the first 2 years of DPP.

CONCLUSIONS

A community-based translation of the DPP can be delivered effectively and with reduced costs.

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.

Impaired aerobic capacity and physical functional performance in older heart failure patients with preserved ejection fraction: role of lean body mass

BACKGROUND

Exercise intolerance is the primary chronic symptom in patients with heart failure and preserved ejection fraction (HFPEF), the most common form of heart failure in older persons, and can result from abnormalities in cardiac, vascular, and skeletal muscle, which can be further worsened by physical deconditioning. However, it is unknown whether skeletal muscle abnormalities contribute to exercise intolerance in HFPEF patients.

METHODS

This study evaluated lean body mass, peak exercise oxygen consumption (VO2), and the short physical performance battery in 60 older (69 ± 7 years) HFPEF patients and 40 age-matched healthy controls.

RESULTS

In HFPEF versus healthy controls, peak percent total lean mass (60.1 ± 0.8% vs. 66.6 ± 1.0%, p < .0001) and leg lean mass (57.9 ± 0.9% vs. 63.7 ± 1.1%, p = .0001) were significantly reduced. Peak VO2 was severely reduced including when indexed to leg lean mass (79.3 ± 18.5 vs. 104.3 ± 20.4 ml/kg/min, p < .0001). Peak VO2 was correlated with percent total (r = .51) and leg lean mass (.52, both p < .0001). The slope of the relationship of peak VO2 with percent leg lean mass was markedly reduced in HFPEF (11 ± 5 ml/min) versus healthy controls (36 ± 5 ml/min; p < .001). Short physical performance battery was reduced (9.9 ± 1.4 vs. 11.3 ± 0.8) and correlated with peak VO2 and total and leg lean mass (all p < .001).

CONCLUSION

Older HFPEF patients have significantly reduced percent total and leg lean mass and physical functional performance compared with healthy controls. The markedly decreased peak VO2 indexed to lean body mass in HFPEF versus healthy controls suggests that abnormalities in skeletal muscle perfusion and/or metabolism contribute to the severe exercise intolerance in older HFPEF patients.

Reliability of peak exercise testing in patients with heart failure with preserved ejection fraction

Exercise intolerance is the primary symptom in patients with heart failure and preserved ejection fraction (HFpEF), a major determinant of their decreased quality of life, and an important outcome in clinical trials. Although cardiopulmonary exercise testing (CPET) provides peak and submaximal diagnostic indexes, the reliability of peak treadmill CPET in patients >55 years of age with HFpEF has not been examined. Two CPETs were performed in 52 patients with HFpEF (70 ± 7 years old). The 2 tests were separated by an average of 23 ± 13 days (median 22) and performed under identical conditions, with no intervention or change in status between visits except for initiation of a placebo run-in. A multistep protocol for patient screening, education, and quality control was used. Mean peak oxygen consumption was similar on tests 1 and 2 (14.4 ± 2.4 vs 14.3 ± 2.3 ml/kg/min). Correlation coefficients and intraclass correlations from the testing days were determined (oxygen consumption, r = 0.85, p <0.001, intraclass correlation 0.855; ventilatory anaerobic threshold, r = 0.79, p <0.001, intraclass correlation 0.790; ventilation per carbon dioxide slope, r = 0.87, p <0.001, intraclass correlation 0.864; heart rate, r = 0.94, p <0.001, intraclass correlation 0.938). These results challenge conventional wisdom that serial baseline testing is required in clinical trials with exercise-capacity outcomes. In conclusion, in women and men with HFpEF and severe physical dysfunction, key submaximal and peak ET variables exhibited good reliability and were not significantly altered by a learning effect or placebo administration.

Toll-like receptor 7 suppresses virus replication in neurons but does not affect viral pathogenesis in a mouse model of Langat virus infection

Toll-like receptor 7 (TLR7) recognizes guanidine-rich viral ssRNA and is an important mediator of peripheral immune responses to several ssRNA viruses. However, the role that TLR7 plays in regulating the innate immune response to ssRNA virus infections in specific organs such as the central nervous system (CNS) is not as clear. This study examined the influence of TLR7 on the neurovirulence of Langat virus (LGTV), a ssRNA tick-borne flavivirus. TLR7 deficiency did not substantially alter the onset or incidence of LGTV-induced clinical disease; however, it did significantly affect virus levels in the CNS with a log(10) increase in virus titres in brain tissue from TLR7-deficient mice. This difference in virus load was also observed following intracranial inoculation, indicating a direct effect of TLR7 deficiency on regulating virus replication in the brain. LGTV-induced type I interferon responses in the CNS were not dependent on TLR7, being higher in TLR7-deficient mice compared with wild-type controls. In contrast, induction of pro-inflammatory cytokines including tumour necrosis factor, CCL3, CCL4 and CXCL13 were dependent on TLR7. Thus, although TLR7 is not essential in controlling LGTV pathogenesis, it is important in controlling virus infection in neurons in the CNS, possibly by regulating neuroinflammatory responses.

Effect of endurance training on the determinants of peak exercise oxygen consumption in elderly patients with stable compensated heart failure and preserved ejection fraction

OBJECTIVES

The purpose of this study was to evaluate the mechanisms for improved exercise capacity after endurance exercise training (ET) in elderly patients with heart failure and preserved ejection fraction (HFPEF).

BACKGROUND

Exercise intolerance, measured objectively by reduced peak oxygen consumption (VO(2)), is the primary chronic symptom in HFPEF and is improved by ET. However, the mechanisms are unknown.

METHODS

Forty stable, compensated HFPEF outpatients (mean age 69 ± 6 years) were examined at baseline and after 4 months of ET (n = 22) or attention control (n = 18). The VO(2) and its determinants were assessed during rest and peak upright cycle exercise.

RESULTS

After ET, peak VO(2) in those patients was higher than in control patients (16.3 ± 2.6 ml/kg/min vs. 13.1 ± 3.4 ml/kg/min; p = 0.002). That was associated with higher peak heart rate (139 ± 16 beats/min vs. 131 ± 20 beats/min; p = 0.03), but no difference in peak end-diastolic volume (77 ± 18 ml vs. 77 ± 17 ml; p = 0.51), stroke volume (48 ± 9 ml vs. 46 ± 9 ml; p = 0.83), or cardiac output (6.6 ± 1.3 l/min vs. 5.9 ± 1.5 l/min; p = 0.32). However, estimated peak arterial-venous oxygen difference was significantly higher in ET patients (19.8 ± 4.0 ml/dl vs. 17.3 ± 3.7 ml/dl; p = 0.03). The effect of ET on cardiac output was responsible for only 16% of the improvement in peak VO(2).

CONCLUSIONS

In elderly stable compensated HFPEF patients, peak arterial-venous oxygen difference was higher after ET and was the primary contributor to improved peak VO(2). This finding suggests that peripheral mechanisms (improved microvascular and/or skeletal muscle function) contribute to the improved exercise capacity after ET in HFPEF. (Prospective Aerobic Reconditioning Intervention Study [PARIS]; NCT01113840).

Pregnancy increases myometrial artery myogenic tone via NOS- or COX-independent mechanisms

Myogenic tone (MT) is a primary modulator of blood flow in the resistance vasculature of the brain, kidney, skeletal muscle, and perhaps in other high-flow organs such as the pregnant uterus. MT is known to be regulated by endothelium-derived factors, including products of the nitric oxide synthase (NOS) and/or the cyclooxygenase (COX) pathways. We asked whether pregnancy influenced MT in myometrial arteries (MA), and if so, whether such an effect could be attributed to alterations in NOS and/or COX. MA (200-300 μm internal diameter, 2-3 mm length) were isolated from 10 nonpregnant and 12 pregnant women undergoing elective hysterectomy or cesarean section, respectively. In the absence of NOS and/or COX inhibition, pregnancy was associated with increased MT in endothelium-intact MA compared with MA from nonpregnant women (P < 0.01). The increase in MT was not due to increased Ca(2+) entry via voltage-dependent channels since both groups of MA exhibited similar levels of constriction when exposed to 50 mM KCl. NOS inhibition (N(ω)-nitro-L-arginine methyl ester, L-NAME) or combined NOS/COX inhibition (L-NAME/indomethacin) increased MT in MA from pregnant women (P = 0.001 and P = 0.042, respectively) but was without effect in arteries from nonpregnant women. Indomethacin alone was without effect on MT in MA from either nonpregnant or pregnant women. We concluded that MT increases in MA during human pregnancy and that this effect was partially opposed by enhanced NOS activity.

Exercise training improves heart rate variability in older patients with heart failure: a randomized, controlled, single-blinded trial

Reduced heart rate variability (HRV) in older patients with heart failure (HF) is common and indicates poor prognosis. Exercise training (ET) has been shown to improve HRV in younger patients with HF. However, the effect of ET on HRV in older patients with HF is not known. Sixty-six participants (36% men), aged 69±5 years, with HF and both preserved ejection fraction (HFPEF) and reduced ejection fraction (HFREF), were randomly assigned to 16 weeks of supervised ET (ET group) vs attention-control (AC group). Two HRV parameters (the standard deviation of all normal RR intervals [SDNN] and the root mean square of successive differences in normal RR intervals [RMSSD]) were measured at baseline and after completion of the study. When compared with the AC group, the ET group had a significantly greater increase in both SDNN (15.46±5.02 ms in ET vs 2.37±2.13 ms in AC, P=.016) and RMSSD (17.53±7.83 ms in ET vs 1.69±2.63 ms in AC, P=.003). This increase was seen in both sexes and HF categories. ET improved HRV in older patients with both HFREF and HFPEF.

Relationship of flow-mediated arterial dilation and exercise capacity in older patients with heart failure and preserved ejection fraction

BACKGROUND

Older heart failure patients with preserved ejection fraction (HFpEF) have severely reduced exercise capacity and quality of life. Both brachial artery flow-mediated dilation (FMD) and peak exercise oxygen uptake (peak VO(2)) decline with normal aging. However, uncertainty remains regarding whether FMD is reduced beyond the degree associated with normal aging and if this contributes to reduced peak VO(2) in elderly HFpEF patients.

METHODS

Sixty-six older (70 ± 7 years) HFpEF patients and 47 healthy participants (16 young, 25 ± 3 years, and 31 older, 70 ± 6 years) were studied. Brachial artery diameter was measured before and after cuff occlusion using high-resolution ultrasound. Peak VO(2) was measured using expired gas analysis during upright cycle exercise.

RESULTS

Peak VO(2) was severely reduced in older HFpEF patients compared with age-matched healthy participants (15.2 ± 0.5 vs 19.6 ± 0.6 mL/kg/min, p < .0001), and in both groups, peak VO(2) was reduced compared with young healthy controls (28.5 ± 0.8 mL/kg/min; both p < .0001). Compared with healthy young participants, brachial artery FMD (healthy young, 6.13% ± 0.53%) was significantly reduced in healthy older participants (4.0 ± 0.38; p < .0002) and in HFpEF patients (3.64% ± 0.28%; p < .0001). However, FMD was not different in HFpEF patients compared with healthy older participants (p = .86). Although brachial artery FMD was modestly related to peak VO(2) in univariate analyses (r = .19; p = .048), it was not related in multivariate analyses that accounted for age, gender, and body size.

CONCLUSION

These results suggest that endothelial dysfunction may not be a significant independent contributor to the severely reduced exercise capacity in elderly HFpEF patients.

Simultaneous measurement of left and right ventricular volumes and ejection fraction during dobutamine stress cardiovascular magnetic resonance

OBJECTIVE

During cardiovascular stress, if right ventricular (RV) stroke volume exceeds left ventricular (LV) stroke volume, then a large volume of blood is displaced into the pulmonary circulation that may precipitate pulmonary edema. We sought to determine the metrics by which cardiovascular magnetic resonance (CMR) could measure simultaneous displacement of RV and LV stroke volumes during dobutamine stress.

METHODS

Thirteen healthy subjects (5 women) aged 53 ± 10 years without medical conditions and taking no medications underwent 2 CMR examinations at 1.5 T separated by 4 to 8 weeks in which RV and LV stroke volumes were determined during intravenous dobutamine and atropine infused to achieve 80% of the maximum predicted heart rate response for age.

RESULTS

The RV and LV stroke volumes were highly correlated at each level of stress (rest: r = 0.98, P = 0.007; low stress: r = 0.87, P = 0.001; and peak stress: r = 0.88, P = 0.001), and the mean difference in SV at each level of stress (rest, low stress, and peak stress was 0 to 2 mL on examinations 1 and 2.

CONCLUSIONS

Simultaneous change in right and left ventricular stroke volumes can be assessed in a highly reproducible manner throughout the course of dobutamine CMR stress administered to achieve 80% of maximum predicted heart rate response for age. This technology may help identify discrepancies in RV and LV stroke volumes during cardiovascular stress that are associated with the development of pulmonary edema.

Determinants of exercise intolerance in elderly heart failure patients with preserved ejection fraction

OBJECTIVES

The purpose of this study was to determine the mechanisms responsible for reduced aerobic capacity (peak Vo(2)) in patients with heart failure with preserved ejection fraction (HFPEF).

BACKGROUND

HFPEF is the predominant form of heart failure in older persons. Exercise intolerance is the primary symptom among patients with HFPEF and a major determinant of reduced quality of life. In contrast to patients with heart failure and reduced ejection fraction, the mechanism of exercise intolerance in HFPEF is less well understood.

METHODS

Left ventricular volumes (2-dimensional echocardiography), cardiac output, Vo(2), and calculated arterial-venous oxygen content difference (A-Vo(2) Diff) were measured at rest and during incremental, exhaustive upright cycle exercise in 48 HFPEF patients (age 69 ± 6 years) and 25 healthy age-matched controls.

RESULTS

In HFPEF patients compared with healthy controls, Vo(2) was reduced at peak exercise (14.3 ± 0.5 ml·kg·min(-1) vs. 20.4 ± 0.6 ml·kg·min(-1); p < 0.0001) and was associated with a reduced peak cardiac output (6.3 ± 0.2 l·min(-1) vs. 7.6 ± 0.2 l·min(-1); p < 0.0001) and A-Vo(2) Diff (17 ± 0.4 ml·dl(-1) vs. 19 ± 0.4 ml·dl(-1), p < 0.0007). The strongest independent predictor of peak Vo(2) was the change in A-Vo(2) Diff from rest to peak exercise (A-Vo(2) Diff reserve) for both HFPEF patients (partial correlate, 0.58; standardized β coefficient, 0.66; p = 0.0002) and healthy controls (partial correlate, 0.61; standardized β coefficient, 0.41; p = 0.005).

CONCLUSIONS

Both reduced cardiac output and A-Vo(2) Diff contribute significantly to the severe exercise intolerance in elderly HFPEF patients. The finding that A-Vo(2) Diff reserve is an independent predictor of peak Vo(2) suggests that peripheral, noncardiac factors are important contributors to exercise intolerance in these patients.

Intraperitoneal fat is associated with thickening of the thoracic aorta in individuals at high risk for cardiovascular events

Increased intraperitoneal (IP) fat is associated with increased cardiovascular (CV) risk, but mechanisms for this increase in risk are not completely established. We performed this study to assess whether IP fat is associated with ascending aortic wall thickness (AOWT), a risk factor for CV events. Four hundred and forty-one consecutive participants, aged 55-85 years, with risk factors for CV events underwent magnetic resonance measures of AOWT and abdominal fat (subcutaneous (SC) fat + IP fat). For the ascending aorta, mean wall thickness of the 4th quartile of the IP fat was higher relative to the 1st quartile (P ≤ 0.001). This difference persisted after accounting for SC fat (P ≤ 0.001), as well as age, gender, height, weight, smoking, diabetes, hypertension, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), and C-reactive protein (CRP) (P < 0.03). Elevated IP fat volume is associated with an increase in ascending AOWT, a condition that promotes CV events in middle aged and elderly adults.