Judith G. Regensteiner

Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes

BACKGROUND Weight loss is recommended for overweight or obese patients with type 2 diabetes on the basis of short-term studies, but long-term effects on cardiovascular disease remain unknown. We examined whether an intensive lifestyle intervention for weight loss would decrease cardiovascular morbidity and mortality among such patients. METHODS In 16 study centers in the United States, we randomly assigned 5145 overweight or obese patients with type 2 diabetes to participate in an intensive lifestyle intervention that promoted weight loss through decreased caloric intake and increased physical activity (intervention group) or to receive diabetes support and education (control group). The primary outcome was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for angina during a maximum follow-up of 13.5 years. RESULTS The trial was stopped early on the basis of a futility analysis when the median follow-up was 9.6 years. Weight loss was greater in the intervention group than in the control group throughout the study (8.6% vs. 0.7% at 1 year; 6.0% vs. 3.5% at study end). The intensive lifestyle intervention also produced greater reductions in glycated hemoglobin and greater initial improvements in fitness and all cardiovascular risk factors, except for low-density-lipoprotein cholesterol levels. The primary outcome occurred in 403 patients in the intervention group and in 418 in the control group (1.83 and 1.92 events per 100 person-years, respectively; hazard ratio in the intervention group, 0.95; 95% confidence interval, 0.83 to 1.09; P=0.51). CONCLUSIONS An intensive lifestyle intervention focusing on weight loss did not reduce the rate of cardiovascular events in overweight or obese adults with type 2 diabetes. (Funded by the National Institutes of Health and others; Look AHEAD ClinicalTrials.gov number, NCT00017953.).

Exercise and Type 2 Diabetes The American College of Sports Medicine and the American Diabetes Association: joint position statement

Although physical activity (PA) is a key element in the prevention and management of type 2 diabetes, many with this chronic disease do not become or remain regularly active. High-quality studies establishing the importance of exercise and fitness in diabetes were lacking until recently, but it is now well established that participation in regular PA improves blood glucose control and can prevent or delay type 2 diabetes, along with positively affecting lipids, blood pressure, cardiovascular events, mortality, and quality of life. Structured interventions combining PA and modest weight loss have been shown to lower type 2 diabetes risk by up to 58% in high-risk populations. Most benefits of PA on diabetes management are realized through acute and chronic improvements in insulin action, accomplished with both aerobic and resistance training. The benefits of physical training are discussed, along with recommendations for varying activities, PA-associated blood glucose management, diabetes prevention, gestational diabetes mellitus, and safe and effective practices for PA with diabetes-related complications.

Diabetes and cancer: a consensus report.

Epidemiologic evidence suggests that cancer incidence is associated with diabetes as well as certain diabetes risk factors and diabetes treatments. This consensus statement of experts assembled jointly by the American Diabetes Association and the American Cancer Society reviews the state of science concerning 1) the association between diabetes and cancer incidence or prognosis, 2) risk factors common to both diabetes and cancer, 3) possible biologic links between diabetes and cancer risk, and 4) whether diabetes treatments influence risk of cancer or cancer prognosis. In addition, key unanswered questions for future research are posed.

Benefit of exercise conditioning for patients with peripheral arterial disease.

Patients with atherosclerotic peripheral arterial disease (PAD) of the lower extremities have impaired walking ability due to exercise-induced muscle ischemia and the resultant pain of intermittent claudication. To evaluate the benefit of exercise training as a treatment for patients with PAD, as well as possible mechanisms associated with improvement, we randomly assigned 19 men with disabling claudication to treated and control groups. Treatment consisted of supervised treadmill walking (1 hr/day, 3 days/wk, for 12 weeks) with progressive increases in speed and grade as tolerated. Graded treadmill testing was performed to maximal toleration of claudication pain on entry and after 12 weeks of training to define changes in peak exercise performance. After 12 weeks, treated subjects had increased their peak walking time 123%, peak oxygen consumption 30%, and pain-free walking time 165% (all p less than 0.05). Control subjects had no change in peak oxygen consumption, but after 12 weeks, peak walking time increased 20% (p less than 0.05). In treated subjects, maximal calf blood flow (measured by a plethysmograph) increased 38 +/- 45% (p less than 0.05), but the change in flow was not correlated to the increase in peak walking time. Elevated plasma concentrations of acylcarnitines have been associated with the functional impairment of PAD and may reflect the metabolic state of ischemic skeletal muscle. In treated subjects, a 26% decrease in resting plasma short-chain acylcarnitine concentration was correlated with improvement in peak walking time (r = -0.78, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise training improves functional status in patients with peripheral arterial disease

PURPOSE In patients with intermittent claudication (IC) a structured walking exercise program improves exercise performance. However, few studies have evaluated the effects of exercise training on functional status during daily activities. We hypothesized that a supervised exercise training program would improve functional status in patients with IC, with 24 weeks of training more beneficial than 12 weeks. A secondary aim was to evaluate the effects of strength training and combinations of strength and treadmill training on functional status. METHODS Twenty-nine men with disabling IC were randomized to 12 weeks of either supervised treadmill training (3 hr/wk at a work intensity sufficient to produce claudication), strength training (3 hr/wk of resistive training of six muscle groups of each leg), or to a nonexercising control group. Functional status was assessed by questionnaires characterizing walking ability (Walking Impairment Questionnaire, WIQ), habitual physical activity level (Physical Activity Recall, PAR), and physical, social, and role functioning, well-being, and overall health (Medical Outcomes Study SF-20, MOS). Patients alos had their activity levels monitored with an activity monitor (Vitalog). RESULTS After 12 weeks of treadmill training PAR scores increased by 48 metabolic equivalent hr/wk, the MOS physical functioning score by 24 percentage points, and the number of bouts of walking activity measured by the Vitalog by 4.5 bouts/hr (all p < 0.05). No changes were seen in WIQ scores. After 12 additional weeks of treadmill training improvements initially observed in the PAR, MOS, and Vitalog scores were maintained, and in addition the ability to walk distances (WIQ) improved by 31 percentage points, and the IC severity score had improved by 29 percentage points (both p < 0.05). After 12 weeks of strength training patients improved their WIQ walking speed, stair climbing scores, and MOS well-being scores with no other changes in functional status. Subjects in the control group did not improve functional status by any measure. Twelve weeks of treadmill training after the strength training program maintained WIQ walking speed scores, and activity level defined by Vitalog improved. Twelve weeks of combined treadmill and strength training after the control period had no effect on functional status. CONCLUSIONS A supervised treadmill training program improved functional status during daily activities, with 24 weeks more effective than 12. In addition, treadmill training alone was more effective in improving functional status in patients with IC than strength training or combinations of the training modalities.

Exercise and Type 2 Diabetes: The American College of Sports Medicine and the American Diabetes Association: Joint Position Statement Executive Summary

Although physical activity (PA) is a key element in the prevention and management of type 2 diabetes, many with this chronic disease do not become or remain regularly active. High-quality studies establishing the importance of exercise and fitness in diabetes were lacking until recently, but it is now well established that participation in regular PA improves blood glucose control and can prevent or delay type 2 diabetes, along with positively impacting lipids, blood pressure, cardiovascular events, mortality, and quality of life. Structured interventions combining PA and modest weight loss have been shown to lower risk of type 2 diabetes by up to 58% in high-risk populations. Most benefits of PA on diabetes management are realized through acute and chronic improvements in insulin action, accomplished with both aerobic and resistance training. …

Superiority of treadmill walking exercise versus strength training for patients with peripheral arterial disease. Implications for the mechanism of the training response.

BACKGROUND In patients with intermittent claudication, a supervised walking exercise program increases peak exercise performance and community-based functional status. Patients with peripheral arterial disease also have muscle weakness in the affected extremity that may contribute to the walking impairment. However, the potential benefits of training modalities other than walking exercise, such as strength training, have not been critically evaluated in this patient population. The present study tested the hypothesis that a strength training program would be as effective as treadmill walking exercise and that combinations of strengthening and walking exercise would be more effective than either alone in improving exercise performance. METHODS AND RESULTS Twenty-nine patients with disabling claudication were randomized to 12 weeks of supervised walking exercise on a treadmill (3 h/wk at a work intensity sufficient to produce claudication), strength training (3 h/wk of resistive training of five muscle groups of each leg), or a nonexercising control group. Graded treadmill testing was performed to maximally tolerated claudication pain to define changes in peak exercise performance. After 12 weeks, patients in the treadmill training program had a 74 +/- 58% increase in peak walking time as well as improvements in peak oxygen consumption (VO2) and the onset of claudication pain. Patients in the strength-trained group had a 36 +/- 48% increase in peak walking time but no change in peak VO2 or claudication onset time. Control subjects had no changes in any of these measures over the 12-week period. After the first 12 weeks, patients in the initial walking exercise group continued for 12 more weeks of supervised treadmill training. This resulted in an additional 49 +/- 53% increase in peak walking time (total of 128 +/- 99% increase over the 24 weeks). After the initial 12 weeks, patients in the strength-trained group began 12 weeks of supervised treadmill training, and patients in the control group participated in a 12-week combined program of strengthening and treadmill walking exercise. The combined strength and treadmill training program and treadmill training after 12 weeks of strength training resulted in increases in peak exercise performance similar to those observed with 12 weeks of treadmill training alone. CONCLUSIONS A supervised treadmill walking exercise program is an effective means to improve exercise performance in patients with intermittent claudication, with continued improvement over 24 weeks of training. In contrast, 12 weeks of strength training was less effective than 12 weeks of supervised treadmill walking exercise. Finally, strength training, whether sequential or concomitant, did not augment the response to a walking exercise program.

Exercise and type 2 diabetes: American College of Sports Medicine and the American Diabetes Association: joint position statement. Exercise and type 2 diabetes.

Although physical activity (PA) is a key element in the prevention and management of type 2 diabetes mellitus (T2DM), many with this chronic disease do not become or remain regularly active. High-quality studies establishing the importance of exercise and fitness in diabetes were lacking until recently, but it is now well established that participation in regular PA improves blood glucose control and can prevent or delay T2DM, along with positively affecting lipids, blood pressure, cardiovascular events, mortality, and quality of life. Structured interventions combining PA and modest weight loss have been shown to lower T2DM risk by up to 58% in high-risk populations. Most benefits of PA on diabetes management are realized through acute and chronic improvements in insulin action, accomplished with both aerobic and resistance training. The benefits of physical training are discussed, along with recommendations for varying activities, PA-associated blood glucose management, diabetes prevention, gestational diabetes, and safe and effective practices for PA with diabetes-related complications.

Clinical Trials for Claudication Assessment of Exercise Performance, Functional Status, and Clinical End Points

Peripheral arterial disease (PAD) affects a large proportion of the general population, with an age-adjusted prevalence of approximately 12% and a prevalence of intermittent claudication of 3% to 7%.1 2 In symptomatic persons, the limited lower extremity arterial supply cannot meet the dynamic metabolic demand of the muscles during ambulatory activities, resulting in the symptom of claudication. Claudication is associated with a severe limitation in walking ability,3 which may adversely affect social, leisure, and occupational activities in many patients.4 The treatment of all patients with PAD is initially directed at cardiovascular risk factor modification, since these individuals have a high future risk of cardiovascular mortality.5 Severely affected patients who have ischemic rest pain or tissue loss are candidates for interventional therapy (bypass surgery or angioplasty) to maintain limb viability.6 7 However, since the majority of patients with claudication are not at short-term risk of limb loss, the primary therapeutic goal is to improve exercise performance and community-based functional status. The past decade has witnessed a marked increase in the evaluation and utilization of therapies to treat patients with claudication.8 Percutaneous transluminal angioplasty is considered an appropriate intervention for patients with “earlier stages of symptomatic disability” due to claudication,9 and the American Heart Association has recently recommended that invasive interventions are appropriate for patients with incapacitating claudication.6 In addition, there is increased interest in medical therapies for claudication. Exercise training elicits well-established and clinically important changes in treadmill exercise performance and community-based walking ability.3 10 11 Recent pharmacological advances have led to a greater use of drugs to treat claudication, with new agents in clinical development. Examples include drugs that alter blood rheology12 and drugs that improve ischemic skeletal muscle metabolism.13 A clinical classification to evaluate therapies for PAD has …

2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Jonathan L. Halperin, MD, FACC, FAHA, Chair Glenn N. Levine, MD, FACC, FAHA, Chair-Elect Sana M. Al-Khatib, MD, MHS, FACC, FAHA Kim K. Birtcher, PharmD, MS, AACC Biykem Bozkurt, MD, PhD, FACC, FAHA Ralph G. Brindis, MD, MPH, MACC Joaquin E. Cigarroa, MD, FACC Lesley H. Curtis, PhD, FAHA