Effects of exercise in diabetes mellitus in adults Parisa akhavan MD

INTRODUCTION Worldwide, one out of every five adults is physically inactive. Physical inactivity is particularly prevalent in more developed countries and among women, older persons, and those with lower incomes. In addition to lack of regular exercise, the percentage of time spent in sedentary behaviors (watching television or in front of a computer) is increasing. Prev Med 2011,53:24

Benefits of exercise Strong evidence  Lower risk of early death coronary heart disease stroke high blood pressure adverse blood lipid profile type 2 diabetes metabolic syndrome colon cancer breast cancer

Prevention of weight gain Weight loss, particularly when combined with reduced calorie intake Improved cardiorespiratory and muscular fitness Prevention of falls Reduced depression 2008 Physical Activity Guidelines for American

Regular exercise may prevent type 2 diabetes in high- risk individuals. Diabetes care 2007;30:744 Exercise is an important part of the diabetes management plan.

A meta-analysis of 10 prospective cohort studies of physical activity and type 2 diabetes reported a lower risk of developing diabetes with regular moderate physical activity, including brisk walking, compared with being sedentary (RR 0.69, 95% CI ). The benefits persisted after adjustment for BMI, suggesting an independent effect of exercise on glucose metabolism. Diabetes care 2007;30:744

Cardiovascular disease and mortality In several randomized trials, exercise has been shown to improve cardiovascular risk factors (dyslipidemia, blood pressure, and body composition) in patients with type 2 diabetes Diabetes care 2011;34:1228

However, no clinical trials to date have demonstrated a reduction in major cardiovascular endpoints or mortality. In prospective cohort studies, exercise was associated with improvement in cardiovascular outcomes and a reduction in cardiovascular and overall mortality in type 2 diabetic patients.

Among the 5125 women who reported having type 2 diabetes in the Nurses' Health Study, the women who spent at least four hours per week performing moderate (including walking) or vigorous exercise had a 40 percent lower risk of developing cardiovascular disease than those who did not. This improvement in risk remained after adjustment for smoking, body mass index, and other cardiovascular risk factors Ann intern med 2001:134:96

In meta-analyses of prospective cohort studies examining the impact of exercise Kodama S et al. Diabetes Care 2013;36:

RESULTS Qualitatively, the highest PA category had a lower RR [95% CI] for ACM (0.61 [0.52–0.70]) and CVD (0.71 [0.60–0.84]) than the lowest PA category.

Glycemic control Exercise improves glycemic control in patients with type 2 diabetes, as illustrated by the findings of several meta-analyses of trials. Exercise training reduces A1C values by approximately 0.5 to 0.7 percentage points compared with control participants.

In a trial of 251 adults with type 2 diabetes randomly assigned to resistance, aerobic, combined exercise, or control groups All three exercise groups were associated with improvements in A1C compared with controls (absolute change in A1C to percentage points) Ann Intern Med 2007;147:357

The combined exercise program was associated with the greatest reduction in A1C (approximately one percentage point compared with controls). However, the combined program was also associated with a longer duration of exercise than the other groups, which may account for the greater improvement in glycemic control.

The search yielded nine relevant trials that evaluated 372 people with type 2 diabetes.

Results: progressive resistance exercise led to small and statistically significant absolute reductions in HbA1c of 0.3% (SMD –0.25, 95% CI –0.47to –0.03). When compared to aerobic exercise there were no significant differences in HbA1c.

Type 2 diabetic patients (n = 40) were randomly assigned to aerobic training or resistance training. Before and after 4 months of intervention,metabolic phenotypes Diabetes care 35:676682,2012

RESULTS HbA1c was similarly reduced in both groups (- 0.40% [95% CI to -0.18] vs % [-0.59 to -0.10], respectively).(P = 0.759). HDL cholesterol,triglycerides, and blood pressure also improved significantly, to a similar extent,in both groups. Insulin sensitivity, as assessed by the Insulin sensitivity and lean limb mass were similarly increased. b-Cell function showed no significant changes.

The American Diabetes Association, and The American College of Sports Medicine recommend:

Advise people with diabetes to perform  at least 150 minutes per week  moderate-intensity aerobic activity (50-70% of maximum heart rate) The activity should be distributed over  at least three days each week  no more than two consecutive days of inactivity. Diabetes Care Volume 37, Supplement 1, January 2014

Resistance training Resistance training can be done with weights, machines, or exercise bands. A repetition is a single completed back and forth motion of a resistance exercise. A set is a number of repetitions done without resting.

In the absence of contraindications, patients with type 2 diabetes should be encouraged to do  at least two weekly sessions of resistance exercise with each session consisting of  at least one set ( including 8 to 12 repetitions )of five or more different resistance exercises involving the large muscle groups.

Stretching exercise The guidelines suggest that adults also do muscle strengthening activities that involve all major muscle groups 2 days/ week.

Pre-exercise Evaluation of the Diabetic Patient

Prior guidelines suggested that before recommending a program of physical activity, the provider should assess patients with multiple cardiovascular risk factors for CAD. The area of screening asymptomatic diabetic patients for CAD remains unclear

CAD A recent ADA consensus statement on this issue concluded that routine screening is not recommended Providers should use clinical judgment in this area. Certainly, high-risk patients should be encouraged to start with short periods of low-intensity exercise and increase the intensity and duration slowly. J Diabetes 2010;2:36–40

Exercise in the Presence of Specific Long-Term Complications of Diabetes

PDR In the presence PDR or severe (NPDR), vigorous aerobic or resistance exercise may be contraindicated because of the risk of triggering vitreous hemorrhage or retinal detachment.

peripheral neuropathy Prior recommendations have advised non– weight-bearing exercise for patients with severe peripheral neuropathy. However, studies have shown that moderate- intensity walking may not lead to increased risk of foot ulcers or reulceration in those with peripheral neuropathy. Diabetes Care 2006;29;1294–1299

All individuals with peripheral neuropathy should wear proper footwear and examine their feet daily to detect lesions early. Anyone with a foot injury or open sore should be restricted to non–weight-bearing activities. Diabetes Care 2006;29;1294–1299

Albuminuria Physical activity can acutely increase urinary protein excretion. There is no evidence that vigorous exercise increases the rate of progression of diabetic kidney disease There is likely no need for any specific exercise restrictions for people with diabetic kidney disease.

Autonomic neuropathy Autonomic neuropathy can increase the risk of exercise induced injury or adverse event through decreased cardiac responsiveness to exercise, postural hypotension, impaired thermoregulation, impaired night vision due to impaired papillary reaction Unpredictable carbohydrate delivery from gastroparesis predisposing to hypoglycemia.

Autonomic neuropathy is also strongly associated with CVD in people with diabetes. People with diabetic autonomic neuropathy should undergo cardiac investigation before beginning physical activity more intense than that to which they are accustomed. (ACCORD) trial. Diabetes Care 2010;33: 1578–1584

Exercise in the Presence of Nonoptimal Glycemic Control Vigorous exercise should be avoided in the presence of ketosis. However, it is not necessary to defer exercise based on mild hyperglycemia (<250 [13.9 mmol/L]), as long as the patient feels well and there is no ketonemia or ketonuria.

For patients who take insulin (particularly those with type 1 diabetes), adjustments of their insulin regimen before, during, and after exercise are often empiric and aided by the results of SMBG. For patients who take insulin or insulin secretagogues, blood glucose should be measured before, during, and after exercise so that the changes in blood glucose can be documented and then predicted for subsequent exercise sessions.

If the pre-exercise blood glucose is <100 mg/dL insulin- or insulin secretagogue-treated patients:  should ingest extra food, in the form of 15 to 30 grams of quickly absorbed carbohydrate such as glucose tablets, hard candies, or juice  which should be taken 15 to 30 minutes before exercise and approximately every 30 minutes during exercise, based on repeat blood glucose testing during the exercise.

Such patients are also at risk of late hypoglycemia four to eight hours after the termination of exercise due to replenishment of depleted glycogen stores

Hypoglycemia is uncommon in patients with type 2 diabetes not treated with insulin or insulin secretagogues and, therefore, ingestion of extra carbohydrates is not typically required.

Long-term compliance in a 10-year study of 255 diabetic patients enrolled in a diabetes education program that emphasized exercise, compliance fell from 80 percent at six weeks to less than 50 percent at three months to less than 20 percent at one year Diabetes care 1992;15:1800

The exercises should be enjoyable and simple to carry out to encourage a long-term commitment. It may be best to vary the exercises you do each week (such as swim on three of the days and walk on three of the days) to decrease repetitive strain to your muscles and other tissues.

THANK YOU