Healthy Aging

Diabetes & Aging
by Elysia Davis

There are many inevitable changes that one’s body undergoes due to the natural process of aging. These changes can include fluctuations in weight, energy levels, strength, and many more. Some of these changes can lead to the increased risk for various chronic conditions by reducing an individual’s ability to cope to stressors in their body and environment. There are also a number of age associated changes that are modifiable and preventable through lifestyle choices. One of these modifiable age related changes is type 2 diabetes. Although it is termed ‘adult-onset diabetes’ it is not an uncontrollable side effect of aging. There is a great deal of information related to the causality, prevalence, and treatment for this disease, however, it is still not well understood by many, and continues to be a growing epidemic. Physical activity can play a major role in maintaining a healthy life with diabetes, can increase one’s healthy life expectancy, and decrease the period of morbidity faced by diabetics (Meneilly, 2001). The purpose of this paper is to (a) gain insight on the current literature supporting physical activity as an intervention for individuals with type two diabetes, (b) identify the positive effects it can have on the quality of life of diabetics, and (c) outline tools to implement physical activity in the aging population with diabetes.

Background Information

In order to discuss this topic, a comprehensive understanding of the disease is helpful. There are two common types of diabetes: type 1 and type 2. It is a chronic condition, and according to the World Health Organization, in 2000, at lease 171 million people around the world suffered from diabetes, with type two being more prevalent in the developed countries (Wild et al., 2004). It is also estimated that this number is likely to double by 2030 due to population growth and aging. It is for these reasons that understanding this disease is of the utmost importance. Type 1 diabetes is a disease in which the body does not produce insulin. The mechanism attributed to this insulin deficiency is an autoimmune destruction of the cells in the pancreas that produce insulin ( Gambert & Pinkstaff, 2006). In North America, only approximately 5-10% of diabetics are type 1 which is incurable and managed through insulin injections ( Gambert & Pinkstaff, 2006). There are many adverse side effects of this disease, among them are blindness, heart disease, kidney problems, nerve damage, impotence, and a reduced healing ability (Canadian Diabetes Association). What most people are unaware of is that type 2 diabetes has the same potential side effects as type 1, however is preventable and can be managed without the use of medications. Insulin is normally produced after eating a meal, and aids in the removal of sugar from the blood stream to either be stored or used for energy. Type 2 diabetes is caused by the insulin resistance of tissues in the body such as muscle, liver and fat, as well as a relative decrease in insulin production in the pancreas (Campbell & Carlson, 1993). Although the exact cause of this disease is unknown, it is often associated with obesity, especially centralize fat accumulation, physical inactivity, increased age as well as a small genetic component. Approximately 55% of people diagnosed with type 2 diabetes are obese (Eberhart et al., 2004), however, even those with a healthy weight, but with fat centrally located are at a higher risk. This disease has increased exponentially in the past few decades due to the prevalence of high sugar and high fat processed foods that are cheap and readily available (Meneilly, 2001). The population that has most notably increased in the occurrence of type 2 diabetes is children due to the obesity epidemic.

So why is type 2 diabetes more prevalent in the aging population? Insulin production decreases due to age-related changes in the insulin producing cells of the pancreas. Also, the accumulation of fat and loss of lean tissue, which are also natural and expected changes due to aging, increases the insulin resistance in tissues (Meneilly, 2001). Glucose tolerance also decreases with age, leading to hyper-glycemia, or high blood sugar levels (Meneilly, 2001), which is a precursor to diabetes. All of these physiological changes do make the body more susceptible to type 2 diabetes, but this does not mean that diabetes is inevitable. One should be aware of the changes their body undergoes as part of aging, and modify lifestyles accordingly. Physical activity can be one of those modifications implemented in order to enhance one’s quality of life.

Physical Activity and Diabetes

It seems as if diet alone would be a suitable answer to preventing diabetes, and although it is an integral component, physical activity also plays an essential role. The answer to why is not so simple and has been studied by many in search of this relationship. It has been shown that reducing body weight, especially through fat loss in the mid section, can increase insulin sensitivity (Simonson, et al., 1984). An increase in insulin sensitivity would help individuals at risk of developing diabetes as well as those already trying to manage the disease. Jonker et al (2006) created a multi-state life table and analyzed groups based hazard ratios for various physical activity levels, which were corrected for age and gender. Among their results they found a decreased mortality in diabetics who participated in physical activity. Moderately and highly active people also had a longer total life expectancy and lived more years free of diabetes than their sedentary counterparts. From this study they also found that higher levels of physical activity were associated with lower rates of incidence of diabetes. Hu et al (2001) had similar findings; that increasing physical activity is associated with a significant reduction in risk for diabetes, whereas a sedentary lifestyle (which was indicated by prolonged TV watching) is directly related to an increased risk. Their findings suggested the importance of reducing sedentary behaviour in the prevention of type 2 diabetes.

In a study looking at the effects of exercise on insulin sensitivity, Borghouts and Keizer (2000) found that up to two hours after exercise, glucose uptake is in part elevated due to insulin independent mechanisms. This finding is relevant for both individuals with type one and type two diabetes. The side effects of diabetes are due predominantly to the reduced glucose uptake and higher blood glucose levels in the body, therefore finding ways to improve glucose uptake independent of insulin is essential for non-pharmacological interventions. A single bout of exercise can increase insulin sensitivity for at least 16 hours post exercise in healthy as well as diabetic subjects (Menielly, 2001). This study determined that physical training can be considered to play an important, if not essential role in the treatment and prevention of insulin insensitivity.

Chio and Shi (2001) used data from a National population health survey to determine the potential risk factors for diabetes. They examined factors including age, sex, body mass index, energy expenditure, smoking, drinking, income, marital status, education and rural or urban residence. From their results, they found that 10-14% of individuals who reported having diabetes were in the 75+ group. Their results also showed that the odds of diabetes increases by 9% each year of increase in age. Although they found a linear dose response association between an increase in physical activity and a decrease in diabetes, they found it hard to determine epidemiologically whether or not it is the reduction in BMI caused by physical activity, or the increase in energy expenditure itself that is beneficial to the reduction in prevalence and severity of type 2 diabetes. In either case of causality, their results show the benefits of physical activity for diabetics.

It is clear from the research presented that physical activity can play a major role in the control and suppression of type 2 diabetes. The difficult part is knowing how to implement some of these strategies into activities of daily living in order to benefit from physical activity as a diabetic, or someone who may be at risk. There is a great deal of information available on-line, from physicians and other health practitioners, and it is always advisable to consult your doctor before adhering to a new exercise plan, changing medication or altering your diet. The following provides a few guidelines for older adults with or without diabetes looking to implement a physical activity component to their daily routine.

Implementing Physical Activity

Physical activity includes all activities of daily living such as running errands, doing house or yard work, as well as additional exercise programs. According to the American College of Sports Medicine, a balanced exercise routine should include an aerobic and resistance training element. Resistance training is any form of exercise that requires your muscles to contract against a force and can include the use of exercise equipment, pushing against water in a pool, or lifting weights. Including this type of training 2-3 times per week will not only build strength and allow you to complete activities of daily living with more ease, but with also increase resting metabolic rate (Tudor-Locke, 2001). This reduces blood sugar levels and can increase the loss of excess fat. Table 1 in Appendix A lists examples of aerobic exercises suitable for older adults with type 2 diabetes as provided by the Canadian Diabetes Association. According to their research, brisk walking was found to be an affective exercise intervention in terms of adoption and adherence. Table 2 outlines some general guidelines to follow when starting a resistance training program, again given by the Canadian Diabetes Association. When implementing an exercise program it is important to build up the activity level gradually. If previously sedentary, it is good to start with as little as 5-10 minutes per day. It is also beneficial to break up activity into multiple bouts throughout the day.

ALCOA, which stands for Active Living Coalition for Older Adults, provides research updates on issues related to aging. In the first issue of ALCOA Research Update, Dr. Catrine Tudor-Locke, PhD, provides some helpful tips for implementing a walking program. Her list includes: investing in a good pair of comfortable walking shoes, lengthening walks before trying to increase pace, work towards walking for thirty minutes each day in addition to regular activities, to vary the location of your walks to keep it interesting, and to share this health benefit with a friend.

If walking isn’t right for you, there are many other alternative forms of physical activity. Aquatic programs provide a low impact aerobic and resistance training workout that will increase fitness and energy levels. These classes are a good option because they provide a social atmosphere, are fun, instructed by a professional and allow for modifications to accommodate any fitness level. Another option is a fitness program like yoga. There has been multiple research projects conducted examining the benefits of participating in yoga to reduce the symptoms of diabetes (Monroe et al., 1992, Jain et al., 1993). The lifestyle alone is conducive to losing weight, maintaining a positive outlook on life and increasing overall well being. In addition to the exercise component, some yoga poses are thought to improve the function of certain organs including the pancreas, although literature to support this is scarce.

Conclusion

We belong to a range of cohorts that are far more educated that at any other time in history. We have access to a wealth of information at the click of the mouse and it is our responsibility to stay informed as to how we can improve our health and well being. Diabetes is a wide spread, powerful and potentially fatal condition. Modern day technology, advancements in research and the pursuit of longevity have provided many tools in order to maintain a healthy life with diabetes, reduce the prevalence and severity of symptoms, and hopefully decrease the occurrence of the disease altogether. This paper has addressed one of those mechanisms which is physical activity. It has been shows through scientific research that participating in physical activity is a beneficial intervention for type 2 diabetes and that it can be easily added to daily living.

References

Borghouts, L. B. & Keizer, H.A. (2000). Exercise and insulin sensitivity: a review. International Journal of SportsMedicine, 21, 1–12

Choi, B. C. K. & Shi, F. (2001). Risk factors for diabetes mellitus by age and sex: results of the National Population Health Survey. Diabetologia, 44, 1221–1231.

Eberhart, M.S., Ogden, C., Engelgau, M., et al. (2004). Prevalence of Overweight and Obesity Among Adults with Diagnosed Diabetes. Morbidity and Mortality Weekly Report, 53 (45), 1066-1068.

Gambert, S. & Pinkstaff, S. (2006). Emerging Epidemic: Diabetes in Older Adults: Demography, Economic Impact, and Pathophysiology. Diabetes Spectrum, 19, 221-228

Hu, F.B., Leitzmann, M.F., Stampfer, M.J., et al., (2001). Physical activity and television watching in relation to risk for type 2 diabetes mellitus in men. Archives of Internal Medicine, 161, 1542–1548

Jain, S.C., Uppal, A ., Bhatnagar, S.O., &Talukdar, B. (1993). A Study of response pattern of non-insulin dependent diabetics to yoga therapy. Diabetes Research and Clinical Practice, 19, 69-74.

Jonker, J. T., De Laet, C., Peeters, A., et al. (2006). Physical Activity and Life Expectancy With and Without Diabetes. Diabetes Care, 29, 38–43

Meltzer, S., Leiter, L., Daneman, D., et al. (1998) Clinical practice guidelines for the management of diabetes in Canada. Canadian Medical Association Journal, 159(8), S1-S29.

Meneilly, G.S. (2001). Pathophysiology of diabetes in the elderly. Diabetes in Old Age. 2nd ed. Sinclair AJ, Finucane P, Eds. Chichester, U.K., John Wiley & Sons, 2001, p. 155–16

Monro, R., et al., (1992). Yoga Therapy for NIDDM: A controlled trial. Complementary Medical Research, (6):1, 66-68

Simonson, D. C., Ferrannini, E., Benlacqua, S., et al., (1984). Mechanisms of improvement in glucose metabolism after chronic glyburide therapy. Diabetes, 33, 838-845.

Tudor-Locke, C. (2001). Type 2 diabetes and physical activity for older adults. ALCOA Research Update, 1, 1-4.

Wild S., Roglic, G., Green, A., Sicree, R. & King, H. (2004). Global prevalence of diabetes: estimates for the year 2000 and projections for 2030. Diabetes Care, 27, 1047-1053.

 

Appendix A

Table 1. Aerobic Exercise: Canadian Diabetes Association, Clinical Practice Guidelines

Definition	Intensity	Examples
Rhythmic, repeated and continuous movements of the same large muscle groups for at least 10 minutes at a time	Moderate effort: 50-70% of person’s maximum heart rate	Brisk walking Biking Continuous swimming Dancing Water aerobics Raking leaves
	Vigorous effort: > 70% of a person’s maximum heart rate	Brisk walking up an incline Jogging Aerobics Hockey Basketball Fast swimming Fast dancing

Table 2. Resistance Exercise: Canadian Diabetes Association, Clinical Practice Guidelines

Definition	Examples
Activities that use muscular strength to move a weight or work against a resistance load	weight lifting exercise with weight machines Start with 1 set of 10-15 repetitions, progress to 2 sets of 10-15 repetitions, then progress to 3 sets of 10-15 repetitions, 3 times/week