| Quick Search | |
 |
|
|---|---|
Diabetes has been a hot topic in recent months due to proposed changes in European rules that could lead to up to one million people with Diabetes losing their driving licences, many of whom have been driving for years without any problems. Under the proposed changes the definitions of ‘severe’ and ‘recurrent’ hypoglycaemic episodes has changed and drivers now need to declare any hypoglycaemic episodes that occur whilst an individual is asleep, this could result in a ban when re-assessing ones fitness to drive.
Whilst this may not concern those of you who do not have Diabetes, it raises a number of questions to the general public, firstly do we really understand the related health issues and risks that can occur as a result of high or low blood sugar levels and are we aware of the signs and symptoms of developing Diabetes and how we can prevent this?
So what is Diabetes, it is one of the oldest know human diseases, its full medical name is Diabetes Mellitus. When you are diagnosed with Diabetes it means that there are permanent changes in your body’s ability to produce insulin or your body loses the ability to respond to the insulin that is released into the blood stream. What does insulin do? Put simply, when we eat food it is digested and converted to glucose, this glucose is transported in the blood stream to be stored in the cells as an energy reserve. In order to store the glucose the hormone insulin which is made in the pancreas is released, this hormone regulates the amount of glucose that is taken out of the blood and stored in the cells, thereby maintaining a steady balance of sugar in the blood. In the absence of insulin the cells do not take up adequate glucose from the blood, the levels of glucose in the blood then increase and the whole system goes out of balance, if there is no control on the amount of glucose absorbed the levels in the blood just keep on rising, the excess glucose then spills out of the bloodstream into the urine and causes increased frequency in urination, one of the many symptoms that can be experienced. Other symptoms that may be experienced in different combinations are thirst, tiredness, unexplained weight loss and blurred vision. Over time other complications and conditions that can develop are vascular complications such as atherosclerosis or hardening of the arteries which results in an increased risk of heart attack, stroke and poor circulation. The eyes can be affected with increased risk of cataracts, blurred vision and retinopathy. The kidneys can be damaged as a result of the excess glucose accumulating in the small capillaries as well as the nerves which can lead to muscle weakness and sensory changes.
It is estimates that 2.5 million adults in the UK suffer from Diabetes. There are two types of Diabetes. Type I Diabetes is more prevalent in younger people, it usually occurs before the age of 15 as a result of the body’s immune system attacking the pancreas and eventually destroying its ability to make insulin, the cause of this is still unknown, it is difficult to manage and patients are reliant on insulin medication for life, hence its name insulin dependent Diabetes. Type II is more common with age and is referred to as late onset Diabetes or non insulin dependent Diabetes. A greater proportion of Diabetics have type II with a similar number believed to be undiagnosed. Lifestyle can be a major factor in the development of late onset diabetes as most type II diabetics are usually overweight and sedentary, there is a close link between the two and this may be due to the fat cells in obese people overproducing a hormone that suppresses the protein which enables the cells to take up the glucose. This raises grave concerns over the growing obesity epidemic in the younger population and recent diagnosis in younger children as a result of this. Symptoms gradually develop over time and in many cases can be delayed or possibly reduced by exercise, weight loss and a healthy diet. In some cases if lifestyle changes fail to manage the condition then your GP may prescribe certain oral medications to control your blood sugar levels, and it may be that you will eventually require insulin injections.
So how does exercise affect this and can we change things, the answer is yes: Firstly if you have Type II Diabetes or are at risk of developing this it is important to note that when we exercise the protein which enables the cells to take up the glucose is increased which in turn increases the sensitivity of your body cells to insulin and uptake of glucose, there is also a depletion of the muscle glycogen stores which contributes to improving blood sugar levels. This benefit can continue for up to 72 hours. Recent studies (Boule et al 2001, 2003) found that lifestyle interventions consisting of 150 minutes of physical activity a week along with dietary changes and weight loss of 5-7% can reduce the risk of developing full blown type II Diabetes. The American Diabetes Association recommends 150 minutes a week of moderate-intensity aerobic exercise or at least 90 minutes a week of vigorous aerobic exercise distributed over at least 3 days a week and not more than 2 -3 days apart. Moderate activity is something that makes you breath more heavily but are still able to talk and answer questions, heart rate should be between 50 – 70 % of maximum, this doesn’t need to be a hot sweaty high impact activity but can include such things as walking to work, cleaning and hoovering, even gardening can be an aerobic activity. Vigorous activity is a little harder and heart rate is above 70 % of maximum. The benefits of cardiovascular exercise have been discussed in previous articles and are numerous, it helps to improve muscle strength, increase bone density, lower blood pressure and cholesterol levels, improve circulation and lower the overall risk of heart disease, other less measurable benefits are an increase in energy levels and reduction in stress and anxiety. Following an exercise routine and sensible eating plan should also help you lose weight by burning excess calories which can help to reduce the amount of medication needed to control your diabetes or even prevent the onset of type II diabetes.
Resistance training can also be beneficial as a number of studies (Ivy Et Al 1997), (Dunstan Et Al 2002) have shown that this improves insulin sensitivity the same as with aerobic exercise and has the added benefits of increased muscle mass, increased resting metabolic rate and reduced body fat.
There is no reason why you should stop exercising or participating in sport if you have diabetes, however there are risks associated with this and it is important to discuss any exercises routine or goals with your GP to ensure that your plans are realistic. The important thing to be aware of is the necessity to monitor your blood glucose levels before, during and after exercise. There are risks of having a hypoglycaemic (low blood sugar) episode not only during exercise but up to 12 hours after exercise, as explained this is because the muscles increase their use of glucose and are more receptive to the effects of insulin, whilst the levels of sugar in the blood decrease they may go beyond safe levels if not managed appropriately. There are many sources of information that can help with understanding how to manage food intake and medication during exercise and to advise on the signs and symptoms of a hypoglycaemic episode which are confusion, sweating and shakiness, if untreated they can lead to coma and seizures in severe cases. If you are starting a new exercise programme then it is important that you review your medical history and current condition with a GP as they will need to assess your risk of other Diabetic complications and can give you further advice and information to get you started.
Sources:
Diabetes UK
American Diabetes Association
References:
Sigal, RJ. MD, Kenny GP. PHD, Wasserman DH, PHD. Castaneda-Sceppa C. MD, White RD. MD: Physical Activity/Exercise and Type 2 Diabetes: A consensus statement from the American Diabetes Association. Diabetes Care 29 no. 6 1433-1438, 2006
Boulé NG, Haddad E, Kenny GP, Wells GA, Sigal RJ: Effects of exercise on glycemic control and body mass in type 2 diabetes mellitus: a meta-analysis of controlled clinical trials. JAMA 286:1218–1227, 2001
Boulé NG, Kenny GP, Haddad E, Wells GA, Sigal RJ: Meta-analysis of the effect of structured exercise training on cardiorespiratory fitness in type 2 diabetes mellitus. Diabetologia 46:1071–1081, 2003
Ivy JL: Role of exercise training in the prevention and treatment of insulin resistance and non-insulin-dependent diabetes mellitus. Sports Med 24:321–336, 1997
Dunstan DW, Daly RM, Owen N, Jolley D, de Courten M, Shaw J, Zimett P: High-intensity resistance training improves glycemic control in older persons with type 2 diabetes. Diabetes Care 25:1729–1735, 2002
Castaneda C, Layne JE, Munoz-Orians L, Gordon PL, Walsmith J, Foldvari M, Roubenoff R, Tucker KL, Nelson ME: A randomized controlled trial of resistance exercise training to improve glycemic control in older adults with type 2 diabetes. Diabetes Care 25:2335–2341, 2002
