Physiology, Health & Exercise

1. Physiology, Health & Exercise Lesson 19 Effects & diagnosis of DM Effects of exercise on DM

2. Diagnosis & Exercise on DM Includes: • Effects of diabetes • Glucose tolerance test • Effects of exercise in prevention of NIDDM • Effects of exercise in treatment of NIDDM

3. “Normal” situation • Normal range of BGL is 4-8mmol/l. • Even after a meal rich in carbohydrates BGL never goes above 10mmol/l • Even if go for ages without food BGL never falls below 3.5mmol/l • Glucose is the only “fuel” that the brain & nerves can use • But nervous system cannot store glucose so needs a constant supply from the blood

4. Diabetes • Is a multifactorial disease • i.e. both genes and the environment contribute • IDDM (Type 1 )- is an autoimmune disease • b- cells in Islets of Langerhans are destroyed by persons own immune system

5. Diabetes- both types • Inability to store glucose after a meal • Limited uptake of glucose into cells • Causes rapid rise in BGL (hyperglycaemia) • At very high levels kidneys unable to absorb all glucose passing through them • Hence glucose in urine  glycosuria • Large volume of urine produced polyuria, with large volume of water • Hence- thirst  polydipsia

6. Diabetes- Effects • If BGL fall too low >4mmol/l (hypoglycaemia) brain receives insufficient glucose  coma  death • Many of the symptoms of mild hypoglycaemia are caused by release of adrenaline • E.g. feeling hungry, trembling, sweating, anxiety & irritability, going pale, fast pulse & palpitations • If untreated starts to affect the brain confusion  hallucinations  coma  death

7. Diabetes- Diagnosis • Urine tests for glucose using clinstix -glycosuria • Measure random or fasting blood glucose or glucose intolerance test

8. Glucose intolerance test • The fasting blood glucose level (collected after an 8 to 10 hr fast) is used to screen for and diagnose diabetes. • An oral glucose tolerance test (OGTT / GTT) may also be used to diagnose diabetes. • To be certain of a diagnosis two tests (either the fasting glucose or the OGTT) should be done at different times.

9. Glucose intolerance test • The OGTT involves a fasting glucose measurement, followed by the patient drinking a glucose drink to 'challenge' their system, followed by another glucose test two hours later.

10. Glucose intolerance test

11. Glucose intolerance test

12. Glucose intolerance test Glucose drink

13. Glucose intolerance test • Differences:

14. Effects of exercise • Physically fit individuals have greater ability to take up glucose from the blood • Regular exercise  increased capillary network in skeletal muscle & blood flow • Effect of regular exercise on active insulin receptors: • Is an increase in sensitivity • & increase in actual number on cell membranes of target cells especially skeletal muscle cells

15. Effects of exercise • Increase in enzymes associated with glucose storage • Improved insulin sensitivity (reduced insulin resistance) is lost within 5-7 days of last exercise • Very important to have regular exercise • i.e. recommend moderate intensity exercise 5 to 7 times a week

16. Effects of aerobic exercise • Also reduces body weight • &/or body fat • Which in turn reduces many of risk factors for NIDDM • Thought that 80-90% of overweight NIDDM sufferers can normally achieve metabolic control of BGL by following: • Low energy diet • & moderate intensity exercise programme.