Physiology, Health & Exercise Lesson 19 z Effects & diagnosis of DM zEffects of exercise on DM

2 Diagnosis & Exercise on DM Includes: zEffects of diabetes zGlucose tolerance test zEffects of exercise in prevention of NIDDM zEffects of exercise in treatment of NIDDM

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

4 Diabetes zIs a multifactorial disease zi.e. both genes and the environment contribute zIDDM (Type 1 )- is an autoimmune disease   - cells in Islets of Langerhans are destroyed by persons own immune system

5 Diabetes- both types zInability to store glucose after a meal zLimited uptake of glucose into cells zCauses rapid rise in BGL (hyperglycaemia) zAt very high levels  kidneys unable to absorb all glucose passing through them zHence glucose in urine  glycosuria zLarge volume of urine produced polyuria, with large volume of water zHence- thirst  polydipsia

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

7 Diabetes- Diagnosis zUrine tests for glucose using clinstix - glycosuria zMeasure random or fasting blood glucose or glucose intolerance test

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

9 Glucose intolerance test zThe 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 Fasting Blood glucose mmol/lNormal glucose tolerance mmol/lImpaired glucose fasting >7.0mmol/lProbable diabetes

11 Glucose intolerance test OGTT Results 2 hours after a 75g glucose drink <7.8mmol/lNormal glucose tolerance mmol/lImpaired glucose tolerance >11.1mmol/lProbable diabetes

12 Glucose intolerance test Glucose drink

13 Glucose intolerance test zDifferences: Non-diabetic BGLDiabetic BGL reach peak of 7mmol 30 mins after glucose meal Higher fasting levels Fall to 4mmol/l after 2 hours Levels rise to above 11mmol/l within 30mins Pancreas secreted insulin Levels remain high for several hours

14 Effects of exercise zPhysically fit individuals have greater ability to take up glucose from the blood zRegular exercise  increased capillary network in skeletal muscle & blood flow zEffect of regular exercise on active insulin receptors: yIs an increase in sensitivity y& increase in actual number on cell membranes of target cells especially skeletal muscle cells

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

16 Effects of aerobic exercise zAlso reduces body weight z&/or body fat zWhich in turn reduces many of risk factors for NIDDM zThought that 80-90% of overweight NIDDM sufferers can normally achieve metabolic control of BGL by following: yLow energy diet y& moderate intensity exercise programme.