Blood glucose levels and obesity

What do you know now? From your previous knowledge in N5 or elsewhere Brainstorm with a partner what you know about the control of blood glucose levels and obesity Distil the information into the 5 most important points and note them on a white board for class discussion

What you are learning Why blood glucose control is important How blood sugar is controlled including the hormones involved and their effects What happens when blood sugar cannot be controlled What is obesity What are the consequences of being obese How to avoid being obese

Number of People with diabetes Diabetes in the UK Country in UK Number of People with diabetes England 2,913,538 Northern Ireland 84,836 Scotland 271,312 Wales 183,348 Reference http://www.diabetes.co.uk/diabetes-prevalence.html

Graph of obesity prevalence https://www.noo.org.uk/NOO_about_obesity/adult_obesity/UK_prevalence_and_trends Public Health England

Trends in adult prevalence in adult obesity in the UK https://www.noo.org.uk/NOO_about_obesity/adult_obesity/UK_prevalence_and_trends Public Health England

Blood glucose levels Why is blood glucose (sugar) important? Why is it important to control blood glucose levels? Chronic elevated blood glucose levels are associated with some serious problems Blood vessels are damaged when endothelium cells take in more glucose than normal Atherosclerosis may develop increasing risk of CVD, stroke or PVD Damaged blood vessels may lead to haemorrhaging in the retina, cause renal failure or peripheral nerve dysfunction

Blood glucose level control Part of the homeostatic systems in body Process involves negative feedback Look at diagram you have been given and summarise the information using bullet points

Blood glucose level control Pancreatic cells detect levels of blood glucose If blood glucose is too high insulin is secrete from β cells in the pancreas Insulin activates conversion of glucose to glycogen in liver removing glucose from blood More glucose taken into fat and muscle cells If blood glucose is too low glucagon is secreted by α cells in pancreas Glucagon activates conversion of glycogen to glucose in liver releasing glucose into blood

Blood glucose level control Adrenaline (epinephrine) is released from adrenal glands Adrenaline stimulates glucagon secretion but inhibits insulin secretion Glucose is released into blood to cope with the situation Adrenaline is known as the flight or fight hormone Adrenaline is also released during exercise

Diabetes Type 1 and Type 2 Type 1 Usually occurs in childhood Person cannot produce insulin Person is treated with injections of insulin and careful diet Type 2 Typically occurs later if life Mainly in overweight people Individuals produce insulin but cells are less sensitive to it Fewer insulin receptors present in liver cells so glucose is not converted to glycogen Exercise, weight loss, diet control to control (insulin for some)

Diabetes Both types lead to chronic complications including vascular disease leading to retinal damage, renal failure, capillary damage, nerve damage. Blood glucose levels rise rapidly after a meal. Glucose is lost in the urine because kidneys cannot cope with the rise

Testing for diabetes Urine test for diabetes is used as an indicator of diabetes Diagnosis is done with a glucose tolerance test Individual fasts (do not eat) for 8 hours Blood glucose is then measured Individuals drink 250 – 300ml of glucose solution (set conc.) Blood glucose is monitored for next 2.5 hours (150 mins) Results give a plot for sugar tolerance

Comparing diabetes types Type 1 diabetes Type 2 diabetes % all cases 5 - 10 90 – 95 First occurs Childhood/early teens Adulthood Typical body mass Normal/underweight Overweight/obese Ability to produce insulin absent Present Sensitivity to insulin (liver/skeletal muscle) Normal insulin receptor number respond if insulin is present Decreased receptor number glucose does not enter cells or get converted to glycogen Treatment Regular insulin injections and careful diet Exercise, weight loss, diet control and insulin in some cases

Obesity Accumulation of excess body fat compared to lean tissue (muscle) Fat on outside and inside Increases risk of health problems including CVD, kidney failure, type 2 diabetes, osteoarthritis Variety of method used to determine ideal weight for each individual Body mass index (BMI) Densitometry Skin fold thickness Bioelectrical impedance Waist/hip ratio

Body Mass Index (BMI) BMI = Body mass (Kg) height (m2) Most often use as easy to calculate and works for most average individuals, good indicator for ideal weight for height BMI limited exceptions athletes, body builders, rugby players have high BMI due to mass of muscle BMI value Expert opinion Health risks 20 – 25 Ideal Average 26 – 30 Overweight Increased 31 – 40 Very overweight (obese) Greatly increased Over 40 Very obese (morbidly) Very greatly increased

Other body measurements Densitometry measures mass of person in air and water. Fat and muscle have set masses and can be compared Skin fold thickness measures skin fold in a number of places to get average Bioelectrical impedance passes current through body and calculates fat as it impedes electrical current more than muscle Waist/hip ratio

Obesity causes Genetic Psychological Environmental Metabolic Dietary For most people too much energy rich food in and not enough physical activity to use it up

Obesity avoidance Obesity associated with high fat level in diet and reduced physical activity Limit intake of fat and free sugars (energy) Fats are calorie rich Free sugars require no metabolic activity to digest Energy in to equal energy out for balance Exercise to increase energy expenditure and maintain lean tissue (muscle)

Being Healthy – exercise and diet Exercise can help with Reducing cardiovascular disease Keeping weight under control Reducing stress Reducing hypertension Improving HDL levels in the blood Controlled balanced diet will help with Control body mass to appropriate level Reducing risk of type 2 diabetes Reducing risk of CVD

What you should be able to do Explain how blood glucose levels are controlled Explain why high levels of blood glucose are harmful Explain the 2 types of diabetes – cause and effect Explain the diagnosis of diabetes Describe obesity and how body mass is measured Explain why obesity is a problem Describe how obesity can be avoided Describe the benefits of exercise and a controlled balanced diet