modern chronic diseases obesity_16_4_11.pdf
TRANSCRIPT
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MODERN CHRONIC DISEASES:OVERWEIGHT, OBESITY AND DIABETES
LECTURER: LU ZHAO, PH.D., M.D.
OVERWEIGHT AND OBESITY
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GOALS What are Overweight & Obesity?
What are the causes?
What are the health risks?
How to prevent?
CONCEPTS: OVERWEIGHT AND OBESITY Overweight: having more body fat than is
optimally healthy.
Obesity: a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health.
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DIAGNOSIS: OVERWEIGHT AND OBESITYFor adult:
Body Mass Index (BMI) kg/m2
Overweight: BMI ≥ 25 (24)
Obesity: BMI ≥ 30 (28)
For children and adolescents (2-19 yr)
Age- and sex- specific percentile for BMI
Overweight: 85th ≤ BMI < 95th
Obesity: BMI ≥ 95th
OTHER MEASURING METHODS
Waist circumference
Waist to hip ratio
Skin fold thickness
Bioelectrical Impedance Analysis (BIA)
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TYPES OF OBESITY Central Obesity
Also called as abdominal, visceral, android or apple-shaped obesity.
Increased abdominal fat (intra-abdominal fat)
More common in men
Generalized Obesity
Gynoid or pear-shaped obesity
Subcutaneous fat
More common in women
TYPES OF OBESITY
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WHAT CAUSES OVERWEIGHT AND OBESITY? Lack of Energy Balance
Health Conditions
Medicines
Emotional Factors
Smoking
Age
Pregnancy
Lack of Sleep
Genetic Factors
WHAT CAUSES OVERWEIGHT AND OBESITY?
Lack of Energy Balance: Energy IN > Energy OUT
• Excessive energy intake
(Eat Too Much)
http://www.nhlbi.nih.gov/health/public/heart/obesity/wecan/healthy-weight-basics/balance.htm
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WHAT CAUSES OVERWEIGHT AND OBESITY?
Lack of Energy Balance:
Energy IN > Energy OUT Excessive energy intake (Eat Too Much)
e.g. eating 150 calories more a day than you burn
= extra 5lb (2.3 kg) in 6 month = extra 10lbs (4.6) per year.
http://www.nhlbi.nih.gov/health/public/heart/obesity/wecan/healthy-weight-basics/balance.htm
OR X 365 days =
WHAT CAUSES OVERWEIGHT AND OBESITY?Lack of Energy Balance:
Energy IN > Energy OUT Inadequate energy expenditure
(An Inactive Lifestyle)
WALL. E (2008)
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WHAT CAUSES OVERWEIGHT AND OBESITY?Lack of Energy Balance:
Energy IN > Energy OUT Environment
WHAT CAUSES OVERWEIGHT AND OBESITY? Health Conditions (hormone problems)
Hypothyroidism
Cushing’s syndrome
Polycystic ovarian syndrome
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WHAT CAUSES OVERWEIGHT AND OBESITY? Medicines
Slower body metabolism, increase appetite, or increase water retention.
WHAT CAUSES OVERWEIGHT AND OBESITY?Others
Emotional Factors
Smoking cessation
Age
Pregnancy
Lack of sleep
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WHAT CAUSES OVERWEIGHT AND OBESITY?Genetic Factors
Genetic obesity syndromes• Bardet-Biedl syndrome
• Prader-Willi syndrome (15q11-13)
Complex interactions among multiple genes
The “Thrifty Genotype” hypothesis
Genes and the environment are linked
EPIDEMIOLOGY OF OVERWEIGHT & OBESITY Data and statistics
5th leading risk for global health.
Cause 2.8 million death each year.
>35% of the world’s adult population are overweight and 11% are obese
>30 million overweight children are in developing countries, and 10 million in developed countries.
From WHO
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OBESITY IN CHINA Overall obesity rates 5%, but >20% in some cities.
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CHILDHOOD OBESITY One of the most serious public health challenges of the
21st century.
In 2010, >42 million children <5 yr were overweight. ~35 million are living in developing countries.
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WHAT ARE THE HEALTH RISKS OF OBESITY & OVERWEIGHT ? Cardiovascular Diseases
High Blood Pressure
Type 2 Diabetes
Dyslipidemia
Metabolic Syndrome
Gallstones
Cancer
Reproductive problems
WHAT ARE THE HEALTH RISKS OF OBESITY & OVERWEIGHT ? Mechanical stress:
Osteoarthritis
Sleep Apnea
Obesity Hypoventilation Syndrome
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Overweight and Obesity-Related Health Problems in Children and Teens
WHAT ARE THE HEALTH RISKS OF OBESITY & OVERWEIGHT ? Overweight and Obesity-Related Health Problems in
Children and Teens
Full spectrum of health-related risks as in adults
More likely to be obese as adults
Low self-esteem, anxiety and depression
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HOW TO TREAT OVERWEIGHT & OBESITY?
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HOW TO TREAT OVERWEIGHT & OBESITY? Set Realistic Goals
Lifestyle Changes
Reduce energy IN • reduce 500-1000 calories per day, but should >800 calories
• 1000-1200 calories for female and 1200-1600 calories for male.
Healthy eating plan low in saturated fat, trans fat, cholesterol, sodium, and sugar
High in lean meat, fish, beans, whole-grain foods, fruits and vegetables.
HOW TO TREAT OVERWEIGHT & OBESITY? Foods to limit
Saturated fat• Fatty cuts of meat (ground meat)
• Poultry with the skin
• High-fat dairy
• Saturated cooking oils
Trans fat• Partially hydrogenated oils
• Baked products and snack foods
Cholesterol Egg yolks, organ meats (e.g. liver), shrimp, whole milk
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Life style changes: Physical Activity
Adults:
for maintain their weight 150-300 min of moderate-intensity activity per week
Short periods of at least 10 min each
for loss weight > 300 min of moderate-intensity activity per week
Children: >60 min/day
Step up the level of activity
HOW TO TREAT OVERWEIGHT & OBESITY?
Behavior Changes
Changing the habits related to overeat or an inactive lifestyle
HOW TO TREAT OVERWEIGHT & OBESITY?
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Weight-loss medicine
Sibutramine (Meridia)
Orlistat (Xenical and Alli)
Lorcaserin Hydrochloride (Belviq)
Others Other medicines treating depression, seizures and diabetes
OTC (dietary supplements) Ephedra (ma huang), Chromium, Diuretics and herbal laxatives,
Hoodia.
HOW TO TREAT OVERWEIGHT & OBESITY?
Weight-loss Surgery (Bariatric surgery)
Banded gastroplasty
Roux-en-Y gastric bypass
HOW TO TREAT OVERWEIGHT & OBESITY?
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PREVENTION OF OVERWEIGHT & OBESITY Follow a healthy lifestyle (from childhood)
Make healthy food choices
Focus on portion size
Be active
Reduce screen time < 2 hour of non-work or homework screen time
Keep track of your weight, BMI and waist circumference
SUMMARY Obesity is the most serious health problem in the 21st
century, esp. childhood obesity.
Energy imbalance is the key factor causing obesity and overweight.
Obesity is related to a wide range of diseases including CVDs, diabetes and cancers.
Lifestyle changes are the most important approaches in combating obesity.
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DIABETES
GOALS What are diabetes and what are the differences between
Type 1 and type 2 diabetes?
What are the causes?
What are the health risks?
How to prevent?
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DIABETES
A group of metabolic disease characterized by chronic hyperglycaemia.
pancreas does not produce enough insulin
the body cannot effectively use the insulin
** Insulin: a peptide hormone, produced by β-cell of the pancreas, is central to remove excess blood glucose.
DIAGNOSIS OF DIABETES
Condition 2 hour glucose
Fasting glucose
Hb A1C
unit mmol/l (mg/dl) mmol/l (mg/dl) %
Normal <7.8 (<140) <6.1 (<110) < 6.0
Impaired fasting glycaemia
<7.8 (<140) ≥6.1 (≥ 110) & <7.0 (<126)
6.0-6.4
Impaired glucosetolerance
≥7.8 (≥140) <7.0 (<126) 6.0-6.4
Diabetes Mellitus ≥ 11.1 (≥200) ≥ 7.0 (≥126) ≥ 6.5
OGTT: oral glucose tolerance test
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TYPES OF DIABETES
Type 1 diabetes
Type 2 diabetes
Gestational diabetes
Other types
TYPES OF DIABETES
Type 1 diabetes (T1D) insulin-dependent diabetes mellitus (IDDM)
deficiency of the insulin produced by the pancreas, due to the autoimmune destruction of β-cells.
patients require lifelong insulin injections.
usually develops in children and adolescents
patients are usually not obese
Increased risk with coma and ketoacidosis.
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TYPES OF DIABETES
Type 2 diabetes (T2D) Non-insulin-dependent diabetes mellitus (NIDDM)
Insulin resistance and relative insulin deficiency.
Blood glucose can be controlled with diet and exercise alone, or in combination with oral medications, or with insulin.
Usually develops in adulthood
Related to obesity, physical inactivity and diets.
Increased risk with microvascular/macrovasular complications.
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TYPES OF DIABETES
Gestational diabetes (GDM)
Hyperglycemia during pregnancy (w/o diabetes history) .
usually (but not always) resolving within 6 weeks of delivery.
Increased risk of T2D later in life.
OTHER TYPES
Diabetes LADA
Diabetes MODY
Double diabetes
Steroid-induced diabetes
Secondary diabetes
…
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SYMPTOMS OF DIABETES
Classical symptoms: polyuria, polydipsia, polyphagia, and weight loss.
Nervous system: numbness in extremities, pain in feet, fatigue, and blurred vision.
Immunity system: recurrent or severe infections.
Severe symptoms: diabetic coma
COMPLICATIONS OF DIABETES Diabetic Retinopathy
Cardiovascular disease
Nephropathy
Neuropathy
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EPIDEMIOLOGY
Affecting 347 million people worldwide.
More than 80% of diabetes occur in low- and middle-income countries
WHO projects that diabetes will be the 7th leading cause of death in 2030.
WHO 2013
Source: Hossain et al. NEJM 2007
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DIABETES IN ASIA
Asians are more prone to have diabetes.
Ethnic and genetic predisposition:
Younger age
Lower BMI and waist circumference
Rapid urbanization and socioeconomic transition result in:
Physical activity decreases
Diet habits shift to high-energy food
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DIABETES IN ASIA
A great economic burden
Esp. in lower income groups, who spend 25-34% of their income of diabetes care
<30% of the patients achieve the desired glycemic goals.
ETIOLOGY AND RISK FACTORS
T1D:
Autoimmune destruction of the β cells.
Genetic factors: e.g. IDDM1
Environmental factors: • Virus triggered immune defects?
• Antibodies against cow milk proteins?
• Short breastfeeding period
• Chemicals and drugs: e.g. streptozocin.
• Pancreatic diseases
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ETIOLOGY AND RISK FACTORSGDM:
Polycystic ovary syndrome
Prediabetes
Family history of T2D
Maternal age (>35 yr)
Ethnic background
Overweight & obesity
Previous pregnancy of high birth weight baby
Poor obstetric history
Genetic risk factors: multiple genes.
Smoking: 2-fold risk
ETIOLOGY AND RISK FACTORS
T2D:
Lifestyle + Genetics + Environmental
lifestyle factors
Obesity Fat distribution --- abdomen fat Physical inactivity Diet Stress Sleep deprivation
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ETIOLOGY AND RISK FACTORST2D:
Lifestyle + Genetics + Environmental
environmental factors
Urbanization
BPA (Bisphenol A)
genetic factors
Family history
Ethnic factors
others
Age (>45 yrs)
Disease background
PREVENTION/TREATMENT:LIFESTYLE INTERVENTIONS Diet
Exercise
Weight loss
Adequate sleeping hours
Psychological health
Medical Treatment
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DIETS AND DIABETES
DIETS AND DIABETES Carbohydrate (60-70% of total energy)As in normal population, whole grains, fruits, vegetables, and low-
fat milk are recommended.
The total amount is more important than the source or the type.
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DIETS AND DIABETES Protein ( ~15% of total energy) Intake of protein does not appear to be associated with the
development of diabetes or diabetic nephropathy
< 20% of total energy
A diet high in protein and low in carbohydrate may produce short-term weight loss, but the long-term effect is not established.
DIETS AND DIABETES
Fat ( <10% of total energy) Limit saturated fat and dietary cholesterol intake
Limit trans-unsaturated fatty acids
Monounsaturated fat and polyunsaturated fat
Fat substitutes
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FAT SUBSTITUTES with the same functions, stability, physical, and chemical
characteristics as regular fat, with fewer kilocalories per gram than fat.
utilized in the production of low fat and low calorie foods.
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DIET AND DIABETESFor special populations
T1D• For persons with fixed insulin regimens, consistency of
carbohydrate intake is recommended.
Children• Maintain normal growth and development without
hypoglycemia• Individualized food/meal plans
Pregnancy women• Provide adequate maternal and fetal nutrition, with high
protein and necessary vitamin and minerals supplements.
Older adults• Less energy requirement than younger adults
TAKE-HOME MESSAGE
Diabetes linked deaths are caused by its severe complications.
T2D is the most common type of diabetes.
Most T2D can be prevented/treated only through lifestyle interventions.
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QUESTIONS?
QUIZ
Laatikainen, et al. (2005) Am J Epidemiol .
** AMI, acute myocardial infarction; CABG, coronary artery bypass graftingPTCA, percutaneous transluminal coronary angioplasty.
This figure is extracted from a study tried to explain the decline of CHD from 1982 to 1997 in Finland. Based on this figure, describe why the mortality of CHD declined in Finland. What are the major methods of reducing blood cholesterol?