Lecture 8 - Obesity, Metabolic Syndrome, Dyslipidaemia Flashcards
What is Obesity?
It’s an excess of body fat frequently resulting in a significant impairment in health.
Ways to measure overweight and obesity:
Height and weight tables:
-considered obese if >20% above desired weight listed
BMI [for adults]
- overweight <25 kg/m2
- preobese 25< BMI <29.99 kg/m2
- Grade 1 obesity: 30< BMI < 34.99 kg/m2
- Grade 2 obesity: 35 < BMI <39.99 kg/m2
- Grade 3 obesity: >40kg/m2
Waist Girth:
-Significant risks at WG >102cm for men and WG > 88cm for women.
Waist to Hip Ratio:
- Significant risks at WHR >0.8 for women and >0.9 for men.
Phenotype:
- Type I = Excess body mass or %fat
- Type II = Excess subcutaneous truncal-abdominal fat [android]
- Type III = Excess abdominal visceral fat
- Type IV = Excess gluteal-femoral fat [gynoid]
Body fat percentage:
- Significant risks at >25% fat for men and >35% fat for women
- Skin folds
- Hydrostatic weighing
- DEXA
What influences predispose individuals to obesity?
BEHAVIOURAL:
- socioeconomic status [education]
- activity level
- nutrition
METABOLIC:
- genetic factors
- metabolic and endocrine factors
BIOLOGICAL:
- Race
- Gender
- Age
- Pregnancy
CULTURAL/SOCIETAL:
- Media
- Work Practices
- Transport
- Urbanisation/modernisation
Drugs for Treating Obesity:
- Phentermine [ Adipex-P, Lonamin]
Current weight loss are appropriately recommended for individuals with a BMI >30 or with a BMI>27 if they have obesity relate comorbidities
is recommended for short term use - Acts as an appetite suppressant but causes dry mouth, palpitations, and anxiety
Drugs for Treating Obesity:
- Lorcaserin [Belviq]
It’s a serotonin receptor agonist: reduces appetite
Given in addition to lifestyle modifications, lose about 2-3kg more than placebo over the course of a year
Side effects: headaches, dizziness, fatigue, nausea, dry mouth and constipation. Rare chemical imbalance [serotonin syndrome], suicidal thoughts, psychiatric problems.
Drugs for treating obesity:
- Orlistat [Xenical, Alli]
It’s a pancreatic lipase inhibitor: blocks the digestion and absorption of fat in your stomach and intestines.
It decreases fat absorption by 30% = further increase of dietary fat [leakage!!!] - excess fat is release through oily diarrhoea.
Phentermine and Topiramate [Qsymia] [appetite suppresant] = capable of 12% to 14% weight loss
Health Benefits of a 10% Weight loss:
BP : decline of about 10mmHg is systolic and diastolic BP in patients with hypertension equivalent to that with most BP medication
Diabetes:
Decline of up to 50% in fasting glucose for newly diagnosed patients
Prediabetes:
>30% decline in fasting or 2h post glucose insulin level >30% increase in insulin sensitivity, 40-60% decline in the incidence of diabetes
Lipids: 10% decline in TC 15% decline in LDL chol 30% decline in TRIG 8% increase in HDL chol
Mortality:
>20% decline in all cause mortality
> 30% decline in deaths related to diabetes
>40% decline in deaths related to obesity
ACSM Guidelines:
Prevent gain weight:
- 150-250min/week of mod int PA is associated with prevention
- more than 150min/w of mod int PA is associated with modest weight loss
Weight loss:
- 150 -250min/week only provides modest weight loss
- greater amount [>250] provide clinically significant weight loss
For weight maintenance after weight loss:
- there’s some evidence that >250min/week will prevent weight re-gain
Exercise prescription:
Both cardiorespiratory + resistance
Frequency:4-5 days/week
Duration: 40-60min
Intensity: 50-60% VO2max
RT may not enhance weight loss but may increase/maintain fat free mass and is associated with reductions in health risk
Safety concerns during PA for obesity:
- Musculoskeletal screening recommended for obese clients
- 12 lead ECG
- BP response
- Signs of dyspnoea
- Signs of metabolic disturbances [hypoglycaemia] - BGL’s
Considerations to make when developing physical activity programmes for the severely obese:
Barriers:
- Physical, psychological, economic, an programme based
Safety issues:
- co morbid medical conditions
PA options:
- low intensity activity [gardening]; non-weight bearing activity [swimming, water aerobics]; walking [increases caloric expenditure]
Programme goals:
-caloric expenditure and weight loss [300-500kcal/session and 2000 kcal/week], QOL, improved mood, improved physical conditioning
Promoting adherence:
- develop good rapport, patient eduction, address barriers, provide progressive feedback, use prompts and rewards, develop social support.
Management of Metabolic syndrome:
If focus is on obesity as underlying cause - prevent and treat obesity
If focus is on insulin resistance as underlying cause - treat insulin resistance and prevent T2D
If focus is on individual risk factors - treat individual risk factors, such as: Low HDL chol, high Total C
Hoes does exercise help:
Well as MetS is a clustering of risk factors, exercise helps by reducing/preventing/treating each of them
Exercise is the only therapy that can do so
Lipids
A study exercised 13 men with hyperlipidaemia and 12 men with normal lipids on a treadmill at 70% of peak VO2max. They exhibited a significant decrease in TRIG
A single bout of exercise can increase TRIG removal at the next meal.
Aerobic exercise that’s at least moderate intensity 3x/week can
- increase HDL-C
- Reduce total chol, LDL & TRIG
Lowering blood cholesterol:
Primary focus of diet therapy is on lowering LDL-C:
- high saturated fat intake and high dietary chol reduce LDL clearance
- diets high in polyunsaturated fat may reduce HDL levels
- high carbohydrate diets may reduce HDL levels and raise TRIG’s
- monounsaturated fats apparel to lower Total- C and possibly increase HDL levels
- fibre sequesters bile and can reduce LDL levels by 5-10%