Ch. 14 Flashcards
Top five leading causes of death due in 2013
- Diseases of the heart
- Malignant neoplasms (cancer)
- Chronic respiratory diseases
- Accidents (unintentional injuries)
- Cerebrovascular diseases (stroke)
3 categories of major risk factors for diseases
- Inherited biological: age, gender, race, susceptibility to disease
- Environmental: physical (air, noise) socioeconomic (income, status) family (divorce, death of loved one)
- Behavioral: smoking, drinking alcohol, poor nutrition
Difference between infectious disease and chronic degenerative disease?
- infectious disease has a single pathogen may be the cause of disease
- harder to establish cause of chronic because genetic, environmental, and behavioral factors interact in a complex manner to cause disease
Behavioral causes of diseases
- actual causes of death describe which behaviors are linked to death
- smoking is at the TOP of the list
- smoking is NUMBER ONE cause of death (18%)
What do the three major classes of risk factors cause?
Atherosclerosis
What are the 3 top actual causes of death
- Smoking (18% of all death)
- Poor diet and physical inactivity (15.2%)
- Alcohol consumption (3.5%)
What is the Web of Causation?
Difficulty of establishing cause for these complex diseases is described by epidemiological model
What is atherosclerosis?
Condition in which a fatty plaque builds up in (not on) the inner wall of an artery
Many of the risk factors interact to cause which kinds of health complications?
- overweight, obesity, and type 2 diabetes
- connected to cardiovascular disease
What is coronary heart disease?
Associated with gradual narrowing of arteries serving the heart due to a thickening of the inner lining of the artery
What is the leading contributor to heart attack and stroke deaths?
Atherosclerosis
How were risk factors for CHD divided historically?
- Primary (major): factor in and of itself increased risk of CHD
- Secondary (contributing): certain factor increased risk of CHD only if one of the primary factors was already present
What are the guidelines epidemiologists apply to determine the cause for cardiovascular disease?
- Temporal association: does the cause precede the effect?
- Plausibility: Is the association consistent with other knowledge
- Consistency: have similar results been shown in other studies
- Strength: What is the strength of the association (relative risk) between the cause and the effect?
- Dose response relationship: is increased exposure to the possible cause associated with increased effect?
- Reversibility: does the removal of the possible cause lead to a reduction of the disease risk?
- Study design: is the evidence based on strong study design?
8: Judging the evidence: how many lines of evidence lead to the conclusion?
American College of Sports Medicine lists 8 risk factors for CHD:
- Age
- Family history
- Cigarette Smoking
- Sedentary lifestyle
- Obesity
- Hypertension
- Dyslipidemia
- Prediabetes
What are some dietary factors that have an impact on risk factors for CHD?
What diseases can result from them?
- High dietary salt and transfat intake and low omega 3 fatty acids
- obesity, hypertension, dyslipidemia, and prediabetes
What did Powell find in his study of how physical inactivity impacts the cause of coronary heart disease?
The relative risk of CHD due to inactivity is similar to that of hypertension and high cholesterol
In general the 2008 US physical activity guidelines found thatt
- Volume of physical activity done was the MOST important variable tied to health outcomes
- Risk of many chronic disease was reduced 20-40% by regular participation in physical activity with the greatest gains made by those moving from no activity to doing some activity
- Some activity is better than none and there is no lower threshold for benefits
- Dose response relationship existed for most health outcomes meaning that more is better
What is the intima?
Inner lining of the artery
What associations did the 2008 US physical activity Guidelines find with regular participation in physical activity
- Lower rates of all cause of mortality, CVD, and coronary heart disease incidence and mortality
- Increased weight loss and reduced amount of weight regain after weight loss
- A lower incidence of obesity
- A lower risk of colon and breast cancer
- An improvement in the ability of older adults to do activities of daily living
- Reduced risk of falls in older adults at risk of falling
- A reduction in depression and cognitive decline in adults and older adults
- Favorable changes in cardiovascular risk factors, including blood pressure and blood lipid profile
The investigators calculated the relative risk of CHD due to inactivity to be about….
1.9 meaning that sedentary people had about twice the chance of experiencing CHD that physically active people had
Most heart attacks and strokes occur from what?
Sudden rupture of the lacquer that triggers a blood clot and blocks blood flow
What is Low grade chronic inflammation linked to? What is characterized by?
- linked to wide variety of chronic diseases including hypertension, heart diseases, and stroke, cancer, type 2 diabetes and metabolic syndrome
- characterized by 2 to 3 fold increase in inflammatory cytokines
T/F Physical inactivity is an independent risk factor for CHD
TRUE
The relative risk of CHD is similar to those of
Hypertension and high cholesterol
In atherosclerosis, the decrease in the diameter of the lumen is due to a
Buildup of lipid and fibrous materials in inner lining of the artery called intima
most heart attacks and strokes occur not from gradual occlusion of an artery, but from
Sudden rupture of the plaque that triggers a blood clot and blocks blood flow
What is inflammation
Response of a tissue to injury that involves the recruitment of white blood cells (leukocytes) to the site of the injury
Normally, the endothelial cells that line the inner surface of the artery do not support the binding of leukocytes; however how does endothelium become activated to do so?
Activated by risk factors such as smoking, high blood pressure, a high fat diet, or obesity, endothelium generates adhesion molecules on its surface that bind to leukocytes
Low grade chronic inflammation is linked to a wide variety of chronic diseases such as
Hypertension, heart disease, stroke, and some cancers, metabolic syndrome,
Currently what percentage of adult population in US is obese?
35.7%
The chronic low grade inflammatory is characterized by
2 to 3 fold increase in inflammatory cytokines (TNF-alpha, interleukin-6, and c reactive protein CRP)
Under normal conditions, what do adipocytes do?
- synthesize and store lipids and release anti-inflammatory hormones (adiponectin)
- however they are capable of secreting inflammatory cytokines (IL-6)
What happens when adipocytes especially those in visceral area increase in size due to obesity?
- they secrete more IL-6 and less adiponectin
- macrophage infiltrate the enlarged visceral adipose tissue to promote a local inflammation and secrete TNF-alpha
What is TNF-alpha?
A potent inflammatory cytokines
Increased amounts of of FFA, IL-6, and TNF-a are released from
- verbal adipose tissue into the liver and then general circulation
FFA, TNF-A, and IL-6 in combination interfere with
Accumulation of insulin which is linked to type 2 diabetes, cardiovascular disease, and metabolic syndrome
What is C-reactive protein released from and what is its purpose?
- released from liver in response to inflammatory factors
- [] of CRP in blood is used as a marker of inflammation
- useful predictor of disease risk in those with other risk factors
What has dramatically reduced CRP and IL-6 concentration
- healthy eating especially a Mediterranean style diet for 2 years
Dietary induced reduction in inflammatory markers is believed to be linked to
Suppression of pathways that stimulate the transcription of genes involved in the inflammation process
Reduction in inflammation may be due more to
-weight loss than exercise EXCEPT in populations that have a higher baseline levels of inflammation
Mechanisms through which exercise training might reduce chronic inflammation in obesity
- acute exercise stimulates IL-6 release from skeletal muscle which suppresses pro inflammatory cytokines
- exercise training may increase angiogenesis in adipose tissue to result in an increase in blood flow and reduction in hypoxia and associated chronic inflammation in adipose tissue
- exercise reduces adhesion molecule production in endothelial cells and lowers vascular wall inflammation
- exercise training may reduce the expression of toll like receptors and number of pro inflammatory monocyte
Mechanisms through which exercise training might reduce chronic inflammation in obesity
- acute exercise stimulates IL-6 release from skeletal muscle which suppresses pro inflammatory cytokines
- exercise training may increase angiogenesis in adipose tissue to result in an increase in blood flow and reduction in hypoxia and associated chronic inflammation in adipose tissue
- exercise reduces adhesion molecule production in endothelial cells and lowers vascular wall inflammation
- exercise training may reduce the expression of toll like receptors and number of pro inflammatory monocyte
In order to reduce many chronic diseases, we must implement
- dietary changes to Mediterranean style, reduction in body weight to appropriate level, and increase in physical activity or cardiorespiratory fitness 5
- The metabolic syndrome model describes connections between
- hypertension
- obesity
- peripheral resistance,
- dyslipidemia
What is syndrome X?
What is Deadly quartet?
- coexistence of insulin resistance, dyslipiedmia, and hypertension
- add obesity to it
Scientists claimed that a person who has 3 or more of the following has Metabolic syndrome
- abdominal obesity: waist circumference > 102 cm in men & >88 cm in women
- hypertriglyceridemia: >-150 mg/dl
- low high density lipoprotein cholesterol: <40 mg/dl in men and <50 mg/dl in women
- high blood pressure: >-130/85 mm Hg
- high fasting blood glucose: >- 100 mg/dl
The overall presence of metabolic syndrome in the US from 2003-2012 was what %
33%; greater prevalence for women than men
What 2 theories causes metabolic syndrome
- a low grade chronic inflammation
- elevated level of oxidative stress
What is oxidative stress?
It exists when free radicals accumulate because they are being produced faster than our antioxidant systems can neutralize them or because the level of antioxidants is inadequate or both
The sheer complexity of web of causation makes it difficult to identify a single cause of metabolic syndrome. Two potential interpretations include the following:
- Increased levels of inflammatory cytokines cause the insulin resistance that leads to obesity and type 2 diabetes
- The central obesity leads to an increase in inflammatory cytokines and FFA that in turn cause the insulin resistance
