NS 1400 Test 1

What is health?

a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity

"Range of behavioral, biological, socio-economic and environmental factors that influence the health status of individuals or populations"

Determinants of health

Multifactorial - social, economic, psychological and physiological factors

Impacts of the determinants of health

Produces an impact on 1) individual level pathology (the study of the causes and effects of disease or injury) and 2) patterned health differences in populations

Yield health disparities

Determinants work through ________________________ ______________ _________________

discernable causal pathways --> this allows for prevention and amelioration of disease

Biological determinants of health (1)

Innate - Effects or characteristics of the body that are innate in origin or have an innate component that may directly and measurably determine health and/or disability

GENETICS - Effects or characteristics of the body that are genetic in origin or have a heritable component that may directly and measurably determine health and/or disability.

Biological determinants of health (2)

Body Structure - Effects or characteristics of body structure that may be protective or risk factor determinants of health; they may be causally related or strongly associated with the propensity for health or for disease, disability, or injury

ANATOMY - Effects or characteristics of body anatomy that may be protective or risk factor determinants of health; they may be causally related or strongly associated with the propensity for health or for disease, disability, or injury.

Biological determinants of health (3)

Body Functioning - Effects or characteristics of body functioning that may be protective or risk factor determinants of health; they may be causally related or strongly associated with the propensity for health or for disease, disability, or injury

PHYSIOLOGY - Effects or characteristics of physiology that may be protective or risk factor determinants of health; they may be causally related or strongly associated with the propensity for health or for disease, disability, or injury.

Genetic subclass

Single-gene

•Caused by defect in one specific gene

•Known as Mendelian disorders

•Rare -only 18,000 known single gene disorders

Chromosomal

•Defect due to an excess or lack of the genes contained in a whole chromosome or chromosome segment.

•Chromosomal disorders include: Down syndrome, Klinefelter syndrome, and Turner syndrome.

Multifactorial

•Result from interactions of several genes and the environment

•Polygenic

•Most common

•cancer, coronary heart disease, hypertension, and stroke.

Mitochondrial DNA-linked

•Defect arise from mutations in mitochondrial DNA.

•>60 hereditary disorders

•Maternal transmission

Anatomical subclass

Height - Anthropometric measure used to assess a person's relationship to the accepted standards for growth and development.

Weight - Anthropometric measure used to assess a person's relationship to the accepted standards for growth and development.

Waist-hip ratio - Anthropometric measure used to approximate abdominal fat; regarded as a better predictor of health risk than body mass index (BMI).

Bone density - Measure of bone mass in relation to bone volume used to determine risk of developing osteoporosis.

Physiological subclass

Risk Factor - Organ System

Blood Pressure - Cardiovascular

Nutritional Status - Digestive

Pulmonary Function - Respiratory

Sensory Function - Nervous

Movement and Balance - Musculoskeletal Nervous Strength - Musculoskeletal

Fitness - Cardiovascular Respiratory

Biochemical Measures - Endocrine, Urinary, Immune

What is disease?

A harmful deviation from the normal structural or functional state of an organism, generally associated with certain signs and symptoms

What influences food choices?

- Taste

- Smell

- Texture

- Hunger/Satiety levels

- Experience

- Family

- Culture

- Cost

- Access and Availability

- Sustainability/Climate

Social =

Personal factors, behaviors, & environments

How many Americans are health illiterate?

9/10

What is economics?

A social science which is concerned with the study of the allocation of scarce resources among competing ends

What is opportunity cost?

The forgone benefit that would have been derived by an option not chosen

What non-biological factors influence health?

Occupation

Education

Income

Price of health goods

Prices of non-health goods that affect health status (food, housing)

In terms of non-biological factors that influence health, there are many disparities in _________________, __________________, and. ________________

occupation, education, and income

Life insurance companies, to be profitable (or more precisely, to set premiums accurately)....

they need to know what type of person is more likely to die at different ages

Keys and co-authors find that the measure with the best correlation between subcutaneous fat and weight & height measures was something called the 1. _______________ ____________ which they re- name as the ________________ ______________ ________________ (_______)

1. Quetelet Index

2. Body mass index (BMI)

How do you calculate BMI?

BMI = weight / height^2

Overweight: _____________________

Obese: ____________________

1. BMI between 25.0 and 29.9

2. BMI 30 or greater

Advantages of BMI

• Relatively easy to do

• Relatively inexpensive

• Non-invasive

• And can be readily understood

Criticisms of BMI

-Much of the original work on BMI and mortality relied on somewhat idiosyncratic (individual) samples that were predominantly male and Caucasian

-It does not distinguish between muscle mass and fat

-Correlation between % body fat and BMI is not perfect

-In some populations, correlation with certain diseases begins at lower BMI levels (eg in south Asian populations, risk of diabetes rises once BMI is above 23)

-It is possible to use more accurate means of measuring body fat; eg bioelectrical impedance analysis (muscle is a conductor; fat is an insulator)

-Does not account for impact of lean muscle mass to total body weight

-Nor does it account for body fat distribution

NHANES

National Health and Nutrition Examination Survey

Globally _______ of adults are obese

13%

Globally ______ of adults are considered overweight and obese

39%

At a basic level, obesity arises because of:

• Increased caloric intake that results in the accumulation of fat

• Reduced physical activity

• If energy (caloric) intake exceeds energy consumption, the body stores the excess

Obesogenic

an environment that enables weight gain and/or is not conducive to weight loss

Why would you say we live in an obesogenic environment?

• Rise in the availability of sugar sweetened beverages

• Changes in the relative prices of foods, with obesogenic foods becoming relatively less expensive

• Increased ease of access to unhealthy foods co-existing with food deserts

What individual behavior changes cause obesity?

• Reductions in physical activity

• Changes in time use, specifically reductions in time spent preparing healthier meals from scratch

What health consequences is obesity associated with?

- Cardiovascular diseases

- Diabetes

- Some musculoskeletal disorders such as osteoarthritis

- Some cancers

- Mood disorders (depression, anxiety); substance abuse

What are the economic costs of obesity?

- Direct medical costs

- Economic productivity costs

- Externalities in terms of higher medical premiums

Characteristics of disease

-Disease is a condition of the body, its parts, organs, or systems or an alteration thereof

-Results from infection, parasites, nutritional, environmental, genetic, or other causes

-Has a characteristic, identifiable, marked group of signs or symptoms

-Deviates from normal structure or function

What is obesity?

A complex disease characterized by a disproportionate body weight for height owing to an excessive accumulation of adipose tissue.

What is the ICD (International classification of disease) code for obesity?

Endocrine, nutritional, and metabolic diseases

What are the biomechanical health risks of obesity?

- Obstructive sleep apnea

- Obesity-hypoventilation syndrome

- Asthma/Reactive Airways Disease

- Osteoarthritis

- Urinary stress incontinence

- Gastroesophageal Reflux Disease

- Immobility/Disability

Obesity health risks diagram

What are the cardiometabolic health risks of obesity?

- Prediabetes

- Type 2 Diabetes

- Dyslipidemia

- Hypertension

- Non-Alcoholic Fatty Liver Disease

- Polycystic Ovary Syndrome

- Female infertility

- Male hypogonadism

What is required for the diagnosis of obesity?

An assessment of body composition (total body adiposity)

How to measure body fat?

- Hydrostatic Weighing (gold standard)

• Limited to fat and fat-free mass (fat is less dense)

- Dual X-Ray Absorptiometry (DEXA - new gold standard)

• Discriminates across more compartments

• Fat, lean mass, and bone

• Can inform on fat distribution

- Air Displacement Plethysmography (Bod Pod)

More feasible options include:

- Bioelectric Impedance (flow of electrical current)

- Skin-fold Thickness, BMI, waist circumference, waist:hip ratio

Effectiveness of tools to determine body composition

Body mass index

-Relative measure of total body weight to height

-Approximation, at best of total adiposity

-Shown to moderately correlate with direct measurements of body fat

-But does predict cardiometabolic and biomechanical risk

Underweight BMI

Normal BMI

18.5-24.9

Overweight BMI

25-29.9

Obese class I BMI

30-34.9

Obese class II BMI

35-39.9

Obese class III BMI

≥40

Android Obesity

Excess central adiposity

-associated with greater risk of health complications

What are some of health complications associated with android obesity?

-Hypertension

-Dyslipidemia

-Insulin resistance

-Diabetes

Gynoid obesity

Excess adiposity below the waist

-relatively benign

Waist-to-hip ratio

Better predictor of cardio-vascular disease (CVD) risk factors and events than BMI

White adipose tissue is classified into what two compartments based on location?

-Subcutaneous adipose tissue

-Visceral adipose tissue

_______________________ ________________ ______________ is the larger storage compartment

-Under the dermis of the skin

-Stores >80% of total body fat

Subcutaneous adipose tissue

__________________ ________________ __________________ surrounds the internal organs

-Intra-abdominal, perirenal and pericardial adipose tissue

Visceral adipose tissue

____________________ _______________________ correlates most closely with obesity-related health risks

Visceral accumulation

Anatomic differences in fat deposition

What is physiology?

A branch of biology concerned with the functioning of living organisms, and their constituent tissues or cells

First law of thermodynamics states that _____________ ______ ____________.

Energy is conserved

Once growth is completed, any excess energy not needed to maintain body temperature, cellular work, and body movement is stored and converted to _______

fat (65% of excess calories)- adipose tissue is easiest way to store energy

Obesity is characterized by an excessive accumulation of _______________

adiposity

What contributes to the positive energy balance that causes obesity (deviation from energy homeostasis)?

Low physical activity (a sedentary lifestyle) and over-consumption of dietary intake (energy) exceeds the metabolic needs of an individual

Factors of energy intake

-nervous system

-endocrine system

-microbiota

-stress or emotional factors

-medications

Factors of energy expenditure

-resting energy expenditure

-thermic effect of nutrients

-controlled ambient temperatures

-lack of sleep or shift work

-physical activity-related energy expenditure

The physiology of body weight regulation involves a ____________________________ ___________________ involving peripheral organs and the central nervous system (CNS)

endocrine network

-Hormones maintain a balance between energy intake and expenditure

Homeostatic mechanism functions on a ________________ ______________ system

negative feedback

-Senses positive or negative fluctuations in energy balance

-Nutrient and/or hormone-related

-Initiates counter-regulatory physiological response to off-set the deviation in energy balance

-Food intake and/or alteration in metabolism

__________________ is the main site of sensory integration

Hypothalamus (also cortico-limbic system and hindbrain)

What are the main peripheral organs involved in weight regulation?

Gut, pancreas, and adipose tissue

What does the hypothalamus do?

• Integrates hormonal and nutrient signals from the peripheral circulation

• Coordinates neuronal inputs to generate feedback responses

Location near the ____________ ________________ facilitates access to peripheral signals

median eminence

• Fenestrated capillaries

• "Leaky" blood brain barrier

• Permeable so hormones can enter and interact with hypothalamus

Two sets of hypothalamic neurons in the arcuate nucleus (ARC)

________________ _________ _______________ and _______________ _________________

regulate food intake and energy balance

-Functionally antagonistic

orexigenic neurons

- appetite-stimulating

- predominate in fasted state

Examples of orexigenic neurons

Agouti-Related Peptide and Neuropeptide Y (AgRP/NPY)

Anorexigenic neurons

-appetite-suppressing

-predominate in the fed state

Example of anorexigenic neurons

Pro-opiomelanocortin (POMC)

Neural circuits are regulated by ____________________ __________

peripheral cues (hormones sent from gut, pancreas, and fat)

______________ is produced by ________________ ______________ in levels proportional to whole-body fat store

Leptin is produced by adipose tissue in levels proportional to whole-body fat stores

Leptin directly activates ____________ expression and directly inhibits ____________ expression

Leptin directly activates POMC expression and directly inhibits AgRP/NPY expression

What is the net effect of leptin action?

To inhibit food intake and increase energy expenditure

Insulin is secreted from __________________ ________________ upon nutrient ingestion.

pancreatic β-cells

What does the activation of insulin receptors on POMC and AgRP neurons cause?

It changes neuronal sensitivity (long-term regulator)

Insulin potentiates the satiety action of ______________

Leptin

___________ produced by the stomach stimulates food intake

Ghrelin

-Activates AgRP/NPY neurons

What is ghrelin?

A hormone produced by the stomach during the fasted state

What are some intestinal hormones that act on hypothalamic feeding circuits to inhibit food intake?

-Glucagon-like peptide 1 (GLP-1)

-Peptide YY3-36 (PYY3-36)

-Cholecystokinin (CCK)

How can the trillions of microbiota (mostly symbiotic) benefit health?

- Detoxify compounds

- Synthesize vitamins

- Digest indigestible foods

- Yield short chain fatty acids (nutrient source and prevention of chronic disease)

What is total energy expenditure the sum of?

1. Resting energy expenditure

- resting metabolic rate

-obligatory thermogenesis (energy needed to maintain vital functions)

2. Thermic effect of food

- post-prandial thermogenesis (energy needed to metabolize meals)

3. Energy spent in physical activity

- exercise and non- exercise activity thermogenesis

-most modifiable

Factors of resting energy expenditure

-Age

-Sex

-Body size

-Body composition

-> Lean muscle mass

- Hormones

Factors that affect BMR

Physical activity

-energy spent makes second largest contribution

-most modifiable component

-exercise and non-exercise activity thermogenesis

Thermic effect of food

-lowest contribution to energy expenditure

- also called post-prandial thermogenesis

- energy expended to utilize nutrients after a meal during digestion, absorption, transport, metabolism, and storage

- depends on amounts and types of food consumed

- high protein = high TEF

- high fat = lowest TEF

What is anatomy?

A branch of biology concerned with the study of the structure of organisms and organization of their parts

What are tissues?

Groups of cells similar in structure and function

What are the subtypes of tissues?

1. Epithelial tissue (covering)

2. Muscle tissue (movement)

3. Nerve tissue (control)

4. Connective tissue (support)

-> adipose tissue (binding, protection, and storage)

Types of adipose tissue

-Brown

-Beige

-White (majority of body)

______________ __________________ are most abundant

White adipocytes

What is the function of white adipocytes?

-Energy storage function

-Secrete various bioactive substances (adipokines)

________________ _______________ is an endocrine organ

Adipose tissue

__________________ _________________ are least abundant

Brown adipocytes