Final Section 3: Sodium and Public Health

Question 1

function of electrolytes

Answer 1

fluid compartment balance, acid-base balance, muscle contraction (Ca-Mg), conduction of nerve impulses

Question 2

water intake recommendation

Answer 2

1-1.5ml /kcal/energy expenditure
2.7L for women, 3.7L for men
increased for pregnancy/lactation, diarrhea, vomiting, fever, heavy exercise, hot environments, diabetes (glucose and water), bleeding

Question 3

what is thirst?

Answer 3

slow response, can lag behind - when you feel thirst you are already dehydrated
mouth sensations, stomach, hypothalamus

Question 4

fluid intake and output

Answer 4

always matched, increased intake will increase output
intake from fluids, food and metabolic processes
output through kidneys (obligatory 500mL), skin, lungs, feces

Question 5

sodium as an electrolyte

Answer 5

extracellular cation, blood volume regulation, Na-K ATPase

Question 6

Potassium as an electrolyte

Answer 6

intracellular cation, blood volume regulation, high blood volume leads to cardiac arrest, deficiency due to vomiting/diarrhea, or diuretics (for hypertension)

Question 7

regulation of fluid balance

Answer 7

GI tract handles 10L per day of fluid secretion reabsorption
Kidneys regulate fluid balance with Renin-Angiotensin-Aldosterone System to regulate water and sodium excretion

Question 8

how a nephron works

Answer 8

working unit of kidney
glomerulus is filtering site passing waste products into tubule
tubule is site of reabsorption of fluid and nutrients

Question 9

Renin-Angiotensin-Aldosterone System

Answer 9

1. Kidneys respond to reduce blood flow by releasing renin
2. Renin initiates activation of angiotensinogen protein to angiotensin
3. Angiotensin signals adrenal glands to secrete aldosterone and causes blood vessels to constrict, raising BP (and signals pituitary release of ADH)
4. Aldosterone and ADH signal kidneys to retain Na and water to increase blood volume

Question 10

ADH system

Answer 10

1. hypothalamus responds to high Na in blood and stimulates pituitary
2. pituitary releases ADH
3. ADH signals kidneys to retain Na and water to raise blood volume

Question 11

normal and hypertensive BP

Answer 11

normal: 120 mm Hg over < 80 mm Hg
elevated: 120-129 mm Hg over < 80
stage 1 HT: 130-139 mm Hg over 80-89 mm Hg
stage 2 HT: >/=140 mm Hg over >90mm Hg

systolic - pressure in left ventricle contracting
diastolic - pressure in left ventricle relaxing

Question 12

evidence with Na

Answer 12

linked high Na intake to hypertension
linked hypertension to CVD and stroke
no direct link of Na intake to CVD and stroke

Question 13

consequences of high BP

Answer 13

stroke, memory loss, loss of vision, heart attack, kidney damage

Question 14

modifiable risk factors for hypertension
non modifiable risk factors for hypertension

Answer 14

smoking, secondhand smoke, excess weight, physical inactivity, unhealthy diet and stress

genetics, family history, ethnicity, older age, male sex, psychosocial stress

increased risk with comorbidities: heart diease, dyslipidemia, diabetes, insulin resistance, kidney disease, sleep apnea, obesity

Question 15

hypertension treatment

Answer 15

DASH (Dietary Approach to Stop Hypertension) high K diet, decreased sodium intake, physical activity, weight control, stress management, diuretics medications
ACE inhibitors - angiotensin converting enzyme inhibitor

Question 16

DASH diet

Answer 16

high fruit/veg, high K
30% kcal from fat (nuts, fish, whole grains, low fat dairy)
vegetarian protein
low sugar
nutrient dense
increase K, decrease Na, high Mg, and Ca
lowers cholesterol and LDL specifically

Question 17

Na AI and CDRR, K AI and UL
stats

Answer 17

Na AI: 1500 mg/day, CDRR 2300 mg/day
K AI: 4700 mg/day, UL none
90% men, 60% consume above CDRR of Na (mostly women over 70)
most people consume less than 50% of K AI

Question 18

goal of Health Canada Sodium Working Group?

Answer 18

get people to average AI intake of 1500mg per day Na

Question 19

hypertension stats

Answer 19

20% hypertensive, 20% pre-hypertensive
reduced Na intake to 1800mg/day would save 3 billion in health care costs

Question 20

CDRR is contained in
% intake sources

Answer 20

1 tsp of salt, 6g
10% is table salt, processed and fast foods is 75% intake

Question 21

salt functional properties in food industry

Answer 21

microbial food preservation, texture, flavor, color, controlled fermentation of bread and cheese
breads are highest source of added Na

Question 22

why didn’t bill pass in 2010?

Answer 22

Bill did not pass because parliament was worried people would just add the salt back on their own food
Difficult to show direct link between Na and CVD

Question 23

how to increase sodium literacy

Answer 23

consumer education is new target
change DV to AI instead of CDRR (higher %DV)
adding no salt added labels
moving Sodium to bottom of label (stands out more)

Question 24

ACE inhibitors are

Answer 24

angiotensin converting enzyme inhibitor