A L1.3 BP & env Flashcards Preview

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Flashcards in A L1.3 BP & env Deck (15):
1

BP correlations within the family

Genetic correlation                 Results correlation

MZ twins (1.0)                           0.46

DZ twins (0.5)                          0.32

Siblings (0.5)                            0.30

Parent offspring (0.5)              0.24

Spouse-spouse (??)                 0.15

2

Differences b/w parent and offspring

Generation Gap: Env of parent & offspring is different

3

Difference b/w MZ/DZ twins & Siblings

  • MZ & DZ twins share similar/same environment (even same gestation)
  • ∴ show significant difference from siblings

4

Source of different variations

Variations                      Source

b/w pop                         Env

b/w individuals             Genes

Within individuals         Env

5

Observe/measure env factors

  • Intervening
    • Take out of env and put in new
  • Observational
    • Change env they are in

6

Na+

  • ↑ Salt → ↑ ECF in body → ↑ BP
  • 150mmol Na/day recommended; BP ↑0.04mmHg/mmol Na/day
  • Correlation of salt & BP:
    • Weak b/w pop for healthy subjects
    • None within pop for healthy subjects
    • Steep for elderly
      • Kidney starts to lose function with age → unable to balance Na
    • Hypertensive subjects → low salt diet ↓BP

7

Alcohol

  • ↑ alcohol → ↑ BP
    • Independent of other factors
  • But is reversible (i.e cut down beer → BP & CV risks)
  • Sympathetic NS activated by alcohol (may contribute to ↑BP)

8

K+

  • ↑K+ → ↓BP (weak correlation) (But low K+ diet ↓BP in hypertensive subjects
  • From fruits and veg

9

Na/K ratio

  • Na/K ratio best express correlation with BP variations within pop
    • i.e those with high Na & low K diet shows a high BP
    • But not very accurate (does not take into account lifestyle differences, i.e. amount of processed food taken by different groups & amount of exercise…)

10

Ca2+ & Mg2+

  • ↓Ca → ↑BP
  • Controversial

11

Fats

  • No relationship b/w fats & BP
  • Only for omega3-polyunsaturated fats → ↓BP in hypertensive subjects
    • May make prostanoids (vasodilator compounds)

12

Exercise

  • Fitter → ↓BP

13

Psychosocial stress

  • Hard to measure ∴ unreliable conclusions

14

Smoking

  • BP rises during smoking
  • BUT long-term smokers tend to have lower BP
    • May be result of smoking being an appetite depressant → ∴↓BMI

15

Population variations

  • Populations variation in BP differs more in mean than shape
  • Migration studies:
    • Japanese moved from Japan → Hawaii (continue observations)
    • ↑BMI → ↑BP over the years & after generations