Lecture 13

Question 1

Vitamin intake

Answer 1

Ca2+: females need an increase in daily Ca intake after 50 years while males need increase after 70 years old.

Vitamin D: Deficiencies increase risk of osteoporosis. Older adults are likely to have deficiency due to decreased capacity to produce and absorb Vit D, decrease sun exposure, decrease dietary intake, drug interactions. As we age, increase Vit D intake

Question 2

Estrogen

Answer 2

Estradiol is most potent. They can directly or indirectly impact osteoblasts and osteoclasts. In males, testosterone is used to produce estrogen through enzymatic conversion.

Question 3

After menopause

Answer 3

decrease in ovarian E2 production. Rapid bone loss ~3-5% loss annually for 5-10 yrs. Severity and onset influenced by genes, exercise, BMI, smoking and nutrition.

Question 4

Testosterone decrease

Answer 4

Due to medical treatment (prostate cancer treatment) and developmental factors. Decreases estradiol levels. Risk of osteoporosis.

Question 5

Effects of hormone deprivation on bones

Answer 5

E2 and T deficiency increases rate of bone remodelling, osteoclastogenesis, osteoblastogenesis, bone reabsorption and formation. But, bone reabsorption > formation.

Question 6

Muscle Mass

Answer 6

MM and strength peaks in you adulthood then plateus before decreasing, but MS declines faster than MM

Question 7

Grip strength

Answer 7

increases and peals in early adult life. Maintained through midlife then decreases.

Question 8

Gait speed

Answer 8

Increases in early life then slowly decreases after teenage years.

Question 9

sarcopenia

Answer 9

Progressive and generalised skeletal muscle disorder involving the increase loss of muscle mass and function. Associated with increase in falls, functional decline. fragility and death. Prevalence 10-27%. Involves at least 2 parameters out of MM, MS, physical performance. Range in prevalence due to different cut offs.

Question 10

Nutritional

Answer 10

decrease protein, energy, micronutrients

Question 11

Inactivity

Answer 11

Best rest, decrease activity

Question 12

Diseases

Answer 12

bone and joint disease

Question 13

Iatrogenic

Answer 13

Medical treatments

Question 14

Muscular changes in sarcopenia

Answer 14

decrease size and no. of myofibres, transition of muscle fibres from T1 (slow) to T2, decrease satellite cells in T2 (important for maintenance and repair). Fat infiltration due to decrease energy expenditure from

Question 15

hormonal changes in sarcopenia

Answer 15

decrease E2 and T production after menopause. In healthy men, theres no sharp decrease initially but there is an increase in variability in T levels unless due to treatments or medicine or injury. Estrogens are involved in muscle strength/force generation but not muscle size generation.

Question 16

sarcopenia in men

Answer 16

T deprivation cause muscle atrophy and increased adiposity. Strength may decrease due to atrophy. Walking and balance alters increases risk of falling

Question 17

Bone matrix

Answer 17

balance between collagen and hydroxyapetite is vital. Too much collagen = bendy bones, too much HA= brittle bones