Physical Development in Middle & Late Adulthood

University of Lethbridge - KNES 3630: FIAT LUX

Instructor

• Kelsey Kendellen, PhD

Lecture Objectives

• Summarize the physical changes that occur in old age

• Describe menopause

• Identify the pros & cons of hormone replacement therapy (HRT)

Physical Development in Late Adulthood

Height Changes

• Average shrinkage: 1/4 to 1/3 inch per decade after 40

• Men: lose ~0.5 inch from ages 30 to 50; additional ¾ inch from 50 to 70

• Women: lose approximately 2 inches over 50 years (ages 25 to 75)

• Causes of shrinkage:

  • Loss of fluid in discs between vertebrae (spine shrinks)

  • Loss of muscle mass contributing to poor posture

Weight Changes

• Increase in the percentage of overweight/obese adults from early to late adulthood:

  • 18-34 years: 31%

  • 50-64 years: 39%

  • 65+ years: 39%

• Overweight and obesity correlate with increased risks for:

  • Type 2 diabetes

  • High blood pressure

  • Heart disease (Source: Statistics Canada, 2021)

Muscle Strength

• Sarcopenia:

  • Age-related loss of muscle mass and strength

  • Maximum physical strength occurs in 20s

  • After age 50, muscle loss is approximately 1-2% per year

  • Decreased muscle mass can lead to a “sagging” appearance

Bone Health

• Osteoporosis:

  • Extensive loss of bone mass and tissue

  • Commonly referred to as the “silent thief”

  • Most susceptible: older women post-menopause due to decreased estrogen levels

  • Common fracture sites: hip, spine, wrist, and shoulder

Joint Health

• Arthritis:

  • Inflammation of joints leading to pain, stiffness, and movement difficulties

  • Approximately 1 in 5 Canadians live with arthritis

Osteoarthritis (OA)

• Degeneration of protective cartilage and joint fluid, making movement painful

Rheumatoid Arthritis (RA)

• Autoimmune disorder where the body attacks its own joint tissues

  • Usually affects parallel joints on both sides of the body

Sensory Functioning

• Decline in all five senses with aging:

  • Vision

    • Presbyopia: gradual loss of ability to focus on nearby objects starting in early/middle adulthood

    • Significant vision decline in late adulthood, especially in contrast sensitivity and glare tolerance

    • Age-Related Macular Degeneration (AMD): deterioration of the macula leads to loss of central vision, sparing peripheral vision

    • Cataracts result in cloudy or opaque lens, can progress to blindness

  • Hearing

    • Hearing loss begins by age 40, affecting ability to hear high frequencies

    • Men generally lose sensitivity sooner than women

  • Smell and Taste

    • Loss starts around age 60 due to fewer taste buds and changes in brain structure

  • Touch and Pain

    • While touch sensitivity declines, many older adults report persistent pain, primarily back pain, peripheral neuropathy, and chronic joint pain

Physical Development: Women

Menopause

• Definition: the cessation of menstrual periods, marks the end of reproductive years

• Menopause is influenced by hormonal changes:

  • Ovaries stop releasing eggs monthly

  • Decrease in estrogen and progesterone levels

  • Occurs after 12 consecutive months without a period

• Typical age range: around 51, but may vary (45-55)

• Perimenopause: 6-8 years prior to menopause, gradual decrease in estrogen production

• Premature menopause occurs in 1 in 100 women before age 40, can be due to genetics, metabolic issues, or autoimmune conditions

Treatment-Induced Menopause

• Can be a result of surgical removal of ovaries, chemotherapy, or pelvic radiation

• Symptoms may be more intense than natural menopause

Symptoms of Menopause

• Fluctuating hormonal levels lead to:

  • Irregular periods

  • Memory loss

  • Joint aches

  • Changes in sexual desire and vaginal dryness

  • Hot flashes, fatigue, sleep disruption, mood swings

  • 75% of women report symptoms affecting their daily lives

Hormone Replacement Therapy (HRT)

Types of HRT

• Estrogen-only: for women without a uterus

• Combined HRT: estrogen plus progestin, available in various forms (patches, pills, creams, etc.)

Risks and Benefits of HRT

• Benefits:

  • Effective for vasomotor symptoms (hot flashes) and genitourinary issues

  • Helps maintain bone density and improve quality of life

• Risks:

  • Long-term combined HRT (5+ years) associated with:

    • Increased risks of breast & ovarian cancer, heart disease, stroke, and pulmonary embolism

Current Recommendations

• HRT should be individualized based on severity of symptoms and health status

• Not recommended if there’s a history of specific cancers or cardiovascular issues

• Best suited for healthy women under 60 who have been menopausal for less than 10 years

Physical Development: Men

Hormonal Changes in Middle-Aged Men

• Gradual decline in testosterone levels by approximately 1% per year after age 40

• By age 70, testosterone levels can drop to 30% below peak

• Most men maintain fertility through middle age

Sperm Quality

• Age affects semen parameters:

  • Sperm concentration, volume, and motility decline with age

  • Total sperm count = sperm concentration x volume of ejaculation

  • Sperm motility (ability to swim) is key for fertility