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Sex affects health: women are different
than men
I.
II.
III.
IV.
Osteoporosis
Different patterns of Melanoma occurrence
Autoimmune conditions
Body composition & metabolism
Sex affects health


Males & females have different patterns of
illness
Diseases other than those of the reproductive
system affect both sexes, often with different
frequencies or presentations – or they may
require different treatments
I. Osteoporosis

Osteoporosis –

Results when the rate of
bone resorption outstrips
the rate of bone
formation

35% of all women >65
years old have
osteoporosis (15% of all
Caucasian women)
Normal bone: T-score better than -1.
Osteopenia: T-score between -1 and -2.5
Osteoporosis: T-score less than -2.5
Factors that contribute to bone health
1) Dietary Calcium & Vitamin D required for bone
formation
•
•
Premenopausal women should obtain 1,000 mg/day
Postmenopausal women – 1,200 to 1,500 mg/day
2) Estrogen & testosterone critical for
maintenance of peak bone mass
3) Weight bearing exercise creates strong bone
structure
4) Smoking weakens the bone structure
5) Certain drugs ( e.g. Corticosteroids) promote
bone loss
II. Different patterns of Melanoma
occurrence





non-melanoma =
Melanoma –
Incidence higher among women, however
mortality higher among men
Cause –
Risk factors –
Early detection
is critical!!!
III. Autoimmune conditions

The adaptive immune response

Activation of the complement and coagulation systems

plasma activity level of phospholipase A2, a key enzyme in
causing chronic inflammatory diseases, is significantly
higher in Caucasian women than their male counterparts
Interleukin-1-receptor-II (reduces the inflammatory
response), is present in higher concentration in men than
women

A. Autoimmune disease



May be localized or ubiquitous
Difficult to identify leading causes, difficult to diagnose
May be associated with infectious agents (virus, bacteria)



Hypothesized that "molecular mimicry” may be occurring- epitopes of
the microorganism closely resemble self-antigens
"bystander effect" microorganisms expose self-antigens to the
immune system by directly damaging tissues during an active
infection
Many autoimmune disease are highly predominant in females,
most during their child-bearing years
 “

Systemic and organ-specific autoimmune diseases, (e.g. rheumatoid
arthritis, myocarditis) are the leading cause of death in women >65
years of age
Infections occur before the onset of symptoms of autoimmune disease,
making links to specific causative agents difficult. When a person is first
infected (day 0), usually no symptoms are apparent. Signs and symptoms
of autoimmune disease are clearly present and easily confirmed by
physicians during the chronic stage of autoimmunity. However, the
infection has been cleared by this time, making it difficult to establish that
an infection caused the autoimmune disease (from Fairweather & Rose,
2004)
Some common autoimmune diseases:

Hashimoto’s thyroiditis (underactive thyroid)





Graves’ disease (overactive thyroid)




swelling and damage to the joints, skin, kidneys, heart, lungs, blood vessels,
and brain
rashes on parts of the body
Multiple sclerosis (MS)




Insomnia, irritability, weight loss, heat sensitivity, fine brittle hair
weakness in your muscles, shaky hands
Lupus


Tiredness, depression
sensitivity to cold, muscle weakness and cramps
weight gain, dry hair, tough skin
constipation
weakness and trouble with coordination, balance, speaking, and walking
tremors
numbness and tingling feeling in arms, legs, hands, and feet
Rheumatoid arthritis


inflammation of the joints
muscle pain, weakness, fatigue
Symptoms of autoimmune diseases can come and go, and severity can vary
~6.7 million women affected by autoimmune disease
B. Why are these autoimmune diseases affecting more
females than males?
1)
2)
3)
Genetics?

AD tend to cluster in families and in individuals which suggests
that common mechanisms are involved in disease susceptibility

However, twins studies indicate that genetic as well as
environmental factors are necessary
Hormones?

Variety of sex hormone receptors found on immune cells &
cytokine receptors have likewise been discovered on hormoneproducing tissues, which suggests bidirectional regulation of the
immune response

Proinflammatory cytokines stimulate the release of
glucocorticoids from the hypothalamus-pituitary-adrenal axis,
which regulates the inflammatory process, along with androgens
and estrogen

Recent study found that Estrogen amplifies the immune
response to coxsackievirus B3 in mice, increasing TNF-α and IL4 levels
Different environmental exposure than men?
IV. Body composition & metabolism

Body fat –

Hormonal changes may increase a female’s appetite
Menopause is associated with a shift toward more
fat + deposition of fat in abdominal region
Different energy requirements due to different body
size, composition and activity levels –

