Although Charles Pierre Louis De Gardanne coined the term menopause in the first-ever article written on the subject—Menopause: The Critical Age of Women (1821)—the condition had already been described by Greek philosopher Aristotle.
Menopause is the final menstrual period, confirmed after 12 straight months without a period. Perimenopause is the transitional time immediately before natural menopause when the changes of menopause begin. At menopause, there is a sharp decrease in hormone levels, especially oestrogen and progesterone, owing to cessation of ovarian function. During perimenopause, however, oestrogen levels can fluctuate wildly, being higher than those seen at a younger age, giving rise to periods. The impact of lower progesterone levels is mainly on the menstrual cycles. There is also a decline in testosterone, present in small quantities in women. But this is related to ageing rather than menopause. The decline in testosterone has been linked to reduced libido.
Most of the classic menopause symptoms are thought to be owing to oestrogen deficiency. Oestrogen keeps the genital tract and reproductive organs healthy—moist, elastic and well nourished with blood. The muscles and mucosa of the urinary and genital tracts become weak and dry in the absence of oestrogen. This could result in vaginal and vulval dryness, itching, irritation and painful intercourse. Urinary frequency, cystitis and incontinence are also commonly observed. Hot flushes and night sweats are the typical symptoms of menopausal transition. The exact genesis of these 'vasomotor' symptoms is still unclear, but the impact of oestrogen deficiency on thermoregulation is thought to play a major role.
The skin is impacted by oestrogen deficiency, resulting in dryness, loss of elasticity, thinning and wrinkling. Poor wound healing, hair loss, acne and body hair growth, too, are a result of lack of oestrogen.
Bone and joint symptoms are common at menopause. However, they are not entirely owing to lack of oestrogen. Osteoarthritis is also common at this stage, so it is difficult to distinguish the effects of age from oestrogen deficiency. Oestrogen has direct action on the bone-resorbing cells, the osteoclasts. Decline of oestrogen at menopause accelerates bone loss. This makes women prone to osteoporosis and fractures as they grow older.
Weight gain is a concern during this period. From 45 to 55 years, most women gain at least 5 kilos. Unlike what most seem to believe, this weight gain is related to slowing of metabolism with age, compounded by changes in lifestyle, and not owing to oestrogen deficiency. Increased central fat deposition leading to change in body contours from pear to apple shaped is, however, a result of oestrogen deficiency. Weight gain, in turn, leads to increased risk of conditions like diabetes and heart disease.
The association between depression and menopause has been known for more than a century. It is thought that drastic, rapid hormone fluctuations during perimenopause could affect brain neurotransmitter equilibrium in vulnerable women. It is possible that the troublesome hot flushes, night sweats and consequent insomnia also contribute to depression and mood changes. With the settling down of oestrogen levels as menopause is established, these features become less marked.
Thus, the complex changes that occur in a woman's body and mind at menopause are a result of a marked change in her hormonal milieu, with the dominant feature being initial fluctuations and ultimate deficiency of oestrogen.
Dr Mithal is chairman, division of endocrinology and diabetes, Medanta-The Medicity, Gurgaon.