Diabetes Mellitus

I

Introduction

Diabetes Mellitus, common disorder of metabolism in which the amount of glucose, or sugar, in the blood is too high, a condition known as hyperglycaemia.

II

Causes

Diabetes develops either because the body’s pancreas is not producing enough of the hormone insulin to metabolize glucose, or because the insulin fails to act on receptor cells in the blood. When blood glucose rises above a certain level, it spills over into the urine. The condition, which may be hereditary, affects roughly 3 per cent of men and 2 per cent of women; up to half of the affected population may not have been diagnosed.

Though there is no cure for diabetes mellitus, proper insulin and other therapy together with a correct diet enable most patients to live virtually normal lives with minimal side effects, though their mortality rate is higher.

III

Effects

Moderately raised blood glucose levels can eventually cause kidney failure; damage to vision from ruptured blood vessels in the eyes; and restricted blood flow to the limbs, which may lead to gangrene and subsequent amputation. Diabetes mellitus is also associated with a risk of coronary heart disease that is two to three times higher in men, and four to five times higher in women before the menopause. The risk of a stroke is increased two to three times.

Untreated, the disease can lead to coma and death, which was the usual outcome before the discovery of insulin in 1921. In the mid 20th-century, about 30 per cent of pregnancies among women with diabetes mellitus ended in stillbirth or death of the child within weeks of birth, as well as a high percentage of abnormalities. Today, the stillbirths figure is far lower and the perinatal mortality rate (total of stillbirths plus deaths in the first four weeks of life) 5.6 per cent, compared with l.4 per cent in the general population. Babies of mothers with diabetes tend to be larger and have an increased risk of complications, such as breathing problems and hypoglycaemia (low blood sugar) at birth.

IV

Symptoms

A common symptom of diabetes mellitus is weight reduction caused by the loss of fluids and fat; this is because of the inability of the body to break down carbohydrates. Other symptoms are passing copious amounts of urine; increased thirst; disturbances of vision; limb numbness; genital itching; cessation of menstruation in women; and a tendency to boils and skin infections. About half of people affected are undiagnosed for some years until high glucose levels are detected in samples of blood or urine during medical tests.