It is a disorder of carbohydrate metabolism due to deficiency of internal secretion of the pancreas, insulin, and is associated with rise of sugar content of the blood and appearance of sugar in the urine. Earlier it was considered as a breakdown of body’s insulin-glucose economy. Lately, much study has been done and the role or intervention by medication at appropriate level and stage is being appreciated.
Causes of Diabetes
There are many points in the sequence of events between insulin synthesis and release, its clearance and action, and glucose uptake by the various organs, where abnormality or biochemical fault may upset the normal balance and produce the diabetic state. With advancing years, protein synthesis is generally slowed down and this also applies to insulin production. It is not surprising therefore that recent studies show a high prevalence of hyperglycaemia (up to 50 per cent) among the elderly. The close correlation between obesity and diabetes indicates that under-exercise and the deposition of adipose tissue lead to a breakdown in the body’s insulin-glucose economy despite normal or over-production of insulin by beta cells. In young-diabetics there seems to be an idiopathic failure of beta cell function.
The aggravation of hyperglycaemia in Cushing’s disease, by steroid therapy and in pregnancy, may be attributed in part to changes in protein metabolism, and in part to alteration of tissue sensitivity to insulin. The association between acromegaly and diabetes and the production of intense ketonuria when growth hormone is given to insulin-dependent diabetics indicates that this hormone, too, increases the body requirement for insulin.
Depending largely upon the severity and rapidity of the metabolic decompensation, hyperglycaemic patients may present in four ways, irrespective of the possible precipitating factors :
(b).Less frequent symptoms : include irritability, vomiting, abdominal pain, muscle cramps and peripheral tingling, This onset is usual (but not universal) among children and adolescent diabetics, but may occur among the elderly.
2(a).Gradual Onset: There is less intense thirst and polyuria, although nocturia may be noted. The obese may lose weight over a period of months, or may have gained weight lately.
(b). Pruritus vulvae or crops of boils : may occur; lassitude is common, and middle-aged males may complain of loss of libido, and impotence. This onset is usual in middle life, but may be observed among younger and older patients.
3.Symptoms of complications : Many older people present symptoms of complications of diabetes in the eye (cataract, retinitis), peripheral nerves (neuritis), Kidneys (nephritic syndrome), blood vessels (gangrene, intermittent claudication, and coronary artery disease)