Diabetes mellitus is caused by a deficiency in the secretion of insulin.


Predisposing factors:-






Heredity: – A familial tendency to diabetes has been found to exist. Genetic factors are involved when the disease develops before the age of 40 years.

Age: – The disease occurs at all ages but a greater percentage of the cases occurs in persons over 45 years of age.

Sex: – The disease affects both sexes. The incidence of the disease is somewhat greater in men than in women.

Obesity: – The incidence of diabetes is greater among obese persons than in persons of normal weight.

Stress: – stress of various types e.g.  Frequent infections, worry, irregular meals, etc, may also contribute to the development of the disease.


Metabolism in diabetes mellitus:-

The metabolism of carbohydrates, fat and proteins in diabetes mellitus is briefly discussed below;

Carbohydrate metabolism:- Due to decreased oxidation of glucose in the tissues, the level of blood glucose is increased markedly, leading to glycosuria. The quantity of glucose present in urine may vary from 0.5 to 6 per cent depending on the severity of the disease. The volume of urine is increased (polyuria).

Fat metabolism: – Since glucose is not utilized, there is increased breakdown of fats to acetate and ketone bodies (acetoacetic acid, acetone and b-hydroxybutyric acid). The ketoacidosis which develops may lead to dehydration and coma.

Protein metabolism: – Since carbohydrates are not utilized for the production of energy, there is increased breakdown of tissue proteins and increased oxidation of dietary proteins for use as energy. Hence there is an increase in nitrogen excretion leading to negative nitrogen balance. Wasting of muscles is a common symptom in chronic diabetes.  Hence diabetics need more proteins (about 2 g/kg body weight) than normal subjects. The protein allowances should be correspondingly higher (50 percent higher) for diabetic children and expectant and nursing mothers. Increased protein intake may help to increase insulin production.


Clinical types of diabetes:-

 The classification of diabetes from the clinical point of view is as follows:-

Juvenile Diabetes: – This includes all diabetics below the age of 20 years. The disease is primarily due to deficiency of insulin. The subjects are generally undernourished and emaciated. They require a high calorie- high protein diet and insulin for maintaining the blood sugar level within normal limits.

Adult Diabetes: – A majority of them are obese subject. The treatment will consist of a reducing diet rich in proteins and carbohydrates along with insulin parenterally to maintain the blood glucose within normal limits. These subjects require more insulin than juvenile diabetes.


Treatment of Diabetes mellitus:-

The principles of treatment are as follows:-

Diet: – Only weighed quantities of food should be consumed according to the diet schedule prescribed by the physician. The most important considerations should be given to

Calorie  needs

The proportion of calories from carbohydrates, fats and proteins.

Calorie requirements:  The calorie requirements should be about 5 percent  less than the actual requirements for the patient’s height and ideal body weight. In the case of an obese person, the calorie requirements for weight (for his height).


The proportion of protein, fat and carbohydrate in the diet:-

Proteins: – Since diabetics, in general, are in negative nitrogen balance, they should receive about twice as much protein as normal subjects. The proteins should provide about 20 to 25 per cent of the calories in the diet.

Fluid: – A liberal fluid intake is desirable.

Carbohydrates: – The daily intake of carbohydrates should provide about 40 per cent of the calories to prevent ketonuria. The carbohydrate intakes should not exceed 40 per cent of the total calorie intake (except in the case of obese diabetes as indicated in table above) as otherwise, it will be difficult to control the blood sugar level.

Fat: – The fat intake should be adjusted to provide about 40 per cent of  total calories in the form of fat. In the case of obese diabetics, it may be desirable to limit the fat intake to provide about 20 per cent of the total calories, as the body fat will be mobilized and oxidized besides fat.

Vitamins: – It is desirable to include one multivitamin tablet in the diet or provide the daily requirements of all essential vitamins.


Uses of Saccharine and Sorbitol:-

Saccharine can be consumed in moderation as a sweetener. Saccharine should not be consumed in excess as it may prove harmful to the patients. Sorbitol is an alcohol obtained by hydrogenation of glucose. It is almost completely absorbed and utilised. The rate of absorption is so slow that it does not increase the blood sugar level. It is used in place of sucrose in the manufacture of diabetic jams, fruits chunks, chocolates, etc.

Exercise: – Moderate exercise such as brisk walking for 3 or 4 miles a day will help to increase the calorie needs and avoid the development of obesity.

Insulin and oral anti diabetic drugs:-                          

In addition to the diet insulin and oral anti diabetic drugs should be taken as advised by a physician. These will be essential for controlling blood sugar level.