Diabetology

This affects approximately 10% of people with diabetes (300,000 in Italy), and more often occurs at a young age. It is due to reduced insulin production in the pancreas, and is therefore commonly referred to as insulin-dependent diabetes. Its direct cause is unknown, but immunological factors are involved, supported by genetic factors and probably also environmental factors.

There is a rarer form of diabetes, whose onset occurs in adulthood, called LADA diabetes (acronym from the English: Latent Autoimmune Diabetes in Adults). This typically involves a deficiency in insulin production. 6-10% of the patients initially defined as type 2 are actually suffering from this form of slow-developing autoimmune diabetes towards insulin-dependency which, according to various authors, is a form of type 1 diabetes in adults.

This is the most widespread form and includes approximately 90% of diabetes cases, about 3 million people in Italy and 5.5% of the general population; Type 2 diabetes occurs more often in adulthood/advancing age and is therefore also commonly known as “maturity” diabetes (although there are rare forms with juvenile onset, called MODY – Maturity Onset Diabetes of the Young). In type 2 diabetes there is no defect in insulin production by the pancreatic Beta-cells (whose activity, however, may become insufficient in the long term), but at the origin of this type of diabetes there is a defect in the use of insulin by the cells of the body. The most probable cause is the interaction of predisposing genetic and environmental factors, which are often responsible for the onset and continuation of the disease over time. Among the environmental factors, lack of exercise and excess body weight play a large part, especially with increased abdominal adiposity; excess weight and obesity are associated with type 2 diabetes in almost 80% of patients, and in many cases weight loss alone results in a regression of the disease.

This is a specific form of diabetes, to be remembered for its clinical significance. It develops in women with high levels of glucose for the first time during pregnancy. It is a condition that affects approximately 4% of pregnancies and is probably related to a reduced function of insulin, whose activity is inhibited by that of other hormonal substances produced by the placenta; in fact in a high percentage of cases, this form of diabetes subsides after giving birth, but during pregnancy requires careful monitoring, a specific diet and often drug therapy.

There is considerable variation in symptoms and clinical course depending on the type of diabetes.

Type 1 can have an acute onset (for example in conjunction with infection or fever). The symptoms, which may give rise to suspicion of diabetes already in the initial stages of the disease, are characterised by fatigue – asthenia, excessive thirst – polydipsia, high volumes of urine – polyuria, and weight loss).

Type 2, however, has a very slow development. It can remain silent for years and the direct symptoms (similar to those of type 1) are very blurred and late, so that in many cases the first clinical symptoms are more closely related to the complications than the disease in itself.

Complications of diabetes can affect various organs and systems, and are mainly caused by damage to small and large arteries, resulting in sustained high blood sugar levels over time. For this reason, acute complications are more rare and are more often concerned with type 1 diabetes, with dehydration, cardiac and blood disorders or even ketoacidosis coma, a life-threatening condition.

In type 2 diabetes, acute complications are quite rare, while chronic complications of varying severity can commonly affect various organs and tissues, including the eyes (with retinopathy and progressive reduction in vision or blindness), the kidneys (with renal insufficiency that may even require dialysis), the cardiovascular system (with ischaemia, heart attack and heart failure, the causes of 50% of deaths due to diabetes); the lower limbs, particularly the feet (with ischaemic damage, pain and ulceration that can even lead to amputation), the central nervous system (due to vascular damage with ischaemia and stroke) and peripheral nervous system (with pain and sensitivity disorders), and the reproductive system (including erectile dysfunction in males).

As previously mentioned, apart from the type 1 disease, which has an acute onset, diabetes, especially type 2, is in most cases detected accidentally many years after the beginning of the disease (for example during surgery) or during laboratory tests. The fasting blood sugar level can only be an indicative index, but to aid diagnosis there are precise criteria set at an international level, based on specific fasting blood sugar values repeated over time, or based on certain changes in blood sugar in the space of 3 hours after sugar intake (the test used is the glucose load curve (Oral Glucose Tolerance Test-OGTT), usually using 75 g of glucose.

Laboratory tests helpful in diagnosis are the plasma C-peptide dosage (baseline or after stimulation with glucagon), which is a marker of beta-cell function, and the search for specific antibodies that act as autoimmunity markers (ICA, IA-2, IM, GADA).

In addition to the diagnostic criteria for diabetes in the strict sense, it should also be remembered that there are criteria indicative of other changes in sugar metabolism. These changes, commonly known as “pre-diabetes”, diagnosed using OGTT, are Impaired Fasting Glucose-IFG) and Impaired Glucose Tolerance-IGT): they do not constitute a medical condition but indicate a high risk of developing diabetes and an increased risk of cardiovascular events, and are often associated with other issues such as dyslipidemia, excess weight and obesity.

Once the disease has been established, it is clearly important to prevent and slow the progression of the damage, by carefully checking the metabolic picture and the possible impact of other potentially contributing factors (such as blood pressure, body weight and abdominal fat). Of particular importance is the periodic checking of laboratory tests, which must include, along with blood sugar, blood count and eg. urine, glycated haemoglobin – HbA1c, which is the most indicative marker of the glycemic trend over time, renal and hepatic function indices, cholesterol (total, HDL and LDL) and triglycerides.  Moreover, even in the absence of symptoms, adequate specialised monitoring of the target organs is necessary, with the appropriate periodic diagnostic instrumental investigations.

In all cases, the pivotal factor in the treatment of diabetic disease is the adoption of an appropriate lifestyle, with particular emphasis on eating habits and physical activity. This is recommended to all diabetic patients and, even more so, to those with weight problems and obesity.

The choice of type of diet and exercise depends on many factors (age, type of diabetes, body weight, etc.), which must be assessed; for this reason, as with the pharmacological treatment, the recommendations on this matter must be provided by expert specialists.

In many cases of diabetes, it is still necessary to resort to pharmacological therapy. Even in these cases, however, it is essential to maintain proper nutrition and adequate exercise.

At the same time, the frequently associated factors of hypertension and dyslipidemia (excess fat in the blood) must be dealt with, and treated with medication where appropriate.

The pharmacological treatment of diabetes makes use of many different drugs, with different mechanisms of action; when good glycemic control cannot be achieved using oral hypoglycaemic drugs, insulin should be used. Insulin, which is taken by subcutaneous injection, is also available in different types of products of varying composition and varying duration of action. Treatment with insulin is more typical of type 1 diabetes, but sometimes it is also required by people with type 2 diabetes.

The choice of drug therapy therefore varies from one patient to another, according to personal characteristics and the glycemic response; the efficacy and suitability of the treatment must be constantly monitored and periodically adjusted, when appropriate, depending on the clinical picture and the evolution of the disease.