Diabetes mellitus, an overview

By Cristiano Antonino On Apr 21, 2023

Diabetes is a chronic metabolic disease caused by an elevated blood glucose level, a condition known as ‘hyperglycaemia’ that appears as a result of a defect in the production or function of insulin normally secreted by the pancreas

According to the most recent research of the WHO (World Health Organisation), the number of sufferers has quadrupled since the 1980s and is constantly growing.

In Italy, estimates speak of around 3 million sufferers (source: ISTAT), most of whom are adults aged between 70 and 75.

It is not uncommon to find this pathology also in children and adolescents, just as cases of gestational diabetes (which can affect up to 8% of future mothers) are not uncommon.

Experts point out that the number of sufferers could be even higher, since in many individuals (around 1 million) the disease remains asymptomatic and latent.

To this end, it is important for everyone to carry out preventive tests in order to eventually initiate the appropriate treatment and avoid complications.

These diagnostic investigations must be accompanied by a healthy lifestyle, made up of good habits, a balanced diet and regular physical activity, since one of the risk factors for the onset of diabetes mellitus are overweight and obesity.

Diabetes: what it is and how to recognise it

Diabetes mellitus, a particular type of diabetes, is a condition caused by incorrect management of insulin secreted by the pancreas.

In every individual, glucose intake and insulin secretion are necessary for the body to function properly.

The former represents the main source of sugars, providing the energy needed for the proper functioning of cells; the latter is a hormone released by the beta cells of the pancreas, aimed at regulating and managing the utilisation of glucose by cells.

When the pancreas’ production of insulin is insufficient, glucose is present in excessive quantities and generates a condition called hyperglycaemia, which can lead, if prolonged over time, to the onset of diabetes.

It can also happen that insulin is present but that the body’s organs and tissues have little reactivity to it, allowing glucose to be deposited in excess.

To date, medicine defines three macrocategories of diabetes: type 1 diabetes mellitus, type 2 diabetes and gestational diabetes, which affects women during pregnancy and normally disappears after delivery.

Diabetes is neither a painful nor contagious disorder, but it is necessary to intervene promptly with the appropriate treatment because, if left untreated, a prolonged condition of hyperglycaemia can lead to damage to various systems, especially the cardiovascular and renal systems.

The most common and widely used therapy involves the parenteral administration of insulin

Diabetes presents rapidly growing numbers, with type 2 diabetes mellitus in particular registering more cases among the world’s population.

A number of common risk factors have been observed: many sufferers are overweight and obese due to an unhealthy lifestyle, consisting of an unbalanced diet and sedentary lifestyle, as well as high levels of stress.

Diabetes: the existing types

The new classification drawn up by the WHO in 1997 establishes the presence of three main types of diabetes, to which one can add the so-called ‘prediabetes’ stages, particular and intermediate situations between a healthy individual and one who is affected by the disease.

Type 1 diabetes mellitus is caused by a malfunctioning of the immune system

The white blood corpuscles, which during their normal activity should only attack and destroy potential pathogens (such as viruses and bacteria), act against the individual’s own cells, which are essential for the correct functioning of the body (self-reactivity).

Recognised as foreign are, in this case, the pancreatic beta cells that represent a specific cell subpopulation of the pancreas and are found within the ‘islets of Langerhans’.

This particular type of diabetes is also called juvenile diabetes, because it affects individuals mainly during their childhood and adolescent phases.

It is often difficult to recognise early on, because the symptoms appear very slowly and develop over years.

In type 2 diabetes mellitus, the main symptom is insulin resistance

Insulin is secreted by the pancreatic glands, but the patient suffers from a deficiency on the part of tissues and organs of the body that do not react appropriately to the insulin produced, and thus do not lower blood glucose levels.

Either insulin is produced but in insufficient quantities for normal vital and energy functions, or it is produced correctly but used incorrectly by the body.

This type of diabetes is the most common worldwide and predominantly affects individuals between 40 and 50 years of age.

Type 1 and type 2 diabetes mellitus can also be caused by viral infections (rubella, cytomegalovirus) or genetic disorders (Down syndrome, Klinefelter syndrome, Turner syndrome, Friedreich’s ataxia, Laurence – Moon syndrome, myotonic dystrophy, Prader – Willi syndrome).

The third and last case is gestational diabetes

As the word itself says, it can affect women during pregnancy.

This happens because certain hormones released by the placenta affect the proper release or functioning of insulin.

In most cases, the condition disappears with the end of pregnancy but makes mothers more at risk of developing the same type of diabetes in subsequent pregnancies.

Having gestational diabetes does not preclude carrying the pregnancy to full term, but it is important that glycaemic balance is kept under control during that period.

Therefore, constant insulin therapy is necessary, combined with a healthy, balanced diet, glycaemic control and constant check-ups.

When is prediabetes?

Prediabetes is an intermediate state between the individual’s normal condition and the presence of diabetes.

It is often nothing more than an alarm bell of the latter’s arrival.

Generally asymptomatic, it can only be recognised when an inexplicably high blood sugar level is found.

It is not to be considered a real disease, but it is nevertheless a state to be monitored because it can easily lead to the onset of diabetic forms.

They are part of prediabetes:

impaired fasting blood glucose (IGF): when 8 hours after the last meal blood glucose levels are above normal (up to 100 mg/dL), but not high enough to be considered and included among cases of diabetes (above 126 mg/dL).
impaired glucose tolerance (IGT): when, after taking the oral glucose tolerance test, the results are between 140-200 mg/dL.

A final type of diabetes that is universally known, but much less talked about, is diabetes insipidus.

Its symptoms consist of excessive thirst and diuresis.

It differs from classic diabetes in that the problem is not the high amount of glucose in the blood: it appears, in fact, due to lack of or insufficient production of a hormone called vasopressin (which serves to keep the blood plasma constantly liquid), a diuretic hormone or ADH.

If vasopressin is absent or insufficient, we speak of central or ADH-sensitive or neurogenic diabetes insipidus.

Whereas if it does not work adequately at the renal level it is called ADH-insensitive or nephrogenic.

Diabetes can also result from genetic causes: this is the case of monogenic diabetes (MODY Maturity Onset Diabetes of the Young), which is transmitted from one generation to the next.

Lastly, diabetes may be secondary to other diseases (chronic pancreatitis, liver cirrhosis, chronic renal failure, acromegaly, Cushing’s syndrome) or to medication (prolonged cortisone therapy, pancreas removal).

Diabetes: the symptoms that enable us to recognise it

When it comes to diabetes, it is not possible to recognise just one symptom, as the manifestations are different and vary between patients, especially according to age of onset and gender.

In all cases, hyperglycaemia, i.e. an above-average concentration of glucose in the blood, is present.

Other classic symptoms of diabetes are

tiredness and generalised malaise
increased thirst, which cannot be quenched in any way (polydipsia);
increased diuresis (polyuria). Large amounts of sugar are also noted in the urine;
unintended weight loss and often associated with a strange increase in appetite;
blurred vision;
bad breath;
abdominal pain and cramps;
wounds that heal more slowly;
in the most severe cases, mental confusion and loss of consciousness;
diagnosis of prediabetes, i.e. presence of impaired fasting blood glucose or impaired glucose tolerance.

It has also been diagnosed that constant above-average blood glucose values can lead to:

cardiovascular diseases of the heart and blood vessels (myocardial infarction, ischaemic heart disease, cerebral stroke);
neurological diseases such as alteration of the nervous system resulting in decreased sensitivity and motor skills;
kidney diseases, as the filtering structures of the kidneys no longer function properly.

Diabetes: the causes

Among the causes of the onset of diabetes are genetic and environmental factors, mainly an unhealthy and very sedentary lifestyle, consisting of an unbalanced diet and little exercise.

To these bad habits can be added the effect of viral infections or the taking of certain drugs, which can unleash the disease in all those individuals who are already predisposed by nature.

Other triggering factors that can contribute to the onset of diabetes are:

overweight and obesity
unbalanced diet (too much sugar and saturated fatty acids);
lack of exercise; sedentary lifestyle;
genetics;
advanced age (people between 70-75 years of age are the most affected);
presence of other autoimmune diseases.

Smoking, hypertension, dyslipidaemia, hyperuricidaemia or gout are also aggravating factors.

Type 2 diabetes mellitus can also easily appear in women already suffering from gestational diabetes.

Stress, which negatively influences the blood glucose threshold and increases it, cannot be ruled out.

Diabetes: how it is diagnosed

If a diagnosis of diabetes is suspected as a result of certain symptoms, it is a good idea to visit your doctor as soon as possible, who will prescribe all the necessary tests.

A correct diagnosis involves assessing blood sugar levels.

The patient can only tell if he or she is suffering from hyperglycaemia and possibly diabetes by taking a blood sample.

Once the body fluid has been analysed, it will be possible to assess the presence of glucose and thus determine whether one has diabetes.

It is also common for a urine test to be suggested in addition to the blood test, as it is useful in detecting whether large amounts of sugar are present in the urine.

The diagnosis of diabetes is certain when blood glucose values are greater than or equal to 200 mg/dl, at any time of day, even after meals.

It can happen that diabetes is totally asymptomatic in its early stages and can, therefore, be discovered by chance during other, non-specialist clinical tests.

Once diabetes has been diagnosed, doctors recommend constant monitoring, consisting of regular visits and tests both by one’s GP and by a diabetes specialist.

Regular screening will also be prescribed to observe possible complications.

The most effective treatments for diabetes

There are many different effective treatments for diabetes.

Only the doctor can prescribe the most effective treatment based on the patient’s medical history and the type of diabetes encountered, as well as the severity of the symptoms.

For type 1 diabetes mellitus, the most effective therapy remains the classic insulin-based one.

It will be up to the patient himself, or his carer, to prepare for daily injections using a syringe or insulin pen.

The injections are intended to supplement the lack of or insufficient activity of the pancreas.

It should be remembered that in order for treatment to be truly effective, it is important to combine it with maintaining a correct lifestyle.

By following this advice, most patients manage to live a normal life without serious complications.

New frontiers in medicine propose the use of insulin pump therapies.

This is an electronic device that mimics the regular functioning of the pancreas and provides the body, 24 hours a day, with the correct dose of insulin as needed. It also constantly monitors blood glucose levels.

For type 2 diabetics, unfortunately, there is still no totally effective drug, but there are certain treatment modalities that can be prescribed depending on the specific situation.

Likewise, type 2 diabetes cannot be easily managed without treatment.

Diabetes is a chronic disease that one must learn to live with for life.

For this reason, doctors recommend a therapeutic education phase during which experienced staff instruct the patient on how to manage the disease and its various aspects.

The patient’s behaviour helps define the course and final outcome of treatment.

It is not uncommon for dieticians and sports physicians to be present at therapeutic sessions, for all-round education on a healthy lifestyle.

Diabetes prevention: good rules to observe in daily life

Diabetes prevention starts with maintaining a healthy lifestyle, based on a regular diet (preferring unsaturated fatty acids rich in Omega 3, such as those found in fish) and constant physical exercise (at least 30 minutes a day, of medium intensity).

Although a screening (blood test) is recommended for everyone – also due to the often asymptomatic nature of the disease – it is strongly recommended for those with a family history of the disease.

These individuals must constantly keep their blood glucose levels under control, as alterations may occur even with a correct lifestyle.

During travel and holidays, the diabetic is required to carry a glucose meter, a special instrument that allows glycaemic control.

Even if away from home, the patient must try not to vary his or her diet too much, and if he or she does, to adjust physical activity or consult his or her doctor in order to modify the therapy.