Diabetes

Generality

Diabetes, whose most appropriate name would be diabetes mellitus, is the best known metabolic disease that can affect humans.

Its onset is related to insulin ; to be precise, it may depend on a reduced availability of insulin (whose production does not meet the body's needs), on the low sensitivity to the hormone by the target tissues or, finally, on a combination of these factors.

A clinical feature of diabetes is hyperglycaemia, resulting from the aforementioned changes to insulin.

Currently, the medical-scientific community recognizes the existence of 3 major types of diabetes mellitus, which are: type 1 diabetes, type 2 diabetes and gestational diabetes; at one time, the classification of diabetes was broader and less simple to consult.

The presence of diabetes in the world population is increasing in the last 30-40 years: consider that, while in 1980 the patients were 108 million, in 2014 the number of people with diabetes reached 422 million.

What is diabetes?

Diabetes mellitus, or more simply diabetes, is a metabolic disease resulting from a decline in insulin activity, a hormone produced by the beta cells of the islets of Langerhans of the pancreas .

In particular, diabetes may be due to:

• Reduced insulin availability → To understand: there is less insulin than the body would need for its proper functioning;
• An impediment to the normal action of insulin → To understand: insulin is present, but the body cannot make good use of it;
• A combination of the two aforementioned factors → To understand: insulin is low and does not work properly.

A feature always present in diabetes mellitus is hyperglycemia (high concentration of glucose in the blood), which, over time, tends to be associated with vascular complications, such as:

• macroangiopathy (a particularly severe and early form of atherosclerosis)
• microangiopathy (an alteration of the blood circulation inside the small arterial vessels, manifested mainly in the retina, kidney and nerves).

While microangiopathy is specific to the disease in question, macroangiopathy is not.

Types of Diabetes

There are various types of diabetes mellitus and it is for this reason that the medical community has always tried to draw up a classification that was as reliable, complete and above all easy to consult, even by the less experienced.

Among the various classifications of diabetes proposed over the last few decades, two are reported: one dating back to 1980, drawn up by the WHO (World Health Organization) in force until 1997, and one dating back to 1997, formulated by the WHO and by the ADA ( American Diabetes Association, in English, and American Diabetes Association, in Italian) to replace the one just named and still in force today.

THE "OLD" CLASSIFICATION

The classification proposed by the WHO in 1980 foresees the division of diabetes mellitus into five different classes, identified as:

1. Insulin-dependent diabetes, also defined by the acronym IDDM or infant-juvenile diabetes;
2. Non-insulin-dependent diabetes, also defined by the acronym NIDDM or diabetes of adulthood or maturity;
3. Malnutrition diabetes. This was the name of the widespread diabetes in tropical countries;
4. Gestational diabetes or GDM. This name was taken from diabetes linked to pregnancy;
5. Other types of diabetes. With this statement, the experts referred to forms of diabetes mellitus secondary to: pathologies, including:

• pancreatic diseases (chronic pancreatitis and pancreatic cancer),
• endocrine disorders responsible for excessive secretion of counterinegular insulin hormones (Cushing's syndrome, acromegaly, pheochromocytoma, hyperthyroidism, glucagonoma, somatostatinoma and aldosteronoma)
• the use of drugs that induce hyperglycaemia (glucocorticoids, thyroid hormones, interferon, pentamidine and adrenergic agonists)
• the intake of toxic substances;
• the abnormalities of insulin or its receptor;
• specific genetic abnormalities.

THE "NEW" CLASSIFICATION

Internationally recognized, the classification of diabetes mellitus drawn up in 1997 by the WHO and ADA is decidedly simpler than the previous one. In fact, it divides diabetes into three main types:

1. Type 1 diabetes mellitus . This includes almost all the immunomediated diabetic forms ; in these circumstances, the underlying cause is a malfunction of the immune system, which, recognizing the pancreatic beta cells of the Langerhans islands as foreign, attacks them and destroys them.

   Since the immune system is implicated, type 1 diabetes mellitus is rightfully among the autoimmune diseases.

2. Type 2 diabetes mellitus . This includes all forms of diabetes due to
   • a deficiency of insulin secretion, by pancreatic beta cells of the islets of Langerhans,
   • resistance of the body's tissues to the action of insulin (a condition known as insulin resistance).
3. Gestational diabetes . As it was in the old classification, this includes the forms of diabetes secondary to the state of pregnancy. Generally, it is a transient phenomenon.

It should be noted that the types "type 1 diabetes" and "type 2 diabetes" also include the diabetic forms associated with: viral infections (eg rubella, cytomegalovirus), genetic syndromes (Down syndrome, Klinefelter syndrome, Turner syndrome, Friedreich's ataxia, Laurence-Moon syndrome, myotonic dystrophy, Prader-Willi syndrome, Huntington's chorea, etc.) and hereditary genetic defects in the pancreatic beta cells of the islets of Langerhans (known as MODY, or Maturity Onset Diabetes of the Young ).

Curiosity

Regardless of the stage in which it is found, any form of diabetes mellitus may require insulin-based therapy; therefore, the use of insulin by itself does not classify the present diabetic form.

In fact, it is also for this reason that, in 1997, ADA and WHO considered it incorrect to classify diabetes as insulin-dependent and non-insulin-dependent.

Epidemiology

Diabetes mellitus is a common disease; among the metabolic diseases, it is certainly the most known and probably also the most widespread.

According to WHO reports, in 2014, the prevalence of diabetes among adults around the world over the age of 18 was 8.5% and the number of individuals with diabetes mellitus in the population of all the world was 422 million.

Comparing these statistical results with those of 1980, a disturbing difference emerges: 34 years earlier, the prevalence on the same category of people was 4.7%, while the number of sick people worldwide was only 108 million. Therefore, from 1980 to 2014, the prevalence almost doubled and the number of sick individuals has quadrupled.

Between type 1 diabetes mellitus and type 2 diabetes mellitus, the latter is decidedly more widespread than the first: according to most estimates, about 90% of the diabetic population suffers from type 2 diabetes and only the remaining 10% carries type 1 diabetes.

As far as gestational diabetes is concerned, the most reliable estimates say that this diabetic form affects 8% of the female population.

Statistical data and interesting numbers, related to diabetes mellitus:

• The prevalence of diabetes mellitus increases with age and, in Italy, reaches its peak in the population aged around 70-75 years.
• People in a state of impaired fasting glucose (IGF) have a 50% chance of developing type 2 diabetes mellitus over the 10 years following the diagnosis of IGF.
• According to the WHO, in 2012, around 1.5 million people worldwide died directly from diabetes mellitus.
• Worldwide, about half of all deaths from diabetes mellitus involve people around 70 years old. According to WHO estimates, diabetes will be the 7th leading cause of death in the general population in 2030.
• In 2008-2009, the annual incidence of diabetes in young people measured 18, 436 cases, with regard to type 1 diabetes, and 5, 089 cases, as regards type 2 diabetes.
• 90% of diabetes cases are type 2 diabetes, while the remaining 10% are type 1 diabetes.
• In Italy, diabetes is more widespread among overweight (7%) and obese (14%) people, among people with many economic difficulties and among individuals without educational qualifications or with the only elementary license.

ITALIAN SITUATION

In Italy, the 2015 ISTAT data indicate that 5.4% of Italians (both males and females) suffer from diabetes mellitus, which means over 3 million people .

As regards the prevalence of diabetes in our country, this has increased from 3.9% in 2001 to 4.7% in 2015.

At the geographical level, the areas where the prevalence of diabetes is the highest are the regions of the South, in particular Calabria.

prediabetes

Prediabetes: what it is and how to distinguish it from diabetes mellitus. Hints of diagnosis

As mentioned, by definition, diabetes mellitus is characterized by hyperglycemia.

To determine the presence of hyperglycaemia - and to determine whether or not there is diabetes - a venous blood sample is taken and the subsequent measurement, on this blood sample, of the amount of glucose present.

According to the latest criteria proposed by the ADA experts, a person suffers from diabetes when the following three conditions are met:

1. Blood glucose (ie blood glucose concentration) is ≥ 200 milligrams of glucose per deciliter of blood (mg / dl) at any time of the day.
2. Fasting blood glucose is ≥ 126 mg / dl.

   In normal conditions it should be less than 100 mg / dl.

3. Blood glucose after 120 minutes from the OGTT (oral glucose tolerance test or oral glucose loading test) is ≥ 200 mg / dl.

   In normal conditions it should be less than 140 mg / dl.

The need to define such precise parameters, to establish when a person has or does not have diabetes, arose when doctors and experts identified the existence of an intermediate metabolic state between normality and type 2 diabetes mellitus, to which they have given the name of prediabetes .

Prediabetes is a condition that often precedes the onset of type 2 diabetes mellitus, therefore its identification must sound like an alarm bell.

Those suffering from prediabetes do not have the same symptomatology as the diabetes patient and often do not even have a symptom of the latter; nevertheless, like the diabetic subject, it presents abnormal blood glucose levels, higher than normal.

According to the ADA and the WHO, there are two subtypes of prediabetes: the subtype called impaired fasting glucose or IGF and the subtype called impaired glucose tolerance or IGT .

Altered fasting blood glucose

To diagnose impaired fasting blood glucose, glucose levels higher than normal, but not high enough to be in a state of diabetes, must be detected after at least 8 hours of fasting.

Altered glucose tolerance

On the contrary, to diagnose impaired glucose tolerance, it is necessary that the glycaemia, after the so-called oral glucose tolerance test, is between 140 and 200 mg / dl (in substance it is above the normal threshold, but lower than the limit that establishes the presence of diabetes).

Prediabetes according to the American Diabetes Association

The ADA speaks in these terms of the prediabetes: "the prediabetes are not to be considered a real clinical entity, but rather an increased risk of diabetes and cardiovascular diseases".

Prediabetes are associated with obesity (especially abdominal or visceral obesity), dyslipidemia with high triglycerides and / or low HDL cholesterol and hypertension . [...] usually has no symptoms; the only clinical sign is a high amount of sugar in the blood.

Insipid diabetes

Another form of diabetes: diabetes insipidus

Next to diabetes mellitus with its two types, there is another form of diabetes: the so-called diabetes insipidus .

Except for excessive diuresis and insatiable thirst, diabetes insipidus is completely different from diabetes mellitus and is in no way correlated to diabetes.

In diabetes insipidus, in fact, the current problems do not involve increased blood glucose levels (following a decrease in insulin activity), but depend on a lack or insufficient production of the vasopressin hormone * (or ADH or antidiuretic hormone ) or by its lack of renal activity.

Summing up quickly, therefore, the condition of diabetes insipidus can be established because:

• Hypothalamus and posterior pituitary do not produce vasopressin at all

or

• Hypothalamus and posterior pituitary produce insufficient amounts of vasopressin to meet the needs of the human body

or

• Vasopressin does not adequately perform its activities in the kidneys.

When vasopressin production is absent or insufficient, diabetes insipidus is called central, ADH-sensitive or neurogenic ; when vasopressin is present but has no effects on the kidneys, diabetes insipidus is called ADH-insensitive or nephrogenic .

* Note: secreted as told by the posterior pituitary and hypothalamus, vasopressin has the important task of keeping the liquid part of the blood constant (the so-called plasma); to fulfill this task, it acts on the kidney level, where it favors the reabsorption of water and opposes the production of urine (hence the name of antidiuretic hormone).

Insights on Diabetes

Select the article of your interest to learn more about the disease, its symptoms and available treatments.

Know the disease and its complications

Diabetes, Types of Diabetes Causes of Diabetes Symptoms of Diabetes Acute Complications Long-term Complications Diabetic Nephropathy Diabetic Retinopathy Diabetic Foot Reactive Hypoglycemia Hypoglycemic Crisis Altered Glucose Tolerance Prediabetes Insulin Resistance Diabetes, Find out if you are at risk Quiz Diabetes prediabete: Are you sufficiently informed?

Other forms of diabetes

Gestational diabetes Diabetes in the dog Diabetes insipidus Diabetes in the cat

The diet against diabetes

Diet and diabetes Diet and gestational diabetes Example diet for type 2 diabetes Diabetes: fiber, salt and alcohol Diabetes: fats, proteins, cholesterol Diabetic foods Bananas and Diabetes Carrots and diabetes Fruits and diabetes Diabetes fruits Fructose and diabetes Honey for diabetics Wine and diabetes Vegetables and diabetes: which ones to choose? Video Recipes for Diabetics Quiz: Diet and Diabetes Type 2: Do You Know How to Eat? Basic Level Quiz: Diet and Diabetes Type 2: Do you know how to eat? Advanced level

Defeat diabetes with sport

Physical activity and diabetes Diabetes and circuit training Diabetes and personal trainer Type 2 physical activity and diabetes

... and with natural remedies

Natural Remedies for Diabetes Tisanes against Diabetes Medicinal Plants and Diabetes Chromium and Diabetes: Effective Remedy? Diabetes - herbal medicine

Defeat diabetes with drugs

Diabetes Care and Therapy Diabetes Medications Type 2 Diabetes Medications Type 1 Diabetes Medications Diabetic Diabetes Medications Rapid Insulin and Slow Insulin Insulin in the Treatment of Diabetes Amiline and Diabetes Oral Hypoglycemics

Medical examinations and diagnosis of diabetes

Blood glucose and glycemic peak Peptide C and diabetes Glucose in urine OGTT blood glucose curve Postprandial glycaemia Ketones in urine Hypoglycemia Glycated hemoglobin Hyperinsulinemia