**2. The autonomic nervous system (ANS)**

	- The orthosympathetic (or sympathetic) system which intervenes in the involuntary activities of the stressful and arousal situations. It is preponderant in the conflicts of the organism with its external environment, when life is threatened. The sympathetic system stimulates all the organs that play a role in the defense response. The sympathetic nerve centers are essentially bulbospinal and their organization is segmental. The preganglionic fibers exit through the

ventral root of the corresponding spinal nerve. They separate to form the white communicating branch which joins the corresponding para-vertebral ganglion. These paravertebral ganglia are united in a chain by inter-ganglionic fibers. The fibers which exit from the paravertebral ganglia join the corresponding spinal nerve by the gray communicating branch to go to the target organ.

	- a.Nervous centers located within the central nervous system (medulla oblongata, thalamus and hypothalamus.) and in the spinal cord, constitute the "motor" of the autonomic nervous system.
	- b.Peripheral ganglia located on three floors:
		- The first ganglionic stage comprises the para- vertebral sympathetic chain. This chain is located laterally in the spine and extends from the end of the cervical segment to the coccygeal segment. It includes 3 cervical ganglia, superior, middle and inferior through which the sympathetic fibers of the cervical segment pass.
		- A second ganglionic stage consists of the pre-visceral ganglia or plexus. They are less numerous than the paravertebral ganglia. They are more ganglion plexuses than ganglia. They are paired and lateral in the neck (carotid plexus, pharyngeal, …) and pelvis but single and medial in the thorax (cardiac, pulmonary plexus) and abdomen (solar plexus, lumbo-aortic). At the cervical level, this second stage is associated with the 1st stage.
		- A third lymph node stage includes the visceral or terminal lymph nodes located on the surface or in the thickness of the target organ.
	- c.Fibers that connect these levels to each other and to the viscera:

Between the nerve center and the target organ, the autonomic nervous path is always interrupted by at least one synapse located in a ganglion.

An autonomous nerve pathway is therefore made up of at least two fibers: the pre-ganglionic fiber and the post-ganglionic fiber.

The nerve fibers of the autonomic system travel either alongside the fibers of the somatic system (mixed nerves) or independently, along the blood vessels. Norepinephrine is the neurotransmitter at all levels of the sympathetic system, except the ganglionic (acetylcholine) level, while acetylcholine mediates the parasympathetic or vagal system.

**219**

the last decades.

a.ANS and insulinoresistance

*Type 2 Diabetes and Dysautonomy*

Holter ECG [6].

**4. Epidemiological data**

mortality.

*DOI: http://dx.doi.org/10.5772/intechopen.95043*

**3. The ANS measurement methods**

very precise and minimally invasive.

sympathetic hyperactivity is implicated in various symptoms or pathologies such as essential hypertension [4], obesity [4, 5], permanent resting tachycardia,

hyperlipidemia, type 2 diabetes [5], sleep apnea [5] or sedentary lifestyle.

• Considered difficult, the assessment of ANS activity has been greatly facilitated by the development of systems allowing non-invasive clinical exploration based mainly on the continuous recording of blood pressure and heart rate by a

• Sympathetic activity can be measured directly by the technique of microneurography which measures muscle sympathetic nerve activity (ANSM) by inserting electrodes into a nerve (usually the peroneal nerve). This technique is

• On the other hand, the measurement of the "spill over" of catecholamines is reliable but is not easily applicable due to its very invasive nature. We can also measure catecholamines and their metabolites (metanephrines) in peripheral blood or 24 hours urine, but studies show that plasma catecholamine levels are not sensitive markers of sympathetic activity. Also, they objectify that the urinary catecholamines are not sufficiently sensitive to estimate the sympathetic [6].

○ Its increasing prevalence throughout the world, around 463 million diabetics

○ Its association with a remarkable increase in cardiovascular morbidity and

• The 2000 World Diabetes Congress in Mexico City placed particular emphasis on the metabolic syndrome by sounding the alarm on the impact of such a prevalence on the population. This puts the metabolic syndrome and diabetes

A global approach of the responsibility of a dysfunction of the ANS in the genesis or the aggravation of the 3 main pathophysiological mechanisms of type 2 diabetes, which are insulin resistance, decrease in insulin secretion and hyperglucagonemia, has been attempted, by several studies all over the world especially during

• Currently there is evidence that sympathetic hyperactivity is responsible for resistance to the action of insulin. Indeed, it can even precede the installation

in 2019 according to IDF, and to increase to 700 million in 2045.

• The importance of the type 2 diabetes (T2DM) stems from:

far ahead of HIV-AIDS in terms of morbidity and mortality.

**5. Relationship between type 2 diabetes and ANS**

• There is a strong interaction between the autonomic nervous system and the endocrine system, especially the hypothalamic–pituitary–adrenal axis. Also, *Lifestyle and Epidemiology - The Double Burden of Poverty and Cardiovascular Diseases...*

nerve by the gray communicating branch to go to the target organ.

equivalent to the chain of sympathetic paravertebral ganglia.

the "motor" of the autonomic nervous system.

b.Peripheral ganglia located on three floors:

associated with the 1st stage.

• The autonomic or vegetative nervous system is made up of several levels:

sympathetic fibers of the cervical segment pass.

c.Fibers that connect these levels to each other and to the viscera:

the pre-ganglionic fiber and the post-ganglionic fiber.

mediates the parasympathetic or vagal system.

a.Nervous centers located within the central nervous system (medulla

oblongata, thalamus and hypothalamus.) and in the spinal cord, constitute

○ The first ganglionic stage comprises the para- vertebral sympathetic chain. This chain is located laterally in the spine and extends from the end of the cervical segment to the coccygeal segment. It includes 3 cervical ganglia, superior, middle and inferior through which the

○ A second ganglionic stage consists of the pre-visceral ganglia or plexus. They are less numerous than the paravertebral ganglia. They are more ganglion plexuses than ganglia. They are paired and lateral in the neck (carotid plexus, pharyngeal, …) and pelvis but single and medial in the thorax (cardiac, pulmonary plexus) and abdomen (solar plexus, lumbo-aortic). At the cervical level, this second stage is

○ A third lymph node stage includes the visceral or terminal lymph nodes located on the surface or in the thickness of the target organ.

Between the nerve center and the target organ, the autonomic nervous path is always interrupted by at least one synapse located in a ganglion.

An autonomous nerve pathway is therefore made up of at least two fibers:

The nerve fibers of the autonomic system travel either alongside the fibers

of the somatic system (mixed nerves) or independently, along the blood vessels. Norepinephrine is the neurotransmitter at all levels of the sympathetic system, except the ganglionic (acetylcholine) level, while acetylcholine

• There is a strong interaction between the autonomic nervous system and the endocrine system, especially the hypothalamic–pituitary–adrenal axis. Also,

○ The parasympathetic system which takes care of the involuntary activities of the situations of relaxation and rest. Its nerve centers are located in the brainstem and the sacral marrow. The preganglionic fibers follow the path of the corresponding nerves. They synapse into a pre-visceral or intra-visceral ganglion. The parasympathetic system therefore does not have a structure

ventral root of the corresponding spinal nerve. They separate to form the white communicating branch which joins the corresponding para-vertebral ganglion. These paravertebral ganglia are united in a chain by inter-ganglionic fibers. The fibers which exit from the paravertebral ganglia join the corresponding spinal

**218**

sympathetic hyperactivity is implicated in various symptoms or pathologies such as essential hypertension [4], obesity [4, 5], permanent resting tachycardia, hyperlipidemia, type 2 diabetes [5], sleep apnea [5] or sedentary lifestyle.
