Sleep Loss and Hunger

In this age of cellphones in every pocket and headphones in every ear, it’s no wonder most teens do not get enough sleep. Sleep-deprived teens suffer from various problems. Their health suffers, they experience mood problems, and their performance in school suffers.

These are only a few of the adverse effects of sleep loss. Another one includes weight gain. Poor sleep hygiene is one of the main causes of obesity. Teens who get inadequate sleep say they are too tired to exercise. Thus, they “burn less calories.”

Additionally, lack of sleep disrupts the key hormones involved in controlling hunger, leptin and ghrelin. Leptin inhibits hunger. It tells ours bodies to stop eating when we are full. Ghrelin, also called the “hunger hormone,” stimulates hunger.

Inadequate sleep results in more production of ghrelin and less production of leptin. The result? We keep on eating and gain weight.

The weird part is that obesity increases the risk of getting sleep apnea. Additionally, obesity and sleep apnea share common health risks like hypertension and diabetes. Sleep apnea also causes sleep deprivation, which in turn causes obesity. So, sleep loss causes obesity, which causes more sleep loss...where does this cycle end?

Source: Judd, Sandra J. Sleep disorders sourcebook. Detroit, MI: Omnigraphics, 2010. Print. 

Caffeine Kicks in, part 3

Hey everyone!

Last post of the week! I’ve been talking a lot about caffeine and its effects on adenosine and dopamine levels. I am going to end this week off by talking about another really important hormone, adrenaline.

Caffeine makes us more alert by prompting the release of more dopamine and speeding up the electrical activity in the brain. This in turn stimulates the adrenal gland to release adrenaline, or epinephrine, and the result is a response similar to the “fight-or-flight” one.

You may have wondered about the mechanisms behind this response. Why do our bodies react the way they do when put in a stressful situation? Why does our heart rate increase? Why does our blood pressure rise?

All of this is controlled by one specific branch of the nervous system, the sympathetic nervous system. When we are required to take action really fast, this branch of the nervous system signals to the adrenal gland to release adrenaline.

The result is an increase in heart rate and blood pressure. The pupils dilate and veins constrict to allow for more blood flow to the heart. The digestive system shuts down so more energy can be put to deal with the stress.  Smooth muscles relax so more oxygen can flow into the lungs.

Therefore, when we drink something that is caffeinated, the result is…MORE ADRENALINE! Adrenaline prepares the body for activity. Now, the body is primed for action, definitely not for sleep! 

P.S. I’ve attached a picture relating caffeine and all of the neurotransmitters I have talked about.

Source: Judd, Sandra J. Sleep disorders sourcebook. Detroit, MI: Omnigraphics, 2010. Print. 

Caffeine Kicks In, part 2

Hello everyone! I hope you had a restful spring break and are ready for some more good stuff about sleep disorders!

Before break, I talked about how caffeine affects the body by taking up adenosine receptors and preventing adenosine from binding. This week, I am going to talk about the effect caffeine has on neurotransmitters like dopamine and adrenaline.

Let’s leave adrenaline for later and talk about dopamine now. Dopamine is a neurotransmitter responsible for controlling emotions and motor abilities. It also controls cognition and feelings like pleasure.

Caffeine causes an increase in the production of dopamine. This elevates our moods, which results in an increase in brain activity and neuron firing. When our brains generate a lot of electrical activity, it is harder for us to fall asleep.

Researchers also consider dopamine the cause of caffeine addiction. This is because some of the withdrawal symptoms of caffeine include mild depression, irritability, and other emotional changes that dopamine is responsible for.

Sorry for such a short first post this week. In my next one, I’ll elaborate on the relationship between caffeine and the neurotransmitter adrenaline.  

Caffeine Kicks In, part 1

I am going to end this week off by starting to talk about caffeine. When many people drink tea or coffee, they tend to stay awake longer. This is because caffeine is a stimulant; it makes people alert and gives them more energy.

Caffeine affects many neurotransmitters and hormones in the body. In this post, I will talk about one of them, adenosine. Adenosine is the neurotransmitter that inhibits many processes associated with wakefulness.

Adenosine levels build up throughout the day and fall rapidly when we sleep. High levels lead to sleepiness and blocking adenosine’s actions results in an increased alertness. A stimulant like caffeine blocks adenosine’s actions.

Caffeine looks like adenosine to a neuron. It works as an antagonist and binds to the adenosine receptor, as shown below. Caffeine molecules take up all of the adenosine receptors and adenosine cannot bind. It does the opposite of what adenosine does and speeds up the neuron’s electrical activity.

The effect caffeine has on the neuron is it increases the number of times the neuron fires. This causes more sympathetic nervous system activity and the pituitary gland, or “master gland,” releases hormones that prompt the release of adrenaline (I will talk about it in the next post).

This release of adrenaline results in the pupils dilating, the heart beating faster, the blood pressure rising, blood flow to the stomach slows and blood flow to the muscles increases, and the liver releases more sugar.

The next few posts will cover the effect caffeine has on other chemicals, like dopamine and adrenaline. Next week is BASIS Phoenix’s spring break and I will also be taking the week off and going out of town. So, see you all after spring break!  

~Shubhangi 

Source: Judd, Sandra J. Sleep disorders sourcebook. Detroit, MI: Omnigraphics, 2010. Print. 

Periodic Limb Movement Disorder (PLMD)

My latest post was about Restless Leg Syndrome (RLS), a disorder in which patients experience uncomfortable twitches and prickly feelings in the legs.

About 80% of RLS patients also experience periodic limb movements. Patients with periodic limb movement disorder (PLMD) complain of insomnia and frequent awakenings during the night, sometimes due to excessive leg jerking. They also kick during their sleep.

I am going to go a little deeper into PLMD in this post. PLMD patients typically display periodic contractions of the tibialis anterior (shown in the picture below), a muscle in the leg that plays a role in the dorsiflexion of the toes and ankle. Dorsiflexion is the action of moving the foot in an upward direction. For this reason, PLMD patients also sometimes experience periodic dorsiflexion, which causes a leg jerk or a kick.

           

                             

PLMD also affects the quality of life in general. For instance, many patients cannot travel in airplanes or drive for long distances in cars. They also cannot sit and enjoy movies because they constantly need to be walking around to alleviate the tingling sensation in their legs.

Having this condition has caused many people to make drastic lifestyle changes. Some people have quit their jobs due to amount of discomfort they felt. Additionally, one patient suffered from this condition as a child. He was excluded and humiliated by the way he was treated, and he eventually entered a period of depression.

PLMD tortures patients during the day as well as during the night. During sleep, the patient is usually not aware of the leg jerks. He is, however, aware of waking up frequently. Thus, his sleep is fragmented. For this reason, PLMD can cause excessive daytime sleepiness. It is also a problem to bed partners in that they complain of the patient being very restless and kicking frequently.  

This speaks to the seriousness of this condition. PLMD is one of the causes of sleep disorders like insomnia and can force patients to reconsider their lifestyle altogether.

More to come soon!

Source: Reite, Martin, Michael P. Weissberg, and John Ruddy. Clinical manual for the evaluation and treatment of sleep disorders. Washington, DC: American Psychiatric Pub., 2009. Print.

What is Restless Leg Syndrome?

Hello everyone,

In the previous post, I mentioned that sleep disorders can be caused by chemical imbalances. In this post, I will talk about a physiological reason behind sleep disorders.

As well already know, physiological reasons are what cause sleep apnea. Abnormalities in other parts of the body may also cause sleeplessness. Research suggests that restless legs may be keeping people from getting proper sleep at night.

In the 1990s, there was not much known about restless leg syndrome (RLS). The doctors did not know what to do when their patients complained of staying up at night due to uncomfortable twitching and a prickly sensation in the legs. Now that we have become more familiar with RLS, it is easier to diagnose.

There are many things that can cause RLS:

1. It is believed to be hereditary, which means it runs in families and is passed on from generation to generation.
2.  It can be caused by peripheral neuropathy, or damage to the nerves in the legs.
3. Anemia, or a deficiency of red blood cells, can cause RLS.
4. Many pregnant women suffer from RLS, probably due to the pressure on nerves and blood vessels resulting in a restricted blood flow to the legs. RLS usually clears up after giving birth.
5. An iron deficiency can also cause RLS.

Many of the patients that have RLS also experience a condition called periodic limb movement disorder (PLMD). This can affect people during the day as well as the night, making this such a serious condition. In later posts, I will talk about PLMD in more detail. Stay tuned!

Melatonin

Before going deeper into how the different sleep disorders can affect the brain, I would like to touch upon a couple things that play a role in causing problems with sleep.

Anxiety, stress, and emotional problems all contribute to sleep disorders.  Additionally, according to research, many sleep disorders are caused by chemical imbalances in the brain and body. One of the hormones that appears to influence circadian rhythms is melatonin.

Melatonin enhances people’s ability to fall asleep. Its secretion is regulated by the pineal gland. The pineal gland is pea-sized pineal gland located in the center of the brain (pictured below).

The production of melatonin is controlled by the amount of light information relayed to the pineal gland from the suprachiasmatic nucleus (SCN). Secretion can be blocked by exposure to bright light at normally dark times (this is why they say that using our phones at night is eating away our sleep).

This is the reason night shift workers suffer from circadian rhythm disorders.  They sleep during the day when the sun is rising and their eyes are absorbing light when they are trying to sleep.

The cycle of regular melatonin release throughout the night is shown below. In most people, the pineal gland starts release melatonin a few hours before bedtime. It continues releasing it throughout the night. Production slows as we wake up and absorb the new day’s light.

It is also interesting to note that as we age, the amount of melatonin produced by our pineal glands decreases. This may be why many older adults have a more difficult time falling asleep.

Until next time!