Showing posts with label obesity. Show all posts
Showing posts with label obesity. Show all posts
Saturday, November 24, 2012

Cushing's Syndrome after Hemodialysis for 21 Years

Koki Mise, Yoshifumi Ubara, Keiichi Sumida, Rikako Hiramatsu, Eiko Hasegawa, Masayuki Yamanouchi, Noriko Hayami, Tatsuya Suwabe, Junichi Hoshino, Naoki Sawa, Masaji Hashimoto, Takeshi Fujii, Hironobu Sasano and Kenmei Takaichi

- Author Affiliations

Nephrology Center (K.M., Y.U., K.S., R.H., E.H., M.Y., N.H., T.S., J.H., N.S., K.T.), Surgical Gastroenterology (M.H.), Pathology (T.F.), and Okinaka Memorial Institute for Medical Research (Y.U., K.T.), Toranomon Hospital, 1058470 Tokyo, Japan; and Department of Pathology (H.S.), Tohoku University Graduate School of Medicine, 9800872 Sendai, Japan

Address all correspondence and requests for reprints to: Koki Mise, M.D., Nephrology Center, Toranomon Hospital Kajigaya, 1-3-1, Kajigaya, Takatu-ku, Kawasaki-shi, Kanagawa-ken, 213-0015, Japan. E-mail: kokimise@yahoo.co.jp.

Abstract

Context: Hyperkalemia and weight loss are critical clinical problems for hemodialysis patients. There have been no documented reports of adrenal Cushing's syndrome with central obesity and hypokalemia in a hemodialysis patient.

Objective: The aim of the study was to report a patient with Cushing's syndrome after chronic hemodialysis, review the published literature, and discuss the significance of hypokalemia and obesity in anuric hemodialysis patients from the perspective of cortisol metabolism.

Patient: A 61-yr-old woman who had been on hemodialysis for 21 yr presented with persistent hypokalemia and central obesity. In 2002, her dry weight was 48.1 kg, but thereafter she gained weight to 60 kg.

Results: Adrenal Cushing's syndrome was diagnosed from endocrinological findings such as increased cortisol secretion without a circadian rhythm and suppression of plasma ACTH. Spironolactone was administered (25 to 50 mg/d), and her serum potassium became normal. Then, left adrenalectomy was performed by laparoscopic surgery. The resected specimen contained a well-circumscribed adrenal adenoma expressing P450c17. After surgery, hypokalemia improved gradually without medication, and her weight gain stopped.

Conclusions: This is the first documented case of adrenal Cushing's syndrome in a patient on long-term hemodialysis, although several authors have reported a relation between hypokalemia and primary hyperaldosteronism in hemodialysis patients.

Wednesday, February 15, 2012

Making sense of your child's health numbers

Excerpt from: http://thechart.blogs.cnn.com/2012/02/14/
making-sense-of-your-childs-health-numbers/

"...Unfortunately, as obesity becomes more common among children, diseases once thought to be primarily a problem of adulthood are showing up in kids. For this reason, children should be screened for medical complications of obesity, such as diabetes, high blood pressure and high cholesterol.

Not everyone agrees when you should start screening your children, but the latest recommendation is to test cholesterol between 9 and 11 years old and then again between 17 and 21. Ask your pediatrician for his or her opinion based on your child’s BMI. Blood pressure can be measured with a cuff at the doctor’s office, and diabetes and high cholesterol can be checked with simple blood tests.

These tests may include blood sugar, hemoglobin A1c and insulin levels for diabetes; a lipid panel (such as cholesterol and triglycerides) which, along with blood pressure, is a marker for heart disease; and tests for liver problems that can occur with obesity.

In some situations it might be important to rule out medical causes of obesity. For example, patients who have a higher concentration of fat in the neck and head region could have Cushing's syndrome, and those who are relatively short for their weight and age and have other symptoms might have low thyroid function..."

Read the entire article at http://thechart.blogs.cnn.com/2012/02/14/
making-sense-of-your-childs-health-numbers/

Monday, January 02, 2012

A New Link in the Stress Response Could Mean Better Treatment Soon

Hoping to pave the way for improved treatment options, researchers have found that they can significantly reduce our response to stress.

 

A team at Tufts University appears to have found an important step in the body's stress reaction, and blocking this step from occurring can significantly reduce the response. The finding may pave the way for improved treatments for depression and anxiety.

The stress cascade is governed by the brain's hypothalamus, which communicates with the pituitary and adrenal glands, which in turn secrete stress hormones like cortisol. Disruptions in this pathway are also connected with problems like postpartum depression, obesity, Cushing's syndrome (hypercortisolism), premenstrual syndrome (PMS), epilepsy, and osteoporosis, according to the study's press release.

Using mice as their subjects, the researchers set out to fill in some of the blanks in the cascade of events that leads to the secretion of the stress hormone coriticosterone (the mouse equivalent to our cortisol). They used brain samples from mice, and tracked the activity of the brain cells that release corticotrophin-releasing hormone (CRH), which ultimately stimulates the secretion of stress hormones.

They discovered that specific "neurosteroids" are needed to bind to receptors on the CRH neurons to activate them, serving as an important early step in the stress response. The team reasoned that disrupting the synthesis of the neurosteroids should significantly reduce the stress response by stopping it almost before it begins.

This is just what they found. When they blocked the neurosteroids' synthesis in live mice, their coriticosterone levels were reduced after stressful situations compared to normal mice. Additionally, if neurosteroid synthesis was halted, the mice did not show anxiety-like behaviors after they had been stressed.

One of the authors, Jamie Maguire, said that the data "suggest that these receptors may be novel targets for control of the stress-control pathway. Our next work will focus on modulating these receptors to treat disorders associated with stress, including epilepsy and depression-like behaviors."

The study is published in The Journal of Neuroscience.

From http://www.theatlantic.com/health/archive/2012/01/a-new-link-in-the-stress-response-could-mean-better-treatment-soon/250570/

Sunday, January 01, 2012

Red alert: Hypertension on the prowl

The family of Mr. Adulphus Opara of Umunokwu in Okwuato, Aboh Mbaise Local Government Area of Imo State was shocked to its nerves as the man slumped from the chair on which he was sitting and cuddling his little daughter who was just less than five months. Scampering and running up and down, all efforts by family members to revive their breadwinner were too little and too late as he died that sunny Saturday afternoon. It was later revealed by doctors at a private hospital that Adolphus died of hypertension attack.

The case of Adolphus is just one out of the numerous complaints of the havocs wreaked by untreated or unchecked hypertension. Medical experts say it has sent so many victims to their untimely grave. 

Dr. Francis Duru, a physician and senior lecturer in Human Anatomy, College of Medicine, University of Lagos Teaching Hospital (LUTH), Idi Araba, described hypertension as a silent killer and the major cause of most sudden deaths in Nigeria. He said high blood pressure is when one’s BP is consistently above 140/90 mmHg. 

According to him, “Normal blood pressure is when your blood pressure is measured at 120/80 mmHg most of the time. If your blood pressure is consistently above 140/90, then the person has hypertension or is hypertensive. Untreated hypertension can lead to many health complications and the worst of all is sudden death.”

MedicinePlus, a medical publication, defines hypertension or high blood pressure as a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump blood around the body. Blood pressure involves two measurements, systolic and diastolic. Normal blood pressure is 120/80 mm/Hg. 

The first figure is the systolic blood pressure, the pressure there is in the arteries when your heart is contracting. The second, or lower figure, is the diastolic blood pressure, which is the pressure in your arteries between heartbeats. High blood pressure is anything above 140/90 mm/Hg. Hypertension is the opposite of hypotension. Hypertension is classified as either primary (essential) hypertension or secondary hypertension; about 90–95% of cases are categorised as “primary hypertension,” which means high blood pressure with no obvious medical cause. 

The remaining 5–10% of cases (secondary hypertension) are caused by other conditions that affect the kidneys, arteries, heart or endocrine system. MedicinePlus added: “Persistent hypertension is one of the risk factors for stroke, myocardial infarction, heart failure and arterial aneurysm, and is a leading cause of chronic kidney failure. Moderate elevation of arterial blood pressure leads to shortened life expectancy. Dietary and lifestyle changes can improve blood pressure control and decrease the risk of associated health complications, although drug treatment may prove necessary in patients for whom lifestyle changes prove ineffective or insufficient.” 

The American Heart Association, in one of its recent reports, made it known that the World Health Organisation (WHO) attributes hypertension, or high blood pressure, as the leading cause of cardiovascular mortality. The World Hypertension League (WHL), an umbrella organisation of 85 national hypertension societies and leagues, recognised that more than 50% of the hypertensive population worldwide are unaware of their condition. To address this problem, the WHL initiated a global awareness campaign on hypertension in 2005 and dedicated May 17 of each year as World Hypertension Day (WHD). Over the past three years, more national societies have been engaging in WHD and have been innovative in their activities to get the message to the public. In 2007, there was record participation from 47 member countries of the WHL. During the week of WHD, all these countries – in partnership with their local governments, professional societies, nongovernmental organisations and private industries – promoted hypertension awareness among the public through several media and public rallies. 

Causes and risk factors

Although Duru noted that there were several causes of hypertension, he still insisted that there were instances when it had no direct link or cause. He said: “Medically, we have causes, incidences and risk factors that are associated with hypertension. I am talking about factors that can cause or lead to hypertension. In this case we have issues like the level of water or salt in a person’s body; ability or inability of some organs like the kidneys or blood vessels to function at optimum levels; life history, that is, does hypertension run in your family? lifestyle, that is, the type of food you eat; lack of exercises and always being in a noisy place or being in a state of anxiety all the time. Let me also quickly add that excessive smoking and over-indulgence in alcohol can lead to hypertension.” 

He added: ‘“You can easily become hypertensive when you reach the stage of adult age because one’s blood vessels are stiffer as one reaches old age. This leads to HBP. I can also tell you that high blood pressure increases your chances of having a stroke, heart attack, heart failure, kidney disease, and early death. I must also state it here that there are some conditions of health one will find oneself and one will surely expect to be hypertensive. For instance, some pregnant women are usually hypertensive especially from the sixth month until they put to birth. Diabetic patients are sometimes hypertensive although there is no causal relationship between hypertension and diabetes.

People who are obsessed are at risk of suffering from hypertension just as chronic kidney diseases and poor conditions or disorders of the adrenal glands can as well lead to hypertension.” The LUTH medical expert revealed that wrong or too much application of some drugs could also lead to hypertension. “Wrong application or continuous administration of some medications such as birth control pills, diet control pills, cold medications, etc are other ways by which hypertension can hit at a person”, he warned. Meanwhile, Duru noted that there were some instances when hypertension had no cause or trace and it is described as essential hypertension. 

Symptoms 

Most medical experts agree that hypertension, in most cases, has no external symptoms. To this effect, Duru said: “You can now see why we call hypertension a silent killer. It is a silent killer because it gives no sign, no symptom and no warning before it strikes. I must comment here that most Nigerians are suffering from hypertension without knowing it. This is why we also recommend that people should go for BP check regularly to confirm their status. Based on these facts, so many Nigerians develop sicknesses like heart diseases, kidney failures and other complications without any prior knowledge that all their problems started from untreated or unchecked hypertension. 

It is also important to note that a hypertensive patient can live his normal life if he abides by medical advice and that means taking his drugs.” ADAM Medical Encyclopedia listed certain conditions as symptoms of hypertension. According to its report, “If you have a severe headache, nausea or vomiting, bad headache, confusion, changes in your vision, or nosebleeds you may have a severe and dangerous form of high blood pressure called malignant hypertension.” The publication recommended that there should be several checks before it could be ascertained that one has hypertension. It noted that: “Your health care provider will check your blood pressure several times before diagnosing you with high blood pressure. It is normal for your blood pressure to be different depending on the time of day. Blood pressure readings taken at home may be a better measure of your current blood pressure than those taken at your doctor’s office.”

Among the tests to be taken to confirm whether or not one has hypertension, according to Duru, are physical examinations to look for bad conditions of the heart or diseases severely affecting it, poor state or damage of the eyes, as well as other bad physical changes in your body. In this case, tests that enable doctors to handle the situation well include: cholesterol level; level of heart disease like echocardiogram or electrocardiogram; level of metabolic panel/ urinalysis or ultrasound of the kidney and this is when the case has become a chronic one.

Types

A widely posted medical material stated: “A blood pressure is usually classified based on the systolic and diastolic blood pressures. Systolic blood pressure is the blood pressure in vessels during a heartbeat. Diastolic blood pressure is the pressure between heartbeats. A systolic or the diastolic blood pressure measurement higher than the accepted normal values for the age of the individual is classified as pre hypertension or hypertension. Hypertension has several sub-classifications, including hypertension stage I, hypertension stage II, and isolated systolic hypertension. Isolated systolic hypertension refers to elevated systolic pressure with normal diastolic pressure and is common in the elderly. 

These classifications are made after averaging a patient’s resting blood pressure readings taken on two or more office visits. Individuals older than 50 years are classified as having hypertension if their blood pressure is consistently at least 140 mmHg systolic or 90 mmHg diastolic. Hypertension is also classified as resistant if medications do not reduce blood pressure to normal levels.” 

Accelerated hypertension – this is associated with headache, drowsiness, confusion, vision disorders, nausea, and vomiting. These symptoms are collectively called hypertensive encephalopathy. Hypertensive encephalopathy is caused by severe small blood vessel congestion and brain swelling, which is reversible if blood pressure is lowered. 

Secondary hypertension– some additional signs and symptoms suggest that the hypertension is caused by disorders in hormone regulation. Hypertension combined with obesity distributed on the trunk of the body, accumulated fat on the back of the neck (“buffalo hump”), wide purple marks on the abdomen (abdominal striae), or the recent onset of diabetes suggests that an individual has a hormone disorder known as Cushing’s syndrome. Hypertension caused by other hormone disorders such as hyperthyroidism, hypothyroidism, or growth hormone excess will be accompanied by additional symptoms specific to these disorders. For example, hyperthyroidism can cause weight loss, tremors, heart rate abnormalities, reddening of the palms, and increased sweating.

In pregnancy–Hypertension in pregnant women is one symptom of pre-eclampsia. Pre-eclampsia can progress to a life-threatening condition called eclampsia, which is the development of protein in the urine, generalised swelling, and severe seizures. Other symptoms indicating that brain function is becoming impaired may precede these seizures such as nausea, vomiting, headaches, and vision loss.

In children –Some signs and symptoms are especially important in newborns and infants such as failure to thrive, seizures, irritability, lack of energy, and difficulty breathing. In children, hypertension can cause headache, fatigue, blurred vision, nosebleeds, and facial paralysis. Even with the above clinical symptoms, the true incidence of paediatric hypertension is not known. In adults, hypertension has been defined due to the adverse effects caused by hypertension. However, in children, similar studies have not been performed thoroughly to link any adverse effects with the increase in blood pressure. Therefore, the prevalence of paediatric hypertension remains unknown due to the lack of scientific knowledge. 

Essential hypertension– this is the most prevalent hypertension type, affecting 90–95% of hypertensive patients. Although no direct cause has been identified, there are many factors such as sedentary lifestyle smoking, stress, visceral obesity, potassium deficiency (hypokalemia), obesity (more than 85% of cases occur in those with a body mass index greater than, salt (sodium) sensitivity, alcohol intake, and vitamin D deficiency that increase the risk of developing hypertension. Risk also increases with aging, some inherited genetic mutations, and having a family history of hypertension. An elevated level of rennin, a hormone secreted by the kidney, is another risk factor, as is sympathetic nervous system over activity. 

Secondary hypertension–By definition, this results from an identifiable cause. This type is important to recognise since it’s treated differently to essential hypertension, by treating the underlying cause of the elevated blood pressure. Hypertension results in the compromise or imbalance of the path physiological mechanisms, such as the hormone-regulating endocrine system, that regulates blood plasma volume and heart function. 

Treatment

According to an ADAM Medical Encyclopedia research work, “The goal of treatment is to reduce blood pressure so that you have a lower risk of complications. You and your health care provider should set a blood pressure goal for you. If you have pre-hypertension, your health care provider will recommend lifestyle changes to bring your blood pressure down to a normal range. Medicines are rarely used for pre-hypertension. You can do many things to help control your blood pressure, including: Eat a heart-healthy diet, including potassium and fibre, and drink plenty of water. 

Exercise regularly — at least 30 minutes of aerobic exercise a day. If you smoke, quit – find a programme that will help you stop. Limit how much alcohol you drink — one drink a day for women, two a day for men. Limit the amount of sodium (salt) you eat — aim for less than 1,500 mg per day Reduce stress — try to avoid things that cause you stress. You can also try meditation or yoga. Stay at a healthy body weight — find a weight-loss program to help you, if you need it. 

There are many different medicines that can be used to treat high blood pressure but must be prescribed by well-qualified physician. Often, a single blood pressure drug may not be enough to control your blood pressure, and you may need to take two or more drugs. It is very important that you take the medications prescribed to you. If you have side effects, your health care provider can substitute a different medication. Most of the time, high blood pressure can be controlled with medicine and lifestyle changes. 

Effects 

It has been gathered through various medical work that a patient is at risk and may likely suffer from complications when BP is not treated or controlled. The ADAM Medical publication warned that the following poor conditions of health might result as an evidence of poor treatment: Bleeding from the aorta, the large blood vessel that supplies blood to the abdomen, pelvis, and legs. Chronic kidney disease, heart attack and heart failure, poor blood supply to the legs, stroke and problems with the vision. 

Here Duru was of the view that most of the sudden death now recorded in Nigeria was as a result of untreated hypertension. ‘ I have explained earlier that most Nigerians are hypertensive without knowing it. In other words, they carry on their daily activities or life style without undergoing the tests and living the medically prescribed way a hypertension victim suppose to observe’. ‘ The effect’, he explained, ‘is that the patient might likely be attacked or hit by stroke, kidney failure or heart attack which leads to instant death. You know I described it as a silent killer and this is exactly what I mean. 

So many Nigerians have been killed by heart failure resulting from hypertension. In some instances the person slumps at home, on the road, in the office or anywhere as the case might be. At some other time, the victim goes to bed and does not wake up. When we experience such situations, some us, in the usual Nigerian way, blame it on the wicked landlord, the envious next door neighbour or a witch or wizard in the village.’ 

Prevention

Doctors have unanimously agreed that hypertension has no permanent cure. At best, it can be managed or controlled. Duru explains further. He said: ‘first, for now, there is no permanent cure for hypertension, medically speaking. As a Christian, I believe in miracles but in medical terms, it is yet to be proved that hypertension has any known permanent cure. If you a victim, it means that you have to be on drugs all the days of your life. And such a patient must be ready to go for BP check regularly. He has to abstain from certain behaviour like too much salt in-take, smoking, taking more than two bottles of beer daily and he must watch his weight and do regular exercises.

I am aware the trado-medicine people usually come up with so many claims but they are also not bold enough to submit their claims to empirical proves or thorough laboratory tests.’ A medical sponsored by the American National Heart, Lung and Blood Institute reported that the prevention depends on so many factors: It wrote thus: ‘ The degree to which hypertension can be prevented depends on a number of features including current blood pressure level, sodium/potassium balance, detection and omission of environmental toxins, changes in end/target organs (retina, kidney, heart, among others), risk factors for cardiovascular diseases and the age at diagnosis of pre hypertension or at risk for hypertension. 

A prolonged assessment that involves repeated blood pressure measurements provides the most accurate blood pressure level assessment. Following this, lifestyle changes are recommended to lower blood pressure, before the initiation of prescription drug therapy. According to the British Hypertension Society, the process of managing pre hypertension includes lifestyle changes such as the following: Weight reduction and regular aerobic exercise (e.g., walking): Regular exercise improves blood flow and helps to reduce the resting heart rate and blood pressure. Reduce sodium (salt) in the body by disuse of condiment sodium and the adoption of a high potassium diet, which rids the renal system of excess sodium. 

Many people use potassium chloride salt substitute to reduce their salt intake.’ In 2003 the American Heart Association recommended the following drugs for the treatment of hypertension: Potassium - is essential for the proper functioning of the heart, kidneys, muscles, nerves, and digestive system. Usually the food you eat supplies all of the potassium you need. 

Bosentan - is used to treat Pulmonary Arterial Hypertension (PAH, high blood pressure in the vessels that carry blood to the lungs). Bosentan may improve the ability to exercise and slow the worsening of symptoms in patients with PAH. Tadalafil (Cialis) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Tadalafil (Adcirca) is used to improve the ability to exercise in people with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the lungs, causing shortness of breath, dizziness, and tiredness.

 

From http://www.sunnewsonline.com/webpages/features/icon/2012/jan/01/icon-01-10-2012-003.html

Friday, December 16, 2011

A Pill That Stops Stress In Your Brain Before You Feel It

Stress makes many of us miserable — but it can also kill you. Besides just causing horrible anxiety and depression, the physiological basis for stress has also been linked to diseases as varied as obesity, postpartum depression, Cushing's syndrome, epilepsy, and osteoporosis. But what if we could just turn your brain's stress response off?

Now, researchers from Tufts claim to have pinpointed the way that stress hormones hit specific receptors in your brain — and they've even been able to block them. This could lead to the next great psychopharmaceutical breakthrough.

The Tufts researchers discovered that stress pathways are activated by neurosteroids acting on corticotrophin-releasing hormone neurons in what's known as the Hypothalamus-Pituitary-Adrenal axis. By blocking the synthesis of the neurosteroids, they stopped the elevation of corticosterone, and prevented anxiety in mice.

"We have identified a novel mechanism regulating the body's response to stress by determining that neurosteroids are required to mount the physiological response to stress. Moreover, we were able to completely block the physiological response to stress as well as prevent stress-induced anxiety," said author Jamie Maguire, PhD.

Now the team is focusing on modulating the neuroreceptors to treat some of the diseases that accompany stress — be they depression, anxiety, or epilepsy.

From http://io9.com/5867762/a-pill-that-stops-stress-in-your-brain-before-you-feel-it

Friday, November 18, 2011

Not the Usual Suspects: Animal Study Finds Surprising Clues to Obesity-Induced Infertility

Source: Johns Hopkins Medicine

FOR IMMEDIATE RELEASE

Newswise — Infertility is common among obese women, but the reasons remain poorly understood and few treatments exist. Now a team of Johns Hopkins Children's Center scientists, conducting experiments in mice, has uncovered what they consider surprising evidence that insulin resistance, long considered a prime suspect, has little to do with infertility in women with type-2 diabetes, polycystic ovary syndrome (PCOS) and metabolic syndrome, all obesity-related conditions in which the body becomes desensitized to insulin and loses the ability to regulate blood sugar.

In a report, published online Nov.10 in the journal Diabetes, the Johns Hopkins scientists say the real culprit appears to be insulin sensitivity in the ovaries and the pituitary.

The Johns Hopkins team said its findings show that these organs escape insulin resistance and, awash with high levels of circulating insulin common in obesity, develop abnormal cell signaling that disrupts ovulation and eventually leads to infertility.

"Our findings suggest that the focus should shift from treating insulin resistance in peripheral tissue to taming insulin sensitivity in the pituitary and ovaries," says lead investigator Sheng Wu, Ph.D., of the Johns Hopkins Children's Center. Scientists traditionally have treated obesity-induced infertility by lowering blood insulin to counter the effects of insulin resistance.

A 2010 study by the same team discovered that the pituitary gland, insensitive to insulin in lean mice, became sensitive to elevated levels of insulin seen in human and rodent obesity. By knocking out the insulin receptors in the pituitary glands of obese mice, the researchers were able to partially restore fertility, thus proving that abnormal insulin signaling in the pituitary was only part of the story.

"In the original study, disrupting insulin signaling in the pituitary restored 50 percent of fertility in obese mice, but the search was on for the accomplice," says senior investigator Andrew Wolfe, Ph.D., an endocrinologist at the Johns Hopkins Children's Center. "Our new findings point to the ovaries."

In the pituitary, faulty insulin signaling stimulates increased secretion of luteinizing hormone, the researchers say. In the ovary, it puts testosterone production into overdrive. Both disrupt ovulation, the researchers explain.

In the latest study, lean mice and mice made obese on a three-month high-fat diet received injections of progressively higher doses of insulin to mimic the effects of high circulating insulin seen in obesity, diabetes and PCOS. In lean mice, the ovaries and pituitaries were insensitive to the hormone at low-dose injections, and responded only when injected with higher doses of insulin. The "trigger" doses corresponded to insulin levels typically seen in obesity. Obese mice with naturally elevated insulin levels exhibited high levels of insulin signaling in their pituitary and ovarian cells. When injected with insulin, the livers and muscles of obese mice showed greatly reduced response to insulin -- or insulin resistance. Their ovaries and pituitary glands, however, responded to insulin injections, confirming that in obese mice, these reproductive organs escape the insulin resistance seen in other organs.

To determine insulin sensitivity, the researchers focused on two signaling proteins, IRS-1 and IRS-2, regulators of cell-insulin communication involved in the development of insulin resistance in liver and muscle tissue. The scientists hypothesized that in the pituitary and ovaries, these messenger proteins would remain dormant under normal insulin levels, but would get activated once exposed to high levels of insulin. Indeed, the researchers found, the pituitary glands of obese mice showed higher IRS-2 signaling activity compared with lean mice, while the ovaries of obese mice had higher signaling activity in both IRS-1 and IRS-2 proteins, compared with lean mice.

In a follow-up study now under way, the Hopkins team is trying to determine whether knocking out the insulin receptors in both the ovaries and the pituitary would fully restore fertility in obese mice with high insulin levels.

Other co-investigators on the study included Sara Divall, M.D., and Fred Wondisford, M.D., both of the Johns Hopkins Children's Center.

The research was funded by the Endocrine Fellow Foundation, by The Eunice Kennedy Shriver National Institute of Child Health and Human Development, part of the National Institutes of Health, and by the Baltimore Diabetes Research and Training Center, which is supported by the National Institute for Diabetes and Digestive and Kidney Diseases.

 

 

Founded in 1912 as the children's hospital of the Johns Hopkins Medical Institutions, the Johns Hopkins Children's Center offers one of the most comprehensive pediatric medical programs in the country, treating more than 90,000 children each year. Hopkins Children's is consistently ranked among the top children's hospitals in the nation. 
Hopkins Children's is Maryland's largest children's hospital and the only state-designated Trauma Service and Burn Unit for pediatric patients. It has recognized Centers of Excellence in dozens of pediatric subspecialties, including allergy, cardiology, cystic fibrosis, gastroenterology, nephrology, neurology, neurosurgery, oncology, pulmonary, and transplant. For more information, please visitwww.hopkinschildrens.org

From http://www.newswise.com/articles/not-the-usual-suspects-animal-study-finds-su.../articles/list&category=medicine&page=1&search%5Bstatus%5D=3&search%5Bsort%5D=date+desc&search%5Bsection%5D=10&search%5Bhas_multimedia%5D=

Thursday, November 10, 2011

Diabetes in Cushing syndrome: basic and clinical aspects

Diabetes mellitus is a frequent complication of Cushing syndrome (CS) which is caused by chronic exposure to glucocorticoid excess, either endogenous or exogenous, and that is characterized by several clinical symptoms such as central obesity, purple striae, proximal muscle weakness, acne, hirsutism and neuropsychological disturbances.

Diabetes occurs as a consequence of an insulin-resistant state together with impaired insulin secretion which are induced by glucocorticoid excess. The management of patients with CS and diabetes mellitus includes the treatment of hyperglycemia and, when possible, the correction of glucocorticoid excess.

This review focuses on the disorders of glucose metabolism in patients exposed to glucocorticoid excess, addressing both the pathophysiological aspects and the clinical and therapeutic implications.

Read the entire article at http://www.cell.com/trends/endocrinology-metabolism/abstract/S1043-2760(11)00138-X