Dec
01
2003

Fat Cells Secrete Hormones That Raise Blood Pressure

By | Diabetes, High Blood Pressure, Hormones, Obesity, Prevention

Fat cells are known to secrete a number of substances that affect the lining of the arteries and that are also known to be associated with the metabolic syndrome. One of the observations that physicians were aware of for some time is that aldosterone, a hormone from the adrenal glands, is often elevated in patients with high blood pressure and obesity or people who are overweight.

Dr. Ehrhart-Bornstein and her group from the University Medical Center, Heinrich Heine University of Düsseldorf in Germany investigated this interaction between fat cell metabolites and the cells of the adrenal cortex in more detail. They used a tissue culture model with human adrenocortical cells (NCI-H295R). To their surprise they found two separate hormone factors that were produced by fat cells and that showed in the tissue culture system a 7-fold increase in aldosterone hormone release. As aldosterone is a mineralocorticoid hormone they called these new releasing hormones mineralocorticoid-releasing factors. Further characterization of these factors demonstrated that one was of a higher molecular structure and was heat-sensitive, the other one was smaller in size and was more heat resistant. Each factor alone lost much of the aldosterone releasing activity, but when recombined they had 93% of the original action. Synthesis of messenger RNA inside the adrenocortical cells was stimulated by a factor of 10-fold from the action of the mineralocorticoid-releasing factors. Other hormones were also somewhat stimulated such as release of cortisol by a 3-fold increase and DHEA by a 1.5-fold increase. Other known substances from fat cells were entirely ineffective in this testing system.

Fat Cells Secrete Hormones That Raise Blood Pressure

Adipose cells secreting aldosterone releasing factor

When asked how this new research might fit in with the observation that loss of fat through calorie restriction has a beneficial effect on high blood pressure, the authors commented that with less fat storage in fat cells during weight loss the production of mineralocorticoid-releasing factors would go down significantly and aldosterone would be released at a much lower rate thus decreasing blood pressure through the aldosterone/angiotensin/renin mechanism.

Nov. 12, 2003 paper on which this write-up is based: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC283571/

Last edited October 26, 2014

Aug
01
2003

Newly Detected Hormone May Help Obesity

By | Health, Hormones, Obesity

At a recent meeting of the Endocrine Society in Philadelphia new findings by British researchers were presented regarding hormone interactions with weight problems.

Dr. Simon Aylwin, a consultant from the King’s College Hospital in London, England, presented data showing that peptide hormone PYY levels were much lower in patients who were significantly obese versus normal weight controls.

As Dr. Stephen Bloom’s research group from Imperial College, London, UK had shown earlier, with a meal rich in calories the gut produces the PYY hormone in a way that with higher amounts of calories in food consumed more of the hormone PYY is secreted into the blood stream. The new information that was discussed at the meeting of the Endocrine Society was the fact that these hormone signals are registered in the hypothalamic tissue, a part of the brain situated just above the pituitary gland. It has been known for a long time that weight is regulated by a satiety centre in the hypothalamus. Now it has been appreciated that there are at least two or more pathways of registering weight related hormone signals: one being the gut related PYY hormone that tells the brain that enough food was consumed in a meal, and secondly leptin hormone signals where the hormone leptin is secreted from the fatty tissues in the body, which tells the satiety centre of the brain that not as much food needs to be consumed when our weight has reached a certain threshold.

Newly Detected Hormone May Help Obesity

Newly Detected Hormone May Help Obesity

Dr. Aylwin measured PYY hormone levels in a number of different groups of patients such as in patients who were obese, in patients who had gastric bypass surgery done and in a group who only had gastric banding done. They observed that the group who had bypass surgery done had a higher than normal response of PYY hormone release as a response to a meal. This enabled them to adhere to low calorie meals without any hunger pangs and this group of patients did well in terms of weight control on the longterm.

In contrast to this the group with gastric banding had a flat response curve to the stimulus of a meal with respect to the PYY hormone as did patients with obesity. The low PYY levels in response to meals likely explains why these patients continue to eat too much making their weight loss efforts more difficult.

Dr. Aylwin explained that with future research efforts new forms of medications could be developped that mimic the effects of the PYY hormone leading to satiety and allowing patients to control their weight easier. Dr. Linda Fish, an endocrinologist from the University of Minnesota, mentioned that for excessive obesity with a body mass index of more than 45 the only effective therapy right now would be the invasive gastric bypass procedure. With an anologue type medication that would have the same effect as the PYY hormone, many patients might be able to have persistent weight loss with these new medications allowing them to lose weight persistently without bypass surgery. However, results of this type of research likely would take about 10 years before a new drug would be available to the public.

This summary is based on an article in the July 15, 2003 issue of the Medical Post (page 50) as well as on the newsdesk article entitled “Obesity-is it all in the mind?” in The Lancet Neurology Volume 2, Number 1, January 2003.
Link to related topic (nasal spray for obesity).

Last edited December 9, 2012

Jul
01
2003

Obesity And Metabolic Syndrome

By | Diabetes, Health, Heart Disease, High Blood Pressure, Hormones, Obesity

In the June 10, 2003 edition, following page24, of The Medical Post there was a minisymposium on obesity and the metabolic syndrome (also known as the “syndrome of hyperinsulinism”).

Four specialists had a discussion about this topic: Dr. Ehud Ur (endocrinologist, Dalhousie University, Halifax, N.S., Canada), Dr. Robert Dent (Director of the Weight Management Clinic, Ottawa Hospital, Ont.), Dr. Dominique Garrel (Director of Department of Nutrition and endocrinologist, University of Montreal, Quebec), and Dr. Arya Sharma (Prof. of Medicine, McMaster University, Hamilton, Ont.).

Introduction:

Obesity is now a health threat that about 25% of the North American population is suffering from. There is still a lot of discussion what the exact criteria should be, but the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III) has simplified the detection of the metabolic syndrome.

Obesity And Metabolic Syndrome

Obesity And Metabolic Syndrome

The experts agree that when three or more of the criteria mentioned in this table are positive the person would be considered to have metabolic syndrome.

There is a wide age-related variety: in one study only 7% had metabolic syndrome in the age group of 20 to 29. The same study found 40% of study participants had the metabolic syndrome in the age group of 70 years and older. It is thought that too many calories coupled with too little activity over a longer period of time, perhaps coupled in some people with a genetic tendency to develop metabolic syndrome, leads to an accumulation of abdominal (so-called”visceral”) fat.

Because fat cells have their own hormone systems (leptins etc.) there is a change of metabolism including an elevation of the insulin level with associated loss of “insulin sensitivity”. So, the more obese a person becomes, the less effective insulin becomes in transporting blood sugar through cell walls. At the same time the liver metabolism is changing with the good cholesterol (HDL) being less produced and the bad cholesterol (LDL) being overproduced. The liver will produce a different mix of coagulation factors, which leads to a tendency to form clots in the veins of the legs and in the lungs. As the pancreatic capacity for insulin production gets exhausted over a period of time, the patient eventually develops type 2 diabetes mellitus. Due to the risk of the coronary arteries clogging up with the cholesterol changes and the accelerated hardening of arteries from diabetes, the risk for getting severe heart attacks in obese people with the metabolic syndrome when compared to a normal weight population is about 4-fold.

Elements leading to the diagnosis of “metabolic syndrome”
Finding: Comments:
abdominal obesity waist circumference more than 102 cm in men or more than 88 cm in women
elevated triglyceride level level of 150 mg/dl or higher
low HDL cholesterol level under 40 mg/dl in men or under 50 mg/dl in women
elevated blood pressure systolic or diastolic blood pressure exceeding 130/85 mm Hg
high fasting blood glucose level fasting glucose higher than 110 mg/dl

Treatment of metabolic syndrome:

The experts agreed that a reduction of only 5% to 10% of the body weight through a sensible combination of a mild exercise program (e.g. walking 30 to 45 minutes every day) and a calorie reduced food intake will make a significant difference in terms of normalization of the body chemistry. It is my estimate that perhaps 70% to 90% of all cases of obesity and metabolic syndrome can be treated this way.

However, the remaining cases should continue to see their physician and be followed like the doctor would follow someone who has high blood pressure. There are two types of medications available and they have nothing to do with the Phen-Fen diet pills from not too long ago that were found to cause pulmonary hypertension. These new diet pills are fairly safe and show weight loss results provided the patient co-operates with regard to a modified to low fat diet and some degree of regular exercise.

1. Sibutramine (brand name: Meridia) is a specific brain hormone inhibitor in the area where the appetite zone is located (serotonine and norepinephrine reuptake inhibitor). This medication helps the patient by experiencing satiety sooner so that the patient does not feel deprived despite less calorie consumption.

It is the medication of choice for those who tend to eat a lot. Like with other anti-depressants side-effects are a dry mouth, heart rate increases and sleep loss (insomnia).

2. Orlistat (brand name: Xenical) inhibits fat uptake at the level of the gastrointestinal wall (gastrointestinal lipase inhibitor). This leads to an inhibition of fat absorption by about 30%. The patient needs to keep the fat intake down to about 2 oz. (=60 gm) per day. If the patient consumes more fat, the side-effect of orlistat will be flatulence, abdominal cramps and diarrhea. If the patient is on a strict low fat diet, there would not be enough fat in the gut for the medication to be effective.

At this point it is not known how long the patient should be on such weight loss medication, if this was the chosen route. The experts felt that 1 year would be reasonable, but that the patient should be observed by the treating physician and it may be necessary after some intermission to go for another year of therapy all the way attempting to permanently change eating and exercise habits as an ongoing maintenance program.

Here is a link to another reference about the metabolic syndrome (syndrome of insulin resistance).

Last edited December 9, 2012

 

Dec
02
2002

Obesity (Excessive Weight) A Predictor Of High Risk For Stroke

By | Obesity, Stroke

In the Dec.9th issue of the Archives of Internal Medicine an important follow-up from the US Physicians’ Health Study was published. It examined the effect of obesity on the development of stroke later in life. 21,414 male physicians of the US have been followed now for 12.5 years in this study. At present there were 747 strokes (631 ischemic, 104 hemorrhagic, 12 others).

They found that the rates of strokes were in direct relation to the amount of excessive weight, in other words the higher the weight, the higher the risk to develop a stroke. It did not matter what kind of stroke it was (ischemic stroke or hemorrhagic stroke), a body mass index above 30 was always associated with a 1.9-fold risk to develop a stroke when compared to normal weight controls (body mass index less than 25). This risk of obesity was independent from other risk factors such as diabetes, high cholesterol or high blood pressure. Dr. Kurth from the Brigham and Women’s Hospital, Boston, said that this finding is very significant in view of the fact that many young adults in the US are either overweight or obese and they will be exposed to this risk for a longer period of time inreasing the risk to develop strokes even further. He hopes that physicians will concentrate on treating obesity more aggressively preventing a stroke. In industrial countries strokes are the main cause of disability and are on the third place on the list of causes of death.

Obesity (Excessive Weight) A Predictor Of High Risk For Stroke

Obesity (Excessive Weight) A Predictor Of High Risk For Stroke

(This info based on: Arch Intern Med 2002;162:2557-2562.)

Other information about strokes can be found through this link: http://www.nethealthbook.com/articles/cardiovasculardisease_strokeandcerebralaneurysm.php

Last edited December 10, 2012

Oct
18
2002

Work Stress Is A Killer…More Than 2-Fold Over A Period Of 25 Years

By | Diabetes, Heart Disease, Obesity, Stroke

In mid October 2002 the British Medical Journal(BMJ 2002;325:p.857-860) published a paper by Dr. Mika Kivimäki from the University of Helsinki where 812 healthy factory workers were followed for about 25 years. The issue was whether stress from work would have negative consequences, which could be measured in terms of cardiovascular disease. Various risk groups were defined from low stress to high stress.

Low stress jobs were classified as people who often had more training, more responsibilities, better salaries, physically less strenuous jobs with more job security. High stress jobs involved the opposite(high demand/low job control/low salary/no job security). Depending on which subgroups of high versus low risks were compared, the investigators found a 2.2 to 2.4-fold increase of strokes and heart attacks due to cardiovascular disease.The team measured other cardiovascular risk factors. They found a significant increase of cholesterol in the high stress job group after 5 years. After 10 years there was a marked weight gain in the stressed group with obesity becoming much more frequent. The authors noted that this likely led to a change of metabolism in the sense of hyperinsulinism, which is known to cause high cholesterol levels and leads to hardening of the arteries with heart attacks and strokes.

Work Stress Is A Killer...More Than 2-Fold Over A Period Of 25 Years

Work Stress Is A Killer…More Than 2-Fold Over A Period Of 25 Years

Visit these useful related links to chapters of my free Internet based Nethealthbook:
Hyperinsulinism or syndrome of insulin resistance:
http://www.nethealthbook.com/articles/hormonalproblems_diabetesmellitus.php

Heart disease:
http://www.nethealthbook.com/articles/cardiovasculardisease_heartdisease.php

Stroke:
http://nethealthbook.com/cardiovascular-disease/stroke-and-brain-aneurysm/hemorrhagic-stroke/

Last edited October 25, 2014