Aug
01
2004

Too Much Fat Fuels Metabolic Syndrome

In a review article for physicians from the St. Michael’s Hospital of the University of Toronto (see reference below) Dr. Monge outlined some of the newer human research where links were found between the lining of the blood vessels and the hormones produced by fat cells that lead to the complications of the metabolic syndrome. In obese people there is a cluster of conditions such as high blood pressure, high blood sugar, high cholesterol, lipid abnormalities and high insulin levels, which is known as “metabolic syndrome”. Another name that was used for this condition in the 1990’s was “syndrome of insulin resistance”.

Dr. Monge pointed out that blood vessel health depends on the fine balance between two opposing forces. On the one hand there is a system that leads to blood vessel spasm, blood clotting, growth promoting, inflammation causing and oxidizing. On the other hand there is a system that is responsible for blood vessel relaxation, growth inhibition, blood clot dissolving, inhibiting inflammation and antioxidant activity. Complex changes occur in our metabolism when we put on pounds and accumulate too much fat. It is important to realize that fat is not just sitting there, but is composed of highly active fat cells that respond to insulin and growth factors and in turn produce a number of hormones and factors that affect the cells that are lining the blood vessels. Inflammatory cytokines are produced by fat cells that attack the blood vessels by producing atheromatous plaques, causing them to accumulate fat again and help in the processes that lead to rupture of the plaques.

Too Much Fat Fuels Metabolic Syndrome

Too Much Fat Fuels Metabolic Syndrome

The end result is that the deadly interplay between the fat cells and the endothelial cells lining the blood vessels tips the balance between the two systems mentioned above to the point where heart attacks and strokes suddenly occur.

There are two complex pathways that are involved in this process and that are linked to what was stated above. One crucial aspect of this involves nitric oxide, a small molecule that is normally produced by the endothelial lining cells and that is needed for normal circulation of the heart muscle, skeletal muscles and internal organs. This protective system is where much of the derangement of normal metabolism occurs with regard to the metabolic syndrome.

Dr. Monge pointed out that with these newer insights into the complex metabolic changes associated with the metabolic syndrome in obese people, there will be very practical results in the near future. Anti-inflammatory medications are already being utilized and some of the anti-diabetic medications have been shown to reduce the risk of heart attacks. It is hoped that sensitive tests will be developed to measure the hidden endothelial dysfunction at a time when preventative steps are still effective or early intervention can be done.

More info on the metabolic syndrome: http://nethealthbook.com/hormones/metabolic-syndrome/

Reference: Metabolic Syndrome Rounds (April 2004): J.C. Monge “Endothelial Dysfunction and the metabolic syndrome”

Last edited Oct. 26, 2014

Dec
01
2003

Fat Cells Secrete Hormones That Raise Blood Pressure

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

Jul
01
2003

High Blood Pressure On The Increase In The US

High blood pressure on the rise

Dr. Hajjar, of the University of South Carolina in Columbia and Dr. Kotchen, of the Medical College of Wisconsin in Milwaukee have compared a large group of people in the US in the years 1999-2000 with prior studies in 1988-1991and 1991-1994 where peoples’ blood pressures were measured.

The latest study involved more than 5000 people, the prior studies more than 9000 people each. Almost 29% of the population has a blood pressure of 140/90 or higher in the latest study.

Compared to the 1988-1991study this is a significant increase of 3.7%. More than half of this was explained on the basis that the population’s weight (measured by body mass index calculation) had increased. The sub groups who had the largest increase in blood pressure were as follows:

1. diabetics with high blood pressure. In this high risk group only about 25% had a blood pressure readings of less than 130/85, which is the target value.

2. Mexican Americans had a significantly poorer awareness and control of their elevated blood pressures than the non-Hispanic whites and non-Hispanic blacks.

3. Women as a group were poorer in blood pressure controlling than men.

4. People above the age of 60 had a much higher rate of uncontrolled blood pressure as well.

The study concluded that by concentrating campaigns and efforts on these four target groups significant gains could be made in terms of control of blood pressure, reduction of strokes, heart attacks and kidney damage.

Here are some links regarding high blood pressure, prevention of strokes and heart attacks to various chapters of my nethealthbook.com:

High blood pressure link

Heart attack link

Stroke link

Last edited October 26, 2014

Dec
01
2002

What Goes Around Comes Around With Blood Pressure Medications

A large clinical study with 42,418 men and women 55 years and older has been published in the American Medical Association Journal recently(JAMA 2002:288:2981-2997,3039). The thiazide type water pill chlorthalidone(12.5 mg to 25 mg/day) is the clear winner in this trial, called the ALLHAT trial. It stands for “Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial” and is the largest hypertension trial that was ever performed going over a period of 5 years.

In this trial a calcium channel blocker(amlodipine) and an ACE (=angiotensin converting enzyme)inhibitor(lisinopril) were tested as the initial medication and compared to chlorthalidone.There was a 15% higher risk to develop a stroke with lisinopril and a
38% increased risk with amlodipine to develop congestive heart failure when compared to the chlorthalidone group. The interesting conclusion from this study is that the least expensive therapy for high blood pressure turns out to be the safest. Another ineresting finding was that black patients responded much better to water pills than to ACE inhibitors, which had been noted before by other authors. When more than one medication is required to control high blood pressure, the dosage of the second medication can often be kept lower with a combined therapy thus reducing the likelihood of side-effects and complications.

What Goes Around Comes Around With Blood Pressure Medications

What Goes Around Comes Around With Blood Pressure Medications

Comments: Several decades ago the teaching was that the doctor would start a new high blood pressure patient with a water pill first, and combine this with a second or even third pill of a different medication class, if the water pill would not be effective enough on its own (it was called the “step care therapy”). For decades the side effects of the water pill consisting of low potassium blood levels brought the water pill treatment in disrepute. The original trials,however, were done with chlorthalidone doses of 50 and 100 mg per day, much higher than would now be recommended. It appears that with this study medicine has gone a full circle back to the old stand-by water pill, but at a much safer, lower dosage.

Here is a useful link (regarding hypertension): http://www.nethealthbook.com/articles/cardiovasculardisease_hypertension.php

Last edited December 10, 2012