ABDOMINAL OBESITY & RISK OF DEATH IN WOMEN

There is increasing evidence that “abdominal obesity” (also referred to as “central obesity” or “truncal obesity”) is a particularly dangerous form of obesity in terms of risk for cardiovascular disease and cancer.  However, the actual impact of abdominal obesity on death rates has not been well studied before.  A new study in the journal Circulation provides some important clues about the magnitude of risk associated with abdominal obesity.

The data from this report was culled from the huge Nurses’ Health Study, which prospectively enrolled almost 45,000 nurses in the 1980s.  During an average of 16 years of follow-up, 3,507 study participants died, including 1,748 deaths due to cancer and 751 deaths due to cardiovascular disease.  The authors of this study evaluated the body weight and waist circumferences of the women who died during the course of this study, and then statistically analyzed the results.

When the women were divided into four separate groups, according to their waist circumferences, the data revealed the cost, in terms of risk of death, of increasing abdominal obesity.  Indeed, increasing waist circumference was significantly associated with an increasing risk of death due to both cardiovascular diseases and cancer.  Specifically, women with the greatest waist circumference measurements were, relative the women with the smallest waists, 79% more likely to die, overall.  The relative increase in the risk of death due to cardiovascular diseases (principally heart attack and stroke) among women with the largest waists was 99% higher when compared to the women with the smallest waists.  Likewise, a 63% increase in the relative risk of death due to cancer was observed in the women with the largest waist circumferences. 

Even among women who were still within recommended weight levels (adjusted for height), increased deposits of abdominal fat appeared to place them at a greater risk of premature death.  Despite being of normal weight, women with the greatest ratio of waist-to-hip circumference (> 0.88) were at a whopping three-and-a-half times greater relative risk of dying from cardiovascular diseases when compared to women of normal weight and with normal waist-to-hip ratios. 

This large scale prospective study of generally healthy American women is a real eye-opener, because it not only confirms previous (and smaller) studies suggesting that obesity centered around the abdomen is a particularly dangerous form of obesity, but it also provides strong evidence that an increased amount of abdominal fat, even in women who are within current recommendations for normal body weight, is a potent risk factor for premature death.  Although men were not included in this study, the results of this study have important implications for men too, as men tend to deposit excess weight around the abdomen to a much greater extent than women. 

FOLIC ACID PRETREATMENT & HEART ATTACKS

When coronary arteries become severely narrowed by plaques and blood clots, the heart’s muscle becomes starved for oxygen.  The chest pain (angina) experienced by many patients with severe narrowing of the coronary arteries is a sign that the heart muscle has become ischemic, or deprived of adequate oxygen-carrying blood flow.  When the coronary arteries become completely blocked, vital heart muscle may then begin to die, causing a heart attack, or myocardial infarction.

Folic acid, one of the B vitamins, plays many critical roles in cell metabolism, and is especially important in the function of the “power plants” of our cells, the mitochondria.  Folic acid also appears to have important antioxidant effects that decrease the production of potentially harmful metabolic byproducts known as free radicals.

A new animal study, just reported in the journal Circulation, looked at the effects of high-dose supplements of folic acid in rats that were then subjected to an experimental temporary blockage of one of their coronary arteries.  Another group of rats also underwent the same ischemia-inducing surgery, but did not receive folic acid supplements before undergoing temporary coronary artery occlusion.  When multiple measures of ischemia-induced heart dysfunction, extent of cardiac muscle death, and free radical generation were measured in the two groups of rats, the researchers found that the rats that had received 1 week of folic acid supplementation (prior to coronary artery occlusion) suffered less severe signs of ischemia-induced heart dysfunction, less extensive heart muscle death, and had lower concentrations of potentially toxic free radicals in their blood when compared to the rats that did not receive folic acid supplements.

While it is too soon, yet, to recommend high-dose folic acid supplementation for humans with coronary artery disease, based upon this study alone, the results of this study are nonetheless very intriguing.  Large scale prospective, randomized, double-blinded studies with human volunteers will be required to validate the encouraging findings of this animal study. 

PANCREATIC CANCER REGRESSION AFTER INJECTIONS OF BACTERIA

Cancer of the pancreas continues to exact a terrible toll on patients, and is currently the 4th most common cause of cancer death, even though pancreatic cancer is only the 7th most common cancer.  Despite extensive research, costing many millions of dollars, we still have not found an effective treatment for this dreaded disease.  Only a minority of patients with pancreatic cancer will even be candidates for radical surgery, which offers the only known hope of possible cure.  Even among the fortunate few patients who are even candidates for radical surgery, the majority will still succumb to this terrible disease.

A new study, published in the journal Gut, evaluates a truly novel treatment for pancreatic cancer, using mice implanted with human pancreatic cancer tumors.  The mice were divided into 2 groups.  In the experimental group, Streptococcus bacteria, similar to those that cause “strep throat” in humans, were injected directly into the implanted pancreatic cancer tumors.  In the control group of mice, the same fluid that was used to suspend the bacteria used in the experimental group was injected into the tumors, but without the Streptococcus bacteria.   

The authors of this study found that a single injection of bacteria into the tumors resulted in complete regression, or death, of the pancreatic cancer tumors.  Not only did the injected bacteria appear to directly attack the pancreatic cancer cells, but the presence of the bacteria also appeared to stimulate a massive immune response against the pancreatic tumors as well.  Of course, as many previous animal studies have shown, what works in laboratory mice does not, unfortunately, always work in human beings as well.  Therefore, additional study in humans with pancreatic cancer will be necessary before anyone can say that the injection of Streptococcus bacteria directly into pancreatic tumors in humans will have the same effect, or that it is even safe to do so (one obvious concern regarding this treatment approach is that it also might cause life-threatening infections).  However, this is a fascinating study, and in light of the fact that we simply do not have any highly effective treatments for this awful disease, I suspect that a great deal of consideration will be given to creating an early phase clinical trial in humans, based upon the results of this study.  

 

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Dr. Wascher is an oncologic surgeon, professor of surgery, a widely published author, and the Director of the Division of Surgical Oncology at Newark Beth Israel Medical Center:

 http://www.sbhcs.com/hospitals/newark_beth_israel/mservices/oncology/surgical.html

 

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Send your feedback to Dr. Wascher at:  rwascher@doctorwascher.net
 

 

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http://www.doctorwascher.com

 

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Copyright 2008.  Robert A. Wascher, MD, FACS.  

All rights reserved.

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