SUPER-SIZE ME: FAST FOOD’S EFFECTS ON YOUR LIVER

Obesity is an epidemic in America, and in many societies around the world.  The plentiful availability of relatively inexpensive fat- and calorie-packed foods, along with a plethora of “effort-saving” devices, has helped to make us the fattest civilization in recorded human history. 

In addition to its adverse effects upon the cardiovascular system, joints and other important organs, excess calories can also induce fatty changes in the liver.  This condition, referred to as hepatic steatosis, if severe enough, can cause liver inflammation and dysfunction similar to chronic cirrhosis. A new study, from Sweden, published in the journal Gut, suggests that binging on fast food for as little as a few weeks can, in fact, lead to measurable signs of liver injury.

In this study, 12 healthy men and 6 healthy women volunteered to eat at least two fast food meals a day, and to adopt a sedentary lifestyle, for a period of 4 weeks.  An equal number of “control” volunteers continued with their regular diets and levels of physical activity.  On a weekly basis, all study volunteers underwent testing to measure the level of liver enzymes in the blood that become elevated in the presence of liver inflammation and injury.  Additionally, the subjects underwent weekly scans of their livers in order to estimate the extent of fat deposition within their livers. 

On average, the volunteers who agreed to be “super-sized” gained nearly 15 pounds over the 4 week duration of this clinical study.  Blood levels of ALT, a liver enzyme that rises with injury to the liver, were normal in all study volunteers at the beginning of the study.  At the end of the 4 week study, however, 11 of the 18 (61%) “super-sized” volunteers had abnormally elevated levels of ALT in their blood, signaling the presence of inflammatory changes within their livers.  When they had their livers scanned for fat content, these heavy eaters had nearly 3 times as much fat in their livers at the end of the study as they did when they entered the study only 4 weeks earlier. 

Taken together, this study nicely shows how rapidly the binge-eating of fast food can lead to measurable signs of liver injury and inflammation.  The same injurious effects on the liver are often seen in alcoholics, partly due to the great excess of calories associated with high levels of alcohol intake.  In fact, the authors of this study, citing the results of their research, suggest that physicians consider overeating as another potential cause of liver inflammation and injury in patients with abnormal ALT levels in the blood, in addition to the usual suspects of alcohol abuse, hepatitis caused by viruses, and liver injury caused by other substances that are known to be toxic to the liver.  Based upon the results of this intriguing little clinical study, it would appear that “super-sizing” your diet may potentially lead to rapid and significant harm to your liver.

 

EXERCISE, WEIGHT & CORONARY ARTERY DISEASE

It is well known that obesity is linked to an increased risk of high blood pressure, coronary artery disease, heart attack, and congestive heart failure.  There continues to be a great deal of debate, however, regarding the subgroup of people often referred to as the “fit fat.”  Some studies have purported to show that overweight people who nonetheless exercise regularly, and who appear to be otherwise healthy, may have approximately the same risk of heart attack, and death due to cardiovascular disease, as their leaner compatriots.  Other studies have shown that even vigorous and regular exercise fails to completely erase the added health risks associated with increasing levels of obesity.

A new study has evaluated the effects of physical activity and body weight, in women, on the risk of coronary artery disease.  This study was conducted by researchers at the Beth Deaconess Medical Center and the Brigham and Women’s Hospital in Boston, and is featured in the current issue of the Archives of Internal Medicine.  The data for this research study was derived from a very large study of clinically healthy women.  Nearly 40,000 women have been participating in the Women’s Healthy Study, for an average of 11 years now; and all of them were without clinical evidence of cardiovascular disease, cancer or diabetes when they first entered the study.  This study was designed to assess the impact of both body weight and level of physical activity as risk factors for coronary artery disease (CAD).

A total of 948 cases of new CAD were diagnosed in this huge cohort of women during the study (most of these 948 women experienced a heart attack, or required either coronary artery bypass surgery or stenting of their coronary arteries).  The researchers then calculated the risk of developing CAD for subgroups of study volunteers, based upon body mass (e.g., normal weight, overweight and obese) and average level of physical activity (physically active women who were not overweight served as the basis for comparison with these other subgroups).

Not surprisingly, the women who were both obese and physically inactive had the greatest risk of developing CAD (more than 2.5 times the risk of the physically active women with a normal body weight).  The women who were at the next highest level of risk for CAD were those who were obese but physically active, and those who were overweight but physically inactive.  In fact, the risk of CAD was essentially identical in these two subgroups of women (nearly 2 times the risk of CAD, when compared to the active women with a normal body weight).  The third highest risk category for CAD was found in women who were overweight but physically active (1.5 times the CAD risk as normal weight women who were active).  Next to the physically active women with a normal body weight, the lowest risk category for CAD was observed in the group of women with normal body weight who were physically inactive.  In this particular subgroup, the added risk of CAD was a rather modest 1.08 times the risk observed in the physically active women with normal weight.

The results of this study, essentially, confirm the well known increased risk of CAD associated with either increased body mass or physical inactivity.  In this study, women with both risk factors had the highest overall incidence of CAD.  This study also reveals that increased levels of physical activity do appear to reduce the risk of CAD, but not to the levels observed among women with normal body mass.  That is to say that it appears that the increased risk of CAD brought about by being overweight or obese cannot be completely eliminated by increased levels of exercise and physical activity.  Previous suggestions that being “fit and fat” can bring the risk of CAD down to levels observed in lean individuals appear not to be correct, based upon this large and very high quality prospective public health study. 

Whether or not the findings of this study also apply equally to men as well is unclear.  However, based upon other epidemiological studies, it is reasonable to assume that both women and men can reduce their risk of CAD significantly by maintaining their body mass in the normal range and by engaging in regular, frequent and vigorous exercise.

 

CONTAMINATION OF SURGICAL INSTRUMENTS IN THE OPERATING ROOM

In most cases, operating rooms are completely set up before the patient is wheeled in.  The OR technicians and nurses bring all of the necessary surgical instruments and supplies into the room, and open them up so that surgery can begin promptly once the patient is anesthetized.  In some cases, delays in getting the patient into the operating room, or under anesthesia, may expand the amount of time that sterilized surgical instruments are left exposed to the open air in the OR.  An innovative new study from Wright State University, in Dayton, Ohio, and just published in The Journal of Bone & Joint Surgery, evaluated the incidence of bacterial contamination in trays of surgical instruments after varying durations of exposure to the ambient air in the operating room.

In this study, 45 sterile trays, used to hold sterilized surgical instruments, were opened within a standard operating room.  The exposed surfaces of these trays were then cultured, in standard fashion with sterile swabs, to identify the presence of viable bacteria on them.  Serial cultures were obtained, initially upon opening the trays, and then at 30 minute intervals, for a total of 4 hours.  The trays were divided into three groups, each with 15 sterile trays.  In the first group, the sterile instrument trays were opened and left within a locked OR, and nobody was allowed in except for the person who intermittently swabbed the trays to perform cultures.  In the second group, a single person went into and out of the OR every 10 minutes, for 4 hours.  Finally, in the third group, all opened sterile instrument trays were initially covered with sterile towels, and were then subsequently uncovered, and nobody was allowed to enter this particular operating room except for the person performing the cultures.

Among the 30 trays left uncovered throughout the experiment, 3 of them (10%) were found to be contaminated with bacteria immediately after they were opened!  Of the remaining 27 trays that were left uncovered, a whopping 30% were found to have bacterial contamination after 4 hours of being left open to the air within the operating room (even after only 1 hour of being left open, 15% of these uncovered instrument trays had culture-proven evidence of bacterial contamination).  There was no significant difference in the likelihood of bacterial contamination among the uncovered trays in the OR where no entry was allowed versus the OR where one person was permitted to enter and leave the room every 10 minutes.  On the other hand, none of the 15 instrument trays that were initially covered immediately upon opening were found to have evidence of bacterial contamination 4 hours after being opened. 

To summarize, this study determined that sterile surgical instrument trays were increasingly likely to develop bacterial contamination over time if they were left uncovered after being opened.  Light human traffic into and out of the OR did not appear to have any impact on the risk of bacterial contamination of the uncovered instrument trays, however.  On the other hand, covering the instrument trays until it was time to actually begin the surgical procedure appeared to eliminate this time-dependent risk of environmental bacterial contamination.  The authors concluded, therefore, that sterile surgical instrument trays should be immediately covered until they are ready to be used.  (Seems like a good idea to me.)

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

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

http://www.doctorwascher.com

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

All rights reserved.

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Colorectal cancer is the second most common cause of cancer-related death in the United States.  In 2008, an estimated 150,000 new cases of cancer of the colon and rectum will be diagnosed, and nearly 50,000 deaths from this disease are expected to occur.   As I have mentioned in previous columns, colon and rectal cancers can, in most cases, be prevented or, at least, detected at a very early stage, simply by adhering to standard colorectal cancer screening guidelines (please see my 1/7/2008 column for a more detailed discussion of current colorectal cancer screening guidelines).  Currently, colonoscopy, using a video camera mounted at the tip of a long flexible tube (endoscope), remains the gold standard for the detection of premalignant polyps (also called adenomas) in the colon and rectum.  

While the majority of colon and rectal cancers that develop spontaneously appear to arise from premalignant polyps, which resemble fleshy protrusions sprouting from the lining of the large bowel, cancer has also been reported, much less commonly, to arise from lesions that have a flat shape, or even a slightly depressed appearance, with respect to the surrounding layer of tissue that forms the inner lining of the colon and rectum (the mucosa).   These less common forms of premalignant colorectal lesions, often referred to as nonpolypoid colorectal neoplasms (NP-CRNs), were first  widely reported in the Japanese medical literature, but were thought to occur only very rarely in western populations.  A new research paper in the Journal of the American Medical Association, however, suggests that NP-CRNs may not be all that uncommon in the United States after all. 

This new study, which included more than 1,800 patients, assessed the results from elective colonoscopy performed at a large Veterans Administration medical center in 2003 and 2004.  Far from being rare, NP-CRNs were found in nearly 10% of the colonoscopies performed.  The patients were then broken down into three subgroups for further analysis.  Among patients undergoing colonoscopy for routine screening purposes, NP-CRNs were observed 5.8% of patients.  Patients undergoing colonoscopy because of concerning symptoms (such as rectal bleeding, a change in bowel habits, or other gastrointestinal symptoms) were noted to have NP-CRNs in 6% of case.  Among those patients undergoing colonoscopy because of a prior history of colorectal cancer, NP-CRNs were observed in more than 15% of patients, or 1 in every 6 or 7 patients previously treated for colorectal cancer. 

When the results of biopsies taken from these NP-CRNs were assessed, more bad news resulted.  Although fewer than 1% of all patients (and only 0.3% of the screening colonoscopy group patients) were discovered to have early cancerous changes within a NP-CRN lesion, a comparison between NP-CRNs and the more common colorectal polyps revealed a disturbing finding.  Among all 3 subgroups of patients, the presence of early cancers within flat or depressed NP-CRNs occurred nearly 10 times as frequently as was seen in colorectal polyps.  When looking at specific subgroups of patients, once again, this study revealed that in patients undergoing colonoscopy for routine screening purposes, NP-CRNs were 2 times as likely to harbor small cancers when compared to colorectal polyps.  In those patients undergoing colonoscopy for surveillance purposes, because they had previously been diagnosed with colorectal cancer, NP-CRNs, when identified, were almost 64 times more likely to harbor early cancers when compared to polypoid masses!  When comparing the flat type of NP-CRNs with the depressed type, the depressed lesions were most likely to contain cancer (33% of the depressed lesions already had cancer cells present in them).  These worrisome findings are all the more concerning given that, on average, the NP-CRNs containing cancer tended to be considerably smaller than the polyps also found to have cancer present in them (1.6 centimeters in diameter vs. 1.9 centimeters, respectively). 

The findings of this study raise several important new considerations with respect to colorectal cancer screening strategies.  First of all, despite the previous belief that NP-CRNs were rare lesions within western populations, this study suggests that, in fact, they are rather common, at least in a selected group of veterans (on average, veterans tend to have a greater incidence of risk factors associated with colorectal cancer than the general population).   

The finding that, irrespective of the size of the lesions, that NP-CRNs are more likely to harbor small cancerous tumors suggests that the biology of these flat or depressed lesions may be different than that of the more typical, and more common, polypoid lesions.  In this study, a special colored dye was used to stain the lining of the colon and rectum, which made it easier to detect NP-CRNs.  However, this technique is not generally used in routine colonoscopy at most endoscopy centers, and the results of this study, therefore, raise the issue as to whether or not this technique should be routinely added to the current practice of colonoscopy.  Also, even with special staining of the mucosa, NP-CRNs are still more difficult to identify than polypoid lesions, and the borders, or margins, of these flat or slightly depressed lesions are less distinct than is the case for polyps.   

The current data in the medical literature suggests that approximately 10% of polyps may be missed, even by experienced examiners, during routine colonoscopy.  Given the greater difficulty of identifying NP-CRNs during colonoscopy, one can assume that considerably more than 10% of NP-CRNs are currently being missed with even the most thorough conventional colonoscopic examinations.  As NP-CRNs now appear to be significantly more likely to contain small cancers than are polyps, better and more specialized methods of colonoscopy may be necessary to reduce the chance that an early cancer within a small NP-CRN might be missed (and, for the record, virtual CT colonoscopy, which I have discussed previously in another column, cannot currently detect NP-CRNs).  In addition to the greater challenge of detecting NP-CRNs, when compared to colorectal polyps, NP-CRNs that are identified during colonoscopy, and are amenable to removal with the colonoscope, may be more likely to be incompletely removed when compared to polyps.   

Finally, due to declining reimbursements for colonoscopy, gastroenterologists often feel pressured to perform colonoscopy more rapidly than in the past, in order to increase their productivity.  It has been well demonstrated that the more rapidly a colonoscopy is performed, the greater the likelihood that colorectal polyps will be missed.  Since we know that NP-CRNs are considerably more difficult to detect than polyps, the implications of performing rapid colonoscopy are very clear: more NP-CRNs will be missed, even with the addition of new techniques such as mucosal staining, as GI doctors try to perform more colonoscopies per day to keep pace with declining reimbursements for their professional services. 

Because of the many questions that this study has raised, I predict that it will eventually be viewed as a landmark cancer research paper, and its findings will stimulate a serious review of all of our current colorectal cancer screening guidelines.  Currently, it is not clear if the general public is at the same high risk of having NP-CRNs in their colon and rectum (or the same risk of harboring colorectal cancer within NP-CRNs) as this selected population of veterans.  But the provocative findings of this study will, nonetheless, have major implications on future colorectal cancer screening strategies for all of us.  

HEALTH RISKS AFTER STOPPING HORMONE REPLACEMENT THERAPY (HRT) 

I have written about the various findings published, over the past 6 years, from the landmark Women’s Health Initiative (WHI) study in previous columns.  A new update, published this week in the Journal of the American Medical Association, sheds additional light on the long-term health implications of combination hormone replacement therapy (HRT), as taken by millions of women in this country, over the past 5 decades, for the symptoms of menopause.  As I have mentioned before, the use of combination HRT has unequivocally been linked to an increase in the incidence of breast cancer, coronary artery disease (including heart attack), and stroke, among other serious illnesses.  This new WHI study update takes a look at those women who stopped taking HRT when the WHI released its disturbing preliminary findings (and which resulted in the early termination of the WHI combination HRT research trial) in 2002.  In this update, the health status of women who had stopped taking HRT medications for an average of 3 years is reviewed and analyzed.  The results paint a mixed picture of health risks present even 3 years after cessation of HRT. 

A total of 15,730 postmenopausal women were included in this analysis, and consisted of women who took combination HRT pills during the WHI study and women who took placebo (sugar) pills that appeared identical to the HRT pills.  When the data was analyzed, the good news was that, at an average of 3 years after stopping HRT, the risk of coronary artery disease between the two groups of women had, once again, become equal.  That is to say, the increased risk of coronary artery disease that was observed, during the WHI study, among the women randomized to receive HRT had declined to the same levels observed in the group of women who had received only placebo pills.  However, unfortunately, the increased risk of developing cancer persisted in the group of women who had previously taken HRT pills during the study. 

The overall cancer risk among the women who had previously taken HRT pills was 24% greater than for those women who had received placebo pills, although the total numbers of patients diagnosed with new cancers was still small (1.56% of women in the HRT group vs. 1.26% in the placebo group).  In terms of breast cancer risk, specifically, there was a 27% increase in risk among the women who had previously been assigned to receive HRT pills, when compared to the placebo group although, once again, the absolute numbers were rather small in both groups (0.42% vs. 0.33%, respectively).  While a “modest trend” towards decreasing breast cancer risk was observed, over time, among the women in the HRT group, even at 3 years, a significant increase in both the incidence of cancer and the risk of death (from any cause) was still present when compared to the placebo group of women.  When the WHI study data was reanalyzed, 3 years after the women in the HRT group had stopped using HRT, the results indicated a persistent imbalance between the risks and benefits of combination HRT, with a calculated 12% increased risk-to-benefit ratio favoring risk over benefit. 

To summarize this important WHI study update, the incidence of coronary artery disease associated with an average of 5.6 years of HRT use had, by the third year of HRT abstinence, returned to the level observed in age-matched women who had never taken HRT.  However, the risk of cancer, and breast cancer specifically, continued to be elevated, even 3 years after discontinuing HRT, among the women randomized to receive combination HRT pills during the WHI study.   

Longer follow-up of the women assigned to receive HRT pills during this study will have to occur before we can learn when, if ever, the increased risk of cancer (and the overall increased risk of death from all causes) will return to the same levels as has been observed in women who never received HRT.  Once again, my advice to women passing through menopause is that they avoid HRT if at all possible.  For the couple of percent of women who have truly debilitating menopause-associated symptoms that do no respond to non-hormonal treatment, taking the smallest dose of HRT medications, and for the shortest possible duration of time, appears prudent.  

TELEVISION, CHILDREN & OBESITY 

By now, most of us know that increasing amounts of time spent in front of the television have been associated with increasing levels of obesity in children.  Now, a new randomized research study, just published in the Archives of Pediatric & Adolescent Medicine, sheds new light on this topic.   

In this clinical study, 70 overweight children, ages 4 to 7, were randomized to two groups.  In the intervention group, television and computer usage was restricted, while in the control group, no restrictions were implemented.  All of the children participating in this study were evaluated every 6 months throughout the 2-year study. Weight, height, body mass index (BMI), television and computer viewing habits, calorie intake and levels of physical activity were specifically assessed at these 6-month intervals. 

In this small but innovative study, the children in the intervention group showed significant reductions in overall sedentary behavior, with increased physical activity and decreased calorie intake, when compared to the kids in the control group.  When the researchers looked at socioeconomic status as a factor, they found that the children in the lower socioeconomic groups appeared to benefit to a greater degree from restrictions in television and computer usage than did the children in higher socioeconomic groups.  Finally, when analyzing the data, the researchers noted that restricting TV viewing and computer usage resulted in improvements in the BMI of the kids in the intervention group, and that these improvements in the level of obesity were mediated primarily through decreased caloric intake, and not due to the increased level of physical activity also observed in this group.   

In summary, this small randomized study showed that restricting the amount of time that overweight kids spent in front of a television and computer appeared to aid in weight loss, and that this benefit appeared to be primarily related to these children grazing on fewer calories while engaged in these sedentary activities.  If your young children are like mine, weaning them from prolonged exposure to the mesmerizing effects of the hundreds of cable shows available on television is a huge challenge, but a necessary one. 

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

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

http://doctorwascher.com

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

All rights reserved.

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