Journal of the American Medical Association (JAMA):  By now, virtually everyone knows that obesity is epidemic throughout the western world, and that we have become the heaviest society in the history of the world.  Abundant, cheap and calorie-packed foods, combined with an endless array of effort-sparing devices, have conspired against our genetic hard-wiring for food intake.  Humans, like most animals, are driven to eat by powerful hormonal and neurological signals that primarily involve the GI tract and the hunger and satiety centers of the brain.  We are genetically programmed to binge on calorie-rich foods when they are available, so that we may better weather the leaner times when food is not readily available.  Of course, this genetic programming served pre-industrial humans well, when food was often scarce, particularly during winter months.  Today, however, with fast-food sandwiches available (and for less than five bucks) that provide more calories and fat than our bodies need for an entire day, our genetic drive to stuff our bellies during times of plenty has been corrupted, if not perverted, by a lifestyle that virtually ensures that every day is a day of plenty. 

In 2004, assessments by the Centers for Disease Control (CDC) indicated that obesity had become the second most common cause of preventable death in the US, right behind tobacco, with a projected 365,000 deaths per year due to obesity-related diseases.  Now, in a rather dramatic revision of its earlier estimates, the CDC is significantly scaling back its estimates of obesity-related mortality.  The new CDC estimate of annual deaths due to obesity, while hardly trivial, now places obesity-related deaths at about the seventh most common cause of preventable death in the US.  While the CDC’s retraction of its previous estimates of obesity-related mortality has been prominently reported in the popular media, other still-concerning findings from the same JAMA research paper have been only sparingly reported thus far.

The data analyzed in this report was based upon a huge number of participants in the national Nutrition Examination Survey studies that were conducted between 1971 and 1994, encompassing nearly 37,000 volunteers, altogether.  Body Mass Index, or BMI, values were calculated for all study volunteers, and the patients were closely followed by the study investigators through the year 2000.  (A BMI less than 18.5 is considered “underweight,” while a BMI of 25.0 to 29.9 is considered “overweight.”  People with a BMI of 30.0 and greater are considered to be “obese,” although very muscular people may be falsely classified as overweight or obese, using the BMI formula.)  (You can calculate your own BMI on the Internet at: http://www.cdc.gov/nccdphp/dnpa/bmi/bmi-adult-formula.htm.)

The numbers of deaths in this group of volunteers, based upon BMI, was then extrapolated to the general population, based upon nationwide mortality data for the year 2000.  Once statistically analyzed, these calculations predicted that, relative to people with a normal BMI, there were nearly 112,000 estimated excess deaths in the US among obese people in 2000.  An estimated 34,000 excess deaths occurred in 2000 also occurred among people with BMIs that categorized them as underweight.  Based upon these updated calculations, people who were merely overweight, however, had essentially the same risk of dying as did people with a normal BMI, a finding that has brought sighs of relief from many people (as well as the restaurant industry).

Unfortunately, and contrary to some media reports, this critically important study did not suggest that obesity was a rare cause of preventable death.  In fact, clinical obesity, as defined by a BMI of at least 30, resulted in one-fourth as many preventable deaths as are caused by the number one scourge, tobacco abuse.  (Also, it is interesting to note that underweight people are, like obese people, at increased risk of premature death.)

Unquestionably, the central finding of this study is that being merely “overweight” in the year 2000 did not result in a higher risk for premature death when compared to folks with a normal BMI.  While this is clearly a significant public health finding, it is probably unwise to construe these revised estimates as a green light to let your BMI slide up into the “overweight” category.  While this study suggests that you’re not more likely to die prematurely if you let your BMI rise from the “normal” range to the “overweight” range, it does not say anything about the well-documented increased likelihood of serious diseases associated with increased weight (e.g., cardiovascular disease, high blood pressure, diabetes, joint problems, kidney disease, cancer, and other maladies that are known to be associated with a BMI above the normal range).  This study simply indicates that you are probably no more likely to die from any of these diseases, when compared to folks with a normal BMI, if your BMI is in the 25.0 to 29.9 range.  Indeed, many experts in obesity and cardiovascular disease, noting the progressive reduction in deaths due to cardiovascular diseases attained over the past decade, have attributed these equivalent deaths rates between people with “normal” BMIs and those with “overweight” BMIs to improvements in the prevention and treatment of cardiovascular diseases, as well as diabetes, cancer and other diseases that cause the majority of deaths in our society.

The results of this study, while hugely reassuring to many of us who have a BMI just above the “normal” range, need to be viewed critically in order to fully understand their significance.  Despite the very favorable results of this study, at least for those of us in the “overweight” range, the best advice that this doctor can offer is, still, to eat a healthy and balanced diet, and to get plenty of exercise.

WAIST SIZE + ELEVATED BLOOD TRIGLYCERIDE LEVEL = HEART DISEASE

Circulation:  While we’re on the subject of excess weight and the risk of premature death, a new study takes a look at the impact of increased waist size, and high blood levels of fats called triglycerides, on the cardiovascular health of postmenopausal women.

The study sought to show that a waist size greater than 34.6 inches (88 cm), in the presence of elevated triglycerides in the blood, is associated with a significant increase in the risk of cardiovascular disease, as well as death due to such diseases.  A total of 557 postmenopausal women were observed for an average of almost 9 years, and measurements of their triglyceride levels and waist circumferences were routinely performed.  After adjusting for the effects of age, smoking and cholesterol levels, the presence of elevated triglyceride levels combined with a waist size greater than 34.6 inches was found to be associated with a nearly five-fold increase in the risk developing cardiovascular disease, and a three-fold risk of “fatal cardiovascular events,” when compared to women with normal triglyceride levels and a waistline less than 34.6 inches.  The study’s authors concluded that two simple measures (waist circumference and triglyceride levels in the blood) accurately identified postmenopausal women at increased risk of developing, and dying from, cardiovascular disease.  Indeed, this simple algorithm was found to be as accurate an indicator of cardiovascular disease risk as the far more complex National Cholesterol Education Program list of risk factors.

Once again, the safest approach to good cardiovascular health is to eat a balanced diet, exercise regularly and frequently, and maintain your weight within the established normal range.

ACADEMIC MEDICAL CENTERS & ADVERTISING

Archives of Medicine:  When many of us think about big university medical centers, we envision renowned and altruistic centers of healing, teaching and research.  Often we tend to forget that these academic medical centers are every bit as concerned about their financial bottom lines as are less illustrious community hospitals.  (Virtually all hospitals in the US operate within a highly competitive and high-cost healthcare environment.)  This interesting little study evaluated 17 academic medical centers around the country.  Each of the medical centers studied had been named in 2002 as “America’s Best Hospitals” by US News & World Report.  The advertising practices of these eminent institutions were evaluated by a direct interview with hospital staff regarding hospital advertising practices, as well as by an exhaustive review of all non-research-related print advertisements placed by the same medical centers during 2002.

A total of 16 of the 17 institutions reported that they advertised to attract patients, while the remaining hospital’s staff claimed that their institution relied upon “word of mouth” alone to attract patients.  While all 17 centers routinely utilized an Institutional Review Board to review advertising intended to recruit clinical research subjects, no such review was performed for non-research-related print ads.  A total of 127 non-research-related print ads from the 17 institutions were identified, including 3 ads for community events sponsored by the institutions.  Two additional ads were genuine public service announcements, while the remaining 122 ads were specifically aimed at attracting patients for non-research-related medical or surgical services.  The most common advertising approaches in the latter category of ads was to appeal to the emotions of prospective patients (62%), highlight institutional prestige (61%), mention a specific disease or symptom (53%), and promoting introductory lectures or “special offers” to induce patients to come back for future healthcare needs (48%). 

Of the 21 separate advertisements for individual treatments, most were for medically unproven procedures (38%) or cosmetic procedures (29%).  While more than half of these ads prominently mentioned the purported benefits associated with these procedures, none quantified the actual degree of benefit that could reasonably be expected by patients, and only 1 advertisement mentioned the possibility of potential complications associated with these procedures.  The authors of this study concluded that top academic medical centers frequently advertise to attract new patients, but that they don’t apply the same level of oversight and disclosure in these ads as they do in advertisements soliciting patients to join new research studies.

NATURAL POTASSIUM & HIGH BLOOD PRESSURE

Hypertension:  There is ample research showing that potassium supplements can reduce high blood pressure.  These previous studies have used a pill-form of potassium (potassium chloride) in order to study the effects of this substance on blood pressure in patients with high blood pressure, or hypertension.  However, there has been very little research about the anti-hypertensive effects of natural forms of potassium, which occur naturally in many foods, mostly in the form of potassium citrate.  As many people experience nausea and tummy upset with potassium chloride pills, this small study sought to evaluate potassium citrate’s effects on elevated blood pressure.

A total of 14 hypertensive patients underwent initial measurements of their blood pressure, and were then sequentially provided with potassium chloride tablets, followed by potassium citrate supplements.  Baseline average blood pressure among the 14 patients at the beginning of the study was 151/93 (mild-to-moderate hypertension).  Following treatment with potassium chloride pills, the average blood pressure dropped to 140/88, which is just at the upper limits of normal.  In comparison, the average blood pressure of patients taking the potassium citrate supplements was 138/88 (a statistical dead-heat between the two forms of potassium).  Thus, this elegant little study appears to show that a naturally occurring form of potassium (potassium citrate) is just as effective as the pill-form of potassium (potassium chloride) in treating mild-to-moderate hypertension.  Thus, assuming that these same results are substantiated by research involving larger numbers of patients, a diet with an emphasis on potassium-rich foods may be a healthy and effective method of reducing elevated blood pressure.  Foods known to be rich in potassium include soybeans and soy flower, whole grains, fresh apricots, raisins, figs, bananas, plantains, baked potatoes (with skin), dried mixed fruits, unsalted nuts, tomatoes and tomato sauce, bran, sardines, and meat.

Dr. Robert A. Wascher