‘Reassessing’ the Health Status Assessments
Cynthia K. Buffington, Ph.D.
At a recent dinner engagement, a friend of the author’s, who has gained a substantial amount of weight over the last few years, mentioned that, in spite of her obesity, she was in perfect health. She had recently received the report of her annual physical and, according to the results, was in good health. But, is anyone who is obese actually healthy?
Common health screening tests for physical examinations generally include measurement of blood pressure, urine analysis, and blood tests of fasting blood sugar, cholesterol, certain minerals such as potassium and calcium, and specific markers of kidney and liver function. The tests also measure blood cell counts to check for anemia or infections and, sometimes, the physical includes a blood test for thyroid function.
According to my friend’s report, her blood pressure was normal. She also had normal fasting blood sugar and cholesterol levels, along with normal blood levels of potassium, calcium, and protein. Specific markers of kidney and liver function were within the ‘normal range’, as were blood cell counts. Furthermore, there were no signs of thyroid problems.
Was my friend in good health? Or, did the diagnostic tools used to assess my friend’s health status fail to address those problems caused by obesity?
My friend’s fasting blood sugar levels were 107 mg/dl, which fell within the normal range of 65 to 109 mg/dl. Fasting blood sugar levels are used as an indicator of diabetes or glucose intolerance (pre-diabetes). However, sometimes an individual may have normal fasting blood sugar levels, as my friend has, and still have pre-diabetes or even diabetes, particularly if obese.
To actually rule out diabetes or pre-diabetes, my friend should have been administered a test that determines how effectively her body utilizes sugar, such as an oral glucose (sugar) tolerance test. An oral glucose tolerance test measures blood sugar levels following the consumption of a beverage that contains a known amount of sugar.
After consuming the sugar-containing drink, blood sugar levels rise rapidly, along with the hormone, insulin, which helps drive sugar from the blood into tissues where it is either used for energy or stored. As sugar enters tissues, blood sugar levels fall. But, if the body produces too little insulin or if tissues, such as muscle and liver, are resistant to insulin (which is common with obesity), sugar will not be readily utilized by the body and will remain high. How high these levels remain and for how long after drinking the sugar mixture is used as criteria for the diagnosis of diabetes and pre-diabetes.
Actually, there are a considerable number of obese individuals with pre-diabetes and some with diabetes who have not been diagnosed because their fasting blood sugar levels fall within the ‘normal range’. Fasting sugar levels may be normal for the diabetic or pre-diabetic if fasting insulin levels are quite high, as is often the case with obesity.
Chronically elevated insulin levels, over time, can cause tissues to no longer be responsive to insulin, causing a condition known as insulin resistance.
Insulin resistance is fairly common for someone who is obese, and this condition has extremely adverse effects on health, contributing to the development of diabetes, heart disease, stroke, hypertension, peripheral vascular disease, and many other serious health problems. Fasting insulin levels are often an indicator of insulin resistance but these levels are generally not part of a routine physical exam nor are more specific tests for determining insulin resistance such as those involving intravenous (I.V.) injection or infusion of insulin or glucose (sugar).
The health evaluation my friend received not only did not measure fasting insulin levels but also failed to measure other hormones known to adversely affect, and be affected by, obesity. These hormones include cortisol, growth hormone, dehydroepiandrosterone (DHEA), sex hormones, and more. Excessive adiposity (fat) alters the production or levels of these hormones in ways that suppress the body’s immune system, cause insulin resistance and an increased risk for associated disease, promote muscle or bone loss, cause defects in metabolism, and increase the amount of fat in deep abdominal fat storage depots which, in turn, substantially increases the risk for diabetes, hypertension, and heart disease.
With regard to lipid abnormalities, the results of my friend’s blood tests showed that her total blood cholesterol levels were ‘normal’. However, total blood cholesterol levels are not always indicative of those lipid abnormalities caused or worsened by obesity that increase the risk for heart disease. These defects include increased production of triglyceride, reduced amounts of HDL-cholesterol (the ‘good or anti-heart disease’ cholesterol) and increased amounts of LDL-cholesterol or, more specifically, an increase in amounts of a particular form of LDL (small, dense LDL) that contributes to the development of atherosclerosis (clogged blood vessels) that can cause a heart attack or stroke.
Measurements of the thickness of the walls of major blood vessels is often used as a test to assess the degree of atherosclerosis. Studies have shown that such thickness is far greater (up to 3-times more) for obese vs. normal weight individuals, as is the risk for heart disease and stroke. Furthermore, the obese, even individuals with mild-to-moderate obesity, often have structural changes in their heart that can affect its normal function.
An enlargement of the major pumping chamber of the heart is relatively common with obesity, particularly severe or morbid obesity. This condition is known as left ventricular hypertrophy and results from the increased workload placed upon the heart by the larger body.
An enlargement of the heart can cause the heart to beat irregularly, increasing the risk for sudden death. And, sudden death occurs far more frequently among individuals with obesity than their leaner counterparts, as does congestive heart failure, angina (heart pain), and the occurrence of a myocardial infarct (death of a part of the heart due to a lack blood supply of oxygen and nutrients). My friend thought that because she had normal blood cholesterol levels and a desirable blood pressure that her heart was ‘fit as a fiddle’.
An enlargement of the liver, caused from the accumulation of fatty deposits, is also quite common with obesity, as is inflammation of the fatty liver, a condition known as fatty liver disease or non-alcoholic steatohepatitis. Fatty liver disease can impair liver function and can lead to fibrosis or even cirrhosis and, thereby, irreversible liver damage.
According to the results of my friend’s blood tests, her liver functions were fine. Her bilirubin was normal. The enzyme, alkaline phosphatase, was normal, as were those identified as AST (aspartate aminotransferase) and ALT (alanine aminotransferase), although these later two markers of liver function were nearly outside the range of normal values. Nonetheless, it is highly probably that my friend’s liver was enlarged with fatty deposits or that she even had fatty liver disease. The physician conducting her physical, however, did not examine the liver by palpation (feeling) to determine if it were enlarged, nor did he conduct any other diagnostic tests for liver disease.
Calcium, choloride, postassium, sodium levels were all well within the normal range for my friend. Certain minerals, particularly those with antioxidant potential such as zinc, manganese, and others, were not examined and, as is often the case with obesity, may have been low. Obesity is also associated with low antioxidant vitamins, such as vitamins C, A and E, along with reduced or altered endogenous antioxidants like glutathione, coenzyme Q, DHEA, and melatonin.
Low antioxidant potential, as well as metabolic and hormonal changes associated with obesity, could cause the condition known as oxidative stress. This condition occurs when the production of destructive free radicals exceeds the body’s ability to defend against and scavenge these destructive entities. Free radicals, in turn, destroy cellular components and functions, cause damage to DNA that could lead to cancer or a loss of cell function, alter enzyme and hormone production, and much, much more.
High oxidative stress is believed to be one of the primary causes of aging and for the development of many diseases common to both aging and obesity such as cancer, heart disease, hypertension, diabetes, etc. Obesity increases oxidative stress, as has been measured by blood and urine markers of free radical damage to tissues. And, as mentioned earlier, obesity reduces antioxidant defenses. It is likely, therefore, that my friend had, along with her obesity, high free radical production and associated health risks.
My friend’s physical also failed to measure numerous other obesity-induced changes in the body that could ultimately have serious health consequences. These include: a) reduced lung volume or respiratory muscle strength that increase the risk for respiratory disorders, b) defects in immune functions, c) stress on joints that could cause arthritis, irreversible joint damage, spinal defects, and more, d) sleep abnormalities that could increase the risk for physical or psychological problems, e) defects in body repair systems, f) changes in the production or actions of brain and nervous system messengers that adversely influence eating behavior, psychological well-being, stress responses, and much more.
Is my friend ‘fat and healthy’? Or, does the medical community need to ‘reassess the assessment’ tools for determining the health status of individuals who are overweight or obese?
Cynthia K. Buffington, Ph.D. Dr. Buffington is with Florida Hospital Celebration Health