Monday, February 25, 2013

Adult Disease in Children and Adolescents, a "Growing" Problem

Chronic illnesses, such as high blood pressure, type 2 diabetes, and hypercholesterolemia, are primarily thought of as diseases that affect adults. Over the past decade, however, these same illnesses or their predecessors have become increasingly common in children and adolescents.

High blood pressure (hypertension) is a well-known condition that affects almost a third of adults in the U.S. It is a major contributor to heart disease and stroke which are the first and third leading causes of death in adults. Recent statistics indicate that up to 5% of children also have blood pressure that is higher than normal. Most of these children will have what is known as primary or "essential" hypertension. In primary hypertension, no known cause is identified, although obesity, poor dietary habits, and lack of exercise are major contributing factors. Of concern is that if essential hypertension is allowed to persist, it can lead to heart disease or stroke later in life. Secondary hypertension affects a much smaller percentage of children in whom hypertension is diagnosed. By definition, secondary hypertension is due to an underlying cause, such as kidney or heart disease. In general, the younger the child and the higher the blood pressure, the greater the likelihood that hypertension is due to a secondary cause. Often, special testing to identify the secondary cause and aggressive treatment is required to avoid serious complications. Current guidelines recommend that all children should have their blood pressure checked beginning at age 3.

Type 2 Diabetes is a condition in which the body is resistant to the effects of insulin, the hormone that regulates the movement of glucose (sugar) into the body's cells, or doesn't produce enough insulin to maintain a normal glucose level. The two major forms of diabetes are Type 1 and Type 2. Type 1 diabetes, previously known as "juvenile onset" or "insulin dependent", occurs most often in younger patients. Type 2 diabetes had been called "adult onset" since it was much more likely to develop after the age of 20. Prior to the onset of type 2 diabetes, a condition known as "pre-diabetes" occurs. In pre-diabetes, the body is unable to handle glucose normally, resulting in higher than normal blood sugars. If not addressed, pre-diabetes usually develops into diabetes. The American Diabetes Association (ADA) estimates that 2 million children, or 1 out of every 6, have pre-diabetes. The increase in prevalence in pre-diabetes and type 2 diabetes has paralleled the increased prevalence of obesity among younger people. In fact, of children diagnosed with Type 2 diabetes today, 85% of them are obese. Currently, the ADA recommends screening for type 2 diabetes in those children who are obese (body-mass index above the 85th percentile) along with risk factors, such as a family history of diabetes or signs of insulin resistance (elevated cholesterol, high blood pressure, etc.).

High Cholesterol was at one time considered to be a problem that spared children and adolescents. However, it is now clear that children and adolescents can also have elevated cholesterol. This frequently leads to the development of atherosclerosis ("hardening" of the arteries), the major cause of heart attack and stroke in adults. Just as with hypertension and type 2 diabetes, the increased prevalence of elevated cholesterol appears to primarily be related to the obesity epidemic in children. In 2011, the American Academy of Pediatrics revised their screening guidelines to advise lipid screening to include total cholesterol, LDL ("bad cholesterol") and HDL ("good cholesterol") for all children ages 9-11 years and then again at age 17-21 years.

The common denominator: Obesity Statistics indicate that obesity now affects 17% of all children and adolescents in the United States. This is triple the rate from just one generation ago. Obesity predisposes them to the "adult" diseases mentioned above as well as to other medical conditions such as degenerative arthritis, sleep apnea, and certain types of cancer. In children with one of these conditions, initial treatment should involve a weight reduction diet and institution of a regular exercise program. When obesity is present, weight loss of approximately 10 percent of body weight can return blood pressure and blood sugar back to normal levels.

The American Academy of Pediatrics has published guidelines on treating children as young as 8 years of age with the same cholesterol-lowering medications used in adults. Likewise, medication treatment for children and adolescents with diabetes and hypertension has received approval. Since lifestyle issues such as overeating and lack of exercise appear to be at the root of these "adult" diseases affecting younger people, perhaps a more rational approach would be for physicians to focus on behavioral approaches to motivate families to engage in regular exercise and adopt healthy dietary habits in order to address this growing concern.

Monday, February 18, 2013

Gastric Bypass Surgery Reconsidered

egular readers of eDoc's Health Tips have learned that sensible eating habits and maintenance of ideal weight are important keys to staying healthy. There are instances, however, that in spite of best intentions, weight loss becomes an unachievable goal. In many people who have had no success with conventional methods of losing weight, gastric bypass surgery often becomes a consideration.

Health problems, such as hypertension, diabetes, and high cholesterol often accompany being overweight, particularly in the severely obese. These are major contributors to the development of coronary heart disease and may lead to premature death. Research has found that among severely obese patients, gastric bypass surgery can provide lasting improvement in weight, send Type 2 diabetes into remission, and reduce overall cardiovascular disease risk.

The Journal of the American Medical Association recently published a study that monitored weight and other health parameters of severely obese patients (body mass index greater than 45) who underwent gastric bypass. These patients were followed for an average of 6 years after surgery. Along with the surgical patients, other individuals with similar pre-operative weights were followed. In this "control" group, no organized effort was made to help them lose weight. They were, however, free to pursue weight loss methods on their own. The type of surgery performed in the study group was known as the Roux-en-Y procedure, the most common type of gastric bypass surgery.

From this study, the major benefits noted following gastric bypass surgery were:

Maintenance of weight loss - A major concern with most weight loss methods is that people are not able to maintain the weight loss over the long term. The group of patients treated with gastric bypass surgery in this study kept off nearly 35% of their pre-operative weight after 2 years. At 6 years of follow-up, they remained 28% below their pre-operative weights. By comparison, there was no significant weight loss noted in the control groups who did not undergo surgery.

Remission of diabetes - Type 2 Diabetes is very common in the obese. It is well known that weight reduction can improve blood sugar control, or even cause the diabetes to go into remission. Of the diabetics treated with gastric bypass surgery, there was a 62% remission in diabetes at the end of 6 years. Additionally, over that same 6 year period, there was a much lower occurrence of new cases of diabetes in the non-diabetic subjects who underwent surgery as compare to controls.

Improvement in cholesterol levels - Abnormal cholesterol levels are a well-known risk factor for the development of coronary heart disease. Compared to the control groups, subjects who underwent bypass were noted to have improvement in total cholesterol, LDL (bad) cholesterol, HDL (good) cholesterol and triglycerides, as compared to subjects in the control group.

Reduction of hypertension - High blood pressure was noted commonly among both the subjects who underwent surgery as well as in subjects in the control group. As a result of weight reduction, blood pressure reverted to normal in 42% of the surgical subjects. This was over twice the remission rate among subjects in the control group.

Of note is that over the 6 year period of follow-up there was no significant difference in death rate between the surgical patients and controls. This could be attributed to the relatively short period of time that these patients were followed. Additionally, there were 7 deaths attributed to suicide or "poisoning" in the study with 6 of these occurring in the surgical group. These unexpected deaths, along with a number of complications and hospitalizations in the surgical group, points out that gastric bypass surgery is not without risks and should be considered only after more conventional methods of achieving weight loss have failed. Prior to undergoing gastric bypass, careful evaluation of the physical and psychological make-up of the surgical candidate is necessary.

Wednesday, February 13, 2013

What should be done for osteopenia? Part 2, Treatment

Last week's Health Tip discussed osteopenia, the stage of bone density between normal and the disease state of abnormally low bone mass known as osteoporosis. While treatment with medications is usually warranted in someone with osteoporosis, this is not always the case with osteopenia. This has to do with the unpredictable nature of the progression of osteopenia and the potential for serious side effects from the medications. Fortunately, almost everyone with lower than normal bone mass can benefit from lifestyle measures to retard the progression of bone loss. In today's Health Tip we'll look at those lifestyle measures and discuss medications used in treating osteopenia when progression to osteoporosis is likely to develop.

Lifestyle measures for preventing bone loss:
  1. Receiving an adequate amount of calcium. The National Academy of Sciences recommends that women older than age 50 consume at least 1,200 mg per/day of calcium. In many cases, adequate amounts of calcium can be obtained from the diet. The major food contributors of this nutrient to people in the United States are milk, yogurt, and cheese. Calcium supplements may be required when an adequate dietary intake cannot be achieved.

  2. Getting enough Vitamin D. The National Osteoporosis Foundation recommends a daily intake of 800 to 1,000 international units (IU) of vitamin D for adults age 50 and older. Important dietary sources of vitamin D include vitamin D-fortified milk, breakfast cereals, egg yolks, and fish. The body is also capable of producing Vitamin D through exposure to sunshine.

  3. Performing weight bearing exercise. In weight-bearing exercise, bones are strengthened as the feet and legs bear the body's weight. Examples include walking, jogging, tennis, dancing, and stair climbing. Studies have also shown improvement in bone density from weight training. Resistance exercises that focus on the back and hip (hip extension, hip abduction/ adduction, squats, etc.) appear to be particularly beneficial.

  4. Avoiding cigarette smoking. Studies have shown a direct relationship between cigarette smoking and decreased bone density. This may be due to the effect of toxins in cigarette smoke on certain hormones in the body responsible for bone health. For example, women who smoke often produce less estrogen and tend to reach menopause earlier. .Another explanation is that many smokers have other osteoporosis-related risk factors, such as physical inactivity or excessive alcohol intake. Quitting smoking has been shown to reduce this progression of bone loss.

  5. Moderating alcohol intake. Alcohol consumption can inhibit the body's absorption of calcium. Excessive intake has been linked to an increase in fractures of the hip, spine and wrist. Mental impairment due to alcohol intake can also lead to accidents with subsequent broken bones. It is recommended that women have no more than the equivalent of one drink (e.g. 12 oz. beer or 6 oz. wine) per day.
When medications may be needed. No drugs have been developed specifically for treating osteopenia. The drugs that are sometimes used are the ones used in the treatment of osteoporosis. Treating osteopenia with medications (along with lifestyle manageStomachment) is sometimes referred to as "osteoporosis prevention". The FRAX algorithm, discussed in last week's Health Tip, is an important tool in determining if treatment of osteopenia should be considered.

The most important criteria in this consideration are: 1) a high risk of progressing from osteopenia to osteoporosis based on the FRAX algorithm and 2) an elevated risk of osteoporosis-related fracture. The most common class of medications used in the prevention and treatment of osteoporosis are the bisphosphonates. Alendronate (Fosamax), risedronate (Actonel), and zoledronic acid (Reclast) are bisphosphonates that have received Federal Drug Administration (FDA) approval for this indication. They work by slowing down the natural process that breaks down and repairs bone. Most bisphosphonates are taken by mouth, once a week or once a month, but Reclast is given by injection, usually once a year. Drugs that are sometimes used in treating osteopenia but do not have FDA approval for that indication include calcitonin and teriparatide. Calcitonin (Fortical and Miacalcin) is a hormone produced normally by the thyroid gland that helps to slow the rate at which the bone breakdown occurs. Teriparatide (Forteo) is a preparation of a hormone produced by the parathyroid gland that is it is usually reserved for patients with severe hip or spine osteoporosis. Hormone replacement therapy (HRT), using estrogen with or without progesterone, is sometimes used, but is not generally recommended to prevent osteoporosis in women after menopause. This is because of concern regarding development of breast or uterine cancer, stroke, and blood clots. HRT, however, may be reasonable in younger women whose ovaries do not make estrogen normally. Raloxifene (Evista) is a medication used for osteoporosis prevention that is primarily intended for postmenopausal women. It works in a similar manner as the hormone estrogen to help maintain bone density.

Friday, February 1, 2013

What should be done for osteopenia? Part 1, Assessing Risk

Most people are aware that osteoporosis is a disease characterized by "thinning" of the bones. The reduced bone density in osteoporosis is associated with a susceptibility to fractures, especially of the hip and spine. In the U.S., it is estimated that 10 million individuals, mostly women, have this condition.

It is less well understood by the public that an intermediate stage between normal bone mass and osteoporosis exists, known as osteopenia. Osteopenia is not a disease per se, but an indication that the bone mineral density is below the statistical norm. An estimated 34 million Americans have osteopenia. If measures are not taken to slow down bone loss, many of these individuals will develop osteoporosis.

How do you know if you have osteopenia? Bone mineral density (BMD) testing is required to determine if you have osteopenia or osteoporosis. BMD testing (e.g. DEXA scan) compares the bone density of the person being tested with younger individuals who are at peak bone density. Depending on the variation from this ideal, an assessment of the extent of loss of bone mass can be made. BMD has been shown to correlate with bone strength and is an excellent predictor of future fracture risk. As currently defined, someone with osteoporosis has a BMD that is at least 2.5 standard deviations below the mean of a young person at maximum bone density. This is reported as a T-score of –2.5 on the DEXA report. A higher negative T-value, e.g. –3.0, indicates that the osteoporosis is even more severe. Osteopenia is defined as a BMD that is between 1 and 2.5 standard deviations below the younger person's mean. This would be indicated by a T-score between –1.0 and –2.5.

Does osteopenia always develop into osteoporosis? The short answer is no. A T-score in the osteopenia range does not necessarily mean that you are losing bone, or tell you at what rate that this is occurring. Age, genetics, body stature, and certain diseases or conditions can all affect the baseline bone density. Often a second bone density test is needed to determine if bone loss is occurring at an accelerated rate. Typically, however, a year or more is required before getting a repeat study in order to note a significant difference.

Does everyone with osteopenia require treatment? Most people with osteopenia can be managed by lifestyle measures that will be discussed in next week's "Health Tips". Situations in which it is reasonable to consider treatment with medications to prevent further bone loss and to reduce the risk of more fractures include:
  1. Postmenopausal women with low bone mass (T-score between –1.0 and –2.5 at the femoral neck or spine) AND a high probability of sustaining an osteoporosis-related fracture.

  2. Individuals with T-scores between –1.0 and –2.5 may be considered for treatment with a medication when risk factors are present, such as taking certain medications (e.g. corticosteroids), a strong family history of osteoporosis or fractures, broken bones as an adult, or being very thin.

  3. Individuals with osteopenia due to secondary causes, such as chronic kidney disease, celiac disease or chronic corticosteroid use.
How is the probability of fracture determined? An assessment tool called the FRAX is helpful in deciding when someone with osteopenia is at increased risk for a fracture, and may benefit from treatment with medications. The FRAX tool uses information about bone density and other risk factors for breaking a bone to estimate the risk of sustaining a fracture over the next 10 years. To perform the FRAX test, you will need to enter your T-score from DEXA testing along with other personal information, such as height and weight. Based on FRAX testing, the National Osteoporosis Foundation recommends that treatment be initiated in postmenopausal women and men age 50 and older with osteopenia AND a 10-year hip fracture probability ≥ 3% OR a 10-year major osteoporosis-related fracture probability ≥ 20%. Osteoporosis-related fractures are defined as those that are diagnosed on physical examination (although they may not appear on x-rays), affecting the vertebrae, hip, forearm or upper arm. FRAX testing is intended for postmenopausal women and men age 50 and older and is not intended for use in younger adults or children.

Next week we’ll look at the lifestyle measures that can help slow the progression of osteopenia. We also will look at medications that may be beneficial in someone with osteopenia and high risk for progression to osteoporosis or for the development of a fracture.