Friday, September 12, 2014

Ovarian Cancer, ten facts you should know

September is Ovarian Cancer Awareness month. The American Cancer Society has estimated that in 2014, approximately 22,000 women will receive a new diagnosis of ovarian cancer and over 14,000 will die of this disease.  By learning more about this type of cancer, it is hoped that more women will be directed toward appropriate screening to allow its detection as soon as possible.  Women diagnosed in the earliest stages of ovarian cancer, which has been dubbed “the silent killer”, have a much higher chance of survival.
  
1.  The incidence of ovarian cancer increases as women become older.  While ovarian cancer can occur at any age, approximately half of the women who will be diagnosed with ovarian cancer are over the age of 60. After menopause, women should not "let their guard down" when it comes to being screened or reporting problems that could be caused by ovarian cancer.

2.  The Pap smear is not a screen for ovarian cancer. It is effective in the early detection of cervical cancer, but having a normal pap smear does not exclude the possibility of having ovarian cancer.

3.  Ovarian cancer symptoms may be vague or non-specific.  The most common symptoms of ovarian cancer are abdominal swelling or bloating, pelvic pressure or abdominal pain, difficulty eating or feeling full quickly, and having to urinate urgently or frequently. While these symptoms are more commonly associated with conditions other than ovarian cancer, if one or more of these is present for more than a couple of weeks, you should seek attention from your health care provider.

4.  Survival of ovarian cancer is improved with early detection. If treated before the cancer spreads beyond the ovary, the five-year survival rate is around 92%.  Unfortunately, only 15 to 20% of ovarian cancer is found at this stage.  As a result of this delay in diagnosis, ovarian cancer accounts for more deaths that any other cancer of the reproductive system, including cervical and uterine cancer.

5.   Ovarian cancer risk is higher in women who are overweight. The American Cancer Society reports that obesity (a body mass index of 30 or more) is an important risk factor for developing ovarian cancer.  This risk was increased by 50% in the heaviest women.

6.   Screening tests to look for ovarian cancer include the transvaginal ultrasound (TVUS) and the CA-125 blood test. The TVUS is a special type of ultrasound done with a vaginal probe and CA-125 is a protein in the blood that has been noted to be elevated in many women with ovarian cancer.  When applied to women at average risk, however, these tests have not been shown to reduce the number of deaths from ovarian cancer. For this reason, use of these tests to screen healthy women with no signs or symptoms of ovarian cancer is currently not recommended.  They may be worthwhile, however, in asymptomatic women who are at high risk for the development of ovarian cancer, such as those with a strong family history of ovarian cancer, or to evaluate women with symptoms or physical findings suggestive of ovarian cancer.
  
7.   Ovarian cancer can run in families.  Women who have a mother, daughter, or sister with ovarian cancer have about a three times higher risk of developing the disease. Also, women with a family history of cancer of the breast, uterus, or colon may also have an increased risk of ovarian cancer.  This is caused by a change (mutation) in certain genes leading to a Heredity Cancer Syndrome.

8.   Women with breast cancer may also have an increased risk of developing ovarian cancer.  This is particularly true in women with a strong family history of breast cancer.  In this case, the breast cancer could have developed because of mutations in inherited genes BRCA1 or BRCA2. Inherited mutations of these genes increase the risk of developing breast cancer many times over the risk of women in the general population.

9. Confirmation of ovarian cancer requires a biopsy.  Tests used to evaluate for the presence of ovarian cancer, such as ultrasound, MRI scan, or CT scan may demonstrate an ovarian mass, but the only way to determine for certain if a growth is cancer is to remove a sample of the growth from the suspicious area and examine it under a microscope.  Tissue for examination can be obtained with a minimally invasive procedure called laparoscopy or during an open surgical procedure.

10.  In some cases the risk for developing ovarian cancer can be reduced.  The general recommendations for reducing the risk of most types of cancers include maintaining a healthy weight, eating a balanced diet, and staying physically active.  Women with a family history suggestive of a syndrome linked with a high risk of developing ovarian cancer should consider undergoing genetic screening.  Premenopausal women found to have BRCA gene mutations can reduce their risk of both ovarian and breast cancer following removal of the ovaries.  In certain situations (e.g. women who are carriers of BRCA1- or BRCA2-mutations), taking oral contraceptives may also play a role in preventing ovarian cancer.

Thursday, September 4, 2014

Does muscle really weigh more than fat?

A pound of anything still weighs a pound. A pound of lead weighs the same as a pound of feathers and a pound of muscle weighs the same as a pound of fat.  The misconception that muscle is heavier than fat comes from muscle being more compact or dense than fat, so if you consider same size portions, muscle would weigh more than fat.

To put some numbers to this comparison, let’s look at the density per unit volume of both of these substances.  Muscle has a density of approximately 1.1 grams per milliliter as compared to fat which has a density of 0.9 grams per milliliter.  Therefore, one liter (approximately a quart) of muscle would weigh 1.06 kilograms (2.3 lbs.) and one liter of fat would weigh 0.9 kilograms (1.98 lbs.).  This makes muscle approximately 18% more dense than fat.

What is an acceptable percentage of fat?  Normal or acceptable percentages of body fat increases with age and differs between men and women.  As a guideline, the American Council on Exercise considers percent body fat between 25 and 31% acceptable for women and between 18 and 25% acceptable for men.  Most athletes would have body fat percentages lower than this and obese individuals would be higher.

Determining percent body fat:  There are a number of ways to measure percent body fat, but unfortunately, the best methods are either quite expensive or unavailable to most people.  A few of the most common methods include:
  • Skinfold calipers involves the use of a device to "pinch" the skin at several specific locations on the body.  Results vary depending on the quality of the calipers, the number of locations measured and the skill of the person performing the test.
  • Body-fat scales use a technology called bioelectrical impedance. This involves sending an electrical current into the body and measuring the resistance to electrical flow.  Since muscle conducts electricity better than fat, percent body fat can be calculated by the resistance to electrical flow.  Body-fat scales are the least expensive and most widely available method of measuring percent body fat. Their accuracy, however, can vary widely vary depending on several factors including hydration status.
  • Underwater Weighing involves submerging the person being measured in a water tank and calculating body density and percent body fat from the amount of water that is displaced.  This method is highly accurate, but expensive and not widely available.
Another method, the body mass index, or BMI (nhlbisupport.com/bmi), is calculated from height and weight measurements. It provides information about general body habitus (underweight, recommended, obese, etc.) but does not provide you with a specific percent body fat measurement.  This method, however, is free and does provide a rough measure of body fatness and health risks related to body weight.

Benefits of having a lower percentage of body fat:  The health problems associated with obesity are well known and include a higher risk for developing coronary heart disease, stroke, certain cancers, Type 2 diabetes, osteoarthritis, gall stones, and a host of other medical problems.  The benefits of reducing to an acceptable percentage of body fat can include a heightened self-image, increase in strength and endurance, along with a reduced risk for developing the obesity-related conditions mentioned above.
 
Converting fat to muscle:   Another misconception is that fat can be “converted” into muscle.  Fat and muscle are two different types of body tissue.  Changing one to another is no more possible than a medieval alchemist being able to convert lead into gold.  What really happens when people experience changes in their body composition with diet and exercise is that their bodies are burning fat  (by restricting calories and cardio workouts) and adding muscle mass (through resistance training).   The impression that fat is being converted into muscle is because these changes occur simultaneously.  A bonus to having a higher percentage of muscle over fat, is that while at rest (basal metabolic rate) muscle burns more calories than fat. The difference is relatively small, in the range of an additional 5 to 7 calories per pound of body weight per day, but over time this can add up significantly.

Losing inches vs pounds:  When beginning an exercise/weight loss program, some people become frustrated because they are not losing weight even though they appear to be leaner.  This can occur because of the previously described difference in density between muscle and fat.  Just as a pound of lead would occupy a significantly smaller space than a pound of feathers, two people could be the same height and weight, but the person with the lower body fat percentage would appear to be leaner.  Another way of looking at this is that a 150-pound woman whose body is composed of 25% fat would most likely wear a smaller clothing size than a woman of the same height and weight with 45% body fat.  By reducing body fat and gaining muscle, “inches” could be lost from the waist line or other areas of the body even though the person’s weight remained the same. One lesson from this is that body weight is not the only way to monitor the success of an exercise/weight loss program. In addition to body weight, other parameters should be considered such as percentage body fat, strength, waist circumference, blood pressure, and blood lipids.  Losing weight alone without improvement in these other parameters may not produce the maximal improvement in one’s health, which should be the goal of any exercise and weight management program.

Friday, August 29, 2014

Backpacks for Back-to-School

Backpacks have become the most popular means for school-age children to carry their books and school supplies.  In fact, when used correctly, a properly designed backpack is an excellent way to carry the necessities of the school day. Unfortunately, thousands of children each year experience back pain related to use of school backpacks that are too heavy or used incorrectly. Public awareness of backpack-related back injuries has helped to reduce its incidence, but with the start of the new school year, it is worth offering a reminder to parents and children of ways to prevent these from occurring.

Choose the right backpack – Be sure that the backpack is the appropriate size for the child.  A well-designed backpack will include wide, padded straps to reduce strain on the shoulders and spine.  A chest (sternum) strap and waist belt will help distribute the load over the entire trunk. Some of the best ergonomically designed backpacks are made by companies that specialize in equipment for hiking (Jan Sport, Osprey, North Face, etc.). Additionally, salespersons in outdoor specialty shops can be helpful in making sure that the backpack fits properly. Straps that compress the contents of the backpack will stabilize the load and keep it closer to the back. If carrying heavy loads is unavoidable, a convertible backpack with wheels may be a consideration.  Reflective material to enhance visibility is an important safety feature for children who walk at dusk or after dark.

Wear the backpack properly-- A proper fitting backpack rests evenly in the middle of the back, rather than hanging below the level of the lower back or waist. Both shoulder straps should be used rather than just one. Shifting the weight of the backpack to one side by using only one strap alters back symmetry, which can lead to neck and back strain. This advice also applies to backpacks that are designed with only one strap that crosses the front of the body. When walking a significant distance, encourage your children to use the sternum strap.

Avoid overloading— Most experts recommend that children carry no more than 15% of their body weight in their packs. For a 50 pound child, this would mean that the backpack and its contents should not weigh more than 7.5 pounds. This amount would double to 15 pounds for a 100 pound child. One way of gaging this is to weigh the child with and without the backpack on the bathroom scales. More weight than this compresses the discs that serve as cushions between the bones of the spine and cause excessive curvature of the spine. Studies have shown that the amount of back pain reported by children increases along with the load in the backpack. Parents can help to reduce the weight in their child’s backpack by seeing that only those items needed for the school day are packed. Unnecessary books or items (cell phones, music devices, video games, etc.) should be left at home.
  
Consider alternatives—Whenever possible, children should use lockers or their desks during the school day to minimize the load carried in the backpack. If there is an option, purchase paperback rather than hard-bound books in order to decrease the weight of the books that are being carried. Only those textbooks that are needed for completing homework should be brought home in the backpack.  If unavoidable due to the number or weight of required textbooks, a second set could be purchased for use at home.

Back pain in children should not be ignored.  Since backpack-related back pain is so common, however, parents should consider this as a possible explanation for their child’s problem.  A few of the symptoms or signs that could indicate that a backpack may be responsible for the child’s pain include:
  • Back pain that is present when wearing a backpack but goes away when removed.
  • Excessive back curvature or alteration of posture when wearing a backpack
  • Numbness or tingling affecting the arms or legs
  • Struggling due to excessive weight when putting on or removing the backpack.
Following the recommendations for proper use of the backpack will, in many cases, take care of the problem. Back pain in children that persists despite these measures or that inhibits normal activities, requires regular medication, or affects sleep habits, deserves medical attention.