Medical Associates Clinic

 Quality Care Close To Home

Gettysburg Medical News
 The Clinical View
 by P.E. Hoffsten, MD
3 August 2005

PARATHYROID HORMONE:  A NEW DRUG FOR OSTEOPOROSIS

            The gentleman was 68 years old and had a  relatively slight build weighing a near ideal 160 pounds for his 5 foot 9 inch frame.  Over the years, he had practiced “Standard South Dakota Male Behavior” and paid little attention to his health.  He had been a pack a day smoker for 50 years.  He had no specific exercise program and had been an executive for many years.  There was no attention to calcium intake and he never drank milk.

            He came to the clinic because his back was hurting terribly and his wife had noticed a new lump in the middle of his back.  When x-rays were taken, it was confirmed he had a “compression fracture” of the 8^th thoracic vertebra.  This is a fracture that results from the bone mineral in the vertebra being so depleted that it will no longer support the body’s weight.  It was also seen on x-ray that there was a developing compression fracture of the 6^th thoracic vertebra.  He thus had two sites to explain the pain he was having.  The remainder of his vertebrae in his back had been demineralized to the point where they also were in danger of developing compression fractures.  He was referred to a special orthopedic group who injected some plastic material into the two bones that were collapsing.  This re-enforced the bones to prevent further collapse and also stopped some of his pain.  It also established a more normal posture instead of his being stooped over.

            A special test called a bone mineral density examination was performed and demonstrated quite remarkable loss of bone mineral.  With the two compression fractures now treated, the questions arose as to how prevent further fractures and re-establish his bone mineral.

            Human bones reach their maximum strength and density at about age 22 and remain stable at that level until at least age 28.  Following that, there is a slow deterioration of the bone mineral depending on several factors:

            1.  Adequate calcium intake.  For women in the United States, the daily calcium intake on average is around 600 mg per day.  For men, it is around 800 mg a day.  Needed to prevent bone mineral loss is an intake of at least 1,000 mg per day.  This is equivalent to a quart of milk a day which adults rarely consume.  Even if they eat cheese, the intake of calcium at a 1,000 mg per day can not be achieved unless a calcium supplement is taken.  I advise my patients over age 50 years, to take a 1,000 mg of calcium per day as a supplement.

            2.  Enough Vitamin D.  The government recognized adult minimum daily requirement for Vitamin D as 400 units per day.  If a person already has significant osteoporosis this needs to be at least 800 units per day which could be obtained from two standard vitamin pills.  Alternatively, taking an extra Vitamin D pill to reach 800 units of Vitamin D per day will suffice.

            3.  Neither of these two factors alone will have any impact on bone mineral unless the person has significant weight bearing exercise.  Swimming is great for your heart and lungs but not for weight bearing.  Bicycling is some help but the best exercise is walking.  The recommendation is three miles per day.  Unless a person is a mail carrier or a meter reader, very few people walk three miles a day unless they make an active exercise effort.

            4.  Estrogen for ladies and testosterone for men are hormones that help preserve bone mineral density.  These hormones will not necessarily make the person put more mineral into their bone but these hormones will prevent the loss of mineral from the bone.  This is one of the major reasons for the use of estrogen replacement therapy in women or testosterone replacement in men.

            5.  There is a hormone called parathyroid hormone that is secreted by four pea sized glands in the neck. This hormone nutures bone helping it remodel and make repairs.  To this time, it is the only hormone that will predictably cause an increase in bone mineral density.  Note above, that estrogen and testosterone prevent loss of bone but really are not effective in making new bone mineral enter the bone.  Parathyroid hormone can put new mineral into the bone reversing the progressive losses that occur with age.

            Like all new medications that come on the market, parathyroid hormone (trade name Forteo) can be very expensive.  Because of this substantial expense, insurance programs require pre-authorization.  As expensive as this drug is, there are situations where it is worth every penny. The company that manufactures Forteo has now developed programs for those in need of a drug but without the finances to afford it.  Your local clinics have information regarding these programs and possible provision of this medication for those that need it.

            To finish the story of the gentleman above, he was started on a calcium supplement, daily Vitamin D supplement at 800 units per day and advised to begin a walking program working towards 3 miles per day.  As one might imagine because of his cigarette abuse, his lungs weren’t a whole lot better than his bones and his ability to walk was somewhat limited.  But he was certainly capable of more than he had been doing and any walking that can be tolerated would be a help in stimulating bone remineralization.  He was started on a medication called a bisphosphonate that prevents further bone loss.  After three months, he was still having significant backaches felt to be due to the strain on his demineralized spine.  It was at that point that Forteo was introduced into his program.  Fortunately, he had insurance coverage that would finance this for him and he had the clear indication of the need with the compression fractures in his back and his massive demineralization.  Now 18 months later, he has had a 12% increase in the bone mineral density and almost miraculous improvement.  His back pain is nearly gone and he has assumed a more active life.

            This example of a man with osteoporosis is not the rule.  Most commonly osteoporosis affects woman much more frequently than men.  Fortunately, Forteo works for either men or women and is indicated for those individuals with advanced disease and especially those who already have compression fractures in their back.  Osteoporosis also is associated with hip, wrist and upper arm fractures.  A comprehensive program to prevent these types of problems and reverse osteoporosis is strongly recommended.  The alternative is the fractures and all of the grief that they bring.