OSTEOPOROSIS
Bone tissue undergoes both loss and formation. The balance of resorption and formation changes over ones lifespan. Peak bone mass appears to be reached by age 18 in women. It then remains relatively stable until menopause. With the reduction in estrogen levels at menopause, together with aging leads to a period of relatively rapid bone loss during the first five or so years after menopause. Bone loss then stabilizes and then there is a slow ongoing loss related to aging, which occurs in men as well. A cell called the OSTEOCLAST is the only bone-resorbing cell. Loss of estrogen stimulates the activity of this cell type. Another cell type called the OSTEOBLAST is responsible for bone formation. From the time of maximal bone density (age 18) until menopause osteoclast and osteoblast activity are in balance, bone reabsorption and bone formation are equal and bone density is stable. This has been known for a relatively long time, so the question is what turns on and off osteoclast activity and where does estrogen fit into this process. It has been recently discovered that a protein expressed by osteoblasts called the RANK Ligand (RANKL) binds to a protein made by osteoclasts called RANK and this complex (RANK + RANKL) stimulates osteoclast activity and bone reabsorption. Yet another protein expressed by osteoblasts called the Osteoprotegerin (OPG) inhibits the RANK ligand and can shift the balance to bone formation. Estrogen inhibits the expression of RANK from osteoclasts therefore indirectly inhibiting bone resorption. With the mechanism of bone resorption and formation known at the molecular level there exists the possibility of developing new drugs to inhibit bone resorption and loss, working in an entirely different way then that of drugs currently used ( i.e.: the bisphosphonates: fosamax, boneva and actonel) to prevent and treat osteoporosis.
In an exciting development scientists at the biotech company AMGEN have developed a a monoclonal antibody against the RANKL protein. This will inhibit osteoclast activity and prevent bone reabsorption. This new drug called DENOSOMAB will be eventually released under the trade name PROLIA. It will be administered every six months as a 60 mg subcutaneous injection. It is currently undergoing clinical trials, the final step before FDA approval. If further study proves this drug safe and effective, it will revolutionize the treatment and prevention of osteoporosis.
BIRTH CONTROL PILLS: NEWER IS NOT ALWAYS BETTER
Oral contraceptive pills in general increase the risk of blood clots 2-3 fold. Since the absolute risk is low for blood clots in the general population (about 3 per 10,000) the increased risk from birth control pills is not very significant and is vastly outweighed by all of their benefits. In addition to nearly 100% contraception, birth control pills reduce risk of ovarian and endometrial cancer, reduce menstrual blood loss, decrease cramps, PMS, ovarian cysts, endometriosis, improve long term fertility, reduce fibrocystic breast and the list goes on. Since 1995 there have been numerous published reports on the difference in thromboembolic risk associated with the newer progestins. Several new studies have recently been published showing an increased risk of blood clots with the progestins desogestrel, gestodene and drospirenone (found in Yaz, Yasmin and its generic Ocella) when compared to older formulation containing levonorgestrel and norethindrone. However the absolute risk even with these newer progestins remains small so there is no need to panic if you are taking the newer pills. However you might want to reevaluate which pill is best for you and discuss this with your doctor.
COLONOSCOPY
Colonoscopy is recommended for colorectal cancer screening for adults over 50 years old. Recent developments and studies may now make virtual colonoscopy a reality. A new generation of CT scanner (GE MDCT multidector CT) is now available. This CT scanner uses much less radiation and makes it practical to screen for colorectal cancer using this devise. Also, new studies now seem to indicate that colon polyps under 1 cm in size present only a minimal risk for cancer and don’t have to be automatically removed. This also would make Virtual Colonoscopy an acceptable alternative to traditional colonoscopy with its risks of anesthesia and perforation.
VAGINITIS
The mainstay of treating bacterial vaginitis has been with two FDA approved vaginal drugs-METROGEL and CLINDESE (temporarily unavailable). A third drug has recently been approved called TINDAMAX (Tindazole). It is an oral medication taken as 2 grams daily for two consecutive days. Finally, there is another effective non-messy choice.
Dr. Charles Dubin graduated from UCLA medical school and is a specialist in gynecology, menopause and gynecologic minimally invasive surgery. He is in private practice in Santa Monica, Calif. He was among the first 100 physicians in the United States certified in advanced laparoscopy and hysteroscopy by the Accreditation Council for Gynecologic Endoscopy. He was cofounder of the Westside Menopause Center and a member of the North American Menopause Society. He was founder of the Endometriosis Center of Southern California. Dr. Dubin’s practice caters to the needs of perimemopausal and menopausal women employing a customized, holistic approach using hormonal, herbal, dietary and lifestyle approaches.
