Thanks. First, thanks to all the men who sent e-mail or letters this quarter. I often hear from someone giving me a heads up on a news story or research relating to osteoporosis, and I really appreciate the information.
NIH Consensus Conference on Osteoporosis. I was fortunate to be invited to the NIH Consensus Conference on Osteoporosis in Bethesda, MD this month to tell the participants about my experience with osteoporosis. They had invited one man and one young women to present two perspectives of people with osteoporosis that are often overlooked: That of the premenopausal woman and the man with osteoporosis. Additionally, USA Today ran an article on osteoporosis and included a section about my experiences with osteoporosis. The article ran in Tuesday`s edition, March 28, 2000 and can be found on their Web site, http://www.usatoday.com/usatonline/20000328/2078664s.htm if you would like to review it. The conference and newspaper article brought considerable nationwide attention to the problem of men with osteoporosis and to the fact that we have a men`s support group and Web site to aid men with osteoporosis.
The USA Today article mentioned an upcoming osteoporosis study to involve 6,000 men. I`ve had several enquiries about this study so I checked to see if they were looking for men with osteoporosis to volunteer. I was told that they are not looking for men with osteoporosis and that it is not a study involving any treatment. Essentially, it will be a prospective study to follow "normal" men aged 65 or older to see if they unknowingly have osteoporosis when they start the study or if they develop it. It will also cover other areas of concern to men such as prostate problems. If you want more information, you can call the nearest university to you for more details: University of Alabama at Birmingham, AL (877) 749-6767; University of Minnesota in Minneapolis, MN (612) 626-8022; University of Pittsburgh in Monessen, PA (800) 872-3653; Stanford University in Palo Alto, CA (650) 493-5000 ext. 23301; Oregon Health Sciences University in Portland, OR (503) 494-6529; University of California, San Diego at Rancho Bernardo, CA (858) 673-5574.
Lack of response to therapy. I have had a few e-mails in the last year or so from men concerned about apparent lack of response to osteoporosis therapy. Here are some of the things that could possibly relate to this situation:
1). Be sure you are following directions when taking medications. Fosamax is absorbed best if taken on an empty stomach before breakfast with a large glass of water. Forty percent more medication is absorbed if you wait two hours to eat compared to waiting only one-half to one hour before eating. If you are on the new once-weekly dosage and wait the full two hours before eating after taking Fosamax, you are getting the equivalent of forty percent more medication than if you were only waiting one-half hour on the 10 mg/day regimen. Or, if you are taking 40 mg once weekly and waiting two hours, you are getting virtually the same dose as you were when taking 10 mg/day and waiting one-half hour to eat.
2). Be sure you have been tested for hypercalciuria, and, if you are hypercalciuric, that you are taking hydrochlorothyazide. See the October 1999 newsletter for a discussion of the effectiveness of this therapy in men with osteoporosis.
3). Consider asking for I.V. bisphosphonate therapy to see if that might give better results than the oral method. This bypasses the gastrointestinal tract where it is conceivable that some type of problem is preventing full absorption of the medication.
4). Look for causes of the osteoporosis that might have been overlooked. Celiac sprue, the inability to digest gluten, can cause osteoporosis. Check out the Internet for information on this disease that mostly affects people of European descent. There are many good sites, one in particular is http://www.celiac.com/. You`ll note that, although it often causes gastric symptoms like diarrhea or weight loss, it can be asymptomatic. Wheat, rye, and barley are the grains that cause the problem, and they must be avoided entirely to eliminate the condition. This problem can be diagnosed by excluding these grains in all their forms for several weeks and then slowly adding them back into the diet. If the symptoms go away, and then return, the cause has been found. If it is asymptomatic, other tests would be needed, such as biopsy of the small intestine. It is probable that many people have celiac sprue and have been diagnosed with irritable bowel syndrome, or just haven`t had a diagnosis. Since this disease causes both osteoporosis and stomach cancer, it behooves you to ask your physician about this if you aren`t responding to osteoporosis therapy.
5). I am going to review some recent research later in this newsletter that indicates that vitamin K may be helpful in gaining bone mineral density (BMD). You might want to discuss this with your physician if you feel it is important.
6). Tetracycline and chemically modified tetracycline (CMT), that no longer has antibiotic properties, have been shown in laboratory animals to both increase bone formation and reduce bone resorption. See the Collagenex Web site, http://www.collagenex.com/newhtml/index.html, for more information on this topic. I find the Research and Technologies section of the Collagenex site most educational, and you will find a specific section on osteoporosis there, too. Tetracycline has been prescribed for many years, and for extended periods, for patients with acne and other conditions that require constant antimicrobial medication. It has generally been shown to be safe, although it does have potential for some side effects, as virtually all medications do. But, for an individual with osteoporosis not responding to other therapies, tetracycline could be an option for therapy. It would have to be prescribed as a off-label medication in this case as it hasn`t yet been shown in humans to increase BMD. Also, tetracycline leaves a dark stain in the thyroid gland and bone (or teeth of young people) as it is incorporated into the tissue. There is a way to deal with this as noted by Bowles,WH J Esthet Dent 1998;10(4):182-6, Protection against minocycline pigment formation by ascorbic acid (vitamin C), MEDLINE UI: 99109390. This study showed that the addition of vitamin C along with minocycline prevented the darkening of the thyroid gland. So, anyone taking tetracycline for osteoporosis, or any other reason, should also be on supplemental doses of vitamin C to prevent the staining that occurs otherwise. As the CMTs are developed, these should eventually present an alternative medication to treat osteoporosis that has no antimicrobial properties. Unfortunately, their introduction is many years away, so those reading this newsletter now have to make decisions that involve tetracycline itself, not CMTs. I just present this as one possible therapy that can be discussed with your physician if others have failed. I wish it had several controlled clinical studies to prove its effectiveness, but there are none yet.
7). The apparent lack of response to therapy may have an explanation in recent study by Cummings SR and others, JAMA 2000 Mar 8;283(10):1318-21, Monitoring osteoporosis therapy with bone densitometry: misleading changes and regression to the mean. Fracture Intervention Trial Research Group. MEDLINE UI:20177213. They found that, "Women who had the greatest loss of BMD during the first year of treatment were the most likely to gain BMD during continued treatment." Additionally they noted, "In contrast, those who seemed to gain at least 8% during the first year lost an average of 1% (95% CI, 0.1%-1.9%) during th next year." In summary they conclude: "These results illustrate the principle of regression to the mean and suggest that effective treatments for osteoporosis should not be changed because of loss of BMD during the first year of use." So, unless you are not showing improvement after two or more years of treatment, don`t be discouraged.
Prostate Problems. Prostate problems, and especially prostate cancer, are concerns of all men, and possibly more so many men with osteoporosis who are on testosterone therapy. Testosterone is akin to fanning the flames of a fire if prostate cancer is present, stimulating the growth of cancer cells. So, good information about prostate cancer is important. I`d like to suggest an excellent Web site, http://www.cancerlinkusa.com/prostate/, to book mark. Odds are that either you or a friend will need good advice concerning prostate cancer diagnosis and treatment in the future. This site is loaded with valuable information that will allow much easier decision making in a time of relative crisis. And, it cites the literature to back up recommendations-an attribute often missing from other Web sites.
Ask the Experts
I`ve had a couple of questions lately involving excess serum calcium levels apparently due to hyperparathyroidism (HPTH). So, I asked Dr. Karen Kolba, our expert on osteoporosis-related issues, if she could shed some light on this potential source of osteoporosis.
Answer. Well, yes, HPTH is one of those "other causes" of osteoporosis that we always try to be on the lookout for. The basics are these:
The parathyroid glands, of which there are usually four-but sometimes more-are located next to the thyroid gland in the neck. The basic function of the parathyroid hormone is to maintain the serum calcium level in a very narrow range so as to allow proper function of other cells, especially muscle cells, and MOST importantly, heart muscle cells. If there is too much PTH hormone, the calcium level in the blood goes up. Since the calcium has to come from somewhere, it gets stolen from bone. The gut absorption is also increased and urine excretion is decreased. If the situation continues, you can get severe osteoporosis.
The diagnosis is usually made because the blood calcium level is too high. 8.5 to 10.5 is the normal range, although some labs give a slight variation. If the calcium level is high, we can order a PTH hormone level and usually it is a slam-dunk. By the way, if the serum calcium gets too high it can be fatal. And, it doesn`t have to get much over 12 to be really bad news-again heart muscle is not happy at that serum calcium level. Then the question is what to do about it?
Surgery is the best treatment, but one wants to have this done by a surgeon who does LOTS of this type of surgery-several times a week or more. These physicians are found almost exclusively in university medical centers, and for good reason. We all try to support their skills by sending patients to them. (I can name names in San Francisco and Los Angeles by request). The trouble is that only one or more than one of these glands may be overactive. (Note that it is usually not cancer, just what`s known as an adenoma or benign growth). This is the reason for the great skill of the surgeon being needed: It`s knowing where to find the glands and how to recognize which one is the culprit. The object is to LEAVE one normal gland in place so it can function. Sometimes they will take out all the glands and re-implant one under the skin of the upper arm where it lives quite happily, but where it can be easily taken out if it acts up.
So, especially if someone has had surgery once, they NEED to see one of the super-specialists to get it done the second time. I`m sure even these super-specialists have had to do some repeats, too. It is VERY tough technically, and I can`t even begin to explain why. Taking calcium and Fosamax or whatever will simply NOT be good enough for this type of osteoporosis.
Dr. James Schuster, the radiology consultant to the Men`s Osteoporosis Support Group, also notes that radiologists often do "hunts" for adenomas in hyperparathyroidism, and often find the offending lesion. He likes to start with ultrasound and go to MRI if needed. This should simplify the surgeon`s task of finding the offending gland considerably.
Case history follow up
Last quarter I presented Paul`s case history and wanted to give you an update as to what has transpired since then. I`ll quote from some of his e-mail messages to give you a feel for what has gone on.
1. January 21, 2000. "Yes, the testosterone is discontinued; the new endocrinologist supposes that Fosamax will suffice for increasing BMD. I`m also taking Zocor based in part for congenitally high cholesterol and in part because of the recent research abstract linking Zocor to increased BMD in osteoporosis." [Editor`s note: A recent study by Mundy G and others, Science 1999 Dec 3;286(5446):1946-9, Stimulation of bone formation in vitro and in rodents by statins, MEDLINE UI:20050954, suggested that statin cholesterol-lowering medications may stimulate bone formation. There have been no human trials to prove this theory yet. Statins are promoted as being generally safe, but in the February 2000 issue of Health & Healing Newsletter, Vol. 11, No. 2, Dr. Julian Whitaker suggests that statins may have a negative effect on the production of coenzyme Q10 (CoQ10). See Dr. Whitaker`s Web site, http://www.drwhitaker.com, for information on the newsletter. The statin drugs block the enzyme pathways in the liver that produce both cholesterol and CoQ10. QoQ10 is necessary for normal liver function and energy extraction from all body cells, including the heart. Dr. Whitaker suggests that the wholesale use of statins to lower cholesterol may be implicated in the tripling of congestive heart failure that has been reported in the last 15 years. A recent study relating to this was done by Ghirlanda G and others, J Clin Pharmacol 1993 Mar;33(3)226-9, Evidence of plasma CoQ10-lowering effect by HMG-CoA Reductase inhibitors: a double-blind, placebo-controlled study. MEDLINE UI:93216975. The authors found, "Significant changes in the healthy volunteer group were detected for total cholesterol and CoQ10 levels, which underwent about a 40% reduction after the treatment. The same extent of reduction, compared with placebo was measured in hypercholesterolemic patients treated with pravastatin or simvastatin." Additionally, they noted: "A diminution of CoQ10 availability may be the cause of membrane alteration with consequent cellular damage." Thus it appears that people taking statins for any reason should have serum CoQ10 levels tested. If they are low, CoQ10 supplements should be taken. Or, if in doubt, you just may want to take CoQ10 supplements anyway.]
Paul went to a major university medical center expecting implantation of a catheter for a morphine drip and for radical surgery of the prostate. Here is what he found after arriving. "I was told by the surgeon that my spine is too fragile for that sort of surgery because of the curled position, butt up, required." Paul found out that the glue from the vertebroplasty a year ago protrudes within a hair`s breadth of the spinal cord. [NOTE: Paul asked me to mention that no one he`s talked to ever mentions failures when discussing vertebroplasty, but he is living proof that they do happen. Also, the glue injected into the vertebrae eventually will disintegrate, so readers should be aware of this before having the procedure done.] The surgeon told him, "You won`t live long enough with that spine to die of the cancer." Paul left the hospital for home downhearted after having been told that he could become a paraplegic or dead at any moment, and hoping this was an exaggeration from an overly conservative surgeon. Also, no one had done anything about his constant pain yet.
After arriving home, Paul sent a long an angry e-mail to the endocrinologist he had previously contacted asking for help getting a pain pump. This physician had told him, "I`m not comfortable with these procedures because I don`t know much about them." Finally the physician agreed to arrange for neurology to implant an external pain pump. Paul ended the message with this: "I apologize for continuing to send you little but bad news."
2. February 1, 2000. The first upbeat news I had received from Paul arrived this day. He said, "I`m just back today, and at last the proud recipient of a morphine drip pain pump. There were a few more delays (e.g., 5 days monitoring of the temporary pump before opting for the implanted pump) but nothing I wasn`t well ready for. Even with lowered dosage over those days of monitoring, the pain in T-10 and T-11 has been completely absent. The pump is an Arrow 3000 which has no moving parts and runs on a `propellant.` Naturally, I have no information yet about how long I can go before getting a refill, but I`m prepared to be patient." He went on to say that, "No one at the hospital during the last week seemed to want to overrule the head of oncology surgery for my presumed inoperable condition and so talk of treating my cancer was vague. My wife and I, thus, had already decided to look elsewhere for prostate treatment. Your mention of cryosurgery fits perfectly. Thanks for finding it." [Editor`s note: I had actually found mention of prostate cryosurgery while looking for stock investment opportunities. You can read more about it at the Endocare Web site, http://www.ecare.org/, and there is a good summary on the CancerLinksUSA.com Web site I mentioned previously. Rather than a radical surgical procedure, in cyrosurgery they insert small tubes into the prostate that freeze it and the cancer cells. It involves an overnight stay in the hospital vs. about five nights with radical surgery. There is no incision, and the procedure is done with high-tech rectal ultrasound to help locate the cryoprobes into the prostate. There are possible complications, but they appear to be considerably less than with radical surgery. The VA Hospital system has recently approved prostate cryosurgery, so it has become more recognized as an acceptable alternative to radical surgery or radiation therapy. And, it can be done after failure of surgery or radiation.]
3. February 9, 2000. The good news continued from Paul. He noted, "For the moment, since my PSA seems to be shrinking (last week=5.4), my wife and I are gathering information about prostate procedures quickly but carefully." And best of all, he said, "My pain pump works! I have no pains in my back at all unless I do too much and I take those signals as clues to rest. I seem to have no side effects (certainly none of the dizziness and slowness I had with conventionally administered narcotics). So, almost miraculously, I am pain free and mobile after 3.5 years of hideous pain, chronic immobility, and suicidal inclinations. I`m delighted at almost every waking moment and I`m having to struggle not to do too much until I try things gradually. With the issue of pain now seemingly settled, I move with full focus to getting rid of my prostate cancer."
4. February 27, 2000. Paul has continued with his search for a solution to the prostate cancer. He notes, "I`ve collected many others such bits of information [on prostate cancer options] lately and am in constant communication with prostate experts on the Web. Not one of them, for whatever it`s worth, seems to have thought much about complications and interactions of osteoporosis with prostate cancer. When I mention the obvious risk of increasing testosterone in osteoporosis patients, and of warning urologist according, there is no response." He goes on to say, "My wife and I are corresponding with special focus on all the major sources of treatment and information about cryosurgery. All seem interested in me as a patient, but all would first have to clear me with regard to my osteoporosis. The cryosurgeon in Massachusetts seems most competent and open minded and he, having decided that my cancer is slow growing, advises me to hold back from any intervention, perhaps for several years. Because I cannot see any clear benefit of intervention over none, at least for now, I`m inclined to wait and watch, carefully. Best of all, I suppose, all my suicidal thoughts/inclinations are now completely gone. I`m simply back to my old self in reference to pain, energy, mood, and the ability to get things done. Damned shame I couldn`t have had it earlier. So for the moment, I`m happy to have retained my sexual function and not to have subjected myself to anything more than the small surgery for the pump."
5. March 16, 2000. As a final note before publication in the newsletter, I asked Paul if all was still going well. He said, "The pain pump performs nicely. In fact, yesterday I did too much yard work and actually had my old pain back, but it is gone today. No signs of depression and I`m happy in this beautiful but cool and sunny day in the mountains."
There is a lot to be learned from Paul`s case. First and foremost, it reinforces a common theme in these newsletters about the importance of the Internet in times of medical emergencies. There is just no way that Paul could have gotten the vital information he needed about pain pumps and prostate surgery alternatives without the speed and power of the Net. In this case, the Net was truly a life saver. Second, it shows that in most cases suicide is a permanent cure of a temporary problem. It also shows the importance of educating yourself about your problems and being forceful in getting help for them. Only through repeated efforts on Paul`s part was he able to get the pain pump implanted. And, apparently only through his efforts will he get a resolution to the prostate cancer problem. If he had been willing to give in as easily as his cancer surgeon, there would be little long-term hope. But, since he`s been persistent in finding alternative treatments, there is now great hope for long-term survival.
Literature review
Note: To do MEDLINE searches, go to the PubMed Web site http://www.ncbi.nlm.nih.gov/PubMed/. To search via UI number, be sure you enter only the numeric portion, not the letters "UI."
Vitamin K. There are several recent abstracts in MEDLINE pertaining to the positive effect of vitamin K on BMD. Most of these involve lab animal research, however, two are from human studies. The first is by Feskanich D and others, Am J Clin Nutr 1999 Jan;69(1):74-9, Vitamin K intake and hip fractures in women: a prospective study. MEDLINE UI:99122514. This involved a 1-year prospective analysis within the Nurses` Health Study cohort of 72,327 women aged 38-63. The results showed: "Women in quintiles 2-5 of vitamin K intake had a significantly lower age-adjusted relative risk (RR: 0.70; 95% CI: 0.53, 0.93) of hip fracture than women in the lowest quintile (<109 micrograms/d)." And, the authors concluded, "Low intakes of vitamin K may increase the risk of hip fracture in women."
The second study is by Yonemura K and others, Calif Tissue Int Feb;66(2):123-8, Short-term effect of vitamin K administration on prednisolone-induced loss of bone mineral density in patients with chronic glomerulonephritis. MEDLINE UI:20118563. Ten patients with glomerulonephritis were treated with prednisolone alone, and 10 other patients received prednisolone plus vitamin K (menatetrenone) three times daily. The patients receiving only prednisolone showed significantly reduced BMD by dual energy X-ray absorptiometry (DEXA). Additionally, serum markers for bone formation were greatly reduced while those for bone resorption were greatly affected. When the vitamin K was given with the prednisolone, there was no reduction in BMD and it prevented the reduction in markers of bone formation. The authors conclude, "Menatetrenone is a useful agent in preventing prednisolone-induced loss of BMD."
It is possible that more vitamin K than previous minimal requirements may be needed for ideal bone health. Good sources of vitamin K are wheat germ, soy oil, iceberg lettuce, broccoli, cooked spinach, cabbage, and romaine lettuce. Note that iceberg lettuce is not normally thought of adding much to nutritional requirements, but is a significant source of vitamin K. Vitamin K can be taken as a supplement, but since it is involved in the blood clotting mechanism, should be used with caution if you are on blood thinning agents.
Gastric effects of alendronate. If you frequent any of the osteoporosis bulletin boards on the Internet, you`d think that Fosamax caused gastric irritation in everyone taking it. Two recent studies cast doubt on this commonly held belief. An endoscopic exam of the esophagus, stomach, and duodenum before and after one month of taking alendronate was done in Canada. See Low CE and others, Am J Gastroenterol 2000 March;95(3):634-40. Upper gastrointestinal toxicity of alendronate. MEDLINE UI:20173284. The authors used 32 healthy female volunteers between the ages of 40 and 65 in a double-blind, randomized, placebo-controlled trial. For the results the authors found, "Endoscopic scores before and after treatment with alendronate were not significantly different." They concluded, "Alendronate does not cause predictable esophageal, gastric, or duodenal mucosal damage when used a directed.
Another study involving 6459 women aged 54-81 with low hip bone mineral density looked at alendronate gastric effects over a 3.8 year time period. The women took 5 mg/day for two years and then 10 mg/day thereafter. This research was done by Bauer DC, and others, Arch Intern Med Feb 28;160(4)517-25. Upper gastrointestinal tract safety profile of alendronate: the fracture intervention trial. MEDLINE UI:20158239. It is important to note that this study eliminated women with major upper GI tract disease such as recent ulcers, upper GI tract bleeding, or use of daily medication for dyspepsia. Regular nonsteroidal anti-inflammatory drug users were not excluded. The authors found, "The overall incidence of upper GI tract events was similar in the alendronate and placebo groups (47.5% vs. 46.2%; relative risk [RR], 1.02; 95% confidence interval [CI], 0.95-1.10)." They concluded, "In these older women, upper GI tract complaints, particularly dyspepsia and abdominal pain, were common, but alendronate treatment was not associated with an increased incidence of upper GI tract events, even in high-risk subgroups." These results agree with virtually all the major trials that Merck reports in its package inserts.
Does your surgeon video tape his/her procedures? A recent study from Johns Hopkins Medical Institutions would appear to have great potential, but I`ve not seen much indicating awareness of it results. The researchers videotaped 62 radical retropubic prostatectomy procedures for later review. Eighteen months after the study was started, the videotapes were reviewed and specific steps in the surgery were correlated with patient-reported potency rates. The authors found four specific steps in the surgical procedure that appeared to correlate to lack of potency after surgery. Being aware of these problem areas, future surgeries could be done so as to eliminate the problem steps, thus improving the chance for potency in patients. Although this research doesn`t directly relate to osteoporosis, many men with osteoporosis will need surgery at some point in their lives. I don`t know about you, but I would hope the surgeon working on me videotaped his/her procedures and reviewed them routinely to help prevent untoward consequences. Having this a requirement for board certification seems like an excellent idea to me, and I hope medical/surgical societies push surgeons to start videotaping their procedures to improve outcomes. Reference: Walsh PC and others, Urology 2000 Jan;55(1):62-7. Use of intraoperative video documentation to improve sexual function after radical retropubic prostatectomy. MEDLINE UI:20119057.
Calcium from supplements or food sources
There were three recent studies comparing absorption of various forms of calcium, which is a topic of concern to anyone with osteoporosis or wanting to prevent it. Interestingly, two of the studies compared various forms of supplements and seemingly developed opposite conclusions. Another study compared calcium absorption from food sources to see how that compared to previous studies that looked at absorption from supplements. All of these results will be discussed here.
The first study was by Heaney RP and others, Osteoporosis Int 1999,9(1):19-23, Absorption of calcium as the carbonate and citrate salts, with some observations on method. MEDLINE UI: 99295101. The authors compared absorption of calcium from the carbonate and citrate salts taken as a 300 mg or 1000 mg dose with breakfast. They used a serum tracer method and an absorptive increment in urinary calcium on 37 adult men and women. In summary, "We conclude that, when taken with food, calcium from the carbonate salt is fully as absorbable as from the citrate, and that the urinary increment method is not sufficiently sensitive to be useful in comparing sources in free-living subjects."
The second study was by Heller HG and others, J Clin Pharmacol 1999 Nov;39(11):1151-4, Pharmacokinetics of calcium absorption from two commercial calcium supplements. MEDLINE UI:20046107. In this study the authors compared calcium absorption after a single 500 mg calcium load of Citracal (calcium citrate) or Os-Cal (calcium carbonate). They used 18 postmenopausal normal women from whom they drew venous blood samples on an hourly basis, before and for six hours after ingestion of the calcium supplements with a breakfast meal. The findings showed Citracal gave significantly higher absorbed doses of calcium than the Os-Cal. They authors stated: "In conclusion, Citracal is much more bioavailable than Os-Cal.
If you have searched the medical literature, you`ll find thousands of instances of apparent contradictory findings from research studies. I was very concerned about this strong contradiction between these two studies and e-mailed the lead author of the second study, Dr. Howard J. Heller, Assistant Professor, Internal Medicine, Center for Mineral Metabolism, University of Texas Southwestern Medical School, Dallas, Texas to see if he could shed any light on the situation. He very promptly replied to my query and offered the following explanation:
"I was forwarded your excellent question. There are several differences between the two studies, but I am also puzzled by the contradictory results.
1) Design - We measured increment in blood calcium whereas Dr. Heaney and coworkers measured urinary calcium and isotopic estimation of calcium absorption.
2) Supplement Formulation - Dr. Heaney`s group used powder rather than tablet preparations. It is possible that the excipients had some influence on the results. Moreover, the tablet may disintegrate at different rates providing a delayed response. We chose the two most popular tablets because that is what patients will ingest.
3) Study Meal - Dr. Heaney`s study meal may have included caffeinated coffee (or at least, the protocol does not say it was decaffeinated) which is known to increase urinary calcium excretion. Thus, change in urinary calcium would be less useful. The test diets were also slightly different. Food can affect both intestinal calcium absorption and urinary calcium excretion.
4) Study population - The other study high load group included 10 men and 10 postmenopausal women aged 44-53; the 300 mg load group included 17 premenopausal women. Our group included only postmenopausal women (most of whom were not taking estrogen, of mean age of 62). The older women may have been less able to secrete acid in response to a meal. Many believe that gastric acidification of the calcium enhances absorption.
5) Calcium absorption - This test is an estimate of initial calcium absorption. Dr. Heaney`s group has shown this method to be a fairly reliable method except in very large subjects and subjects at the extremes of absorptive efficiency; he has shown that the results are within 5.5% of the standard fractional calcium absorption. A drawback of this test is that it does not measure the net calcium absorption. While calcium is absorbed in the GI tract, it is also secreted.
Even with all these differences, I am surprised at the conflicting results of the two studies. Since calcium supplements are used to prevent bone loss, it is important to know which supplements are the most bioavailable. It is unusual for primary care physicians to realize that men also need to follow preventive measures. Head-to-head long-term studies are justified between available supplements to see which protects the most against bone loss. This will answer the question more effectively than short-term studies."
Thanks to Dr. Heller for this excellent explanation of possible differences between the two studies to explain the variation. There are times that the research creates more questions that answers, and you have to make an educated guess as to the best medication, therapy, or treatment to choose. If your BMD is improving via DEXA, it is probably safe to assume that the calcium in your diet, or the supplement you are taking, is working effectively. If not, then you have to look for variations in calcium absorption, and other possible causes, for a solution.
The other study that I want to mention is also by Heaney RP and others, J Am Diet Assoc 1999 Oct;99(10):1228-33. Dietary changes favorably affect bone remodeling in older adults. MEDLINE UI:99452017. In this study the authors determined whether dietary counseling to increase milk intake could produce useful changes in calcium economy, and what, if any, other nutrition-related changes might be produced. Using 284 healthy men and women as test subjects, who normally ate less than 1.5 serving of dairy per day, they were instructed to consume 3 servings per day of nonfat or 1% milk for 12 weeks. These people were compared to group members who did not change their milk consumption during the study. In the milk-drinking group, calcium intake increased by 729 mg/day. Several measures of increased bone formation or decreased bone resorption showed significant improvement in the milk group indicating a positive influence on bone formation due to the milk ingestion. The authors conclude: "The changes observed in the calcium economy through consumption of food sources of calcium are similar in kind and extent to those reported previously for calcium supplement tablets." They also state, "Dietitians can be confident that food works, and that desired calcium intakes can be achieved using food sources."
There is probably too much emphasis on calcium supplementation to achieve desired calcium intake levels. This study shows that food is just as important a source of calcium. When you calculate your daily calcium intake, you should include both food and supplements to see that you achieve desired levels. If you get all you need from food, then there is apparently no need to supplement additionally. As I have pointed out in the July 1999 newsletter, it is not enough to just calculate the total dose of calcium since more is absorbed if it is ingested in smaller doses. That is, if you drink a quart of milk at one setting, that is not the same absorbed dose as drinking that quart at 3-4 different times of the day. You`ll absorb much more calcium by dividing the dose throughout the day. Also, Dr. Heller reminded me in one of his e-mails that all dietary sources of calcium are not equal. For example, spinach has a lot of calcium, but very little is absorbed. Kale, on the other hand, is well absorbed. Dairy products provide the best combination of calcium content and bioavailability. Additionally, a few patients can`t absorb any form of calcium well and need a potent form of vitamin D.
Disclaimer. Diagnosis and treatment of osteoporosis are the responsibility of the patient and his or her physician. Nothing in this newsletter is to be interpreted as a recommendation for treatment or to change treatment that your physician has prescribed. Although we attempt to assure that information in this newsletter is factual, errors will occur. It is the responsibility of the reader to verify that information they are acting on is factual. There is no relationship between this newsletter and any national osteoporosis group, including the National Osteoporosis Foundation. All references to any such groups are for informational purposes only.
