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The “telepress” system for self-measurement and monitoring of blood pressure (the “SHAHAL” experience in Israel)
The “Telepress” System for Self-Measurement and Monitoring of Blood Pressure (The “SHAHAL” Experience in Israel) Arie Roth, MD, Michal Golovner, MD, Naomi Malov, RN, Ziv Carthy, MBA, Rachel Naveh, RN, Iki Alroy, BSc, Elieser Kaplinsky, MD, and Shlomo Laniado, elf-measurement of blood pressure (BP) away from the medical setting, which was introduced as S early as 1930, has been advocated to provide com1
plementary information, and obtaining BP measurements at home has gained popularity as a supplementary diagnostic tool. “Shahal,” a medical facility described previously,2– 4 is a service that currently has 44,000 subscribers. It introduced the “Telepress” program in which subscribers transmit, via telephone, a reading of their BP measurement from their home to the monitor center. The current study examines whether the “white coat” effect is applicable in the “Telepress” framework and if a patient’s awareness that the BP measurement transferred on-line to the monitor center contaminates the results. A secondary goal was to document the frequency of use of the Telepress by its subscribers and determine if there is a pattern related to the nature of the subscribers. •••
Thirty consecutive subscribers to SHAHAL were selected. Ten subscribers who were normotensive, did not have any known cardiovascular or other disease, and were not receiving any medical or supplemental treatment composed group A. The other 20 patients were known to have hypertension, for which they were being treated for at least 1 year before inclusion, 10 with b blockers (group B) and 10 with other antihypertensive medications (but not calcium antagonists or tranquilizers) (group C). All participants had regular sinus rhythm. Each subscriber to the blood pressure monitoring program of Shahal receives the Telepress device, which consists of a home-based unit for transtelephonic automatic transmission of BP readings as measured by an automatic oscillometric digital blood pressure meter (UA-731; Meridian, Seattle, Washington). Validation of the device was established by tests based on well-known reported methods. Simultaneous BP measurements were obtained by 50 randomly selected normotensive and hypertensive persons using the UA731 and a mercury sphygmomanometer using a Ttube. After the new member’s subscription to SHAHAL, a qualified medical technician instructs and trains the subject on use of the BP device at home. Subscribers are instructed to attach the arm cuff tightly around the From “SHAHAL” Medical Services, The Tel-Aviv Sourasky Medical Center, Sheba Medical Center, and the Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel. Dr. Roth’s address is: Tel-Aviv Sourasky Medical Center, 6 Weizman Street, Tel-Aviv, 64239, Israel. Manuscript received May 26, 1998; revised manuscript received and accepted September 8,1998.
610
©1999 by Excerpta Medica, Inc. All rights reserved.
MD
upper arm so that the bottom edge of the cuff is positioned 1 inch above the elbow joint. They are advised to perform the measurement quietly, while they are in a relaxed position, to avoid vibrating the instrument. Each BP reading consists of a set of 3 measurements taken at 30- to 60-second intervals. Each completed measurement is automatically transmitted transtelephonically to the monitor center, where an algorithm calculates the mathematic average. If the readings are not within the expected range, the results are displayed on a screen and a nurse will contact the subscriber to reassure and instruct him or her on what measures to take. If the readings are within normal limits, they will not be displayed but they will be stored in the subject’s medical record. At the end of every preset period (generally 3 to 4 months), or earlier when requested, a report that includes all readings and date and time of measurement will be mailed to the patient so that the information is available to the patient and his or her physician. After obtaining consent to participate in the study, subscribers were instructed to take 2 sets of blood pressure readings at the same time of the day for 10 consecutive days. In 1 set, the results were automatically transmitted transtelephonically to the monitor center. In the other set, the device was disconnected from the telephone and the patients entered the results of each individual measurement on a prepared form, which was mailed to the monitor center at the end of the study period. Subscribers were randomly assigned on an alternating daily basis as to which of the 2 measurement protocols they should use first. All Telepress transmissions for the entire membership body were retrieved from the central computer for frequency analysis to explore the subject’ patterns of transmissions. Data are reported as mean 6 1 SD. The Student paired t test was used to compare the 2 modes of measurements, and the 2-sample t test was used to compare differences between measurements and sexes. The Pearson correlation test was used to compare differences between measurements as a function of age. A p value ,0.05 was considered significant. The age of the 30 study patients was 59 6 9 years (range 42 to 72); 20 were men. All participants were in stable clinical and hemodynamic condition, without any concurrent disease at the time of measurement. There was no change in any subject’s medical regimen during the study period. No difference was observed among the entire study population between the group mean blood pressure 0002-9149/99/$–see front matter PII S0002-9149(98)00926-6
FIGURE 1. Mean blood pressure values. Group A 5 10 healthy normotensive subjects (not receiving any medical treatment); group B 5 10 patients with hypertension controlled by b-blocking agents; group C 5 10 patients with hypertension controlled by other antihypertensive medications (not calcium antagonists or tranquilizers).
that was measured and transmitted automatically (87 6 10 mm Hg) and the group mean blood pressure values that were not transmitted (87 6 10 mm Hg). Mean blood pressure values for groups A, B, and C are shown in Figure 1. Interestingly, only group B (patients treated with b blockers) demonstrated a difference associated with the mode of measurement. There were no sex-related differences in readings. When correlating the differences in blood pressure between the 2 modes of readings and age, it was found that the nontransmitted systolic (and calculated mean) BP readings tended to increase slightly with increasing age (Figure 2). A comparison between the mean systolic blood pressure readings of the first set of measurements with the second set revealed slightly higher readings in the former (120 6 14 vs 118 6 17 mm Hg, respectively; p 5 NS), regardless of whether they were transmitted. There are currently 5,486 subscribers to the Telepress program, with a monthly average of 1.8 transmissions of self-measured BP recordings. Fifteen percent of patients had been considered healthy (free of hypertension or other coronary risk factors): 88% of them used the Telepress only 0.33 times in 1 month. Twenty-five percent of patients with a cardiac history used the Telepress 1 to 5 times in 1 month, 3% used it 5 to 10 times, 2% used it 10 to 20 times, and 0.4% used it .20 times. The tendency to use the Telepress increased with increasing age for patients with any notable medical history but not for those in the healthy group. •••
Results of this study demonstrate that no white coat effect contaminated the validity of the Telepress system. This was true for both sexes, which contrasted to previously reported white coat effects on gender interaction.5,6 In addition, being completely automatic, a possible emotional element stemming from a dialogue between the patient and the intimidating medical personnel was obviated, so that measuring BP at home
FIGURE 2. Correlation of the differences in blood pressure between transmitted and nontransmitted self-measurement of blood pressure and age.
did not affect the results as might have occurred in a face-to-face situation.7 We have no explanation for the difference between observed and transmitted results in the group treated with b blockers, although it is possible that there was a b error attributable to the small number of patients. When the patient’s age was taken into account, we found that the transmission of results was associated with less excitement to the patients, as demonstrated by increasing differences between observed and transmitted results. This was more apparent in female subjects, as reported by others, to be gender specific.8,9 Home-based self-measurement should not be confused with the ambulatory automated BP measurement system that has justifiably gained popularity. Although there is some overlap between the information obtained by home and ambulatory monitoring, there are also important differences. Ambulatory monBRIEF REPORTS
611
itoring provides information about the diurnal profile of BP and has great advantages for trials investigating the time course of a particular drug. Self-measurement can provide repeated measurement in the same situation over prolonged periods of time and, therefore, is ideally suited for monitoring changes in BP induced by treatment or progression of the disease. In summary, the Telepress system circumvents direct contact between patient and medical staff. Our concern was that the patient knowing the transmission was simultaneously being “observed” in the monitor center might produce a pseudo white coat effect. In none of the parameters studied was there any indication that this element interfered with the validity of the results. Thus, this home-based self-measurement of BP is a potentially cost-effective way to improve BP control and therapeutic efficacy.
1. Brown GE. Daily and monthly rhythm in blood pressure of a man with hypertension. Ann Intern Med 1930;3:1177–1189. 2. Roth A, Herling M, Vishlitzki V, Aitkin I. The impact of “SHAHAL” (a new cardiac emergency service) on subscribers’ appeal for medical assistance: characteristics and distribution of calls. Eur Heart J 1995;16:129 –133. 3. Roth A, Malov N, Bloch Y, Schlesinger Z, Laniado S, Kaplinsky E. Selfadministration of intramuscular lidocaine in the pre-hospital setting: the “Shahal” experience in Israel. Am J Cardiol 1997;79:611– 614. 4. Roth A, Bloch Y, Villa Y, Schlesinger Z, Laniado S, Kaplinsky E. The CB-12L: a new device for transtelephonic transmission of a 12-lead electrocardiogram. PACE 1997;20:2243–2247. 5. Myers MG, Reeves RA. White coat effect in treated hypertensive patients: sex differences. J Hum Hypertens 1995;9:729 –733. 6. Millar JA, Accioly JM. Measurement of blood pressure may be affected by an interaction between subject and observer based on gender. J Hum Hypertens 1996;10:449 – 453. 7. Le Pailleur C, Landais P. Role of physician-patient dialogue in the “white coat” effect in arterial hypertension. Reproducibility during the consultation. Existence despite of treatment. Ann Cardiol Angeiol (Paris) 1994;43:135–138. 8. Steptoe A, Fieldman G, Evans O, Perry L. Cardiovascular risk and responsivity to mental stress: the influence of age, gender and risk factors. J Cardiovasc Risk 1996;3:83–93. 9. Mansoor GA, McCabe EJ, White WB. Determinants of the white coat effect in hypertensive subjects. J Hum Hypertens 1996;10:87–92.
Loss of Bone Mineral in Patients With Cachexia Due to Chronic Heart Failure Stefan D. Anker, MD, PhD, Andrew L. Clark, MD, Mauro M. Teixeira, Paul G. Hellewell, MD, and Andrew J.S. Coats, DM he phenomenon of cardiac cachexia has been recognized for many centuries. Some degree of musT cle wasting is common even in mild heart failure and 1
2
is associated with a worsened prognosis.3 Osteoporosis in a group of patients awaiting transplantation has been reported.4 The etiology of weight loss remains unclear, but it may involve malnutrition5 and neurohormonal activation, with catabolic–anabolic imbalance6 and cytokine activation.7,8 We explored the extent and nature of possible changes in body composition, particularly to detect changes in bone density in patients having chronic heart failure with and without cachexia, using dual-energy x-ray absorptiometry (DEXA) to investigate the proportions of fat, bone, and muscle. •••
The study was approved by the ethics committee of the Royal Brompton Hospital, and all subjects gave fully informed, signed consent. Fifty-eight patients were recruited. Cachexia was prospectively defined as the presence of documented dry weight loss of $7.5% compared with previous normal body weight over a period of $6 months. The 18 cachectic patients had lost 15 6 1.6% (range 8% to 36%) of body weight, that is, 11.4 61.4 kg over 2.8 6 0.6 years. The noncachectic patients had no history of significant From the Departments of Cardiac Medicine and Applied Pharmacology, National Heart and Lung Institute, London, United Kingdom; and the Fronz-Volhard-Klinik at Max-Debruck-Centrum, Charite´, Campus Berlin-Buck, Berlin, Germany. Dr. Anker’s address is: Cardiac Medicine, NHLI, Dovehouse Street, London SW3 6LY, United Kingdom. Manuscript received March 25, 1998; revised manuscript received and accepted September 8, 1998.
612
©1999 by Excerpta Medica, Inc. All rights reserved.
MD,
weight loss in the previous 2 years. Sixteen agematched control subjects were recruited from a voluntary health check program (Table I). Chronic heart failure was diagnosed in the presence of exercise limitation due to fatigue or breathlessness of $6 months’ duration, with left ventricular systolic dysfunction. No patient was edematous. All had been clinically stable for at least the preceding 3 months. Patients with valvular heart disease, renal failure, or a history of excessive alcohol consumption were excluded. All cachectic patients and 36 noncachectic patients received diuretics. Four patients in the cachectic group and 7 in the noncachectic group did not receive angiotensin-converting enzyme inhibitors, and 9 and 12 patients in each group, respectively, were on digoxin. All subjects underwent maximal incremental treadmill exercise testing using a modified Bruce protocol, and metabolic gas exchange measurements were obtained. Venous blood was drawn for measurement of serum calcium, phosphate, albumin, and total protein. We also measured levels of interleukin-1b (IL-1b),9 interleukin-6 (IL-6),10 and tumor necrosis factor-a (TNF) and its 2 soluble receptors, TNFR-1 and TNFR-2. TNF was measured using an enzyme-linked immunosorbent assay with a lower limit of detection of 3.0 pg/ml (Medgenix, Fleurus, Belgium). We measured levels of IL-1b (sensitivity 0.1 pg/ml), TNFR-1 (25 pg/ml), TNFR-2 (2 pg/ml), and IL-6 (0.094 pg/ml) using test kits from R&D Systems (Minneapolis, Minnesota). Whole-body DEXA scans were performed the same day using a Lunar model DPX total-body scan0002-9149/99/$–see front matter PII S0002-9149(98)000927-8
plementary information, and obtaining BP measurements at home has gained popularity as a supplementary diagnostic tool. “Shahal,” a medical facility described previously,2– 4 is a service that currently has 44,000 subscribers. It introduced the “Telepress” program in which subscribers transmit, via telephone, a reading of their BP measurement from their home to the monitor center. The current study examines whether the “white coat” effect is applicable in the “Telepress” framework and if a patient’s awareness that the BP measurement transferred on-line to the monitor center contaminates the results. A secondary goal was to document the frequency of use of the Telepress by its subscribers and determine if there is a pattern related to the nature of the subscribers. •••
Thirty consecutive subscribers to SHAHAL were selected. Ten subscribers who were normotensive, did not have any known cardiovascular or other disease, and were not receiving any medical or supplemental treatment composed group A. The other 20 patients were known to have hypertension, for which they were being treated for at least 1 year before inclusion, 10 with b blockers (group B) and 10 with other antihypertensive medications (but not calcium antagonists or tranquilizers) (group C). All participants had regular sinus rhythm. Each subscriber to the blood pressure monitoring program of Shahal receives the Telepress device, which consists of a home-based unit for transtelephonic automatic transmission of BP readings as measured by an automatic oscillometric digital blood pressure meter (UA-731; Meridian, Seattle, Washington). Validation of the device was established by tests based on well-known reported methods. Simultaneous BP measurements were obtained by 50 randomly selected normotensive and hypertensive persons using the UA731 and a mercury sphygmomanometer using a Ttube. After the new member’s subscription to SHAHAL, a qualified medical technician instructs and trains the subject on use of the BP device at home. Subscribers are instructed to attach the arm cuff tightly around the From “SHAHAL” Medical Services, The Tel-Aviv Sourasky Medical Center, Sheba Medical Center, and the Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel. Dr. Roth’s address is: Tel-Aviv Sourasky Medical Center, 6 Weizman Street, Tel-Aviv, 64239, Israel. Manuscript received May 26, 1998; revised manuscript received and accepted September 8,1998.
610
©1999 by Excerpta Medica, Inc. All rights reserved.
MD
upper arm so that the bottom edge of the cuff is positioned 1 inch above the elbow joint. They are advised to perform the measurement quietly, while they are in a relaxed position, to avoid vibrating the instrument. Each BP reading consists of a set of 3 measurements taken at 30- to 60-second intervals. Each completed measurement is automatically transmitted transtelephonically to the monitor center, where an algorithm calculates the mathematic average. If the readings are not within the expected range, the results are displayed on a screen and a nurse will contact the subscriber to reassure and instruct him or her on what measures to take. If the readings are within normal limits, they will not be displayed but they will be stored in the subject’s medical record. At the end of every preset period (generally 3 to 4 months), or earlier when requested, a report that includes all readings and date and time of measurement will be mailed to the patient so that the information is available to the patient and his or her physician. After obtaining consent to participate in the study, subscribers were instructed to take 2 sets of blood pressure readings at the same time of the day for 10 consecutive days. In 1 set, the results were automatically transmitted transtelephonically to the monitor center. In the other set, the device was disconnected from the telephone and the patients entered the results of each individual measurement on a prepared form, which was mailed to the monitor center at the end of the study period. Subscribers were randomly assigned on an alternating daily basis as to which of the 2 measurement protocols they should use first. All Telepress transmissions for the entire membership body were retrieved from the central computer for frequency analysis to explore the subject’ patterns of transmissions. Data are reported as mean 6 1 SD. The Student paired t test was used to compare the 2 modes of measurements, and the 2-sample t test was used to compare differences between measurements and sexes. The Pearson correlation test was used to compare differences between measurements as a function of age. A p value ,0.05 was considered significant. The age of the 30 study patients was 59 6 9 years (range 42 to 72); 20 were men. All participants were in stable clinical and hemodynamic condition, without any concurrent disease at the time of measurement. There was no change in any subject’s medical regimen during the study period. No difference was observed among the entire study population between the group mean blood pressure 0002-9149/99/$–see front matter PII S0002-9149(98)00926-6
FIGURE 1. Mean blood pressure values. Group A 5 10 healthy normotensive subjects (not receiving any medical treatment); group B 5 10 patients with hypertension controlled by b-blocking agents; group C 5 10 patients with hypertension controlled by other antihypertensive medications (not calcium antagonists or tranquilizers).
that was measured and transmitted automatically (87 6 10 mm Hg) and the group mean blood pressure values that were not transmitted (87 6 10 mm Hg). Mean blood pressure values for groups A, B, and C are shown in Figure 1. Interestingly, only group B (patients treated with b blockers) demonstrated a difference associated with the mode of measurement. There were no sex-related differences in readings. When correlating the differences in blood pressure between the 2 modes of readings and age, it was found that the nontransmitted systolic (and calculated mean) BP readings tended to increase slightly with increasing age (Figure 2). A comparison between the mean systolic blood pressure readings of the first set of measurements with the second set revealed slightly higher readings in the former (120 6 14 vs 118 6 17 mm Hg, respectively; p 5 NS), regardless of whether they were transmitted. There are currently 5,486 subscribers to the Telepress program, with a monthly average of 1.8 transmissions of self-measured BP recordings. Fifteen percent of patients had been considered healthy (free of hypertension or other coronary risk factors): 88% of them used the Telepress only 0.33 times in 1 month. Twenty-five percent of patients with a cardiac history used the Telepress 1 to 5 times in 1 month, 3% used it 5 to 10 times, 2% used it 10 to 20 times, and 0.4% used it .20 times. The tendency to use the Telepress increased with increasing age for patients with any notable medical history but not for those in the healthy group. •••
Results of this study demonstrate that no white coat effect contaminated the validity of the Telepress system. This was true for both sexes, which contrasted to previously reported white coat effects on gender interaction.5,6 In addition, being completely automatic, a possible emotional element stemming from a dialogue between the patient and the intimidating medical personnel was obviated, so that measuring BP at home
FIGURE 2. Correlation of the differences in blood pressure between transmitted and nontransmitted self-measurement of blood pressure and age.
did not affect the results as might have occurred in a face-to-face situation.7 We have no explanation for the difference between observed and transmitted results in the group treated with b blockers, although it is possible that there was a b error attributable to the small number of patients. When the patient’s age was taken into account, we found that the transmission of results was associated with less excitement to the patients, as demonstrated by increasing differences between observed and transmitted results. This was more apparent in female subjects, as reported by others, to be gender specific.8,9 Home-based self-measurement should not be confused with the ambulatory automated BP measurement system that has justifiably gained popularity. Although there is some overlap between the information obtained by home and ambulatory monitoring, there are also important differences. Ambulatory monBRIEF REPORTS
611
itoring provides information about the diurnal profile of BP and has great advantages for trials investigating the time course of a particular drug. Self-measurement can provide repeated measurement in the same situation over prolonged periods of time and, therefore, is ideally suited for monitoring changes in BP induced by treatment or progression of the disease. In summary, the Telepress system circumvents direct contact between patient and medical staff. Our concern was that the patient knowing the transmission was simultaneously being “observed” in the monitor center might produce a pseudo white coat effect. In none of the parameters studied was there any indication that this element interfered with the validity of the results. Thus, this home-based self-measurement of BP is a potentially cost-effective way to improve BP control and therapeutic efficacy.
1. Brown GE. Daily and monthly rhythm in blood pressure of a man with hypertension. Ann Intern Med 1930;3:1177–1189. 2. Roth A, Herling M, Vishlitzki V, Aitkin I. The impact of “SHAHAL” (a new cardiac emergency service) on subscribers’ appeal for medical assistance: characteristics and distribution of calls. Eur Heart J 1995;16:129 –133. 3. Roth A, Malov N, Bloch Y, Schlesinger Z, Laniado S, Kaplinsky E. Selfadministration of intramuscular lidocaine in the pre-hospital setting: the “Shahal” experience in Israel. Am J Cardiol 1997;79:611– 614. 4. Roth A, Bloch Y, Villa Y, Schlesinger Z, Laniado S, Kaplinsky E. The CB-12L: a new device for transtelephonic transmission of a 12-lead electrocardiogram. PACE 1997;20:2243–2247. 5. Myers MG, Reeves RA. White coat effect in treated hypertensive patients: sex differences. J Hum Hypertens 1995;9:729 –733. 6. Millar JA, Accioly JM. Measurement of blood pressure may be affected by an interaction between subject and observer based on gender. J Hum Hypertens 1996;10:449 – 453. 7. Le Pailleur C, Landais P. Role of physician-patient dialogue in the “white coat” effect in arterial hypertension. Reproducibility during the consultation. Existence despite of treatment. Ann Cardiol Angeiol (Paris) 1994;43:135–138. 8. Steptoe A, Fieldman G, Evans O, Perry L. Cardiovascular risk and responsivity to mental stress: the influence of age, gender and risk factors. J Cardiovasc Risk 1996;3:83–93. 9. Mansoor GA, McCabe EJ, White WB. Determinants of the white coat effect in hypertensive subjects. J Hum Hypertens 1996;10:87–92.
Loss of Bone Mineral in Patients With Cachexia Due to Chronic Heart Failure Stefan D. Anker, MD, PhD, Andrew L. Clark, MD, Mauro M. Teixeira, Paul G. Hellewell, MD, and Andrew J.S. Coats, DM he phenomenon of cardiac cachexia has been recognized for many centuries. Some degree of musT cle wasting is common even in mild heart failure and 1
2
is associated with a worsened prognosis.3 Osteoporosis in a group of patients awaiting transplantation has been reported.4 The etiology of weight loss remains unclear, but it may involve malnutrition5 and neurohormonal activation, with catabolic–anabolic imbalance6 and cytokine activation.7,8 We explored the extent and nature of possible changes in body composition, particularly to detect changes in bone density in patients having chronic heart failure with and without cachexia, using dual-energy x-ray absorptiometry (DEXA) to investigate the proportions of fat, bone, and muscle. •••
The study was approved by the ethics committee of the Royal Brompton Hospital, and all subjects gave fully informed, signed consent. Fifty-eight patients were recruited. Cachexia was prospectively defined as the presence of documented dry weight loss of $7.5% compared with previous normal body weight over a period of $6 months. The 18 cachectic patients had lost 15 6 1.6% (range 8% to 36%) of body weight, that is, 11.4 61.4 kg over 2.8 6 0.6 years. The noncachectic patients had no history of significant From the Departments of Cardiac Medicine and Applied Pharmacology, National Heart and Lung Institute, London, United Kingdom; and the Fronz-Volhard-Klinik at Max-Debruck-Centrum, Charite´, Campus Berlin-Buck, Berlin, Germany. Dr. Anker’s address is: Cardiac Medicine, NHLI, Dovehouse Street, London SW3 6LY, United Kingdom. Manuscript received March 25, 1998; revised manuscript received and accepted September 8, 1998.
612
©1999 by Excerpta Medica, Inc. All rights reserved.
MD,
weight loss in the previous 2 years. Sixteen agematched control subjects were recruited from a voluntary health check program (Table I). Chronic heart failure was diagnosed in the presence of exercise limitation due to fatigue or breathlessness of $6 months’ duration, with left ventricular systolic dysfunction. No patient was edematous. All had been clinically stable for at least the preceding 3 months. Patients with valvular heart disease, renal failure, or a history of excessive alcohol consumption were excluded. All cachectic patients and 36 noncachectic patients received diuretics. Four patients in the cachectic group and 7 in the noncachectic group did not receive angiotensin-converting enzyme inhibitors, and 9 and 12 patients in each group, respectively, were on digoxin. All subjects underwent maximal incremental treadmill exercise testing using a modified Bruce protocol, and metabolic gas exchange measurements were obtained. Venous blood was drawn for measurement of serum calcium, phosphate, albumin, and total protein. We also measured levels of interleukin-1b (IL-1b),9 interleukin-6 (IL-6),10 and tumor necrosis factor-a (TNF) and its 2 soluble receptors, TNFR-1 and TNFR-2. TNF was measured using an enzyme-linked immunosorbent assay with a lower limit of detection of 3.0 pg/ml (Medgenix, Fleurus, Belgium). We measured levels of IL-1b (sensitivity 0.1 pg/ml), TNFR-1 (25 pg/ml), TNFR-2 (2 pg/ml), and IL-6 (0.094 pg/ml) using test kits from R&D Systems (Minneapolis, Minnesota). Whole-body DEXA scans were performed the same day using a Lunar model DPX total-body scan0002-9149/99/$–see front matter PII S0002-9149(98)000927-8