l'affaire de tous Centraliens no632 [mars/avril 2014] Le secteur de la santé, qui est la première source d'emploi en France, est en train de faire face à une mutation quantique que nous vivons en temps réel sans en sentir encore tous les effets. Ce dossier a pour objectif de vous ac- d'invalidité dans le monde (OMS, 2 002). compagner dans un voyage où vous L'industrie pharmaceutique a contribué découvrirez les éléments de cette signifi cativement à la lutte contre les mala-
Long-Term Use of Contraceptive Depot
Medroxyprogesterone Acetate in Young Women Impairs
Arterial Endothelial Function Assessed by Cardiovascular
Morten B. Sorensen, PhD; Peter Collins, MD; Paul J.L. Ong, MA; Carolyn M. Webb, PhD; Christopher S. Hayward, MD; Elizabeth A. Asbury, MSc; Peter D. Gatehouse, PhD; Andrew G. Elkington, MB, BS; Guang Z. Yang, PhD; Ali Kubba, MB, ChB; Dudley J. Pennell, MD Background—Depot medroxyprogesterone acetate (DMPA) inhibits proliferation of ovarian follicles, resulting in
anovulation and a decrease in circulating estrogen; the latter action is potentially disadvantageous to cardiovascularhealth. We therefore investigated the vascular effects of long-term contraceptive DMPA in young women.
Methods and Results—Endothelium-dependent (hyperemia-induced flow-mediated dilatation [FMD]) and -independent
(glyceryl trinitrate [GTN]) changes in brachial artery area were measured using cardiovascular magnetic resonance in13 amenorrheic DMPA users (⬎1 year use; mean age 29⫾4 years) and in 10 controls (mean age 30⫾4 years, P⫽0.25)with regular menstrual cycles after validation of the technique. FMD and GTN responses were measured just beforerepeat MPA injection and 48 hours later (n⫽12) in DMPA users and during menstruation and midcycle (n⫽9) incontrols. Serum-estradiol levels (S-estradiol) were measured at both visits. FMD was reduced in DMPA users comparedwith controls during menstruation (1.1% versus 8.0%, respectively P⬍0.01) without differences in GTN responses.
S-estradiol levels in DMPA users were significantly lower than in controls during menstruation (58 versus 96 pmol/L,P⬍0.01). High levels of circulating MPA 48 hours after injection were not linked to an additional impairment in FMD(2.0% versus 3.1%, P⫽0.23). Estradiol levels were significantly correlated to FMD (r⫽0.43, P⬍0.01).
Conclusions—Endothelium-dependent arterial function measured by cardiovascular magnetic resonance is impaired in
chronic users of DMPA, and hypoestrogenism may be the mechanism of action. DMPA might adversely affect
cardiovascular health, and in particular its use in women with cardiovascular disease should be additionally evaluated.
Key Words: endothelium 䡲 magnetic resonance imaging 䡲 women 䡲 heart disease
Depot medroxyprogesterone acetate (DMPA) is a widely ovarianfailurehavebeenlinkedtoacceleratedcardiovascular used long-acting contraceptive, given as a 150 mg IM disease. In addition to the possible adverse vascular effects of injection every 12 weeks. Contraception is achieved mainly follicular arrest, MPA may have unwanted effects on arterial via interference with the hypothalamic-pituitary-ovarian axis function. It has been suggested that MPA coadministration with inhibition of gonadotropin release at the pituitary level with estrogen for hormone replacement is linked to atheroma and subsequent anovulation.1,2 The induced follicular stagna- development,6 which might be attributed to adverse effects on tion is associated with decreased circulating estrogen,1 which the endothelium.7 In view of these data and the fact that has been linked to adverse effects on estrogen-sensitive DMPA is used for contraception in premenopausal women tissues.3,4 DMPA-induced hypoestrogenism might also affect with cardiovascular disease,8 we assessed the effects of vascular function. Estrogens have powerful vasoactive prop- long-term DMPA use on endothelial function.
erties that inhibit atheroma formation partly via endothelial Endothelium-dependent arterial relaxation9 is attributable effects.5 This may explain why oophorectomy and premature to endothelium-derived NO.10 In arteries lined by healthy Received May 1, 2002; revision received July 10, 2002; accepted July 11, 2002From the Cardiovascular MR Unit (M.B.S., P.D.G., A.G.E., G.Z.Y., D.J.P.), Royal Brompton Hospital, London; Cardiac Medicine (M.B.S., P.C., P.J.L.O., C.M.W., C.S.H., E.A.A., D.J.P.), Imperial College School of Medicine, London; Obstetrics and Gynaecology (M.B.S.), Hvidovre Hospital,University of Copenhagen, Denmark; and Obstetrics and Gynaecology (A.K.), Guys and St Thomas Hospital, London.
Peter Collins has been a recipient of grants and honoraria from Eli Lilly, Wyeth-Ayerst, Novo Nordisk, Solvay, Pharmacia, Bristol Myers Squibb, Organon, and Schering. Peter Collins is also a member of an executive committee and an advisory board for Eli Lilly and Wyeth-Ayerst, respectively.
Ali Kubba has received fees and expenses for lecturing and consultancies from pharmaceutical companies with contraceptive and hormone replacementtherapy products.
Correspondence to Professor Dudley Pennell, Cardiovascular MR Unit, Royal Brompton Hospital, Sydney St, London SW3 6NP, UK. E-mail 2002 American Heart Association, Inc.
Circulation is available at http://www.circulationaha.org
Sorensen et al
Depot MPA and Endothelial Function
Characteristics of 13 Amenorrheic Users of
Contraceptive Progestogen Injection (DMPA) and 10 Controls
Arterial function was assessed twice by CMR. In the DMPA users, With Regular Menstruation
CMR was timed in accordance with the injection regimen (justbefore repeat injection and 48 hours later at highest circulating levels of MPA).2 In controls, CMR was timed in accordance with the menstrual cycle. The first study was performed during the menstrual phase (cycle days 1 through 3, at the expected time of lowest Body mass index, kg 䡠 m⫺2 circulating estradiol levels), and the second study was performed Systolic blood pressure, mm Hg midcycle (two days before to day of ovulation, as calculated from Diastolic blood pressure, mm Hg expected day of subsequent period minus 14 days, at the expected time of highest circulating estradiol levels). CMR was performed Total cholesterol, mmol/L after a 6-hour fast, at the same time of the day, and after at least a HDL cholesterol, mmol/L half-hour sitting rest. Before the first study, all participants were Menopausal symptoms asked if they experienced any of the following complaints, which have been linked to estrogen deficiency: flushing, night sweats, Length of DMPA use, mo sleeplessness, abdominal weight gain, and vaginal dryness/atrophy.
Length of amenorhea, mo Estradiol levels were measured at both visits by radioimmunoassay.
The study was approved by the local ethics committee, and all Values are mean⫾SD.
subjects gave written informed consent.
*P⬍0.05 vs controls.
Validation and Reproducibility Studies
endothelium, blood flow increase causes NO release and To validate the CMR technique, we studied 8 male patients referred arterial dilatation. The degree of arterial dilatation in response for diagnostic coronary angiography (mean age 58⫾8 years). These to an increase in blood flow is used as an index of endothelial subjects underwent measurement of BAR by CMR, intravascular functional integrity. Endothelial dysfunction is associated ultrasound (IVUS), and external ultrasound (EXUS). The EXUS and with early atheroma formation and is linked to an increase infuture cardiac events.11,12 Celermajer et al13 described the useof external ultrasound imaging (EXUS) to measure flow-mediated dilatation (FMD) and nitrate-induced dilatation ofthe brachial artery (BA) (together brachial artery reactivity[BAR]) as a marker of vascular endothelial and nonendothe-lial function, respectively. However, reports have questionedthe accuracy and sensitivity of the method.14,15 Cardiovascu-lar magnetic resonance (CMR) is increasingly being used toassess cardiovascular function, and recent improvements inspatial resolution and tissue differentiation make CMR veryreproducible.16 When using CMR, two-dimensional imagingof the arterial cross section is achieved compared withone-dimensional imaging with EXUS.
The aim of the present study was to investigate, in premenopausal women without known risk of endothelialdysfunction, the effect of chronic DMPA use on endotheli-um-dependent and -independent arterial function measuredby CMR.
Thirteen long-term DMPA users (mean age 29⫾4 years) and 10
controls (mean age 30⫾4 years) with a regular menstrual cycle and
no intake of progestogens were enrolled. Only DMPA users for ⬎1
year with long-lasting (⬎1 year) secondary amenorrhea were in-
cluded. It was ensured that DMPA users had regular menstrual
cycles before commencing DMPA, were not under ideal body weight
(BMI ⬎19), and did not have a history of eating disorder or
excessive exercise performance. Neither DMPA users nor controls
had been prescribed estrogens or other vasoactive medication up to
3 months before inclusion, and they were excluded if any of the
Figure 1. The upper image shows the set up for CMR. The sur-
following factors known to cause endothelial dysfunction were face coil (arrow) and the cuff are mounted. Movement is inhib- present: coronary artery disease (CAD), diabetes, habitual cigarette ited by sand bags. A, Baseline transaxial image of the brachial smoking, hypertension, dyslipidemia, obesity (BMI ⬎31), or a artery (curved arrow) in a healthy subject. The artery appears family history of CAD in a first-degree relative ⬍55 years of age.
oval. B through D, Series of images in a healthy subject. B, Total cholesterol and HDL cholesterol levels were measured at Baseline image; C, During peripheral reactive hyperaemia; and inclusion in all subjects, and normal values were a requirement for D, After a sublingual dosage of GTN. Note the significant inclusion. Patient characteristics are shown in Table 1.
increase in area of the brachial artery (arrows).
September 24, 2002
Comparison of Test-Retest Repeatability of CMR and EXUS for
Measurement of Arterial Cross-Sectional Diameter/Area, FMD, and GTN Response
Mean Difference⫾SD of 2 Measurements Baseline parameter EXUS diameter, mm Flow-mediated dilatation Response to glyceryl trinitrate The coefficient of variability by CMR is significantly lower than by EXUS.
*P⬍0.05, compared with CMR area.
IVUS measurements were performed simultaneously after diagnostic Measurement of arterial function by EXUS was performed by a coronary angiography, and CMR was performed a few days later.
standard technique, as previously described.17 The study group is The subjects were examined fasting and were asked to withhold experienced with the EXUS technique.17,18 Two EXUS observers vasoactive medication for 24 hours before examinations. CAD was performed the data collection; one (P.O.) collected data for the defined as at least one significant coronary artery stenosis with validation studies, and another (E.A.) collected data for the repro- ⬎70% reduction in calibre, as assessed by an independent cardiol- ducibility and repeatability comparisons in the healthy volunteers.
ogist. To compare BAR measurements by CMR and EXUS, in 11 To compare EXUS and CMR directly, the derived area from EXUS healthy males (mean age 32⫾3 years), we performed one study by diameter (d) was also calculated by (d/2)2.
each of the two methods on separate days, less than 1 week apart. Tocompare repeatability of BAR by CMR and EXUS, we performed repeated measurements in 7 subjects, who had a total of 4 measure- A paired/unpaired t test was used for intrasubject and group ments of FMD and GTN responses.
comparisons of effects. Pearson's correlation coefficient was usedfor assessment of association after logarithmic transformation of Measurement of Arterial Reactivity
estradiol levels. The coefficient of variability (CV) was calculated as BAR was measured using 3 different imaging techniques: CMR, the SD of the difference of repeated measures divided by the mean IVUS, and EXUS. CMR measurement of BA area was performed at measurement value. The repeatability of the 2 methods was com- baseline and 1 minute after reactive hyperemia was induced byrelease of a forearm cuff inflated to suprasystolic pressure for 5minutes. Measurement of non– endothelium-dependent vascular re-activity was performed by imaging before and 3 minutes after 400 g sublingual GTN. The BA was imaged with high-resolution CMRusing the following parameters: a segmented FLASH gradient echosequence; 8 views per segment; TE 14 ms; field of view 7⫻3.5 cm;matrix size 256⫻128, pixel size 0.27⫻0.27 mm, and acquisition time12 cardiac cycles; and diastolic trigger delay. Imaging was per-formed with a 1.5T Picker Edge scanner with a small loop surfacecoil attached to the right elbow (left elbow in validation studies). Theimaging position was reproduced by using the transaxial plane wherethe BA was most superficial, and perpendicular position was assuredby 3-dimensional piloting (Figure 1). BA area was measuredobjectively by tracking of the arterial region of interest by in-housedeveloped autosegmentation software. The BA area at the intimalborder was delineated automatically in triplicate and the area wasaveraged (CMRtools, Imperial College). Because each scan wasidentifiable via a unique number, batch analysis was performedblinded in random order after completing the studies.
Measurement of arterial function by IVUS was performed after diagnostic coronary angiography. A 3F 20-MHz IVUS probe (En-dosonics Visions-Five-64) was positioned in the left BA. Measure- Figure 2. Differences in endothelium-dependent (FMD) and en-
ment of BA area was made at baseline and 1 minute after reactive dothelium-independent (GTN) arterial reactivity in long-term hyperaemia (induced by release of a forearm cuff inflated to users of DMPA and healthy controls. FMD and GTN are both suprasystolic pressure for 5 minutes). Non– endothelium-dependent assessed by measurement of area changes by cardiovascular BA responses were then measured 3 minutes after 300 g intrabra- magnetic resonance. FMD in the DMPA patients is significantly chial isosorbide dinitrate. Measurements were performed in triplicate impaired compared with controls, whereas the GTN responses using planimetry by an independent investigator.
Sorensen et al
Depot MPA and Endothelial Function
Repeated Measurements of FMD and GTN
in CAD patients compared with non-CAD patients Response by CMR Area and S-oestradiol Levels in DMPA Users
(0.5⫾0.7% versus 1.9⫾2.5%, P⫽0.29).
Reproducibility and Repeatability of CMR for
Assessment of Arterial Reactivity
The mean difference between 2 blinded measurements (in-traobserver variability) of area and FMD by CMR with the same observer (M.S.) was 0.00⫾0.14 mm2 and 0.29⫾1.5%, respectively. The mean difference between blinded measure- ments (interobserver variability) of BA area and FMD by 2 DMPA users (n⫽12) observers (M.S. and A.E.) was 0.04⫾0.21 mm2 and 0.48⫾2.2%, respectively. Test-retest repeatability (interstudy 48 Hours after injection reproducibility) was significantly better by CMR than by Values are mean⫾SD.
EXUS (Table 2). The more reproducible assessment of FMD Menstruation: First measurement was performed at cycle day 1 to 4.
by CMR results in the need for smaller sample sizes when Ovulation: Second visit was performed from ⬍2 days before the calculated day FMD change is assessed. We calculated that to perform our of ovulation, on the basis of average cycle length.
study using EXUS diameter and EXUS area would have *P⬍0.05 vs previous measurement.
required a total of 158 and 672 subjects, respectively.
†P⬍0.05 vs controls.
Subjects for DMPA Study
pared by performing a 2-tailed paired t test on the logged squared One control subject decided to start DMPA after the first test-retest differences (Bland JM. Comparing within-subject vari- CMR examination and was withdrawn from the rest of the ances in a study to compare two methods of measurement. Availableat: http://www.sghms.ac.uk/depts/phs/staff/jmb/compsd.htm. Ac- study. One long-term user of DMPA decided not to have her cessed July 25, 2002). Data are presented as mean⫾SD, and P⬍0.05 repeat injection after the first scan and was subsequently was considered significant.
withdrawn from the rest of the study.
We calculated the required sample sizes to detect significant differences in FMD by CMR based on our reproducibility data DMPA Study
(Table 2). It has previously been shown that hypoestrogenism in FMD was significantly reduced in DMPA users compared premenopausal women treated with a GnRH agonist is linked to a10% reduced FMD measured by EXUS.19 A sample size of 20 with controls during menstruation (1.1⫾3.0% versus subjects (10 subjects in each group) would be required to detect by 8.0⫾4.8%, P⬍0.01, Figure 2), with no differences in GTN CMR a 3% difference in FMD between DMPA and control groups responses (40⫾10% versus 42⫾18%, P⫽0.38). FMD differ- with ␣⫽0.05 and a power of 90%.
ences between the two groups were paralleled by differencesin S-estradiol levels (57.8⫾31.3 versus 95.6⫾30.1 pmol/L, P⬍0.01). Comparing FMD and S-estradiol levels before and Validation of CMR for Assessment of
at peak concentration of circulating MPA in DMPA users with repeated measurements (n⫽12), changes corresponded CMR measurements of BA area at baseline correlated to without significant changes of both variables (Table 4). In IVUS measurements (21.3⫾5.8 versus 24.1⫾6.6 mm2, controls with 2 measurements (n⫽9), FMD was significantly r⫽0.87, P⬍0.01). The CMR and IVUS measurements of less in the menstrual phase compared with midcycle, with no BAR also correlated (r⫽0.87, P⬍0.01). Five of the 8 patients effect on GTN responses, and the change in FMD was again (62.5%) had coronary artery disease (triple-vessel coronary paralleled by changes in S-estradiol levels (Table 4). In the disease in 4 and isolated LAD stenosis in 1 patient). FMD by entire sample size of healthy premenopausal women and CMR was significantly less in patients with CAD compared correlating all corresponding data sets, S-estradiol levels with patients without CAD (⫺3.6⫾2.4% versus 5.0⫾1.7%, correlated significantly to FMD (r⫽0.43, P⬍0.01). Three P⬍0.01), with no difference in GTN responses. The signifi- DMPA users (23%), but none of the controls, experienced cance was not reproduced by IVUS (⫺3.7⫾4.1% versus symptoms linked to estrogen deficiency (Table 1).
⫺1.0⫾5.4%, P⫽0.22) with the same sample size. There wereno significant differences between non-CAD and CAD pa- tients with regard to total cholesterol (5.4⫾0.7 and Long-term use of DMPA results in endothelial dysfunction, 5.3⫾0.6 mmol/L, P⫽0.42), mean blood pressure (107⫾18 which may result from hypoestrogenism. Both FMD, an and 98⫾8 mm Hg, P⫽0.16), and age (55⫾6 years versus indicator of endothelial function, and S-estradiol were signif- 60⫾10 years, P⫽0.23).
icantly reduced in users of DMPA compared with menstru- In the 8 patients assessed by CMR, there was significant ating controls. To our knowledge, this is the first investiga- noncircularity of the BA cross-section with major and minor tion of the effects of DMPA, and indeed any contraceptive diameters of 4.8⫾0.9 and 4.3⫾0.6 mm (P⬍0.01). The progestogen, on vascular reactivity in young women. A noncircularity was confirmed by IVUS.
similar study showed no negative endothelial effects of The BAR measured by IVUS correlated with EXUS estrogen-progestogen oral contraceptives.20 Whether these (r⫽0.57, P⬍0.05). Using EXUS in the same sample size, we findings can be extrapolated to other ovulation-inhibiting were not able to demonstrate a significant reduction in FMD progestogen-only contraceptive methods and correspond to
September 24, 2002
an increase in cardiovascular morbidity requires additional values often reported; however, the CV was comparable with that reported by other groups.26 We have previously reported Estrogens display a variety of their cardiovascular effects better repeatability of EXUS measurements by another oper- via the endothelium.5 Increased production of endothelial NO ator (mean interstudy difference, 1.40⫾0.95%),18 and differ- has been accredited to estrogen-induced genomic and non- ences in repeatability have also been reported from other genomic activation of nitric oxide synthase.21 FMD increases centers (CV of FMD responses, 0.62 and 1.28, respective- with estrogen replacement after the menopause,22 and FMD ly).26,27 The latter variation in repeatability with EXUS might reduction has been shown with drug-induced hypoestro- be related to selection of subjects and confounding factors, genism (GnRH agonist) in healthy premenopausal women.19 but might also be related directly to the imaging technique.
Our results suggest that the level of S-estradiol is a determi- Measurement of cross-sectional area by CMR versus diame- nant of endothelial function in healthy premenopausal ter by EXUS avoids the inherent problem of identifying an women. DMPA users presented with lower cholesterol levels exact diameter of a blood vessel, thus improving the repeat- than controls, which may be a direct effect of DMPA.23 It is ability.13 The cross section of the brachial artery is not always possible that DMPA-induced metabolic changes may have circular but often oval (Figure 1), raising the possibility that had adverse effects on the endothelium in our study.
dilatation may not occur uniformly in all directions. At least The estrogen levels in DMPA users were in the postmeno- in part, these factors may explain differences between the pausal range, similar to other reports.1 DMPA-induced hy- techniques. The improved repeatability using CMR allows poestrogenism is of concern with regard to osteoporosis risk,4 smaller sample sizes for research studies.
and loss of bone mass with DMPA has been demonstrated.24However, no study has demonstrated increase in fracture incidence in DMPA users. Our results do not provide direct Study data were acquired in a small number of subjects and evidence that DMPA is linked to CAD. Limited epidemio- in a nonrandomized fashion because of the obvious ethical logical evidence of progestogen contraception has not dem- problems of using placebo in a contraceptive study. The onstrated such an effect.25 A case-control study reported no application of CMR to measure arterial reactivity is limited difference in odds ratio (OR) of progestogen use in cardio- by cost and availability of equipment; however, the improved vascular disease.25 However, only 37 cases and 122 controls sensitivity and repeatability will enhance data quality and used injectable progestogen (about 1% of the study popula- reliability in comparison with EXUS.
tion), limiting the power of the conclusions that may bedrawn from this study. Additionally, most users of progestogen-only contraception used oral preparations, where Long-term use of DMPA for contraception is linked to hypoestrogenism is probably less pronounced, because con- impaired brachial artery endothelial function and hypoestro- traception is achieved mainly via endometrial and cervical genism. These findings may have clinical implications, in effects. It may be important to differentiate cardiovascular particular with regard to the prevailing recommendation to risk in users of progestogen-only contraception dependent on use DMPA in women with cardiovascular disease.
intrinsic estrogen levels. The incidence of cardiovascular disease in cases and controls with hypertension was signifi- This work was supported by the Coronary Artery Disease Research cantly greater in users of injectable progestogen than in Association—The Heart Charity, and Wellcome Trust. Dr Sorensen nonusers (OR 7.2; CIs, 1.32 to 38.7). Although our study was supported by The Kodan Grant, The Viliam Christiansen Grant, reports important observations, additional evidence is re- a grant from Pfizer, The Eva and Robert Hansens Grant, the Danish quired to establish causality.
Medical Research Council, and University of Copenhagen.
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Benutzerinformation 3. KurzbeschreibungDas DE04 und das DE10 sind absolute, elektronische Positionsanzeigen. Die werkseitig vorprogram-mierten Anzeigen in Hohlwellenbauform dienen DE04; DE10 zur direkten Ablesung von Positionswerten an Ver- stellspindeln.Durch höhere Auflösung und Genauigkeit, ein güns-tigeres Drehzahlverhalten, sowie weitere Funkti-