The Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) study: design and baseline characteristics

Extensive early mineralization of pre-osteoblasts, inhibition of osteoclastogenesis and faster peri-implant bone healing in osteoporotic rat model: principle effectiveness of bone-specific delivery of Tibolone as evaluated in vitro and in vivo

Hydrophobic drug molecules pose a significant challenge in immobilization on super-hydrophobic metallic surfaces like conventional titanium implants. Pre-coating surface modifications may yield a better platform with improved wettability for such purposes. Such modifications, as depicted in this study, were hypothesized to provide the requisite roughness to assist deposition of polymers like silk fibroin (SF) as a drug-binding matrix in addition to significant improvement in early protein adsorption, which facilitates faster cellular adhesion and proliferation. A silk-based localized drug delivery module was developed on the titanium surface and tested for its surface roughness, wettability, biocompatibility and in vitro differentiation potential of cells cultured on the coated metallic surfaces with/without external supplementation of the active metabolite of Tibolone. Conditioning of the matrix-coated implants with osteogenic as well as osteoclastogenic media supplemented with Tibolone stimulated the expression of early osteogenic gene and calcium deposition in the extracellular matrix. Significant inhibition in resorptive activity was also observed in the presence of the drug. To assess the efficacy of localized delivery of Tibolone via topographically modified titanium implants for inducing early peri-implant bone formation, osteoporosis was artificially induced in rats subjected to bilateral ovariectomy and implants were placed thereafter. Bone-specific release of Tibolone through the biomimetic matrix in osteoporotic rats collectively indicated significant improvement in peri-implant bone growth after 2 and 4 weeks (p < 0.05 compared to dummy-coated implants). These findings demonstrate for the first time that Tibolone released from SF matrix-coated implants can accelerate the biological stability of bone fixtures.

The Association of Self-Reported Muscle-Strengthening Activities With Carotid Intima-Media Thickness in Older Adults: Cooper Center Longitudinal Study

The purpose of the current investigation was to examine the cross-sectional associations of participation in muscle-strengthening activities (MSAs) with carotid intima-media thickness (CIMT) among older adults. The data are from 2,557 older adult participants enrolled in an observational cohort who reported no history of cardiovascular disease. MSA was determined using a questionnaire. Carotid ultrasound was performed to measure the CIMT of the common carotid artery bilaterally. Logistic regression models were constructed to estimate the association of MSA with CIMT after adjustment for potential confounders. The participants were aged 68.6 ± 7.0 years, and the majority were male (71.7%) and White (96.5%); 18% had abnormal CIMT. Meeting the physical activity guidelines for MSA was inversely associated with abnormal CIMT after adjustment for age and sex. However, this observed inverse relation became statistically null after further adjustment for cardiovascular disease risk factors, including aerobic physical activity.

Carotid Intima-Media Thickness Progression as Surrogate Marker for Cardiovascular Risk: Meta-Analysis of 119 Clinical Trials Involving 100 667 Patients

BACKGROUND

To quantify the association between effects of interventions on carotid intima-media thickness (cIMT) progression and their effects on cardiovascular disease (CVD) risk.

METHODS

We systematically collated data from randomized, controlled trials. cIMT was assessed as the mean value at the common-carotid-artery; if unavailable, the maximum value at the common-carotid-artery or other cIMT measures were used. The primary outcome was a combined CVD end point defined as myocardial infarction, stroke, revascularization procedures, or fatal CVD. We estimated intervention effects on cIMT progression and incident CVD for each trial, before relating the 2 using a Bayesian meta-regression approach.

RESULTS

We analyzed data of 119 randomized, controlled trials involving 100 667 patients (mean age 62 years, 42% female). Over an average follow-up of 3.7 years, 12 038 patients developed the combined CVD end point. Across all interventions, each 10 μm/y reduction of cIMT progression resulted in a relative risk for CVD of 0.91 (95% Credible Interval, 0.87-0.94), with an additional relative risk for CVD of 0.92 (0.87-0.97) being achieved independent of cIMT progression. Taken together, we estimated that interventions reducing cIMT progression by 10, 20, 30, or 40 μm/y would yield relative risks of 0.84 (0.75-0.93), 0.76 (0.67-0.85), 0.69 (0.59-0.79), or 0.63 (0.52-0.74), respectively. Results were similar when grouping trials by type of intervention, time of conduct, time to ultrasound follow-up, availability of individual-participant data, primary versus secondary prevention trials, type of cIMT measurement, and proportion of female patients.

CONCLUSIONS

The extent of intervention effects on cIMT progression predicted the degree of CVD risk reduction. This provides a missing link supporting the usefulness of cIMT progression as a surrogate marker for CVD risk in clinical trials.

The Association of Physical Activity With Carotid Intima Media Thickening in a Healthy Older Population: Cooper Center Longitudinal Study

The purpose of this study was to examine the association between self-reported physical activity (PA) and mean common carotid artery intima-media thickness (CCA IMT) among older adults. The data are from 1,811 Cooper Center Longitudinal Study participants, who were aged ≥60 years, with no history of cardiovascular disease. A medical history questionnaire was used to assess PA. Carotid ultrasound was performed to measure CCA IMT and the presence of plaque and stenosis. Logistic regression models were constructed to estimate the association between PA and CCA IMT after adjustment for covariates. The participants were aged 69.2 ± 5.9 years, and the majority were male (73.3%) and White (96.7%). The odds ratio of abnormal thickening of CCA IMT was 0.72 (95% confidence interval [0.54, 0.96]) in physically active participants (≥500 metabolic equivalent·min/week) after adjustment for covariates. In the current study, meeting PA guidelines in older adulthood was associated with lower odds of abnormal thickening of CCA IMT.

The association of midlife cardiorespiratory fitness with later life carotid atherosclerosis: Cooper Center Longitudinal Study

BACKGROUND AND AIMS

While numerous cross-sectional studies have demonstrated an inverse relationship between cardiorespiratory fitness (CRF) and carotid atherosclerosis in middle age, much less is known about the association of midlife CRF with carotid atherosclerosis in later life.

METHODS

We studied 1094 participants, free of cardiovascular disease, who completed a maximal exercise test (GXT) for an objective measure of CRF between ages 40 and 59 and carotid ultrasound after the age of 59, with at least five years between studies. Carotid intima media thickness was measured. Assessments were also made regarding the presence of plaque and percent stenosis in four regions: common carotid, bulb, internal carotid and external carotid arteries. Multivariable logistic regression models were constructed to estimate the association of CRF with carotid artery disease.

RESULTS

At the time of GXT and carotid scan, participants were aged 50.7 ± 5.7 years and 69.3 ± 6.4 years, respectively. Almost half of participants had high midlife CRF (48.6%); 41.3% and 10.1% had moderate and low CRF, respectively. Over a mean follow-up period of 18.6 ± 8.5 years, the odds of having carotid artery disease in later life in the high CRF group was 0.50 (95% CI: 0.29-0.87) compared with the low CRF group. Each 1 MET increase in CRF was associated with 10% lower odds of having carotid artery disease (OR = 0.89, 95% CI: 0.80-0.98).

CONCLUSIONS

Midlife CRF was inversely associated with carotid artery disease measured almost two decades later. This may represent a mechanistic link between high midlife CRF and reduced risk of stroke in later life.

Carotid Intima-media Thickness Measurements: Relations with Atherosclerosis, Risk of Cardiovascular Disease and Application in Randomized Controlled Trials

Advances in the field of carotid ultrasound have been incremental, resulting in a steady decrease in measurement variability. Improvements in edge detection algorithms point toward increasing automation of CIMT measurements. The major advantage of CIMT is that it is completely noninvasive and can be repeated as often as required. It provides a continuous measure since all subjects have a measurable carotid wall. It is also relatively inexpensive to perform, and the technology is widely available. A graded relation between raising LDL cholesterol and increased CIMT is apparent. Increased CIMT has been shown consistently to relate the atherosclerotic abnormalities elsewhere in the arterial system. Moreover, increased CIMT predicts future vascular events in both populations from Caucasian ancestry and those from Asian ancestry. Furthermore, lipid‑lowering therapy has been shown to affect CIMT progression within 12–18 months in properly designed trials with results congruent with clinical events trials. In conclusion, when one wants to evaluate the effect of a pharmaceutical intervention that is to be expected to beneficially affect atherosclerosis progression and to reduce CV event risk, the use of CIMT measurements over time is a valid, suitable, and evidence‑based choice.

Hormone therapy in postmenopausal women and risk of endometrial hyperplasia

BACKGROUND

Reduced circulating estrogen levels around the time of the menopause can induce unacceptable symptoms that affect the health and well-being of women. Hormone therapy (both unopposed estrogen and estrogen/progestogen combinations) is an effective treatment for these symptoms, but is associated with risk of harms. Guidelines recommend that hormone therapy be given at the lowest effective dose and treatment should be reviewed regularly. The aim of this review is to identify the minimum dose(s) of progestogen required to be added to estrogen so that the rate of endometrial hyperplasia is not increased compared to placebo.

OBJECTIVES

The objective of this review is to assess which hormone therapy regimens provide effective protection against the development of endometrial hyperplasia or carcinoma.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2012), The Cochrane Library (Issue 1, 2012), MEDLINE (1966 to January 2012), EMBASE (1980 to January 2012), Current Contents (1993 to May 2008), Biological Abstracts (1969 to 2008), Social Sciences Index (1980 to May 2008), PsycINFO (1972 to January 2012) and CINAHL (1982 to May 2008). Attempts were made to identify trials from citation lists of reviews and studies retrieved, and drug companies were contacted for unpublished data.

SELECTION CRITERIA

Randomised comparisons of unopposed estrogen therapy, combined continuous estrogen-progestogen therapy, sequential estrogen-progestogen therapy with each other or placebo, administered over a minimum period of 12 months. Incidence of endometrial hyperplasia/carcinoma assessed by a biopsy at the end of treatment was a required outcome. Data on adherence to therapy, rates of additional interventions, and withdrawals owing to adverse events were also extracted.

DATA COLLECTION AND ANALYSIS

In this update, 46 studies were included. Odds ratios (ORs) were calculated for dichotomous outcomes. The small numbers of studies in each comparison and the clinical heterogeneity precluded meta-analysis for many outcomes.

MAIN RESULTS

Unopposed estrogen is associated with increased risk of endometrial hyperplasia at all doses, and durations of therapy between one and three years. For women with a uterus the risk of endometrial hyperplasia with hormone therapy comprising low-dose estrogen continuously combined with a minimum of 1 mg norethisterone acetate (NETA) or 1.5 mg medroxyprogesterone acetate (MPA) is not significantly different from placebo at two years (1 mg NETA: OR 0.04; 95% confidence interval (CI) 0 to 2.8; 1.5 mg MPA: no hyperplasia events).

AUTHORS' CONCLUSIONS

Hormone therapy for postmenopausal women with an intact uterus should comprise both estrogen and progestogen to reduce the risk of endometrial hyperplasia.

Biologically implausible carotid intima-media thickness measurement values: effects on rate of change over time

OBJECTIVE

Carotid intima-media thickness (CIMT) is a marker of atherosclerosis that is commonly used to assess the effect of therapeutic interventions. It is currently unclear to what extent biologically implausible values affect treatment effects. We evaluated the impact of biologically implausible CIMT values on the estimated rate of change in CIMT.

METHODS

Data were used from the METEOR (Measuring Effects on Intima-media Thickness: an Evaluation of Rosuvastatin) trial. METEOR was a randomized, placebo-controlled trial showing that rosuvastatin reduced the 2-year change in CIMT among low-risk individuals with subclinical atherosclerosis. In the main METEOR analysis, the data were analyzed without exclusion of biologically implausible data. In this post-hoc analysis, we constructed twelve definitions to define mildly or extremely biologically implausible values using distance from the interquartile range, median or mean. We evaluated the effect of removing implausible values on the estimated rate of change in CIMT.

RESULTS

The percentage of biologically implausible CIMT values ranged from 0.6% to 9.7%, depending on the definition used. Across all definitions, removal of biologically implausible CIMT values marginally reduced standard errors and did not change the primary outcome (i.e., a nonsignificant change in the rosuvastatin group, significant progression in the placebo group, and a statistically significant difference between treatment groups).

LIMITATION

This study was focussed on the impact of implausible values in the analytical part of a CIMT study. Ultrasound images were not re-examined to determine whether an implausible measurement was due to measurement error or temporal morphological thickening,

CONCLUSION

Removal of biologically implausible CIMT values marginally decreased the variability of the estimated rate of change in CIMT without having a large impact on the estimated rate of change.

Carotid intima–media thickness: a suitable alternative for cardiovascular risk as outcome?

BACKGROUND

Surrogate markers for cardiovascular disease might be of great value in observational research, clinical trials, and clinical practice. Carotid intima-media thickness (CIMT) is probably the most commonly used marker for atherosclerotic disease as an alternative for cardiovascular morbidity and mortality. A suitable marker for atherosclerosis, however, should meet several criteria before it can be validly used.

METHODS AND RESULTS

We reviewed the literature following a set of criteria for a surrogate marker. These include a comparison with a 'gold standard'; adequate reproducibility; cross-sectional relations with established risk factors and prevalent disease; relations with severity of atherosclerosis elsewhere in the arterial system; relations with the occurrence with future events; ability for a biomarker to change over time; ability to be affected by interventions over time; and relations between change over time in biomarker level and change in risk. A large number of studies from a variety of populations provide evidence for the validity of CIMT as a suitable measure of atherosclerotic disease. Data on the relation between change in CIMT and change in risk, however, is much sparser.

CONCLUSION

CIMT progression meets the criteria of a surrogate for cardiovascular disease endpoints and may be considered as a valid alternative for cardiovascular events as outcome. Further studies should examine the association between changes in CIMT and changes in risk for future events.

Asymmetrical distribution of atherosclerosis in the carotid artery: identical patterns across age, race, and gender

BACKGROUND

Small autopsy studies and clinical practice indicated that carotid atherosclerosis develops in an asymmetrical helical pattern coinciding with regions of low shear stress. We investigated the distribution of carotid atherosclerosis as determined by maximum carotid intima-media thickness (CIMT), to assess if we could confirm this atherosclerotic configuration across various populations with different cardiovascular risk.

METHODS AND RESULTS

We used the individual baseline CIMT data from 3364 subjects from four recent international multicentre randomized controlled trials in which the carotid artery was systematically examined using the same ultrasound protocol and method to quantify CIMT. For each subject, circumferential information on the maximum CIMT of the left and right carotid arteries was obtained for the common carotid, bifurcation, and internal carotid artery segments. In each segment (common, bifurcation, internal), mixed modelling was used to study the differences in CIMT between angles, sides, gender, age, race, and studies. Each segment showed a different circumferential CIMT pattern. In all segments there were statistically significant differences between maximum CIMT across circumferential angles (p < 0.001); on average CIMT was highest in the posteromedial wall of the bifurcation and internal carotid segments and in the anterolateral wall of the common carotid segment. This asymmetric circumferential pattern was found to be identical in men and women, in young and old age, in different race groups, and across the studies.

CONCLUSIONS

We confirmed the asymmetrical helix-like distribution of atherosclerosis in the carotid arteries and expand the evidence by showing that the atherosclerotic configuration is similar across populations with different vascular risks and across gender, age, and race. This has implications for future design of carotid ultrasound studies, as the angle of insonation is an important predictor of maximum CIMT.

Effects of tibolone on blood flow resistance and intima-media thickness of the carotid arteries: effect of time since menopause

OBJECTIVE

The aim of this prospective study was to evaluate the effects of tibolone on carotid atherosclerosis in healthy postmenopausal women.

METHODS

Twenty-five healthy postmenopausal women were included in the study. Patients received tibolone 2.5 mg daily for 6 months. Resistance indices of the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA) and vertebral arteries, and intima-media thickness of the CCA were measured both at baseline and at the end of the study with ultrasonography.

RESULTS

No significant differences were observed in the resistance indices of the CCA, ICA, ECA and vertebral arteries, as well as intima-media thickness of CCA at 6 months in comparison with baseline. Tibolone significantly improved the intima-media thickness of the CCA of women who were less than 18 months since menopause.

CONCLUSION

Overall, these results demonstrate no significant effects of tibolone on either intima-media thickness or blood flow resistance in the carotid arteries in postmenopausal women. However, the results suggest that tibolone may have a positive effect on the vascular system if commenced within 18 months since menopause; this warrants further investigation.

Premature atherosclerosis in pediatric systemic lupus erythematosus: risk factors for increased carotid intima-media thickness in the atherosclerosis prevention in pediatric lupus erythematosus cohort

OBJECTIVE

To evaluate risk factors for subclinical atherosclerosis in a population of patients with pediatric systemic lupus erythematosus (SLE).

METHODS

In a prospective multicenter study, a cohort of 221 patients underwent baseline measurements of carotid intima-media thickness (CIMT) as part of the Atherosclerosis Prevention in Pediatric Lupus Erythematosus (APPLE) trial. SLE disease measures, medications, and traditional risk factors for atherosclerosis were assessed. A standardized protocol was used to assess the thickness of the bilateral common carotid arteries and the mean maximal IMT of 12 segments. Univariable analysis identified potential associations with CIMT, which were examined in multivariable linear regression modeling.

RESULTS

Based on the mean-mean common or the mean-max CIMT as the dependent variable, univariable analysis showed significant associations of the following variables with increased CIMT: increasing age, longer SLE duration, minority status, higher body mass index (BMI), male sex, increased creatinine clearance, higher lipoprotein(a) level, proteinuria, azathioprine treatment, and prednisone dose. In multivariable modeling, both azathioprine use (P=0.005 for the mean-mean model and P=0.102 for the mean-max model) and male sex (P<0.001) were associated with increases in the mean-max CIMT. A moderate dosage of prednisone (0.15-0.4 mg/kg/day) was associated with decreases in the mean-max CIMT (P=0.024), while high-dose and low-dose prednisone were associated with increases in the mean-mean common CIMT (P=0.021) and the mean-max CIMT (P=0.064), respectively. BMI (P<0.001) and creatinine clearance (P=0.031) remained associated with increased mean-mean common CIMT, while increasing age (P<0.001) and increasing lipoprotein(a) level (P=0.005) were associated with increased mean-max CIMT.

CONCLUSION

Traditional as well as nontraditional risk factors were associated with increased CIMT in this cohort of patients in the APPLE trial. Azathioprine treatment was associated with increased CIMT. The relationship between CIMT and prednisone dose may not be linear.

Ultrasound, atherosclerosis and stroke at a young age: a cross-sectional long-term follow-up in western Norway

BACKGROUND AND PURPOSE

Previous studies have shown significantly higher mortality and vascular morbidity amongst patients with ischaemic stroke onset at a young age compared with controls after a mean observation time of more than 11 years.

METHODS

In the present cross-sectional study, we measured the carotid intima-media thickness (IMT) in 140 (75%) of 187 survivors of ischaemic stroke after a mean observation time of 11.9 years. Their mean age when included was 41.1 years. IMT was measured by B-mode ultrasonography.

RESULTS

Total maximum IMT <1.0 mm was found in 34 (24%) patients, [1.0-1.2 mm) in 29 (21%) patients, [1.2-1.5 mm) in 29 (21%) patients and >or=1.5 mm in 48 (34%) patients. Increasing total maximum IMT was related to increasing age, male gender, recurrent ischaemic stroke, coronary atherosclerosis, peripheral atherosclerosis, smoking, hypertension and diabetes mellitus.

DISCUSSION

IMT changes confirm increased vascular morbidity in patients who suffered ischaemic stroke at a young age.

Carotid intima-medial thickness measured on multiple ultrasound frames: evaluation of a DICOM-based software system

Background

Carotid intima-media thickness (CIMT) measured by B-mode ultrasonography is a marker of atherosclerosis and is commonly used as an outcome in intervention trials. We have developed DICOM-based software that measures CIMT rapidly on multiple end-diastolic image frames. The aims of this study were to compare the performance of our new software with older bitmap-based CIMT measurement software and to determine whether a ten-fold increase in the number of measurements used to calculate mean CIMT would improve reproducibility.

Methods

Two independent sonographers recorded replicate carotid scans in thirty volunteers and two blinded observers measured CIMT off-line using the new DICOM-based software and older bitmap-based software. A Bland-Altman plot was used to compare CIMT results from the two software programs and t-tests were used to compare analysis times. F-tests were used to compare the co-efficients of variation (CVs) from a standard six-frame measurement protocol with CVs from a sixty-frame measurement protocol. Ordinary least products (OLP) regression was used to test for sonographer and observer biases.

Results

The new DICOM-based software was much faster than older bitmap-based software (average measurement time for one scan 3.4 ± 0.6 minutes versus 8.4 ± 1.8 minutes, p < 0.0001) but CIMT measurements were larger than those made using the alternative software (+0.02 mm, 95%CI 0.01–0.03 mm). The sixty-frame measurement protocol had worse reproducibility than the six-frame protocol (inter-observer CV 5.1% vs 3.5%, p = 0.004) and inter and intra-observer biases were more pronounced in the sixty-frame than the six-frame results.

Conclusion

While the use of DICOM-based software significantly reduced analysis time, a ten-fold increase in the number of measurements used to calculate CIMT did not improve reproducibility. In addition, we found that observer biases caused differences in mean CIMT of a magnitude commonly reported as significant in intervention trials. Our results highlight the importance of good study design with concurrent controls and the need to ensure that no observer drift occurs between baseline and follow-up measurements when CIMT is used to monitor the effect of an intervention.

Carotid intima-media thickness as a surrogate marker for cardiovascular disease in intervention studies

BACKGROUND

Cardiovascular trials using clinical endpoints to assess efficacy typically require follow-up of large numbers of participants for 3-5 years. This disadvantage has encouraged the search for well-validated surrogate markers for cardiovascular disease (CVD). These markers may provide earlier indications of efficacy in trials involving fewer participants. One approach gaining interest in recent years is the measurement of atherosclerotic progression, a major underlying cause of CVD.

SCOPE

This review article aims to further substantiate the evidence supporting the use of measurement of carotid intima-media thickness (CIMT) as a surrogate marker for atherosclerosis and cardiovascular risk.

FINDINGS

CIMT has consistently been related to future CVD events in population studies. CIMT is significantly related with other markers for CVD risk, such as elevated levels of risk factors and presence of atherosclerosis in the coronary arteries. Furthermore, almost all lipid-lowering trials and a large number of blood pressure lowering trials have consistently shown a reduction in progression of CIMT. In addition, the ultrasound technique for measuring CIMT is safe and highly reproducible.

CONCLUSION

Thus, CIMT may be used as a surrogate endpoint in clinical trials to enable the benefits of new therapies or regimens to be more rapidly translated into clinical practice.

Effects of tibolone and continuous combined conjugated equine estrogen/medroxyprogesterone acetate on the endometrium and vaginal bleeding: results of the OPAL study

OBJECTIVES

The primary objective of the Osteoporosis Prevention and Arterial effects of tiboLone study was to compare the effect of tibolone and placebo on the progression of the common carotid artery intima-medial thickness; the common carotid artery intima-medial thickness and bone data will be presented elsewhere. A secondary objective was to assess the effects of tibolone (2.5 mg), continuous combined conjugated equine estrogen/medroxyprogesterone acetate [0.625/2.5 mg], and placebo on the endometrium and vaginal bleeding; these results are the subject of this report.

STUDY DESIGN

This 3-year, three-arm, international, randomized, double-blind, parallel group, placebo-controlled clinical trial enrolled 866 postmenopausal women (aged 45-79 years). The endometrium was assessed by annual transvaginal ultrasound scans and end-of-study biopsies (United States/United Kingdom centers only). Vaginal bleeding was recorded in daily diaries.

RESULTS

Endometrial thickness measured by transvaginal ultrasound scan increased slightly during the first year with tibolone and conjugated equine estrogen/medroxyprogesterone acetate, without any further progression. After 3 years, there were no significant differences between the tibolone, conjugated equine estrogen/medroxyprogesterone acetate, and placebo groups in the incidence of proliferation (1.4%, 4.8%, and 0%, respectively), endometrial hyperplasia (0% in all groups), or cancer (1, 0, and 1 case, respectively). During the first 3 months, bleeding/spotting rates were greater with conjugated equine estrogen/medroxyprogesterone acetate (48%) than with tibolone (18%; P < .001) or placebo (3%; P < .001). During 3 years of treatment, the incidence of bleeding/spotting was 66%, 48%, and 23% for conjugated equine estrogen/medroxyprogesterone acetate, tibolone, and placebo, respectively. The mean number of bleeding/spotting days was greater in the conjugated equine estrogen/medroxyprogesterone acetate than the tibolone or placebo groups (61, 28, and 7 days, respectively; P = .023 vs tibolone; P < .0001 vs placebo). The mean number of bleeding/spotting episodes was also greater in the conjugated equine estrogen/medroxyprogesterone acetate group (13 episodes) compared with the tibolone group (six episodes; P < .001) and placebo group (four episodes; P < .001). Vaginal bleeding was more commonly reported as an adverse event with conjugated equine estrogen/medroxyprogesterone acetate than tibolone (26.4% vs 10.8%, P < .0001) and as the reason for premature discontinuation (9% vs 2%, P = .001).

CONCLUSION

Compared with conjugated equine estrogen/medroxyprogesterone acetate, tibolone has a better tolerability profile with respect to vaginal bleeding but with a similar endometrial safety. These results reinforce the endometrial safety profile of tibolone.

Effects of tibolone on body composition in postmenopausal women: a 1-year follow up study

OBJECTIVE

We investigated the effects of 1-year tibolone treatment on body weight, body composition and indices of android obesity in postmenopausal women.

METHODS

Forty-four postmenopausal women participated in this open-label controlled study; mean age was 51.8+/-2.21 years and all women were menopausal for 3.8+/-1.40 years. Twenty-two of them started taking 2.5 mg tibolone (TIB) daily for 1 year, whereas the remaining 22 served as age-matched controls. All subjects underwent a structured interview, physical examination, body composition measurements performed by dual-energy X-ray absorptiometry (DXA) - Hologic QDR 4500 A, as well as bioelectrical body impedance analysis (BI) - Tanita TBF-215, Japan.

RESULTS

The TIB group did not significantly increase their weight (+0.4 kg), while the non-treated controls increased their mean weight by 1.4 kg (p=0.046). In the TIB group, DXA showed a non-significant body fat decrease by a mean of 0.5 kg and a non-significant lean mass increase by 0.8 kg, while in the control group, fat mass increased by 1.7 kg (p=0.032) and lean mass did not change. BI revealed that the TIB group had lost some fat ( approximately 0.6 kg, n.s.) and put some free-fat mass ( approximately 1.0 kg, p=0.048) without changes in total body water. The control group put on some fat ( approximately 1.1 kg, p=0.042) and lost some body water ( approximately 0.4 kg, n.s.).

CONCLUSION

Results from both methods of measuring body composition show a similar trend: a decrease in fat mass and an increase in lean mass in TIB treated subjects. From the body composition perspective, tibolone may be regarded as a preferential alternative to conventional hormonal therapy (HT) in postmenopausal women.

The effect of tibolone and continuous combined conjugated equine oestrogens plus medroxyprogesterone acetate on progression of carotid intima–media thickness: the Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) study

AIMS

At the time of the design of the Osteoporosis Prevention and Arterial effects of tiboLone (OPAL) study in 1996, oral hormone therapy (HT) was assumed to reduce cardiovascular risk. The evidence mainly came from the effects of combined conjugated equine oestrogens plus medroxyprogesterone acetate (CEE/MPA) therapy. Other HT regimes had not been studied widely. Tibolone, a selective tissue oestrogenic activity regulator, has several effects on cardiovascular risk factors, one of which is HDL lowering. Because the overall effect of tibolone on cardiovascular risk was unknown, the OPAL study was designed.

METHODS AND RESULTS

The OPAL study was a three-arm, randomized, placebo-controlled, double-blind study to determine the effect of tibolone (2.5 mg daily) and of CEE/MPA (0.625/2.5 mg daily) over 3 years on progression of carotid intima-media thickness (CIMT) in 866 healthy post-menopausal women. The women were recruited from six US and five European centres. The primary outcome was change in mean common CIMT. Annual common CIMT progression rates in the tibolone and CEE/MPA groups were higher than in the placebo group: 0.0077 mm [95% confidence interval (CI) 0.0051-0.0103] in the tibolone group, 0.0074 mm (0.0048-0.0099) in the CEE/MPA group, and 0.0035 mm (0.009-0.0061) in the placebo group. The differences with placebo (0.0042 mm/year for tibolone and 0.0039 mm/year for CEE/MPA) were statistically significant. HDL cholesterol increased in CEE/MPA group and was lowered in the tibolone group.

CONCLUSION

Both tibolone and CEE/MPA showed increased progression of common CIMT. Translation of the increased common CIMT progression of the CEE/MPA group into cardiovascular disease risk could not fully explain the observed increased cardiovascular risk as observed in the Women's Health Initiative study. This suggests that the net effect of tibolone and CEE/MPA on cardiovascular events may depend on the combined effects on the arterial wall, clotting factors, and possibly inflammation.

High cumulative insulin exposure: a risk factor of atherosclerosis in type 1 diabetes?

BACKGROUND

Since insulin therapy might have an atherogenic effect, we studied the relationship between cumulative insulin dose and atherosclerosis in type 1 diabetes. We have focused on patients with type 1 diabetes instead of type 2 diabetes to minimise the effect of insulin resistance as a potential confounder.

METHODS

An observational study was performed in 215 subjects with type 1 diabetes treated with multiple insulin injection therapy. Atherosclerosis was assessed by measurement of carotid intima-media thickness (CIMT).

RESULTS

The cumulative dose of regular insulin showed a positive and significant relation with CIMT: increase of 21 microm in CIMT per S.D. of insulin use (95% CI: 8-35 adjusted for gender and age), which remained unchanged after adjustment for duration of diabetes, HbA1c, BMI, pulse pressure, physical activity and carotid lumen diameter. A similar relation was found for intermediate-acting insulin: 15.5 microm per S.D. (2-29), which was no longer present after further adjustment.

CONCLUSIONS

These findings provide evidence that a high cumulative dose of regular insulin is a risk factor for atherosclerosis.

Effect of increased convective clearance by on-line hemodiafiltration on all cause and cardiovascular mortality in chronic hemodialysis patients - the Dutch CONvective TRAnsport STudy (CONTRAST): rationale and design of a randomised controlled trial [ISRCTN38365125]

Background

The high incidence of cardiovascular disease in patients with end stage renal disease (ESRD) is related to the accumulation of uremic toxins in the middle and large-middle molecular weight range. As online hemodiafiltration (HDF) removes these molecules more effectively than standard hemodialysis (HD), it has been suggested that online HDF improves survival and cardiovascular outcome. Thus far, no conclusive data of HDF on target organ damage and cardiovascular morbidity and mortality are available. Therefore, the CONvective TRAnsport STudy (CONTRAST) has been initiated.

Methods

CONTRAST is a Dutch multi-center randomised controlled trial. In this trial, approximately 800 chronic hemodialysis patients will be randomised between online HDF and low-flux HD, and followed for three years. The primary endpoint is all cause mortality. The main secondary outcome variables are fatal and non-fatal cardiovascular events.

Conclusion

The study is designed to provide conclusive evidence whether online HDF leads to a lower mortality and less cardiovascular events as compared to standard HD.

Emerging and potential therapies for osteoporosis

Osteoporotic fractures are an important public health problem, contributing substantially to morbidity and mortality in an ageing world population and consuming considerable health resources. Currently available pharmacological therapies for prevention of fragility fractures are limited in scope, efficacy and acceptability to patients. Considerable efforts are being made to develop new, more effective treatments for osteoporosis and to refine/optimise existing therapies. These novel treatments include an expanding array of drugs that primarily inhibit osteoclastic bone resorption; oestrogenic compounds, bisphosphonates, inhibitors of receptor activator of nuclear factor-kappaB ligand signalling, cathepsin K inhibitors, c-src kinase inhibitors, integrin inhibitors and chloride channel inhibitors. The advent of intermittent para-thyroid hormone (PTH) therapy has provided proof-of-principle that osteo-blast-targeted (anabolic) agents can effectively prevent osteoporotic fractures, and is likely to be followed by the introduction of other therapies based upon PTH, such as orally active PTH analogues, antagonists of the calcium sensing receptor, PTH-related peptide analogues, and/or agents that induce osteoblast anabolism via pathways involving key, recently identified, molecular targets (wnt low-density lipoprotein receptor-related protein-5 signalling, sclerostin and matrix extracellular phosphoglycoprotein).

Cardiovascular risk assessment in individual patients from carotid intimal-medial thickness measurements

Carotid intimal-medial thickness measurements are a low-cost, noninvasive method to assess atherosclerotic burden in the general population. A large evidence base exists to validate estimates of absolute cardiovascular risk obtained from measurements of carotid intimal-medial thickness. Precise and reliable carotid intimal-medial thickness measurements from several ultrasonic interrogation angles and anatomic sites are required to obtain the most valid estimates of cardiovascular risk in an individual patient. This paper reviews basic measurement concepts and outlines important considerations in the clinical assessment of absolute cardiovascular risk in individual patients from measurements of carotid intimal-medial thickness.