Duration of fracture prevention after zoledronate treatment in women with osteopenia: observational follow-up of a 6-year randomised controlled trial to 10 years

BACKGROUND

We previously identified that zoledronate administered at 18-month intervals reduced fragility fractures by a third in a 6-year trial of women older than 65 years with osteopenia. This extension aims to identify the persistence of these effects.

METHODS

Of the 2000 ambulant, community dwelling, postmenopausal women older than 65 years recruited in Auckland, New Zealand, with T-scores at the total hip or femoral neck in the range -1·0 to -2·5, we invited participants who received four doses of intravenous zoledronate, completed follow-up to year 6 of the core trial, did not have metabolic bone disease (other than osteoporosis), and were not using bone-active drugs into this 4-year observational study extension, during which further treatment was at the discretion of their own doctors. Participants were asked to notify study staff of any new fractures and were telephoned at 7·5 years and 9·0 years to update their health status. Participants were then invited to an onsite visit at 10·0 years. Fractures and other health events were documented at each contact and analysed in all women who entered the extension, and bone mineral density (BMD; analysed in participants without notable use of bone-active medications who attended an onsite visit at 10 years) and turnover markers (measured from fasting morning blood in a random subset of 50 participants) were measured at year 10.

FINDINGS

Of the 1000 women randomly assigned to receive zoledronate in the core trial, 796 participants were eligible for the extension, of whom 762 (96%) entered the extension between Sept 24, 2015, and Dec 13, 2017. Mean follow-up duration was 4·24 years (SD 0·57, range 0·61-6·55; final follow-up on May 25, 2022). 727 (91%) of participants were assessed at 10 years. 25 women died during the extension, six withdrew for medical reasons, and four were lost to follow-up. 92 women suffered 114 non-vertebral fractures during the extension. Non-vertebral fracture rates increased from a nadir of 15 fractures per 1000 woman-years (95% CI 10-21) in the last 2 years of the core trial to 24 fractures (17-33) in years 6-8 and 42 fractures (32-53) in years 8-10, similar to that in the placebo group in the last 2 years of the core trial. Total hip BMD (relative risk per 0·1 g/cm2 0·73, 95% CI 0·57-0·93; p=0·011) and a previous history of non-vertebral fracture (1·74, 1·12-2·69; p=0·013) at year 6 predicted incident fractures but change in total hip BMD did not. Total hip BMD decreased from 4·2% above study baseline to 0·8% above baseline (p<0·0001) during the extension. Turnover markers were not useful for predicting BMD loss in individuals. Osteonecrosis of the jaw or atypical femoral fractures did not occur in any participants.

INTERPRETATION

The reduced fracture rates following zoledronate in the core trial were substantially maintained for 1·5-3·5 years after the last zoledronate infusion, but not thereafter.

FUNDING

Health Research Council of New Zealand.

No Effect of NSAID Use on Efficacy of Zoledronate: A Post Hoc Analysis of a Randomized Trial in Osteopenic Older Women

Bisphosphonates are widely used for the prevention and treatment of osteoporosis. Nonsteroidal anti-inflammatory drugs (NSAIDs) are also widely used among the older population group at high risk of fractures. NSAIDs have been shown to impact on bone turnover, and a recent reanalysis of a clinical trial of clodronate found that NSAID use at baseline abrogated any effect of clodronate on either bone density (BMD) or fracture risk. To determine whether NSAIDs influence the efficacy of other bisphosphonates, we have reanalyzed our 6-year randomized controlled trial of zoledronate in 2000 osteopenic postmenopausal women. NSAID use was reported at baseline in 38% of the cohort and anytime use was reported by 65%. The evolution of the zoledronate effects on BMD were almost identical whether or not women were using NSAIDs at baseline and were significant in both subgroups at all BMD sites (p < 0.0001). The significant reduction in the risk of fracture in those allocated to zoledronate (p < 0.0001) showed no interaction with baseline use of NSAIDs (p = 0.33) nor with NSAID use at any time during the study (p = 0.28). The odds of fracture were significantly reduced in both NSAID users and nonusers. We conclude that the present analysis provides no support for the suggestion that NSAIDs interfere with the efficacy of potent bisphosphonates in terms of their effects on bone density or fracture. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Impact of Television Depictions of Gout on Perceptions of Illness: A Randomized Controlled Trial

OBJECTIVE

Gout is a chronic disease that can be effectively managed with long-term urate-lowering therapy. However, it is frequently portrayed on screen as an acute disease caused by a poor diet that should be managed with lifestyle changes. This study was undertaken to investigate the impact of a fictional television depiction of gout on perceptions of the disease and its management.

METHODS

In a randomized controlled single-blind study, 200 members of the public watched either a 19-minute commercial television comedy episode that depicted gout as an acute disease caused by poor diet and managed with lifestyle changes, or a control episode from the same television series that did not mention gout or other diseases. Participants completed a survey regarding their perceptions of gout, its likely causes, and management strategies.

RESULTS

Participants randomized to watch the gout-related episode believed gout had greater consequences (mean score of 7.1 versus 6.2 on an 11-point Likert scale; P < 0.001) and were more likely to rank the most important cause as poor eating habits compared to the control group (70% versus 38%; P < 0.001). They were also less likely to believe it is caused by genetic factors or chance. Participants watching the gout-related episode believed a change in diet would be a more effective management strategy (9.0 versus 8.4; P = 0.004) and long-term medication use would be less effective (6.9 versus 7.6; P = 0.007) compared to participants in the control group.

CONCLUSION

Television depictions of gout can perpetuate inaccurate beliefs regarding causes of the disease and underemphasize effective medical strategies required in chronic disease management.

Effect of a Three-Day Course of Dexamethasone on Acute Phase Response Following Treatment With Zoledronate: A Randomized Controlled Trial

Zoledronate is a potent intravenous bisphosphonate effective in the management of osteoporosis, Paget's disease and skeletal-related events in malignancy. Its most frequent adverse effect is the acute phase response (APR), an inflammatory reaction characterized by fever, musculoskeletal pain, headache, and nausea. This randomized, placebo-controlled, double-blind study investigated the efficacy of a three-day course of dexamethasone 4 mg daily in reducing incidence of APR. Participants (n = 60) were randomized to receive either 4 mg of oral dexamethasone 1.5 hours before zoledronate and once a day for the following 2 days, or placebo. Oral temperature was measured at baseline and three times a day for the following 3 days, and questionnaires assessing symptoms of the APR were completed at baseline and for 3 days following zoledronate. Use of anti-inflammatory medication in the 3 days following zoledronate was recorded. The primary outcome was the temperature change from baseline. There was a significant difference in the primary outcome between the dexamethasone and placebo groups (p < 0.0001), with a mean decrease in temperature of 0.10°C (95% confidence interval [CI], -0.34 to 0.14) in the dexamethasone group compared with a mean increase in temperature of 0.84°C (95% CI, 0.53-1.16) in the placebo group on the evening following zoledronate. There was also a difference in APR-related symptom score over time between the two groups (p = 0.0005), with a median change in symptom score in the dexamethasone group 1 day after zoledronate of 0 (95% CI, 0-1) compared with 3 (95% CI, 0-5) in the placebo group. An increase in temperature of ≥1°C to a temperature of >37.5°C occurred in two of 30 (6.7%) participants in the dexamethasone group compared with 14 of 30 participants (46.7%) in the placebo group (p = 0.0005). This study demonstrates that a 3-day course of dexamethasone substantially reduces the APR following zoledronate infusion. © 2023 American Society for Bone and Mineral Research (ASBMR).

Effect of oral zoledronate administration on bone turnover in older women

AIM

The aim of this work is to assess the safety and efficacy of two oral zoledronate preparations by determining their effects on bone resorption in healthy postmenopausal women.

METHODS

The preparations studied were zoledronic acid in enteric-coated capsules or a microparticle preparation of zoledronic acid in these capsules. Bone resorption was measured as β-C-telopeptideof type I collagen (CTX) in fasting serum. Separate cohorts, each of five women, were recruited and allocated in sequence to single doses of 20 mg, 40 mg, or 60 mg of oral zoledronate.

RESULTS

Zoledronate 20 mg enteric capsules were well tolerated, reduced serum CTX by a median 51% at 1 week, but by only 17% at 1 month. Doses of 40 or 60 mg of this preparation produced APR and/or gastrointestinal symptoms in more than half of participants. With these doses, median CTX reduction at 1 week was >80%, ~70% at 1 month, but only ~30% at 6 months. Enteric capsules containing microparticles of zoledronate 20 mg reduced CTX by a median 53% at 1 week, with offset over 3 months. Two or three of these capsules dosed weekly reduced CTX by ~50% at 1 month, and by ~30% at 3 and 6 months.

CONCLUSIONS

Oral zoledronate 20 mg circumvents the problem of APR symptoms but, even with multiple doses, the anti-resorptive effect is smaller and less sustained than with intravenous zoledronate. Probably a viable oral regimen of zoledronate dosing at intervals of weeks to months could be developed, but the advantage of infrequent dosing would be lost.

Long-Term Follow-up of a Randomized Controlled Trial of Allopurinol Dose Escalation to Achieve Target Serum Urate in People With Gout

OBJECTIVE

To determine the long-term use of and adherence to urate-lowering therapy (ULT), serum urate (SU) control, and self-reported flares in participants from a randomized controlled trial of allopurinol dose escalation, in order to achieve target SU concentration (< 0.36 mmol/L) in people with gout.

METHODS

For surviving study participants, ULT dispensing and SU testing within the preceding 12 months was obtained by medical record review. A phone interview was conducted to determine self-reported flares and adherence.

RESULTS

Over a mean follow-up of 6.5 (SD 2.5) years since enrollment, 60 out of 183 (33%) participants had died. Review of the 119 surviving participants showed that 98 (82%) were receiving allopurinol, 5 (4%) were receiving febuxostat, and 10 (8%) were not receiving ULT; for the remaining 6 (5.0%), ULT use could not be determined. In those receiving allopurinol, the mean dose was 28.1 (range -600 to 500) mg/day lower than at the last study visit; 49% were receiving the same dose, 18% were on a higher dose, and 33% were on a lower dose than at the last study visit. SU values were available for 86 of the 119 (72%) participants; 50 out of 86 (58%) participants had an SU concentration of < 0.36 mmol/L. Of the 89 participants who participated in the phone interview, 19 (21%) reported a gout flare in the preceding 12 months and 79 (89%) were receiving allopurinol; 71 (90%) of those receiving allopurinol reported 90% or greater adherence.

CONCLUSION

Most of the surviving participants in the allopurinol dose escalation study had good real-world persistence with allopurinol, remained at target SU, and had a low number of self-reported flares.

Zoledronate Reduces Height Loss Independently of Vertebral Fracture Occurrence in a Randomized Trial in Osteopenic Older Women

Vertebral fractures are associated with height loss, reduced quality of life, and increased mortality and are an important endpoint for osteoporosis trials. However, height loss is associated with quality of life and mortality independent of associations with fracture. We have used data from a recent 6-year trial of zoledronate in 2000 osteopenic women aged >65 years to assess the impact of the semiquantitative and quantitative components of the definition of vertebral fracture on the outcome of that trial, to determine what factors impacted on height loss and to test whether height loss can be used as a surrogate for vertebral fracture incidence. In the trial protocol, an incident vertebral fracture was defined as a change in Genant grade plus both a 20% and 4 mm decrease in a vertebral height. The addition of the quantitative criteria reduced the number of fractures detected but did not change the size of the anti-fracture effect (odds ratios of 0.49 versus 0.45) nor the width of the confidence intervals for the odds ratios. Multivariate analysis of baseline predictors of height change showed that age accelerated height loss (p < 0.0001) and zoledronate reduced it (p = 0.0001). Incident vertebral fracture increased height loss (p = 0.0005) but accounted for only 0.7% of the variance in height change, so fracture could not be reliably inferred from height loss. In women without incident vertebral fractures, height loss was still reduced by zoledronate (height change: zoledronate, -1.23; placebo -1.51 mm/yr, p < 0.0001). This likely indicates that zoledronate prevents a subtle but widespread loss of vertebral body heights not detected by vertebral morphometry. Because height loss is associated with quality of life and mortality independent of associations with fracture, it is possible that zoledronate impacts on these endpoints via its effects on vertebral body integrity. © 2022 American Society for Bone and Mineral Research (ASBMR).

Effect of Zoledronate on Lower Respiratory Infections in Older Women: Secondary Analysis of a Randomized Controlled Trial

A recent observational study of the incidence of pneumonia in patients with previous hip fractures found that bisphosphonate use reduced pneumonia risk by about one-quarter, in comparisons with those either not receiving osteoporosis treatment or receiving treatment with non-bisphosphonate drugs. Mortality from pneumonia was similarly reduced. It was hypothesized that effects of these drugs on immune or inflammatory function might mediate this effect. We have used the adverse event database from our recent 6-year randomized controlled trial of zoledronate in 2000 women over the age of 65 years, to determine whether a similar effect is observed using this more rigorous study design. Seventy-five women had at least one episode of pneumonia (32 [3.2%] zoledronate, 43 [4.3%] placebo) and 119 women had at least one episode of either pneumonia or a lower respiratory tract infection (57 [5.7%] zoledronate, 62 [6.2%] placebo). There were 93 pneumonia events and 167 pneumonia/lower respiratory infection events. For pneumonia, the hazard ratio associated with randomization to zoledronate was 0.73 (95% confidence interval, 0.46-1.16; P = 0.18) and the rate ratio was 0.69 (0.45, 1.04; P = 0.073). For the composite endpoint of pneumonia or lower respiratory infection, the hazard ratio was 0.90 (0.61, 1.30; P = 0.58) and the rate ratio 0.74 (0.54, 0.997; P = 0.048). The proportion of people with events changed approximately linearly over time in both groups, suggesting a progressive divergence in cumulative incidence during the study. In conclusion, these findings lend support to the hypothesis that bisphosphonate use reduces the number of lower respiratory tract infections in older women, though the present study is under-powered for this endpoint and the findings are of borderline statistical significance. Further analysis of other trials of bisphosphonates is necessary to test this possibility further, and exploration of the possible underlying mechanisms is needed.

Predictors of Fracture in Older Women With Osteopenic Hip Bone Mineral Density Treated With Zoledronate

A recent analysis has found that during treatment with denosumab, women attaining higher bone densities (BMD) are less likely to have incident fractures. We have reexamined this important question using data from our recent trial of zoledronate in osteopenic women. One thousand women randomized to treatment with zoledronate were followed for 6 years. Of those, 122 sustained fragility fractures during follow-up. Baseline age, nonvertebral fracture history, total hip BMD, and calculated fracture risk were all significantly different between those who had fractures during the study and those who did not. BMDs achieved during the study were higher in those without incident fractures. However, achieved BMDs were very closely related to baseline values (r = 0.93, p < 0.0001). The increase in BMD during zoledronate treatment was not different between those who had incident fractures and those who did not (0.15 < p < 0.78), and change in BMD was not predictive of fracture (univariate logistic regression analysis). Stepwise regression analysis of all baseline variables showed the best independent predictors of fracture to be age (odds ratio [OR] = 1.08, 95% confidence interval [CI] 1.04-1.13, p = 0.0003), baseline spine BMD (OR = 0.81, 95% CI 0.67-0.96, p = 0.016), and history of nonvertebral fracture (OR = 1.69, 95% CI 1.06-2.69, p = 0.028). Addition of change in BMD to this model did not improve its predictive power. If changes in BMD were included in the stepwise regression analysis of baseline variables, they did not emerge as significant predictors of fracture. It is concluded that age, fracture history, and baseline BMD determine the risk of new fractures. Differences in achieved BMD between those who do or do not fracture arise from the close relationship between baseline and achieved BMDs. These findings suggest that targeting any particular BMD during treatment is unlikely to be a useful or valid strategy. © 2020 American Society for Bone and Mineral Research (ASBMR).

The ABCG2 Q141K hyperuricemia and gout associated variant illuminates the physiology of human urate excretion

The pathophysiological nature of the common ABCG2 gout and hyperuricemia associated variant Q141K (rs2231142) remains undefined. Here, we use a human interventional cohort study (ACTRN12615001302549) to understand the physiological role of ABCG2 and find that participants with the Q141K ABCG2 variant display elevated serum urate, unaltered FEUA, and significant evidence of reduced extra-renal urate excretion. We explore mechanisms by generating a mouse model of the orthologous Q140K Abcg2 variant and find male mice have significant hyperuricemia and metabolic alterations, but only subtle alterations of renal urate excretion and ABCG2 abundance. By contrast, these mice display a severe defect in ABCG2 abundance and function in the intestinal tract. These results suggest a tissue specific pathobiology of the Q141K variant, support an important role for ABCG2 in urate excretion in both the human kidney and intestinal tract, and provide insight into the importance of intestinal urate excretion for serum urate homeostasis.

The common ABCG2 variant Q141K contributes to hyperuricemia and gout risk. Here, using a human interventional study and a new orthologous mouse model, the authors report a tissue specific pathobiology of the Q141K variant, and support a significant role for ABCG2 in urate excretion in both the kidney and intestine.

Nitrates Do Not Affect Bone Density or Bone Turnover in Postmenopausal Women: A Randomized Controlled Trial

Organic nitrates have been reported to have significant effects on bone mineral density (BMD) and bone turnover in previous clinical trials. However, results are inconsistent and some trials with strikingly positive results have been retracted because of scientific misconduct. As preparation for a potential fracture prevention study, we set out to determine the lowest effective dose and the most effective and acceptable nitrate preparation. We undertook a 1-year, double-blind, randomized, placebo-controlled trial of three different nitrate preparations and two different doses in osteopenic postmenopausal women, with a planned 1-year observational extension. The primary endpoint was change in BMD at the lumbar spine, and secondary endpoints included BMD changes at other sites, changes in bone turnover markers, and adverse events. A total of 240 eligible women who tolerated low-dose oral nitrate treatment in a 2-week run-in period were randomized to five different treatment groups or placebo. Over 12 months, there were no statistically significant between-group differences in changes in BMD at any site and no consistent differences in bone turnover markers. When the active treatment groups were pooled, there were also no differences in changes in BMD or bone turnover markers between nitrate treatment and placebo. Eighty-eight (27%) women withdrew during the run-in phase, with the majority because of nitrate-induced headache, and 41 of 200 (21%) women randomized to nitrate treatment withdrew or stopped study medication during the 1-year study compared with 1 of 40 (2.5%) in the placebo group. In summary, organic nitrates do not have clinically relevant effects on BMD or bone turnover in postmenopausal women and were poorly tolerated. These results call into question the validity of previous clinical research reporting large positive effects of nitrates on BMD and bone turnover. © 2020 American Society for Bone and Mineral Research.

Zoledronate Slows Weight Loss and Maintains Fat Mass in Osteopenic Older Women: Secondary Analysis of a Randomized Controlled Trial

Studies in mice have suggested that osteocalcin plays an important role in glucose and fat metabolism. Since anti-resorptive drugs reduce circulating levels of osteocalcin they might be associated with increased fat mass and an increased risk of diabetes. Positive changes in body weight have been found in trials of alendronate and denosumab, but no significant effect in a previous trial of zoledronate. Whether those weight differences were in fat or lean mass is unknown. There were no effects of anti-resorptive treatments on fasting glucose concentrations or incidence of diabetes in those three studies. We have used our recent trial comparing zoledronate and placebo over 6 years in 2000 older osteopenic women to re-examine these questions. Both treatment groups lost body weight during the study (placebo 1.65 kg, zoledronate 1.05 kg), and this was significantly greater in the placebo group (P = 0.01). Both groups lost lean mass, and this loss was marginally (0.17 kg) but significantly (P = 0.02) greater in those receiving zoledronate. The placebo group had a mean loss of fat mass of 0.63 kg but there was no change in fat mass in the zoledronate group (between-groups comparison, P = 0.007). In the placebo group, there were 20 new diagnoses of diabetes, and in the zoledronate group, 19 (P = 0.87). Zoledronate prevented age-related loss of fat mass in these late postmenopausal women. The present study is the first to document a significant effect of zoledronate treatment on body weight, confirming results previously found with alendronate and denosumab. It also demonstrates that this is principally an effect to maintain fat mass rather than influencing lean mass, raising an important physiological question as to how anti-resorptive drugs have this effect on intermediary metabolism. It is possible that this anti-catabolic action contributes to the beneficial effects of anti-resorptive drugs on bone and longevity.

Effects of Zoledronate on Cancer, Cardiac Events, and Mortality in Osteopenic Older Women

We recently showed that zoledronate prevented fractures in older women with osteopenia (hip T-scores between -1.0 and -2.5). In addition to fewer fractures, this study also suggested that women randomized to zoledronate had fewer vascular events, a lower incidence of cancer, and a trend to lower mortality. The present analysis provides a more detailed presentation of the adverse event data from that study, a 6-year, double-blind trial of 2000 women aged >65 years recruited using electoral rolls. They were randomly assigned to receive four infusions of either zoledronate 5 mg or normal saline at 18-month intervals. Supplements of vitamin D, but not calcium, were provided. There were 1017 serious adverse events in 443 participants in the placebo group, and 820 events in 400 participants in those randomized to zoledronate (relative risk = 0.90; 95% CI, 0.81 to 1.00). These events included fractures resulting in hospital admission. Myocardial infarction occurred in 39 women (43 events) in the placebo group and in 24 women (25 events) in the zoledronate group (hazard ratio 0.60 [95% CI, 0.36 to 1.00]; rate ratio 0.58 [95% CI, 0.35 to 0.94]). For a prespecified composite cardiovascular endpoint (sudden death, myocardial infarction, coronary artery revascularization, or stroke) 69 women had 98 events in the placebo group, and 53 women had 71 events in the zoledronate group (hazard ratio 0.76 [95% CI, 0.53 to 1.08]; rate ratio 0.72 [95% CI, 0.53 to 0.98]). Total cancers were significantly reduced with zoledronate (hazard ratio 0.67 [95% CI, 0.51 to 0.89]; rate ratio 0.68 [95% CI, 0.52 to 0.89]), and this was significant for both breast cancers and for non-breast cancers. Eleven women had recurrent or second breast cancers during the study, all in the placebo group. The hazard ratio for death was 0.65 (95% CI, 0.40 to 1.06; p = 0.08), and 0.51 (95% CI, 0.30 to 0.87) in those without incident fragility fracture. These apparent beneficial effects justify further appropriately powered trials of zoledronate with these nonskeletal conditions as primary endpoints. © 2019 American Society for Bone and Mineral Research.

Long-Term Stable Bone Mineral Density in HIV-Infected Men Without Risk Factors for Osteoporosis Treated with Antiretroviral Therapy

INTRODUCTION

Most prospective studies of bone mineral density (BMD) in HIV-infected cohorts taking antiretroviral therapy (ART) have been of short duration, typically < 3 years. Such studies have reported short-term stable or increasing BMD. We assessed whether this BMD stability persists for > 10 years in middle-aged and older men established on ART.

METHODS

A 12-year, prospective, longitudinal study in 44 HIV-infected men treated with ART who had measurements of BMD at the lumbar spine, proximal femur and total body at baseline, 2, 6 and 12 years.

RESULTS

At baseline, the mean age of participants was 49 years, the mean duration of HIV infection was 8 years, and the mean duration of ART was 50 months. After 12 years, BMD increased by 6.9% (95% CI 3.4 to 10.3) at the lumbar spine, and remained stable (range of BMD change: - 0.6% to 0.0%) at the total hip, femoral neck and total body. Only two individuals had a decrease of > 10% in BMD at any site during follow-up and both decreases in BMD were explained by co-morbid illnesses.

CONCLUSIONS

BMD remained stable over 12 years in middle-aged and older HIV-infected men treated with ART. Monitoring BMD in men established on ART who do not have risk factors for BMD loss is not necessary.

Anti-fracture efficacy of zoledronate in subgroups of osteopenic postmenopausal women: secondary analysis of a randomized controlled trial

BACKGROUND

We recently reported that the administration of zoledronate every 18 months to osteopenic older women reduces the incidence of fractures.

OBJECTIVE

Here, we present a more detailed analysis of that trial to determine whether baseline clinical characteristics impact on the anti-fracture efficacy of this intervention.

METHODS

This is a prospective, randomized, placebo-controlled, double-blind trial in osteopenic postmenopausal women aged ≥ 65 years, to determine the anti-fracture efficacy of zoledronate. 2000 women were recruited using electoral rolls and randomized to receive 4 infusions of either zoledronate 5 mg or normal saline, at 18-month intervals. Each participant was followed for 6 years. Calcium supplements were not supplied.

RESULTS

Fragility fractures (either vertebral or nonvertebral) occurred in 190 women in the placebo group (227 fractures) and in 122 women in the zoledronate group (131 fractures), odds ratio (OR) 0.59 (95%CI 0.46, 0.76; P < 0.0001). There were no significant interactions between baseline variables (age, anthropometry, BMI, dietary calcium intake, baseline fracture status, recent falls history, bone mineral density, calculated fracture risk) and the treatment effect. In particular, the reduction in fractures appeared to be independent of baseline fracture risk, and numbers needed to treat (NNT) to prevent one woman fracturing were not significantly different across baseline fracture risk tertiles.

CONCLUSIONS

The present analyses indicate that the decrease in fracture numbers is broadly consistent across this cohort. The lack of relationship between NNTs and baseline fracture risk calls into question the need for BMD measurement and precise fracture risk assessment before initiating treatment in older postmenopausal women.

Dietary Calcium Intake and Bone Loss Over 6 Years in Osteopenic Postmenopausal Women

CONTEXT

Calcium intakes are commonly lower than the recommended levels, and increasing calcium intake is often recommended for bone health.

OBJECTIVE

To determine the relationship between dietary calcium intake and rate of bone loss in older postmenopausal women.

PARTICIPANTS

Analysis of observational data collected from a randomized controlled trial. Participants were osteopenic (hip T-scores between -1.0 and -2.5) women, aged >65 years, not receiving therapy for osteoporosis nor taking calcium supplements. Women from the total cohort (n = 1994) contributed data to the analysis of calcium intake and bone mineral density (BMD) at baseline, and women from the placebo group (n = 698) contributed data to the analysis of calcium intake and change in BMD. BMD and bone mineral content (BMC) of the spine, total hip, femoral neck, and total body were measured three times over 6 years.

RESULTS

Mean calcium intake was 886 mg/day. Baseline BMDs were not related to quintile of calcium intake at any site, before or after adjustment for baseline age, height, weight, physical activity, alcohol intake, smoking status, and past hormone replacement use. There was no relationship between bone loss and quintile of calcium intake at any site, with or without adjustment for covariables. Total body bone balance (i.e., change in BMC) was unrelated to an individuals' calcium intake (P = 0.99).

CONCLUSIONS

Postmenopausal bone loss is unrelated to dietary calcium intake. This suggests that strategies to increase calcium intake are unlikely to impact the prevalence of and morbidity from postmenopausal osteoporosis.

Effects of Intravenous Zoledronate on Bone Turnover and Bone Density Persist for at Least 11 Years in HIV-Infected Men

Previously we reported the results of a 4-year extension of a 2-year randomized placebo-controlled trial showing that the antiresorptive effects of two annual 4-mg doses of zoledronate in HIV-infected men persisted for at least 5 years after the second dose. We set out to determine whether the effects on BMD and bone turnover persist beyond 10 years. We invited all participants in the original trial known to be alive and living in New Zealand to attend an additional visit approximately 12 years after trial entry and 11 years after their second dose of study medication. The outcome measures were BMD at the lumbar spine, proximal femur, and total body, and markers of bone turnover. Twenty-five of the 43 men originally enrolled in the trial attended the final visit, representing 25 of 31 (81%) participants alive and residing in New Zealand at the time. The average duration of follow-up was 12.4 years. At the final visit, BMD remained higher in the zoledronate group than the placebo group (lumbar spine 3.7%, 95% CI, 0.1 to 7.3; total hip 3.7%, 95% CI, 1.2 to 6.2; femoral neck 5.0%, 95% CI, 2.1 to 7.9; total body 2.4%, 95% CI, 0.7 to 4.0), and the between-group differences in BMD remained stable between 6 and 12 years. Serum CTx remained lower in the zoledronate group than the placebo group between 6 and 12 years and, at the final visit, was 45% lower (95% CI, 25 to 64) than the placebo group. P1NP was 26% (95% CI, 4 to 48) lower in the zoledronate group than the placebo group at the final visit. In summary, two annual 4-mg doses of zoledronate have effects on bone turnover and BMD in men that persist for at least 11 years after the second dose. © 2019 American Society for Bone and Mineral Research.

Longitudinal changes in bone mineral density, bone mineral content and bone area at the lumbar spine and hip in postmenopausal women, and the influence of abdominal aortic calcification

Longitudinal studies often report that spine bone mineral density (BMD), measured by DXA, is stable in older adults, which has been attributed to osteophyte development and the presence of aortic calcification. A decline in projected spine area as a result of loss of intervertebral disc height might also contribute to higher BMD. We utilised data from 297 postmenopausal women (mean 73 years) who had DXA measurements of the lumbar spine, total hip and femoral neck 5 years apart, and abdominal aortic calcification scoring from vertebral morphometry. BMD declined by -4.4% at the total hip and -3.9% at the femoral neck (p < 0.001), but did not change at the spine (-0.5%, p = 0.12). In contrast, bone mineral content (BMC) declined by -4.0% at the total hip, -2.5% at the femoral neck and -1.7% at the spine (all p < 0.001). Bone area increased by 0.5% at the hip and 1.6% at the femoral neck but declined by -1.2% at the spine (all p < 0.001). 43% of the cohort had abdominal aortic calcification (AAC) present at baseline. The presence of AAC at baseline was not related to changes in BMD or BMC at the total hip or femoral neck, nor to BMD at the spine. However, women with AAC present had a smaller loss of BMC at the spine than those without (-0.8% versus -2.4%, p = 0.03). AAC score increased more over 5 years among those with AAC at baseline than those without (0.28 versus 0.16, p = 0.036). Thus, the stability of spine BMD is the result of both a loss of projected bone area (as a result of intervertebral disc changes and/or a decrease in projected area of the vertebral bodies) and the effects of aortic calcification. Future clinical trials should consider assessing changes in spine BMC as a more informative index of spine mineral status.

Fracture Prevention with Zoledronate in Older Women with Osteopenia

BACKGROUND

Bisphosphonates prevent fractures in patients with osteoporosis, but their efficacy in women with osteopenia is unknown. Most fractures in postmenopausal women occur in those with osteopenia, so therapies that are effective in women with osteopenia are needed.

METHODS

We conducted a 6-year, double-blind trial involving 2000 women with osteopenia (defined by a T score of -1.0 to -2.5 at either the total hip or the femoral neck on either side) who were 65 years of age or older. Participants were randomly assigned to receive four infusions of either zoledronate at a dose of 5 mg (zoledronate group) or normal saline (placebo group) at 18-month intervals. A dietary calcium intake of 1 g per day was advised, but calcium supplements were not provided. Participants who were not already taking vitamin D supplements received cholecalciferol before the trial began (a single dose of 2.5 mg) and during the trial (1.25 mg per month). The primary end point was the time to first occurrence of a nonvertebral or vertebral fragility fracture.

RESULTS

At baseline, the mean (±SD) age was 71±5 years, the T score at the femoral neck was -1.6±0.5, and the median 10-year risk of hip fracture was 2.3%. A fragility fracture occurred in 190 women in the placebo group and in 122 women in the zoledronate group (hazard ratio with zoledronate, 0.63; 95% confidence interval, 0.50 to 0.79; P<0.001). The number of women that would need to be treated to prevent the occurrence of a fracture in 1 woman was 15. As compared with the placebo group, women who received zoledronate had a lower risk of nonvertebral fragility fractures (hazard ratio, 0.66; P=0.001), symptomatic fractures (hazard ratio, 0.73; P=0.003), vertebral fractures (odds ratio, 0.45; P=0.002), and height loss (P<0.001).

CONCLUSIONS

The risk of nonvertebral or vertebral fragility fractures was significantly lower in women with osteopenia who received zoledronate than in women who received placebo. (Funded by the Health Research Council of New Zealand; Australian New Zealand Clinical Trials Registry number, ACTRN12609000593235 .).

Bone Loss After Romosozumab/Denosumab: Effects of Bisphosphonates

Romosozumab and denosumab are monoclonal antibodies for the treatment of osteoporosis. Both have a rapid offset of effect resulting in loss of bone density (BMD) gained on-treatment and, in some cases, multiple vertebral fractures following treatment cessation. We recently reported disappointing results from transitioning patients from denosumab to intravenous zoledronate at the time the next denosumab injection is due. The present report re-assesses the role of bisphosphonates following the use of denosumab. In the FRAME trial, osteoporotic women were randomized to romosozumab or placebo for 1 year, then both groups were provided with open-label denosumab for the subsequent 2 years. In women completing this study at our center, we offered treatment with either oral or intravenous bisphosphonates. In the eleven women opting for intravenous treatment, zoledronate was given after a median delay of 65 days from trial-end, in the hope that this might increase skeletal uptake of the drug and, thereby, its efficacy to maintain bone density. In these women, spine BMD was 17.3% above baseline at trial-end, and still 12.3% above baseline a year later, a 73% (CI: 61%, 85%) retention of the treatment benefit. The comparable BMD figures for the total hip were 10.7 and 9.2% above baseline, a 87% (CI: 77%, 98%) retention of treatment effect. In contrast, those not receiving treatment after the conclusion of the FRAME trial lost 80-90% of the BMD gained on-trial in the following 12 months. Women treated with risedronate showed an intermediate response. In the zoledronate group, mean PINP 6 months post-FRAME was 23 ± 4 µg/L and at 12 months it was 47 ± 8 µg/L, suggesting that repeat zoledronate dosing is needed at 1 year to maintain the BMD gains. In conclusion, delaying administration of intravenous bisphosphonate when transitioning from short-term denosumab appears to increase the extent to which the gains in BMD are maintained.

Effect of monthly high-dose vitamin D on bone density in community-dwelling older adults substudy of a randomized controlled trial

BACKGROUND

Severe vitamin D deficiency causes osteomalacia, yet trials of vitamin D supplementation in the community have not on average demonstrated benefit to bone mineral density (BMD) or fracture risk in adults.

OBJECTIVE

To determine whether monthly high-dose vitamin D supplementation influences BMD in the general population and in those with low 25-hydroxyvitamin D levels.

METHODS

Two-year substudy of a trial in older community-resident adults. A total of 452 participants were randomized to receive monthly doses of vitamin D3 100 000 IU, or placebo. The primary end-point was change in lumbar spine BMD. Exploratory analyses to identify thresholds of baseline 25-hydroxyvitamin D for vitamin D effects on BMD were prespecified.

RESULTS

Intention-to-treat analyses showed no significant treatment effect in the lumbar spine (between-groups difference 0.0071 g cm^-2 , 95%CI: -0.0012, 0.0154) or total body but BMD loss at both hip sites was significantly attenuated by ~1/2% over 2 years. There was a significant interaction between baseline 25-hydroxyvitamin D and treatment effect (P = 0.04). With baseline 25-hydroxyvitamin D ≤ 30 nmol L^-1 (n = 46), there were between-groups BMD changes at the spine and femoral sites of ~2%, significant in the spine and femoral neck, but there was no effect on total body BMD. When baseline 25-hydroxyvitamin D was >30 nmol L^-1 , differences were ~1/2% and significant only at the total hip.

CONCLUSIONS

This substudy finds no clinically important benefit to BMD from untargeted vitamin D supplementation of older, community-dwelling adults. Exploratory analyses suggest meaningful benefit in those with baseline 25-hydroxyvitamin D ≤ 30 nmol L^-1 . This represents a significant step towards a trial-based definition of vitamin D deficiency for bone health in older adults.

Bone Loss After Denosumab: Only Partial Protection with Zoledronate

A case series of six women with postmenopausal osteoporosis who had received continuous denosumab for 7 years and were then given a single infusion of zoledronate (5 mg) is reported. During denosumab treatment, bone mineral density (BMD) in the spine increased 18.5% (P = 0.006), and total hip BMD by 6.9% (P = 0.03). Post-zoledronate BMDs were measured 18-23 months after treatment, and there were significant declines at each site (P _spine = 0.043, P _hip = 0.005). Spine BMD remained significantly above the pre-denosumab baseline (+9.3%, P = 0.003), but hip BMD was not significantly different from baseline (-2.9%). At the time of post-zoledronate BMD measurements, serum PINP levels were between 39 and 60 μg/L (mean 52 μg/L), suggesting that the zoledronate treatment had not adequately inhibited bone turnover. It is concluded that this regimen of zoledronate administration is not adequate to preserve the BMD gains that result from long-term denosumab treatment.

Randomised trial assessing the impact of framing of fracture risk and osteoporosis treatment benefits in patients undergoing bone densitometry

OBJECTIVES

The accuracy of patients' perception of risk is important for decisions about treatment in many diseases. We framed the risk of fracture and benefits of treatment in different ways and assessed the impact on patients' perception of fracture risk and intentions to take medication.

DESIGN

Randomised trial of 4 different presentations of fracture risk and likely benefits from osteoporosis treatment.

SETTING

Academic centre.

PARTICIPANTS

200 patients undergoing bone densitometry.

INTERVENTION

Presentation that framed the patient's absolute fracture risk either as the chance of having or not having an event, with their likely benefits from osteoporosis treatment in natural frequencies or numbers needed to treat.

OUTCOMES

Participants' views about their fracture risk and the need for osteoporosis treatment.

RESULTS

The median 5-year fracture risk threshold participants regarded as high enough to consider preventative medication was 50-60%, and did not change substantially after the presentation. The median (Q1, Q3) 5-year risk initially estimated by participants was 20% (10, 50) for any fracture and 19% (10, 40) for hip fracture. 61% considered their fracture risk was low or very low, and 59-67% considered their fracture risk was lower than average. These participant estimates were 2-3 times higher than Garvan calculator estimates for any fracture, and 10-20 times higher for hip fracture. Participant estimates of fracture risk halved after the presentation, but remained higher than the Garvan estimates (1.5-2 times for any fracture, 5-10 times for hip fracture). There was no difference in these outcomes between the randomised groups. Participants' intentions about taking medication to prevent fractures were not substantially affected by receiving information about fracture risk and treatment benefits.

CONCLUSIONS

Altering the framing of estimated fracture risks and treatment benefits had little effect on participants' perception of the need to take treatment or their individual fracture risk.

TRIAL REGISTRATION NUMBER

ACTRN12613001081707; Pre-results.

Acute effects of calcium supplements on blood pressure: randomised, crossover trial in postmenopausal women

Calcium supplements appear to increase cardiovascular risk, but the mechanism is unknown. We investigated the acute effects of calcium supplements on blood pressure in postmenopausal women. The reduction in systolic blood pressure was smaller after calcium compared with the placebo in the hours following dosing.

INTRODUCTION

Calcium supplements appear to be associated with increased cardiovascular risk; however, the mechanism of this is uncertain. We previously reported that blood pressure declined over a day in older women, and that this reduction was smaller following a calcium supplement. To confirm this finding, we investigated the acute effects of calcium supplements on blood pressure.

METHODS

This was a randomised controlled crossover trial in 40 healthy postmenopausal women (mean age 71 years and BMI 27.2 kg/m²). Women attended on two occasions, with visits separated by ≥7 days. At each visit, they received either 1 g of calcium as citrate, or placebo. Blood pressure and serum calcium concentrations were measured immediately before, and 2, 4 and 6 h after each intervention.

RESULTS

Ionised and total calcium concentrations increased after calcium (p < 0.0001 versus placebo). Systolic blood pressure decreased after both calcium and placebo, but significantly less so after calcium (p = 0.02). The reduction in systolic blood pressure from baseline was smaller after calcium compared with placebo by 6 mmHg at 4 h (p = 0.036) and by 9 mmHg at 6 h (p = 0.002). The reduction in diastolic blood pressure was similar after calcium and placebo.

CONCLUSIONS

These findings are consistent with those of our previous trial and indicate that the use of calcium supplements in postmenopausal women attenuates the post-breakfast reduction in systolic blood pressure by around 6-9 mmHg. Whether these changes in blood pressure influence cardiovascular risk requires further study.

Acute and 3-month effects of calcium carbonate on the calcification propensity of serum and regulators of vascular calcification: secondary analysis of a randomized controlled trial

SUMMARY

Calcium supplements have been associated with increased cardiovascular risk, but the mechanism is unknown. We investigated the effects of calcium supplements on the propensity of serum to calcify, based on the transition time of primary to secondary calciprotein particles (T50). Changes in serum calcium were related to changes in T50.

INTRODUCTION

Calcium supplements have been associated with increased cardiovascular risk; however, it is unknown whether this is related to an increase in vascular calcification.

METHODS

We investigated the acute and 3-month effects of calcium supplements on the propensity of serum to calcify, based on the transition time of primary to secondary calciprotein particles (T50), and on three possible regulators of calcification: fetuin-A, pyrophosphate and fibroblast growth factor-23 (FGF23). We randomized 41 postmenopausal women to 1 g/day of calcium as carbonate, or to a placebo containing no calcium. Measurements were performed at baseline and then 4 and 8 h after their first dose, and after 3 months of supplementation. Fetuin-A, pyrophosphate and FGF23 were measured in the first 10 participants allocated to calcium carbonate and placebo who completed the study.

RESULTS

T50 declined in both groups, the changes tending to be greater in the calcium group. Pyrophosphate declined from baseline in the placebo group at 4 h and was different from the calcium group at this time point (p = 0.04). There were no other significant between-groups differences. The changes in serum total calcium from baseline were significantly related to changes in T50 at 4 h (r = -0.32, p = 0.05) and 8 h (r = -0.39, p = 0.01), to fetuin-A at 3 months (r = 0.57, p = 0.01) and to pyrophosphate at 4 h (r = 0.61, p = 0.02).

CONCLUSIONS

These correlative findings suggest that serum calcium concentrations modulate the propensity of serum to calcify (T50), and possibly produce counter-regulatory changes in pyrophosphate and fetuin-A. This provides a possible mechanism by which calcium supplements might influence vascular calcification.

Bone density is normal and does not change over 2 years in sarcoidosis

SUMMARY

Small studies have previously suggested that sarcoidosis may be associated with low bone mineral density. In this observational study of 64 patients with sarcoidosis, bone mineral density was within the normal range at baseline, and there was no evidence of accelerated bone loss over 1-2 years.

INTRODUCTION

Several small studies have suggested that sarcoidosis may be associated with low bone mineral density (BMD).

METHODS

We undertook a cross-sectional study of BMD in 64 patients with sarcoidosis. Of these, 27 with 25-hydroxyvitamin D<50 nmol/L entered a 1-year intervention study of vitamin D supplements, and 37 entered a 2-year longitudinal study of BMD, with the primary endpoint of the change in lumbar spine BMD.

RESULTS

The mean age of participants was 58 years, 68% were female, and 8% were currently using oral glucocorticoids. At baseline, BMD for the entire cohort was greater than the expected values for the population at the lumbar spine (mean Z-score 0.7, P<0.001) and total body (0.5, P<0.001) and similar to expected values at the femoral neck (0.2, P=0.14) and total hip (0.2, P=0.14). BMD did not change at any of these four sites (P>0.19) over 2 years in the longitudinal study. In the intervention study, vitamin D supplements had no effect on BMD, and therefore we pooled the data from all participants. BMD did not change over 1 year at the spine, total hip, or femoral neck (P>0.3), but decreased by 0.7% (95% confidence interval 0.3-1.1) at the total body (P=0.019).

CONCLUSIONS

BMD was normal at baseline, and there was no consistent evidence of accelerated bone loss over 1-2 years, regardless of baseline vitamin D status. Patients with sarcoidosis not using oral glucocorticoids do not need routine monitoring of BMD.

Randomised controlled trial of vitamin D supplementation in sarcoidosis

OBJECTIVES

The role vitamin D intake/production plays in sarcoidosis-associated hypercalcaemia is uncertain. However, authoritative reviews have recommended avoiding sunlight exposure and vitamin D supplements, which might lead to adverse skeletal outcomes from vitamin D insufficiency. We investigated the effects of vitamin D supplementation on surrogate measures of skeletal health in patients with sarcoidosis and vitamin D insufficiency.

DESIGN

Randomised, placebo-controlled trial.

SETTING

Clinical research centre.

PARTICIPANTS

27 normocalcaemic patients with sarcoidosis and 25-hydroxyvitamin D (25OHD) <50 nmol/L.

INTERVENTION

50 000 IU weekly cholecalciferol for 4 weeks, then 50 000 IU monthly for 11 months or placebo.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary endpoint was the change in serum calcium over 12 months, and secondary endpoints included measurements of calcitropic hormones, bone turnover markers and bone mineral density (BMD).

RESULTS

The mean age of participants was 57 years and 70% were women. The mean (SD) screening 25OHD was 35 (12) and 38 (9) nmol/L in the treatment and control groups, respectively. Vitamin D supplementation increased 25OHD to 94 nmol/L after 4 weeks, 84 nmol/L at 6 months and 78 nmol/L at 12 months, while levels remained stable in the control group. 1,25-Dihydroxy vitamin D levels were significantly different between the groups at 4 weeks, but not at 6 or 12 months. There were no between-groups differences in albumin-adjusted serum calcium, 24 h urine calcium, markers of bone turnover, parathyroid hormone or BMD over the trial. One participant developed significant hypercalcaemia after 6 weeks (total cholecalciferol dose 250 000 IU).

CONCLUSIONS

In patients with sarcoidosis and 25OHD <50 nmol/L, vitamin D supplements did not alter average serum calcium or urine calcium, but had no benefit on surrogate markers of skeletal health and caused one case of significant hypercalcaemia.

TRIAL REGISTRATION

This trial is registered at the Australian New Zealand Clinical Trials Registry (http://www.anzctr.org.au). The registration number is ACTRN12607000364471, date of registration 5/7/2007.

Testosterone levels following decreases in serum osteocalcin

Recent preclinical studies suggest that osteoblasts are able to induce testosterone production by the testis, a process mediated by osteocalcin. Bisphosphonates substantially reduce osteocalcin levels. If osteocalcin is an important regulator of testosterone levels in adult men, it would be expected that the substantial reductions in osteocalcin induced by zoledronate would impact negatively on testosterone levels. Previously, we carried out a 2-year randomized, controlled trial of annual 4 mg zoledronate in 43 HIV-infected men. To explore the relationship between osteocalcin and testosterone further, we measured serum testosterone at baseline, 3 months, and 2 years; luteinizing hormone at 3 months and 2 years; and total osteocalcin at 2 years in 28 trial participants with available blood samples. At 2 years, total osteocalcin was 39 % lower in the zoledronate group than the placebo group (zoledronate mean 10.1 [SD 3.0] μg/L, placebo 16.5 [SD 4.9] μg/L, P = 0.003). Despite these substantial differences in osteocalcin levels, testosterone levels did not change over time in either group and there were no between-group differences over time, P = 0.4 (mean change at 2 years [adjusted for baseline levels] in zoledronate group -0.4 nmol/L, 95 % CI -2.5 to 1.6; placebo group 0.4 nmol/L, 95 % CI -1.6 to 2.5). Luteinizing hormone was within the normal range and did not differ between the groups at either 3 months or 2 years. Thus, the absence of a change in testosterone despite a substantial reduction in osteocalcin following zoledronate treatment argues against a biologically significant role for osteocalcin in the regulation of testosterone in adult men. This provides reassurance that men receiving potent antiresorptive drugs are not at risk of iatrogenic hypogonadism.

The impact of dietary calcium intake and vitamin D status on the effects of zoledronate

We investigated whether baseline dietary calcium intake or vitamin D status modified the effects of zoledronate. Neither variable influenced the effect of zoledronate on bone mineral density, bone turnover, or risk of acute phase reaction, suggesting that co-administration of calcium and vitamin D supplements with zoledronate may not always be necessary.

INTRODUCTION

Calcium and vitamin D supplements are often co-administered with bisphosphonates, but it is unclear whether they are necessary for therapeutic efficacy or minimizing side effects of bisphosphonates. We investigated whether baseline dietary calcium intake or vitamin D status modified the effect of zoledronate on bone mineral density (BMD) or bone turnover at 1 year, or the risk of acute phase reactions (APR).

METHODS

Data were pooled from two trials of zoledronate in postmenopausal women without vitamin D deficiency in which calcium and vitamin D were not routinely administered. The cohort (zoledronate n = 154, placebo n = 68) was divided into subgroups by baseline dietary calcium intake (<800 vs. ≥800 mg/day) and vitamin D status [25-hydroxyvitamin D (25OHD) <50 vs. ≥50 nmol/L, and <75 nmol/L vs. ≥75 nmol/L] and treatment × subgroup interactions tested.

RESULTS

There were 52, 86, and 36 % of the zoledronate group and 64, 94, and 46 % of the placebo group that had dietary calcium intake ≥800 mg/day, 25OHD ≥50 nmol/L, and 25OHD ≥75 nmol/L, respectively. There were no significant interactions between treatment and either baseline dietary calcium or baseline vitamin D status for lumbar spine BMD, total hip BMD, the bone turnover markers P1NP and β-CTx, or the risk of an APR. There was also no three-way interaction between baseline dietary calcium intake, baseline vitamin D status, and treatment for any of these variables.

CONCLUSIONS

Baseline dietary calcium intake and vitamin D status did not alter the effects of zoledronate, suggesting that co-administration of calcium and vitamin D with zoledronate may not be necessary for individuals not at risk of marked vitamin D deficiency.

Effects of intravenous zoledronate on bone turnover and bone density persist for at least five years in HIV-infected men

CONTEXT

In HIV-infected men, the antiresorptive effects of zoledronate persist for at least 2 yr after the second annual dose.

OBJECTIVE

Our objective was to determine the duration of action of zoledronate in men.

DESIGN AND SETTING

This was 4-yr extension of a 2-yr, double-blind, randomized, placebo-controlled trial at an academic research center.

PARTICIPANTS

Participants included 43 HIV-infected men with bone mineral density (BMD) T score below -0.5, 35 of whom entered the extension study.

INTERVENTION

Intervention was annual administration of 4 mg iv zoledronate or placebo at baseline and 1 yr and no intervention subsequently.

MAIN OUTCOME MEASURES

We evaluated changes in the bone turnover markers, serum osteocalcin and serum C-telopeptide (CTx), and changes in BMD at the lumbar spine, total hip, and total body.

RESULTS

There was no time × treatment interaction between 1 and 5 yr after the second zoledronate dose for osteocalcin or CTx (P > 0.4) or any BMD site (P > 0.7). Between 1 and 5 yr after the second dose, on average, osteocalcin was 41% lower (95% confidence interval = 19-62%; P < 0.001), CTx 52% lower (33-71%; P < 0.001), lumbar spine BMD 3.7% greater (0.3-7.0%; P = 0.03), total hip BMD 2.3% greater (0.3-4.3%; P = 0.02), and total body BMD 2.5% greater (0.8-4.1%; P = 0.004) in the zoledronate group than the placebo group. Five years after the second dose, the between-groups differences were 38% (13-62%) for osteocalcin, 49% (20-77%) for CTx, 3.5% (0.7-6.7%) for lumbar spine BMD, 3.4% (1.4-5.4%) for total hip BMD, and 1.6% (0.2-3.1%) for total body BMD.

CONCLUSION

The effects of two annual 4-mg doses of zoledronate in men persist for at least 5 yr after the second dose. Larger trials assessing the antifracture efficacy of less frequent dosing of zoledronate are justified.

Stable bone mineral density over 6 years in HIV-infected men treated with highly active antiretroviral therapy (HAART)

OBJECTIVE

Most longitudinal studies of bone mineral density (BMD) in HIV-infected cohorts have been of short duration, typically 1-2 years. Some studies, especially of cohorts treated with highly active antiretroviral therapy (HAART), report short-term stable or increasing BMD, but other studies, often in cohorts initiating HAART, report short-term losses in BMD. We assessed BMD changes over the medium term in HIV-infected men already established on HAART at baseline.

DESIGN

Six-year, prospective, longitudinal study.

SUBJECTS

Forty-four HIV-infected men treated with HAART and 37 uninfected, healthy controls.

MEASUREMENTS

Participants had measurements of BMD at baseline, 2 and 6 years.

RESULTS

In the HIV-infected men at baseline, the mean age was 49 years, the mean duration of infection was 8 years, and the mean duration of HAART was 50 months. Over 6 years of follow-up, there was a greater increase in lumbar spine BMD (5·3%, 95% CI 3·8-6·5%) in the HIV-infected men compared with controls (0·3%, 95% CI -1·0 to 1·6%), P < 0·001. There was no difference between the groups in the change in BMD over time at the total hip (HIV group: -0·6%, 95% CI -1·7 to 0·4%, controls -1·0%, 95% CI -2·2 to 0%, P = 0·8) or at the total body (HIV group, 0·3%, 95% CI -0·3 to 1·0%; controls, 0·5%, 95% CI -0·2 to 1·1%, P = 0·15). Lean mass increased in the HIV group, but not in the controls.

CONCLUSIONS

There was no evidence of accelerated bone loss over 6 years in middle-aged, HIV-infected men treated with HAART. For such patients, routine monitoring of BMD is not necessary over the short/medium term.

Prevalent dietary supplement use in older New Zealand men

AIMS

Because of a lack of recent data from New Zealand older men, we examined dietary supplement use in this demographic.

METHODS

We surveyed men aged $gt;40 years who were participating in a trial of calcium supplementation on bone and cardiovascular outcomes.

RESULTS

Forty-seven percent reported using at least one supplement and 30% of users took more than two different supplements. Amongst users, median monthly expenditure on these products was NZ$20 (interquartile range: $10-$45). The most common supplements used were vitamins or minerals (49%), followed by nutritional oils (22%) (including fish oils, 13%) and glucosamine/chondroitin preparations (13%). Supplements were mainly taken for reasons of non-specific prophylaxis or health maintenance (58% of reasons), although 21% of reasons cited treatment or symptom alleviation for a medical condition. Daily requirements for vitamins A, D and E were exceeded, from supplement intake alone, by 12%, 10% and 40% of supplement users respectively.

CONCLUSIONS

Many older New Zealand men spend substantial amounts of money on dietary supplements despite uncertain health benefits. Health professionals should remain alert to supplement use by their patients, including males.

Evaluation of the FRAX and Garvan fracture risk calculators in older women

Fracture risk calculators estimate the absolute risk of osteoporotic fractures. We investigated the performance of the FRAX and Garvan Institute fracture risk calculators in healthy, older, New Zealand, postmenopausal women with normal bone mineral density (BMD) for their age. Fractures were ascertained in women initially enrolled in a 5-year trial of calcium supplements and followed on average for 8.8 years. Baseline data (1422 women, mean age 74 years, mean femoral neck BMD T-score -1.3) were used to estimate fracture risk during follow-up using the FRAX and Garvan calculators. The FRAX-New Zealand tool was used both with and without baseline BMD. The discrimination of the calculators was assessed using the area under the curve (AUC) of receiver operating characteristic curves. The calibration was assessed by comparing estimated risk of fracture with fracture incidence across a range of estimated fracture risks and clinical factors. For each fracture subtype, the calculators had comparable moderate predictive discriminative ability (AUC range: hip fracture 0.67-0.70; osteoporotic fracture 0.62-0.64; any fracture 0.60-0.63) that was similar to that of models using only age and BMD. The Garvan calculator was well calibrated for osteoporotic fractures but overestimated hip fractures. FRAX with BMD underestimated osteoporotic and hip fractures. FRAX without BMD underestimated osteoporotic and overestimated hip fractures. In summary, none of the calculators provided better discrimination than models based on age and BMD, and their discriminative ability was only moderate, which may limit their clinical utility. The calibration varied, suggesting that the calculators should be validated in local cohorts before clinical use.

Relationships between vascular calcification, calcium metabolism, bone density, and fractures

Factors involved with calcium metabolism, such as serum calcium and phosphate and calcium intake, have been associated with vascular disease in different populations. We investigated whether this association is mediated via increased vascular calcification by assessing relationships between these factors and abdominal aortic calcification (AAC) and coronary artery calcification (CAC). A total of 1471 healthy postmenopausal women participated in a 5-year randomized, placebo-controlled trial of calcium 1 g/day, and 323 healthy middle-aged and older men participated in a 2-year randomized, placebo-controlled trial of calcium 600 or 1200 mg/day. AAC was assessed on vertebral morphometric images at baseline and follow-up. Based on computed tomography, 163 men had CAC assessed, on average, 1.5 years after study completion. In elderly women, AAC was positively related to serum calcium (p < .001), phosphate (p = .04), and the calcium-phosphate product (p = .003), but changes in AAC over time and incidence of cardiovascular events were not related to these variables. In middle-aged men, AAC and CAC were not consistently related to these variables. Neither dietary calcium intake nor calcium supplementation was associated with changes in the prevalence of AAC over time, and calcium supplementation also was not related to CAC scores in men. After adjusting for age, AAC was not associated with low bone mineral density (BMD) at baseline, changes in BMD over time, or fracture incidence. CAC also was not related to baseline BMD. In summary, serum calcium and phosphate are associated with AAC in older women, but dietary calcium intake and calcium supplementation were not associated with changes in AAC over 2 to 5 years.

Vitamin D insufficiency and health outcomes over 5 y in older women

BACKGROUND

Vitamin D insufficiency was shown to be associated with adverse musculoskeletal and nonskeletal outcomes in numerous observational studies. However, some studies did not control for confounding factors such as age or seasonal variation of 25-hydroxyvitamin D [25(OH)D].

OBJECTIVE

We sought to determine the effect of vitamin D status on health outcomes.

DESIGN

Healthy community-dwelling women (n = 1471) with a mean age of 74 y were followed in a 5-y trial of calcium supplementation. 25(OH)D was measured at baseline in all women. Skeletal and nonskeletal outcomes were evaluated according to seasonally adjusted vitamin D status at baseline.

RESULTS

Fifty percent of women had a seasonally adjusted 25(OH)D concentration <50 nmol/L. These women were significantly older, heavier, and less physically active and had more comorbidities than women with a seasonally adjusted 25(OH)D concentration > or =50 nmol/L. Women with a seasonally adjusted 25(OH)D concentration <50 nmol/L had an increased incidence of stroke and cardiovascular events that did not persist after adjustment for between-group differences in age or comorbidities. Women with a seasonally adjusted 25(OH)D concentration <50 nmol/L were not at increased risk of adverse consequences for any musculoskeletal outcome, including fracture, falls, bone density, or grip strength or any nonskeletal outcomes, including death, myocardial infarction, cancer, heart failure, diabetes, or adverse changes in blood pressure, weight, body composition, cholesterol, or glucose.

CONCLUSIONS

Vitamin D insufficiency is more common in older, frailer women. Community-dwelling older women with a seasonally adjusted 25(OH)D concentration <50 nmol/L were not at risk of adverse outcomes over 5 y after control for comorbidities. Randomized placebo-controlled trials are needed to determine whether vitamin D supplementation in individuals with vitamin D insufficiency influences health outcomes. This trial was registered at www.anzctr.org.au as ACTRN 012605000242628.

High-dose oral vitamin D3 supplementation in the elderly

SUMMARY

Daily dosing with vitamin D often fails to achieve optimal outcomes, and it is uncertain what the target level of 25-hydroxyvitamin D should be. This study found that large loading doses of vitamin D(3) rapidly and safely normalize 25OHD levels, and that monthly dosing is similarly effective after 3-5 months. With baseline 25OHD > 50 nmol/L, vitamin D supplementation does not reduce PTH levels.

INTRODUCTION

There is concern that vitamin D supplementation doses are frequently inadequate, and that compliance with daily medication is likely to be suboptimal.

METHODS

This randomized double-blind trial compares responses to three high-dose vitamin D(3) regimens and estimates optimal 25-hydroxyvitamin D (25OHD) levels, from changes in parathyroid hormone (PTH), and procollagen type I amino-terminal propeptide (P1NP) in relation to baseline 25OHD. Sixty-three elderly participants were randomized to three regimens of vitamin D supplementation: a 500,000-IU loading dose; the loading dose plus 50,000 IU/month; or 50,000 IU/month.

RESULTS

The Loading and Loading + Monthly groups showed increases in 25OHD of 58 +/- 28 nmol/L from baseline to 1 month. Thereafter, levels gradually declined to plateaus of 69 +/- 5 nmol/L and 91 +/- 4 nmol/l, respectively. In the Monthly group, 25OHD reached a plateau of ~80 +/- 20 nmol/L at 3-5 months. There were no changes in serum calcium concentrations. PTH and P1NP were only suppressed by vitamin D treatment in those with baseline 25OHD levels <50 and <30 nmol/L, respectively.

CONCLUSIONS

Large loading doses of vitamin D(3) rapidly and safely normalize 25OHD levels in the frail elderly. Monthly dosing is similarly effective and safe, but takes 3-5 months for plateau 25OHD levels to be reached.

Does degree of baldness influence vitamin D status?

OBJECTIVE

To determine the association, if any, between male-pattern hair loss (baldness) and serum 25-hydroxyvitamin D (25-OHD) levels.

DESIGN AND PARTICIPANTS

A cross-sectional study of 296 healthy middle-aged and older men.

MAIN OUTCOME MEASURES

Degree of baldness was independently assessed by two researchers using the Hamilton-Norwood scale and serum 25-OHD was measured in all men.

RESULTS

Classification of the degree of baldness by the two researchers showed a high level of agreement (kappa = 0.93). Forty-eight per cent of men had no hair loss or mild frontotemporal recession, 15% had predominant vertex loss, and 37% had significant scalp and vertex loss. After data were adjusted for potential confounding factors - including age, month of 25-OHD measurement, exercise levels, use of sunscreen, skin type and frequency of outdoor hat wearing - no significant differences in 25-OHD levels between these groups was detected (P = 0.60).

CONCLUSIONS

The degree of baldness does not appear to influence serum 25-OHD levels. The high prevalence of baldness in older men does not explain sex differences in 25-OHD levels. Other novel hypotheses are required to help determine whether baldness serves any physiological purpose.

Prospective 10-year study of postmenopausal women with asymptomatic primary hyperparathyroidism

AIM

There are few prospective studies of people with asymptomatic primary hyperparathyroidism (PHPT) who have not had parathyroidectomy. We followed a group of postmenopausal women with asymptomatic PHPT for up to 10 years to determine whether they could be managed conservatively without parathyroidectomy.

METHODS

A 10-year, prospective, longitudinal study of 23 postmenopausal women with asymptomatic PHPT initially enrolled into a 4-year randomised controlled trial of hormone replacement therapy. Serum total and ionised calcium, biochemistry, urine calcium, and bone mineral density were measured every 6-12 months.

RESULTS

Serum ionised calcium, creatinine, and urine calcium:creatinine remained stable throughout follow-up. In contrast, there was a steady increase in the total and adjusted serum calcium and a small rise in serum PTH. Only one woman had an adjusted serum calcium >3.0 mmol/L during follow-up. There were few other clinical events possibly related to PHPT (1 possible episode of nephrolithiasis, 4 fractures, 1 severe osteoporosis). Three women underwent parathyroidectomy, although 19/23 women met the updated criteria for parathyroidectomy from the 2002 NIH-sponsored workshop during follow-up.

CONCLUSIONS

Many postmenopausal women with asymptomatic PHPT do not develop symptoms or complications of PHPT, and their biochemical parameters remains stable. Therefore, such asymptomatic women with PHPT can often be managed conservatively without parathyroidectomy.

Osteomalacia in an HIV-infected man receiving rifabutin, a cytochrome P450 enzyme inducer: a case report

Introduction

People infected with human immunodeficiency virus are frequently treated with medications that can induce or inhibit cytochrome P450 enzymes.

Case presentation

A 59 year old man treated with zidovudine, lamivudine, indinavir, and ritonavir for infection with human immunodeficiency virus volunteered to take part in a study of bone loss. He was found to have vitamin D insufficiency with secondary hyperparathyroidism and received vitamin D and calcium supplementation. He suffered a recurrence of infection with Mycobacterium avium intracellulare for which he received treatment with ciprofloxacin, rifabutin, and ethambutol. Subsequently, he developed worsening vitamin D deficiency with hypocalcaemia, secondary hyperparathyroidism and elevated markers of bone turnover culminating in an osteomalacic vertebral fracture. Correction of the vitamin D deficiency required 100,000 IU of cholecalciferol monthly.

Rifabutin is a cytochrome P450 inducer, and vitamin D and its metabolites are catabolised by cytochrome P450 enzymes. We therefore propose that treatment with rifabutin led to the induction of cytochrome P450 enzymes catabolising vitamin D, thereby causing vitamin D deficiency and osteomalacia. This process might be mediated through the steroid and xenobiotic receptor (SXR).

Conclusion

Treatment with rifabutin induces the cytochrome P450 enzymes that metabolise vitamin D and patients treated with rifabutin might be at increased risk of vitamin D deficiency. In complex medication regimens involving agents that induce or inhibit cytochrome P450 enzmyes, consultation with a clinical pharmacist or pharmacologist may be helpful in predicting and/or preventing potentially harmful interactions.

The effects of seasonal variation of 25-hydroxyvitamin D and fat mass on a diagnosis of vitamin D sufficiency

BACKGROUND

The effect of season on vitamin D status is often overlooked in studies of optimal vitamin D concentrations and in clinical practice.

OBJECTIVES

We aimed to determine the effects of seasonal variation of 25-hydroxyvitamin D [25(OH)D] on a previously selected minimum concentration for vitamin D sufficiency (50 nmol/L) and to determine whether fat mass modifies these effects.

DESIGN

A cross-sectional study evaluated 1606 healthy postmenopausal women and 378 older men from Auckland, New Zealand, who were undergoing single measurements of 25(OH)D.

RESULTS

Concentrations of <50 nmol 25(OH)D/L were seen in 49% (range: 23%-74%) of women and 9% (range: 0%-26%) of men when measured, but 73% of women and 39% of men were predicted to have trough 25(OH)D concentrations < 50 nmol/L, according to the demonstrated seasonal variation. The predicted duration of 25(OH)D concentrations < 50 nmol/L was 250 d/y in women and 165 d/y in men.

CONCLUSION

Seasonal variation significantly affects the diagnosis of vitamin D sufficiency, which requires seasonally adjusted thresholds individualized for different locations. Clinicians should consider the month of sampling and the amount of body fat when interpreting 25(OH)D measurements.

Bone mineral density remains stable in HAART-treated HIV-infected men over 2 years

OBJECTIVE

Recently we reported that human immunodeficiency virus (HIV)-infected Caucasian men treated with highly active antiretroviral therapy (HAART) have normal weight-adjusted bone mineral density (BMD), in contrast to most other cross-sectional analyses, which have reported low BMD in HIV-infected patients. We have now addressed the question of whether there is accelerated BMD loss over time in HIV-infected men.

DESIGN

A 2-year, prospective, longitudinal study.

SUBJECTS

Twenty-three HAART-treated, HIV-infected men and 26 healthy controls.

MEASUREMENTS

All participants had measurements of BMD and bone-related laboratory parameters at baseline, and a repeat measurement of BMD at 2 years.

RESULTS

In the HIV-infected men the mean age was 47 years, the mean duration of infection was 8.2 years, and the mean duration of HAART was 54 months. Over 2 years of follow-up, BMD increased from baseline in the HIV-infected men by 2.6% at the lumbar spine (P = 0.05 vs. baseline), and remained stable at the total hip (mean change 0.1%, P > 0.99) and total body (mean change 0.6%, P = 0.39). Mean changes in BMD in the control group were 1.4% at the lumbar spine, -0.1% at the total hip, and -0.8% at the total body. The HIV-infected men lost less total body BMD than the control group (P = 0.01). In the HIV-infected men, body weight remained stable over 2 years while fat mass decreased and lean mass tended to increase, whereas in the controls, body weight and fat mass increased while lean mass remained stable.

CONCLUSIONS

Accelerated bone loss does not occur in HIV-infected men treated with HAART. Monitoring of BMD in HIV-infected men may not be necessary.

Age-, gender-, and weight-related effects on levels of 25-hydroxyvitamin D are not mediated by vitamin D binding protein

OBJECTIVE

25-hydroxyvitamin D (25OHD) levels are inversely related to body weight, and have been reported to decline with age and be lower in women than men. We hypothesized that these findings might be explained by effects of these variables on vitamin D binding protein (DBP) levels. We set out to determine the relationships between DBP and gender, 25OHD, body weight and body composition.

DESIGN

Cross-sectional analysis.

PATIENTS

One hundred healthy, middle-aged and older, community-dwelling men and women.

MEASUREMENTS

All participants were measured for 25OHD, DBP, body weight, bone mineral density and body composition.

RESULTS

Women had higher mean DBP levels than men but lower total 25OHD levels [DBP: women, mean (SD) 339 (36) mg/l, men 307 (71) mg/l, P = 0.005; 25OHD: women 67 (23) nmol/l, men 91 (39) nmol/l, P < 0.001]. In women, there were significant positive relationships between DBP and albumin (r = 0.33) and 25OHD (r = 0.34) whereas in men there were no significant relationships between DBP and any measured variables. There was no significant relationship between DBP and age, body weight, body mass index, fat mass or percentage fat in men or women.

CONCLUSION

We found no evidence to support the hypothesis that DBP levels are related to age, or adiposity. The changes in 25OHD levels with age, gender, or fat mass are not due to underlying relationships between DBP and these variables. This suggests that the relationships consistently observed between 25OHD and body composition and gender are of biological origin and not due to adaptation to changes in transport proteins.

The effect of treatment with a thiazide diuretic for 4 years on bone density in normal postmenopausal women

SUMMARY

We performed a 2-year extension of our previous 2-year randomized controlled trial of the effects of hydrochlorothiazide on bone mineral density. The improvements in bone density seen in the first 2 years were sustained throughout the extension study. Thiazides provide a further option in the prevention of postmenopausal bone loss.

INTRODUCTION

Thiazide diuretics reduce urinary calcium excretion and therefore might prevent osteoporosis. Previously we reported a 2-year randomized controlled trial of hydrochlorothiazide treatment in 185 postmenopausal women that showed positive benefits of hydrochlorothiazide on bone density. Here, we report the results of a 2-year extension to that study.

METHODS

Of 185 healthy postmenopausal women, 122 agreed to continue in a double-blinded 2-year extension taking 50 mg hydrochlorothiazide or placebo daily. Measurements of bone density occurred every 6 months and of calcium metabolism at 2 and 4 years.

RESULTS

The improvements in bone density seen in the first 2 years of the trial were sustained throughout the extension. There were significant between-groups differences in the change in bone density over 4 years at the total body (0.9%, P<0.001), legs (1.0%, P=0.002), mid-forearm (1.1%, P=0.03), and ultradistal forearm (1.4%, P=0.04). At the lumbar spine (0.9%, P=0.76) and femoral neck (0.4%, P=0.53) the between-groups differences did not reach statistical significance.

CONCLUSIONS

Hydrochlorothiazide produces small positive benefits on cortical bone density that are sustained for at least the first 4 years of treatment. They provide a further option in the prevention of postmenopausal bone loss, especially for women with hypertension or a history of kidney stones.

Annual zoledronate increases bone density in highly active antiretroviral therapy-treated human immunodeficiency virus-infected men: a randomized controlled trial

CONTEXT

Recent studies have reported low bone mineral density (BMD) in HIV-infected patients. Annual iv administration of 4 mg zoledronate has been shown to increase BMD and suppress bone turnover in postmenopausal women.

OBJECTIVE

The objective of the study was to determine whether annual administration of 4 mg zoledronate will increase BMD in HIV-infected men receiving highly active antiretroviral therapy.

DESIGN AND SETTING

A 2-yr randomized placebo-controlled trial was conducted in a clinical research center.

PARTICIPANTS

A total of 43 HIV-infected men were treated with highly active antiretroviral therapy for at least 3 months, with BMD T score less than -0.5.

INTERVENTION

Participants received annual iv administration of 4 mg zoledronate or placebo. All participants took 400 mg/d calcium and 1.25 mg/month vitamin D.

MEASUREMENTS

BMD at the lumbar spine, total hip and total body, and bone turnover markers were measured.

RESULTS

At the lumbar spine, BMD increased by 8.9% over 2 yr in the zoledronate group compared with an increase of 2.6% in the control group (P<0.001). At the total hip, BMD increased by 3.8% over 2 yr in the zoledronate group compared with a decrease of 0.8% in the control group (P<0.001). At the total body, BMD increased by 2.3% over 2 yr compared with a decrease of 0.5% in the control group (P<0.001). Urine N-telopeptide decreased by 60% at 3 months in the zoledronate group and thereafter remained stable.

CONCLUSIONS

Annual administration of zoledronate is a potent and effective therapy for the prevention or treatment of bone loss in HIV-infected men. The current data provide the first trial evidence of the BMD effects of annual zoledronate beyond 1 yr in any population, as well as being the first reported trial in men.

Determinants of vitamin D status in older men living in a subtropical climate

INTRODUCTION

Previously we reported seasonal variation in 25-hydroxyvitamin D (25OHD) levels in postmenopausal women living in a subtropical climate. Because studies have suggested that there are gender differences in 25OHD levels, we sought to determine (1) the levels and determinants of 25OHD in men drawn from the same community, (2) whether seasonal variation of 25OHD occurs in men at this latitude (37 degrees S), and (3) whether these findings were comparable to those we previously observed in postmenopausal women.

METHODS

Cross-sectional study of 378 healthy, middle-aged and older community-dwelling men in Auckland, New Zealand.

RESULTS

The mean 25OHD (SD) level was 85 (31) nmol/l. We found significant seasonal variation in 25OHD levels (peak in autumn 103 nmol/l, nadir in spring 59 nmol/l). Vitamin D insufficiency (25OHD <50 nmol/l) was uncommon (prevalence in summer 0-17%, in winter 0-20%). The major determinants of 25OHD were month of blood sampling, fat percentage, physical activity, and serum albumin. Men had higher levels of 25OHD throughout the year than women did, a finding that persisted after adjusting for potential confounding factors. In men and women the determinants of 25OHD were similar.

CONCLUSION

There is significant seasonal variation in 25OHD levels in men living in a subtropical climate. In contrast to postmenopausal women, men have low rates of suboptimal vitamin D status, even in winter. Routine vitamin D supplementation for this population of men is not warranted.

Bone mineral density is not reduced in HIV-infected Caucasian men treated with highly active antiretroviral therapy

OBJECTIVE

Recent studies have reported low bone mineral density (BMD) in patients infected with human immunodeficiency virus (HIV). Frequently these findings have been attributed to treatment with highly active antiretroviral therapy (HAART). We sought to determine whether BMD in HIV-infected men treated with HAART for at least 3 months is different from that in healthy controls, and, if so, what HIV-related factors might explain this finding.

DESIGN

Cross-sectional analysis.

PATIENTS

Fifty-nine HIV-infected Caucasian men treated with HAART, and 118 healthy community-dwelling controls. Each HIV-infected man was age-matched (within 5 years) to two controls.

MEASUREMENTS

All participants had measurements of BMD and bone-related laboratory parameters.

RESULTS

The mean duration of known HIV infection was 8.5 years, and of treatment with HAART was 52 months. There was no significant difference in mean BMD between groups at the lumbar spine (HIV group: 1.23 g/cm2, controls: 1.25 g/cm2; P = 0.53) or total body (HIV group: 1.18 g/cm2, controls: 1.20 g/cm2; P = 0.09). At the total hip the HIV-infected group had significantly lower BMD than the control group (HIV group: 1.03 g/cm2, controls: 1.09 g/cm2; P = 0.01). The HIV-infected group were, on average, 6.3 kg lighter than the controls. After adjusting for this weight difference, HIV infection was not an independent predictor of BMD at any site (lumbar spine P = 0.79; total hip P = 0.18; total body P = 0.76).

CONCLUSIONS

HIV-infected men treated with HAART are lighter than healthy controls. This weight difference is responsible for a small decrement in hip BMD. Overall, BMD is not significantly reduced in HIV-infected Caucasian men treated with HAART.

Fat mass is an important predictor of parathyroid hormone levels in postmenopausal women

Previously, we reported that people with elevated parathyroid hormone (PTH) levels due to primary hyperparathyroidism have increased body weight compared to eucalcemic controls. We sought to determine whether the same relationship between PTH and body weight exists in eucalcemic healthy postmenopausal women, and to investigate the relationships between components of body weight, PTH, vitamin D metabolites, and metabolic indices. We performed a cross-sectional analysis of 116 healthy community-dwelling postmenopausal women. Pearson correlation analysis was used to test for univariate linear relationships between variables, and stepwise multiple regression analysis to assess for multivariate relationships. We found that PTH was significantly positively correlated with body weight, regional and total fat mass, and percent body fat, and negatively correlated with activity levels, 25 hydroxyvitamin D (25OHD), dietary calcium intake, and serum phosphate. On multivariate analysis, PTH was positively related to percent body fat (P = 0.020; partial r2 = 0.10) and negatively related to dietary calcium intake (P = 0.041; partial r2 = 0.03) and serum phosphate (P = 0.026; partial r2 = 0.04). Adjusting for vitamin D insufficiency or 25OHD levels did not affect the relationship between PTH and fat mass. For 25OHD, there were significant positive correlations with lumbar spine BMD and serum albumin, and significant negative correlations with PTH, total fat mass, trunk fat, and pelvic fat. On multivariate analysis, 25OHD was positively related to serum albumin (P = 0.008; partial r2 = 0.07) and negatively related to pelvic fat mass (P = 0.014; partial r2 = 0.05). Adjusting for PTH levels did not change the relationship between 25OHD and pelvic fat mass. We conclude that fat mass is a significant independent determinant of serum PTH levels, and that this relationship is independent of the inverse relationship between 25OHD and fat mass. This association between fat mass and PTH might contribute to the association between primary hyperparathyroidism and increased body weight.

Determinants of vitamin D status in older women living in a subtropical climate

Studies performed in the Northern Hemisphere and in areas distant from the equator have demonstrated significant seasonal variation in 25-hydroxyvitamin D (25OHD) levels. Whether such variation occurs in a subtropical area such as Australasia is not clear. We performed a cross-sectional study of 1,606 healthy, postmenopausal women recruited over a 33-month period. The study had three goals: to determine the normal levels of 25OHD in healthy postmenopausal women living in Auckland, New Zealand; to determine whether seasonal variation of 25OHD occurs at this latitude; to assess the relationship between 25OHD, biochemical indices, anthropometric variables and bone mineral density (BMD). We found significant seasonal variation in 25OHD levels, with the change in monthly ultraviolet dose from summer to winter being followed 6-8 weeks later by a corresponding change in 25OHD levels. Vitamin D insufficiency (25OHD <50 nmol/l) was common. During summer, 28-58% of participants had suboptimal vitamin D status, while in winter, the frequency increased to 56-74%. 25OHD levels correlated with participants' age (r=-0.15), weight (r=-0.11), body mass index (r=-0.13), fat mass (r=-0.14), percentage body fat (r=-0.16), physical activity (r=0.10) and the month of blood sampling (all P<0.0001). Collectively, age, fat mass, physical activity, and month of sampling explained 21% of the variance in 25OHD. No significant relationships were noted between 25OHD and BMD at any site. Other variables that showed significant monthly variation were glucose (P=0.002), serum phosphate, alkaline phosphatase, and albumin (all P<0.0001). There was no monthly variation in BMD at the lumbar spine or proximal femur. In conclusion, there is significant seasonal variation in 25OHD levels, even in a subtropical climate. Furthermore, despite generous amounts of sunlight, considerable numbers of women have suboptimal vitamin D status, even in summer. Our findings support the suggestion that vitamin D supplementation should become standard practice in this population of women, particularly during winter.

Hydrochlorothiazide reduces loss of cortical bone in normal postmenopausal women: a randomized controlled trial

PURPOSE

Thiazide diuretics reduce urine calcium excretion and might therefore reduce postmenopausal bone loss. In some, but not all, case-control studies, their use has been associated with a reduced incidence of hip fractures. We studied the effects of hydrochlorothiazide on bone loss in normal postmenopausal women.

SUBJECTS AND METHODS

We performed a randomized, double-blind, 2-year trial of the effects of hydrochlorothiazide (50 mg per day) and placebo on bone mineral density in normal postmenopausal women. Participants were not required to have either low bone mineral density or hypertension. Bone mineral density was measured using dual-energy x-ray absorptiometry.

RESULTS

One hundred eighty-five women entered the study, of whom 138 completed 2 years of follow-up. In an intention-to-treat analysis, hydrochlorothiazide produced significant benefits on bone mineral density of the total body (between-group difference at 2 years of 0.8%, 95% confidence interval [CI]: 0.3% to 1.3%, P <0.0001), legs (0.9%, 95% CI: 0.2% to 1.7%, P <0.0001), mid-forearm (1.2%, 95% CI: 0.2% to 2.2%, P = 0.02), and ultradistal forearm (1.7%, 95% CI: 0.1% to 3.2%, P = 0.04). There was no effect in the lumbar spine (0.5%, 95% CI: -0.5% to 1.6%) or femoral neck (0.2%, 95% CI: 1.3% to 1.7%). The between-group changes tended to be greatest during the first 6 months, except in the mid-forearm where there appeared to be a progressive divergence. An as-treated analysis produced similar results. Urine calcium excretion and indices of bone turnover decreased in the thiazide group, but parathyroid hormone concentrations did not differ between the groups. Treatment was tolerated well.

CONCLUSIONS

Hydrochlorothiazide (50 mg per day) slows cortical bone loss in normal postmenopausal women. It may act directly on bone as well as on the renal tubule. The small size of the effect suggests that thiazides may have a role in the prevention of postmenopausal bone loss, but that they are not an appropriate monotherapy for treating osteoporosis.