Vitamin D supplementation and falls: a trial sequential meta-analysis

BACKGROUND

Vitamin D supplementation is often recommended to prevent falls, although vitamin D trials and meta-analyses of these trials have reported conflicting results for this outcome. We aimed to assess if there was a need for further research.

METHODS

We explored the value of doing further randomised controlled trials assessing the effects of vitamin D supplements on falls with trial sequential analysis with a risk reduction threshold of 15%. All analyses were done using the numbers of participants who had a fall in intention-to-treat analyses. Trial sequential analysis performs a cumulative meta-analysis, but reduces the risk of false-positive results from repetitive statistical testing by maintaining the overall risk of type 1 error at 5%.

FINDINGS

In 20 existing randomised controlled trials (n=29,535), the effect estimate for vitamin D with or without calcium on falls lay within the futility boundary, providing evidence that vitamin D supplementation does not alter the relative risk by 15% or more. In a sensitivity analysis using a risk reduction threshold of 10%, the effect estimate also lay within the futility boundary. In subgroup analyses using a risk reduction threshold of 15%, the effect estimate also lay within the futility boundary for trials of vitamin D supplementation (16 trials, n=22,291) and trials of vitamin D with calcium (six trials, n=9919).

INTERPRETATION

In pooled analyses, supplementation with vitamin D, with or without calcium, does not reduce falls by 15% or more. Future trials with similar designs are unlikely to alter these conclusions. At present, there is little justification for prescribing vitamin D supplements to prevent falls.

FUNDING

Health Research Council of New Zealand.

Republished: Paget's disease of bone: clinical review and update

Paget's disease (PD) is a focal disorder of bone remodelling that occurs commonly in older people. In this article, we review clinical aspects of PD with an emphasis on recent findings. The epidemiology of PD appears to be changing rapidly, with several groups in different parts of the world reporting a marked reduction in the prevalence and incidence of PD, as well as in the severity of disease seen by clinicians. These findings seem most likely to be caused by changes in exposure to unknown environmental factors that have a role in the development of PD. However, genetic factors are also important. Mutations in SQSTM1 occur in 25-50% of familial PD. Genotype-phenotype relationships are present, as PD develops at an earlier age and is more extensive and severe in those with SQSTM1 mutations, and these findings are more pronounced in those with truncating mutations. However, the prevalence of PD in adults with SQSTM1 mutations is uncertain, and it is not known how such mutations might cause PD. Ultimately, if the cause of PD is determined, it seems likely that it will include both genetic and environmental factors. Lastly, clinical trials have shown that potent bisphosphonates are highly effective treatments for active PD, and reduce pain, improve quality of life, normalise bone turnover and heal lytic lesions on radiographs. They can also induce sustained remission that persists for many years.

The effect of vitamin D supplementation on skeletal, vascular, or cancer outcomes: a trial sequential meta-analysis

BACKGROUND

Vitamin D insufficiency is associated with many disorders, leading to calls for widespread supplementation. Some investigators suggest that more clinical trials to test the effect of vitamin D on disorders are needed.

METHODS

We did a trial sequential meta-analysis of existing randomised controlled trials of vitamin D supplements, with or without calcium, to investigate the possible effect of future trials on current knowledge. We estimated the effects of vitamin D supplementation on myocardial infarction or ischaemic heart disease, stroke or cerebrovascular disease, cancer, total fracture, hip fracture, and mortality in trial sequential analyses using a risk reduction threshold of 5% for mortality and 15% for other endpoints.

FINDINGS

The effect estimate for vitamin D supplementation with or without calcium for myocardial infarction or ischaemic heart disease (nine trials, 48 647 patients), stroke or cerebrovascular disease (eight trials 46 431 patients), cancer (seven trials, 48 167 patients), and total fracture (22 trials, 76 497 patients) lay within the futility boundary, indicating that vitamin D supplementation does not alter the relative risk of any of these endpoints by 15% or more. Vitamin D supplementation alone did not reduce hip fracture by 15% or more (12 trials, 27 834 patients). Vitamin D co-administered with calcium reduced hip fracture in institutionalised individuals (two trials, 3853 patients) but did not alter the relative risk of hip fracture by 15% or more in community-dwelling individuals (seven trials, 46 237 patients). There is uncertainty as to whether vitamin D with or without calcium reduces the risk of death (38 trials, 81 173).

INTERPRETATION

Our findings suggest that vitamin D supplementation with or without calcium does not reduce skeletal or non-skeletal outcomes in unselected community-dwelling individuals by more than 15%. Future trials with similar designs are unlikely to alter these conclusions.

FUNDING

Health Research Council of New Zealand.

Effects of vitamin D supplements on bone mineral density: a systematic review and meta-analysis

BACKGROUND

Findings from recent meta-analyses of vitamin D supplementation without co-administration of calcium have not shown fracture prevention, possibly because of insufficient power or inappropriate doses, or because the intervention was not targeted to deficient populations. Despite these data, almost half of older adults (older than 50 years) continue to use these supplements. Bone mineral density can be used to detect biologically significant effects in much smaller cohorts. We investigated whether vitamin D supplementation affects bone mineral density.

METHODS

We searched Web of Science, Embase, and the Cochrane Database, from inception to July 8, 2012, for trials assessing the effects of vitamin D (D3 or D2, but not vitamin D metabolites) on bone mineral density. We included all randomised trials comparing interventions that differed only in vitamin D content, and which included adults (average age >20 years) without other metabolic bone diseases. We pooled data with a random effects meta-analysis with weighted mean differences and 95% CIs reported. To assess heterogeneity in results of individual studies, we used Cochran's Q statistic and the I(2) statistic. The primary endpoint was the percentage change in bone mineral density from baseline.

FINDINGS

Of 3930 citations identified by the search strategy, 23 studies (mean duration 23·5 months, comprising 4082 participants, 92% women, average age 59 years) met the inclusion criteria. 19 studies had mainly white populations. Mean baseline serum 25-hydroxyvitamin D concentration was less than 50 nmol/L in eight studies (n=1791). In ten studies (n=2294), individuals were given vitamin D doses less than 800 IU per day. Bone mineral density was measured at one to five sites (lumbar spine, femoral neck, total hip, trochanter, total body, or forearm) in each study, so 70 tests of statistical significance were done across the studies. There were six findings of significant benefit, two of significant detriment, and the rest were non-significant. Only one study showed benefit at more than one site. Results of our meta-analysis showed a small benefit at the femoral neck (weighted mean difference 0·8%, 95% CI 0·2-1·4) with heterogeneity among trials (I(2)=67%, p<0·00027). No effect at any other site was reported, including the total hip. We recorded a bias toward positive results at the femoral neck and total hip.

INTERPRETATION

Continuing widespread use of vitamin D for osteoporosis prevention in community-dwelling adults without specific risk factors for vitamin D deficiency seems to be inappropriate.

FUNDING

Health Research Council of New Zealand.

The Auckland calcium study: 5-year post-trial follow-up

Five years after completion of a randomised placebo-controlled trial of calcium supplements, there was no effect of calcium on total fracture incidence, a significant reduction in vertebral and forearm fractures and, in a subset, no effect on bone density. There was no increased risk of cardiovascular events after discontinuation of calcium.

INTRODUCTION

The Auckland calcium study was a 5-year randomised controlled trial of 1 g/day calcium citrate in 1,471 postmenopausal women. Calcium did not reduce total, vertebral or forearm fracture incidence, increased hip fracture incidence and had beneficial effects on bone mineral density (BMD). A secondary analysis raised concerns about the cardiovascular safety of calcium. The purpose of this study was to determine whether the effects of calcium on fracture incidence, BMD and cardiovascular endpoints persisted after supplement discontinuation.

METHODS

Approximately 5-years post-trial, we collected information on the 1,408 participants alive at trial completion from the national databases of hospital admissions and deaths. We contacted 1,174 women by phone, and from these we obtained information on medical events and post-trial calcium use. We undertook BMD measurements at 10 years in a selected subset of 194 women who took study medication for 5 years in the original trial, and did not take bone-active medications post-trial.

RESULTS

Over the 10-year period, there was no effect on total fracture (HR 0.90, 95% CI 0.75-1.07) or hip fracture incidence (1.40, 0.89-2.21), but significant reductions in forearm (0.62, 0.43-0.89) and vertebral fractures (0.52, 0.32-0.85) in those assigned to calcium. There were no between-group differences in BMD at 10 years at any site. The adverse cardiovascular outcomes observed in the 5-year trial did not persist post-trial.

CONCLUSION

Calcium supplementation for 5 years had no effect on total fracture incidence at 10 years. The positive benefits on BMD and the adverse cardiovascular effects did not persist once supplements were stopped.

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.

Calcium supplements and cardiovascular risk: 5 years on

Calcium supplements have been widely used by older men and women. However, in little more than a decade, authoritative recommendations have changed from encouraging the widespread use of calcium supplements to stating that they should not be used for primary prevention of fractures. This substantial shift in recommendations has occurred as a result of accumulated evidence of marginal antifracture efficacy, and important adverse effects from large randomized controlled trials of calcium or coadministered calcium and vitamin D supplements. In this review, we discuss this evidence, with a particular focus on increased cardiovascular risk with calcium supplements, which we first described 5 years ago. Calcium supplements with or without vitamin D marginally reduce total fractures but do not prevent hip fractures in community-dwelling individuals. They also cause kidney stones, acute gastrointestinal events, and increase the risk of myocardial infarction and stroke. Any benefit of calcium supplements on preventing fracture is outweighed by increased cardiovascular events. While there is little evidence to suggest that dietary calcium intake is associated with cardiovascular risk, there is also little evidence that it is associated with fracture risk. Therefore, for the majority of people, dietary calcium intake does not require close scrutiny. Because of the unfavorable risk/benefit profile, widespread prescribing of calcium supplements to prevent fractures should be abandoned. Patients at high risk of fracture should be encouraged to take agents with proven efficacy in preventing vertebral and nonvertebral fractures.

Paget's disease of bone: clinical review and update

Paget's disease (PD) is a focal disorder of bone remodelling that occurs commonly in older people. In this article, we review clinical aspects of PD with an emphasis on recent findings. The epidemiology of PD appears to be changing rapidly, with several groups in different parts of the world reporting a marked reduction in the prevalence and incidence of PD, as well as in the severity of disease seen by clinicians. These findings seem most likely to be caused by changes in exposure to unknown environmental factors that have a role in the development of PD. However, genetic factors are also important. Mutations in SQSTM1 occur in 25-50% of familial PD. Genotype-phenotype relationships are present, as PD develops at an earlier age and is more extensive and severe in those with SQSTM1 mutations, and these findings are more pronounced in those with truncating mutations. However, the prevalence of PD in adults with SQSTM1 mutations is uncertain, and it is not known how such mutations might cause PD. Ultimately, if the cause of PD is determined, it seems likely that it will include both genetic and environmental factors. Lastly, clinical trials have shown that potent bisphosphonates are highly effective treatments for active PD, and reduce pain, improve quality of life, normalise bone turnover and heal lytic lesions on radiographs. They can also induce sustained remission that persists for many years.

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.

Differences between self-reported and verified adverse cardiovascular events in a randomised clinical trial

OBJECTIVES

In clinical trials, adverse events are usually self-reported but may be adjudicated if serious or of particular interest. After adjudicating cardiovascular events for a 5-year calcium supplement trial, we observed discrepancies between self-reported and verified events. We systematically analysed those differences to assess their importance.

DESIGN

Secondary analysis of adverse cardiovascular events in a 5-year, randomised, placebo-controlled trial of calcium supplementation (1 g calcium daily) in 1471 postmenopausal women (mean age 74 years).

SETTING

Clinical research centre.

METHODS

The participant's medical records were reviewed for all self-reported myocardial infarctions (MIs) or strokes, and the event independently adjudicated. Cause of death was obtained from hospital records or death certificates. To identify unreported events, the national hospital discharge database was searched and related hospital records were reviewed.

RESULTS

45 women reported 64 MIs, of which 33 (52%) were verified after adjudication. An additional 25 MIs were identified: 1 during adjudication of other events, 21 from the hospital discharge database, 3 from death certificates. 68 women reported 86 strokes of which 50 (58%) were verified. An additional 13 strokes were identified: 7 during adjudication of reported transient ischaemic attacks, 5 from the hospital discharge database, 1 from death certificates. Therefore, 43% of verified MIs and 21% of verified strokes were not reported to investigators. For non-adjudicated discharge codes, 10% of MIs and 22% of strokes were not verified after adjudication. Nineteen per cent of verified MIs and 27% of verified strokes were not identified in discharge coding or death certificates. Neither the event source nor the level of adjudication altered the relationship between treatment allocation and cardiovascular events.

CONCLUSIONS

When adverse event accuracy is critical, researchers should consider adjudicating self-reported events and hospital discharge codes, and attempt to identify unreported events.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials registry: ACTRN 012605000242628.

Subgroup analysis for the risk of cardiovascular disease with calcium supplements

Calcium supplements have been reported to increase the risk of myocardial infarction (MI). We wished to determine whether the effects of calcium supplements on cardiovascular risk vary across different population groups. We modeled the effect of calcium (with or without vitamin D) on the time to incident cardiovascular events in pre-specified subgroups based on age, dietary calcium intake, body mass index, smoking history, history of hypertension, diabetes and prevalent cardiovascular disease, using interaction terms in Cox proportional hazards models in two randomized controlled trial data sets—our re-analysis of the Women's Health Initiative Calcium and Vitamin D study (WHI CaD), and our pooled patient-level meta-analysis of trials of calcium supplements with or without vitamin D. For women in WHI CaD not taking calcium supplements at randomization (n=16 718), we found no significant interactions between treatment allocation, the risk of MI, stroke or coronary revascularization, or any of the baseline variables. In the pooled patient-level data set of six trials of calcium with or without vitamin D (n=24 869), there were also no significant interactions between treatment allocation, risk of MI or stroke, and any of the baseline variables. We found no evidence that the increased cardiovascular risk from calcium supplements differs across varying patient subpopulations. These findings suggest that targeted prescription of calcium supplements to specific population subgroups, such as younger people and those with low dietary calcium intake, should not be endorsed.

The effect of treatments for osteoporosis on mortality

The incidence of osteoporotic fractures increases exponentially in later life, in parallel with the progression of frailty and the risk of dying. Several pharmacologic therapies are now available that reduce the risk of fragility fractures. Data from observational studies report that osteoporotic fractures are associated with an increased risk of dying, particularly in the first few years after an event, and that, in osteoporotic populations, bisphosphonate therapy is associated with a reduced risk of death. Data emerging from randomised controlled trials suggest that drugs which significantly reduce fracture risk might also prolong survival in osteoporotic populations. Further research into the nature, magnitude and mechanisms of the effects of osteoporosis treatments on mortality is required, but in the interim, clinicians and their patients should consider the available data in their deliberations about the use of these medications.

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.

Five years of anti-resorptive activity after a single dose of zoledronate--results from a randomized double-blind placebo-controlled trial

Intravenous zoledronate 5 mg, administered annually, prevents fractures in people with osteoporosis, but the optimal dosing schedule is not known. Previously, we reported that a single dose of 5 mg zoledronate stably decreased bone turnover and increased bone mineral density (BMD) for 3 years in a randomized controlled trial in 50 postmenopausal women with osteopenia. We have now completed a 2-year double-blind extension of this trial, during which no additional treatment was administered. The primary endpoint was change in the bone turnover markers procollagen type-I N-terminal propeptide (P1NP) and β-C-terminal telopeptide of type I collagen (β-CTX); the secondary endpoint was change in BMD at lumbar spine, total hip and total body. Mean levels of the each of the bone turnover markers were lower in the zoledronate group throughout the study (P<0.0001 for each marker). After 5 years, mean (95% CI) levels of β-CTX and P1NP were 277 ng/L (150, 404) and 28 μg/L (16, 40) lower in the zoledronate group, corresponding to reductions of 48% and 45%, respectively. BMD was higher in the zoledronate group during the study (P<0.0001 for each site). After 5 years, BMD in the zoledronate group was higher by 4.2% (1.1, 7.2) at the lumbar spine, by 5.3% (2.7, 7.9) at the total hip, and by 2.7% (1.1, 4.2) at the total body. These findings suggest that the anti-resorptive effects of a single 5 mg dose of zoledronate persist for at least 5 years in postmenopausal women. Trials assessing the anti-fracture efficacy of dosing intervals of zoledronate of up to 5 years are justified.

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.

Role of vitamin D deficiency in cardiovascular disease

Vitamin D is a fat-soluble secosteroid produced in the skin as a result of sunlight exposure, and its circulating levels are reduced in a wide variety of chronic illnesses and obesity. Observational studies clearly demonstrate a higher incidence of cardiovascular events in individuals with low circulating 25-hydroxyvitamin D [25(OH)D]. This relationship can potentially be explained by confounding, because individuals with low 25(OH)D are generally older, frailer, heavier, and have more comorbidities and higher estimated cardiovascular risk than individuals with higher 25(OH)D. The vitamin D receptor appears to be widely distributed, including in cardiovascular tissue, although this has recently been contested. Despite these epidemiological and laboratory findings, meta-analyses of clinical trials have not shown evidence of beneficial effects of vitamin D supplementation on cardiovascular endpoints. Trials are underway to assess these possibilities further. At present, there is insufficient evidence to support vitamin D supplementation for improving cardiovascular outcomes.

Incidental vertebral fractures on computed tomography

Vertebral fractures are the most common osteoporotic fracture and predict subsequent fracture and mortality. We undertook an audit (Auckland City Hospital, Auckland, New Zealand) to determine whether targeted assessment for incidental vertebral fractures on computed tomography (CT) examinations of the chest or abdomen in older people would detect previously unidentified vertebral fractures. In 175 consecutive patients aged >65 years, sagittal images of the spine were obtained by reformatting data from CT examinations of the chest or abdomen. Vertebral fractures were assessed using a semi-quantitative technique. The prevalence of vertebral fractures was 13%, with 41 vertebral fractures identified in 22 patients; 12/22 (55%) had vertebral fracture mentioned in the formal CT report, and 2/12 patients with contemporaneous plain films had vertebral fracture mentioned in the X-ray report. The vertebral fracture was newly identified in 17 (77%) patients, but vertebral fracture and osteoporosis were each listed in the relevant discharge summary or clinic letter for only 14% of patients, and only 31% of patients with fracture subsequently received osteoporosis treatment. In summary, assessing sagittal spine images reformatted from CT examinations of the chest or abdomen detects previously unidentified vertebral fractures, offering an undervalued opportunity to assess fracture risk and intervene with treatments that prevent fractures and reduce mortality.

Should measurement of vitamin D and treatment of vitamin D insufficiency be routine in New Zealand?

Epidemiological studies have reported associations between lower vitamin D levels and a great variety of diseases, prompting calls for widespread treatment of individuals with low vitamin D levels. Most of New Zealand's population have vitamin D levels for at least part of the year that are considered insufficient (25-hydroxyvitamin D <50-80 nmol/L). However, evidence for benefits of vitamin D supplementation in such populations is controversial and there is some evidence of harmful effects. Until adequately powered, randomised, controlled trials of vitamin D supplementation demonstrate safe improvements in health, clinicians should not focus on detecting/treating individuals with vitamin D insufficiency, instead treating those at high risk of vitamin D deficiency (25-hydroxyvitamin D <25 nmol/L), such as the frail elderly, and those with specific clinical indications. Treatment for such individuals does not require vitamin D measurements. Requests for vitamin D measurements in Auckland have nearly quadrupled in the past decade, from 8500 in the year 2000 to 32,800 in 2010, with substantial increases in cost. Vitamin D measurement is often inaccurate and imprecise, and the vast majority of tests performed currently do not reveal vitamin D deficiency. Therefore, a move away from routine vitamin D measurements seems sensible, though they are still indicated when investigating suspected metabolic bone disease or hypocalcaemia.

Mortality and morbidity in Cushing's syndrome in New Zealand

OBJECTIVE

Untreated Cushing's syndrome (CS) is associated with significant morbidity and mortality. However, recent operative series suggest low morbidity and mortality for CS, whereas population-based surveys report elevated mortality rates. We investigated the mortality and morbidity of CS in New Zealand.

DESIGN

A nationwide retrospective survey of patients with CS between 1960 and 2005 managed at the four main endocrinology services.

PATIENTS

A total of 253 patients with CS were identified, excluding adrenal carcinoma and malignant ectopic CS. MEASUREMENTS; The primary outcome was the standardized mortality ratio (SMR), comparing the observed number of deaths with the expected number for the population matched for age, sex and duration of follow-up. Secondary outcomes were the change in prevalence of co-morbidities at presentation and at final follow-up.

RESULTS

The approximate prevalence and incidence of CS was 79/million and 1·8/million/y. The mean age at presentation was 39 year, and median duration of follow-up was 6·4 year (range 0-46). Overall, 89% achieved biochemical cure at last follow-up, with >90% achieving biochemical cure for CS from adrenal adenoma and pituitary causes. Thirty-six patients died during follow-up compared with 8·8 expected deaths (SMR 4·1, 95%CI 2·9-5·6). While hypertension, sexual dysfunction, myopathy and mild psychiatric illness were significantly reduced after treatment, hypertension, diabetes mellitus, moderate or major psychiatric illness, and osteoporosis were common at final follow-up.

CONCLUSION

CS is associated with both high mortality and a high prevalence of co-morbidities, even when biochemical cure rates are between 80% and 90%.

Calcium and vitamin D supplements and health outcomes: a reanalysis of the Women's Health Initiative (WHI) limited-access data set

BACKGROUND

Frequent use of personal, nonprotocol calcium supplements obscured an adverse effect of coadministered calcium and vitamin D (CaD) on cardiovascular risk in the Women's Health Initiative (WHI).

OBJECTIVE

We investigated the effects of the use of personal calcium or vitamin D supplements on other outcomes in the WHI CaD Study (WHI CaD) by using the WHI limited-access clinical trials data set.

DESIGN

The WHI CaD was a 7-y, randomized, placebo-controlled trial of CaD (1 g Ca/400 IU vitamin D daily) in 36,282 community-dwelling, postmenopausal women. The incidence of total cancer (excluding nonmelanoma skin cancers), breast and colorectal cancers, hip and total fracture, and mortality was assessed by using Cox proportional hazards models.

RESULTS

In the WHI CaD, interactions between the use of either personal calcium or vitamin D supplements and CaD were found for total, breast, and colorectal cancers but not for fracture or mortality. In 15,646 women (43%) who were not taking personal calcium or vitamin D supplements at randomization, CaD significantly decreased the risk of total, breast, and invasive breast cancers by 14-20% and nonsignificantly reduced the risk of colorectal cancer by 17%. In women taking personal calcium or vitamin D supplements, CaD did not alter cancer risk (HR: 1.06-1.26).

CONCLUSIONS

For women in the WHI CaD who were not taking personal calcium or vitamin D supplements at randomization, CaD decreased the risk of total, breast, and colorectal cancers and did not change the risk of fractures or total mortality. The nonskeletal effects of CaD may be more important than the skeletal effects and should be considered when evaluating these supplements. The WHI CaD trial is registered at clinicaltrials.gov as NCT00000611.

Stable bone density in HAART-treated individuals with HIV: a meta-analysis

CONTEXT

Longitudinal studies of bone mineral density (BMD) in HIV have reported conflicting results.

OBJECTIVE

We investigated whether temporal changes in BMD differ by highly active antiretroviral therapy (HAART) status at baseline.

DATA SOURCES

Data sources included MEDLINE, EMBASE, and the Web of Science for English language studies (1966 to September 2010) and conference abstracts (1997-2010).

STUDY SELECTION

Longitudinal studies reporting BMD at least 48 wk apart in adult patients with HIV with a comparable uninfected control group were eligible. Uncontrolled studies were included in secondary analyses.

DATA EXTRACTION

Data were independently extracted by two researchers.

DATA SYNTHESIS

Data were pooled using random-effects models. In the primary analysis of six controlled studies (follow-up 1.5-2.7 yr), there were no significant differences in the percent change from baseline in BMD at the total hip or femoral neck between HIV cohorts and controls and a decrease of 0.6% (95% confidence interval = -1.1 to -0.1) at the spine in the HIV cohorts. In the secondary analysis of 37 studies (31 uncontrolled, six controlled), cohorts treated with HAART at baseline had stable or slight increases in BMD at 1 yr, stable or slight decreases in BMD at 2 yr, and stable BMD at 2.5 yr or later. In cohorts that were HAART-naive/untreated at baseline, there was accelerated loss of BMD at all time points, and the annualized rate of BMD change was greatest at 1 yr, but thereafter decreased.

CONCLUSION

BMD is stable in HIV cohorts established on HAART, whereas cohorts initiating HAART have short-term accelerated BMD loss followed by a longer period of BMD stability/increases. Routine monitoring of BMD in many HAART-treated patients may not be necessary.