Lower bone mineral density in geriatric patients with monoclonal gammopathy of undetermined significance

What is the significance of monoclonal gammopathy of undetermined significance?

Monoclonal gammopathy of undetermined significance (MGUS) is characterised by the presence of a monoclonal paraprotein in the blood, without the characteristic end organ damage seen in multiple myeloma. MGUS is more common in older age groups and has a risk of progression to myeloma of 1% per year. Population screening is not currently recommended, but retrospective studies have suggested improvements in myeloma outcomes in those under MGUS follow-up; in addition, MGUS has associated complications, including fracture, osteoporosis, renal disease and infection, which can be treated. Given this increasing evidence of disease related directly to MGUS, strategies for early identification might be needed. In this review, we discuss the complications of MGUS and whether MGUS fulfils the criteria needed to implement a screening programme. We also highlight areas where more evidence is needed, including identification of a higher risk population to make screening more practical and economically viable.

Monoclonal gammopathy of undetermined significance and bone health outcomes: a systematic review and exploratory meta-analysis

Monoclonal gammopathy of undetermined significance (MGUS) is a common condition in the elderly. A number of studies have investigated the relationship between MGUS and bone health outcomes including bone mineral density (BMD), osteoporosis and fractures, but no meta-analysis exists. We conducted a systematic review and exploratory meta-analysis comparing bone health outcomes in patients with MGUS. Two independent authors searched PubMed and Scopus from inception until 19 October 2016. A meta-analysis of cross-sectional and longitudinal studies investigating fractures and BMD was conducted. Standardised mean differences (SMD) ± 95% confidence intervals (CIs) were calculated for BMD, and risk ratios (RRs) were calculated for prevalent and incident fractures. Of 174 initial hits, 10 studies of moderate methodological quality were eligible, including 8711 individuals with MGUS vs. 52,865 controls. Compared to controls, subjects with MGUS showed significantly lower values for radial cortical volumetric BMD (1 study; SMD = -5.45, 95% CI: -7.24 to -3.66), but not at the lumbar spine, femoral neck or hip. The incidence of fractures was higher in people with MGUS (n = 7466) vs. controls (n = 52,304) (RR = 1.36, 95% CI 1.28-1.44, I ² = 0%) over a median of 12.5-year follow-up. The incidence of vertebral fractures was particularly elevated (RR = 2.50, 95% CI 1.53-4.06) although limited to two studies. In conclusion, although with limitations, our preliminary meta-analysis suggests that patients with MGUS are at higher risk of fractures despite evidence for differences in BMD being equivocal. Future longitudinal research is required to confirm our findings and determine if fracture prevention interventions are warranted in people with MGUS.

Secondary osteoporosis and metabolic bone disease in patients 50 years and older with osteoporosis or with a recent clinical fracture: a clinical perspective

PURPOSE OF REVIEW

The purpose of this review is to provide guidance to clinicians about which laboratory tests should be performed in patients with osteoporosis or with a recent fracture.

RECENT FINDINGS

Newly diagnosed secondary osteoporosis and other metabolic bone diseases (SECOB) have been found in 5-48% of patients with osteoporosis. In patients with a recent fracture, new SECOB is found in 10-47% of patients with osteoporosis, and in 26-51% if all patients with a fracture regardless of bone mineral density (BMD) are screened. More than one SECOB can be found in the same patient, even when they have already known SECOB. In primary hyperparathyroidism, hyperthyroidism, hypercortisolism, and multiple myeloma, both SECOB and its treatment have an impact on BMD and fractures. For other SECOBs, no treatment is available, or there are no data about the effect of treatment of the SECOB on BMD and fractures.

SUMMARY

We recommend performing the following tests in all patients with osteoporosis or a recent clinical fracture: calcium, phosphate, creatinine, albumin, erythrocyte sedimentation rate in all patients, 24 h urine calcium in men and serum testosterone in men less than 70 years. On indication, additional tests can be performed.

Monoclonal gammopathy of undetermined significance: an update for nephrologists

Screening for a monoclonal protein is a common part of the assessment of patients presenting with a renal injury. While in the settings of acute kidney injury, chronic kidney disease and proteinuria monoclonal proteins can be associated with significant pathologies such as cast nephropathy, amyloidosis, and light chain deposition disease, they can also be an unrelated finding. The purpose of this review is to provide the nephrologist with an update to the diagnostic assessment and risk stratification of monoclonal proteins to avoid unnecessary investigation and monitoring of those patients with low-risk monoclonal gammopathies.

Zoledronic acid markedly improves bone mineral density for patients with monoclonal gammopathy of undetermined significance and bone loss

PURPOSE

Patients with monoclonal gammopathy of undetermined significance (MGUS) have increased rates of bone resorption, osteopenia, osteoporosis, and risk of fractures. This study was undertaken to determine the efficacy and safety of zoledronic acid for patients with MGUS and enhanced bone loss.

EXPERIMENTAL DESIGN

In this phase II open-label study, 54 patients with MGUS and osteopenia or osteoporosis were administered zoledronic acid 4 mg i.v. at 0, 6, and 12 months. The primary efficacy end point was bone mineral density, assessed using a dual-energy X-ray absorptiometry scan in the lumbar (L)-spine done at screening and at 13 months (1 month after the final zoledronic acid infusion).

RESULTS

At study end for all patients (N = 54), L-spine T-scores improved by a median of +0.27 (range, -0.38 to +3.91), corresponding to a median increase in bone mineral density of +15.0% (range, -18.0% to +1,140.0%; P < 0.0001). Hip T-scores improved by a median of +0.10 (range, -2.40 to +2.03), corresponding to a median increase of +6.0% (range, -350.0% to +165.0%). During the study, no new fractures, osteonecrosis of the jaw, or significant renal adverse events were reported.

CONCLUSIONS

Zoledronic acid administered i.v. at a dosage of 4 mg every 6 months for three doses total was well-tolerated and substantially improved bone mineral density for patients with MGUS and bone loss. Zoledronic acid may be effective for the prevention of new fractures in this high-risk population.