Editorial Comment on: The Impact of Thiazides and Potassium Citrate on Bone Mineral Density Evaluated by CT Scan in Stone Formers by Alshara et al.

The current study shows the utility of opportunistic capture of bone mineral density (BMD) measurement utilizing noncontract CT scans in patients being monitored for stone recurrence. With the ubiquitous adoption of CT scanning worldwide, there are many clinical data points that can be measured on each study. Similar studies monitoring bone density loss have been described in male patients who smoke cigarettes (BMD obtained on screening chest CT) and a proof-of-concept study comparing female patients with osteoporosis (BMD measured on noncontrast CT imaging compared with the gold-standard dual-energy X-ray absorptiometry [DEXA] scan.). ^1,2 As expected, the authors documented increased BMD with thiazide diuretic therapy and citrate supplementation on longitudinal BMD measurements. Importantly, two-thirds of the study patients had increased bone density after treatment and 16% had increased bone density back to the normal range after only 1 year of medical therapy. Somewhat surprisingly, citrate therapy alone appeared to demonstrate quite significant increased bone density than either combination therapy or the use of thiazide diuretics alone.

The caveats for the study are the need to correlate the CT density measurement in Hounsfield units with conventional DEXA scanning and to agree on the best anatomic site to follow serial measurements for longer time intervals. Osteopenia and osteoporosis remain important clinical conditions that often require additional pharmacologic therapy for decades. For stone-forming patients, the use of thiazides and citrate is the basis of our stone prevention interventions as documented in the current guidelines for medical treatment of stone disease. ³ With increasing attention to limiting medical expenditures and possibly curtailing imaging studies, physicians should maximize clinical data obtained from all imaging modalities while monitoring patients over time. The authors should be commended for undertaking this study and should continue longitudinal monitoring to help validate this technique for wider clinical practice. Many studies often generate more questions than are answered by the original hypothesis. Ideally, larger population-based studies need to be done to correlate the BMD measurements and possibly modify our medical therapy and surveillance guidelines based on the longer term results.