37 The Routine Use of Bioimpedance Spectroscopy Measurements in the Clinic as a Surrogate for Bone Mineral Content in Oncology Patients: Practical Application of the SOZO Device

Background

Many patients with cancer, particularly those with breast or prostate cancer, receive hormonal manipulation therapies that can significantly impact their bone mineral content (BMC), potentially leading to life-threatening fractures, especially given the often advanced age of patients with these malignancies. Bioimpedance spectroscopy (BIS) is a noninvasive tool that measures fluid and body composition values including skeletal muscle mass (SMM) and fat-free mass (FFM). ImpediMed’s SOZO BIS device can be used easily and quickly at point-of-care as the patient stands on the device, placing their hands and feet on metal electrodes. Multiple studies have shown a strong correlation between SMM and bone, suggesting that a SOZO reading can provide a reproducible, simple, and quick estimate of BMC. To that end, we present initial findings correlating SOZO BIS readings with dual x-ray absorptiometry (DXA) to determine if BIS readings can be applied as an accurate surrogate measure of BMC.

Materials and Methods

Concurrent BIS measures and DXA scans were performed in 75 healthy patients and in 76 with cancer (during and after cancer treatment), including: Group 1 (75 healthy cases [32 male, 43 female]; mean age, 27.4 years [range, 18-66]); Group 2 (35 patients undergoing cancer treatment [8 male, 27 female]; 13 breast, 5 lung, 4 endometrial, 4 colorectal, 3 prostate, 6 other cancers; mean age, 60.4 years [range, 39-79]); and Group 3 (41 patients participating in a 12-week exercise program after cancer treatment [11 males, 30 females]; 20 breast, 5 prostate, 3 colorectal, 3 endometrial, 10 other cancers; mean age, 58.4 years [range, 20-79]).

Results

The Pearson correlation coefficient (R) for DXA BMC and SOZO SMM were strong for all 3 groups (R = 0.92, 0.86, and 0.78 for groups 1, 2, and 3, respectively). Stepwise multiple linear regression for BMC was performed. For group 1, age, FFM, and height resulted in a multiple correlation coefficient of 0.94 (P <.001); for groups 2 and 3 combined, BMC was dependent on height (P = .03) and SMM (P <.0001) for a multiple correlation coefficient of 0.815 (P <.001).

Conclusions

Concurrent measures of SOZO SMM correlated strongly with DXA BMC, demonstrating that SOZO SMM may be a useful surrogate in the clinic to provide a quick, easy, and reproducible indicator of change in BMC, particularly for those patients undergoing treatments that may affect BMC. Tracking SMM during or after cancer treatment with SOZO may provide an estimate of changes in BMC, allowing clinicians to obtain additional diagnostic testing and/or consider treatment modifications.

Author Affiliations:

Steven Shivers,¹ Pat Whitworth,² Rachel Rabinovitch,³ Frank Vicini, Chirag Shah, Fredrik Wärnberg, G. Bruce Mann, Karuna Mittal, Troy Bremer

¹PreludeDx, Laguna Hills, CA
²Nashville Breast Center, Nashville, TN

³University of Colorado, Colorado Springs, CO