Abstract

Background : Osteoporosis in males is largely under-diagnosed and under-treated, with most diagnoses confirmed only after an osteoporotic fracture. There is an urgent need for highly accurate and precise technologies capable of identifying osteoporosis earlier, thus avoiding complications from fragility fractures.

Aims : This study aimed to evaluate the diagnostic accuracy and precision of the non-ionizing technology Radiofrequency Echographic Multi Spectrometry (REMS) for the diagnosis of osteoporosis in a male population in comparison with conventional Dual-energy X-ray Absorptiometry (DXA).

Methods : A cohort of 603 Caucasian males aged between 30 and 90 years were involved in the study. All enrolled patients underwent lumbar and femoral scans with both DXA and REMS. The diagnostic agreement between REMS and DXA-measured BMD was expressed by Pearson correlation coefficient and Bland-Altman method. The accuracy of the diagnostic classification was evaluated by the assessment of sensitivity and specificity, considering DXA as the reference.

Results : A significant correlation between REMS- and DXA-measured T-score values (r = 0.91, p < 0.0001) for lumbar spine and r = 0.90, p < 0.0001 for femoral neck documented the substantial equivalence of the two measurement techniques. Bland-Altman outcomes showed that the average difference in T-score measurement is very close to zero (−0.06 ± 0.60 g/cm² for lumbar spine and − 0.07 ± 0.44 g/cm² for femoral neck), confirming the agreement between the two techniques. Furthermore, REMS proved effective in discriminating osteoporotic patients from non-osteoporotic ones for both lumbar spine (sensitivity = 90.1%, specificity = 93.6%) and femoral neck (sensitivity = 90.9%, specificity = 94.6%). Precision yielded RMS-CV = 0.40% for spine and RMS-CV = 0.34% for femur.

Conclusion : REMS is a reliable technology for diagnosing osteoporosis in men. This evidence corroborates its high diagnostic performance observed in previous studies involving female populations.

Introduction

Osteoporosis is a systemic skeletal disease that leads to low bone mass and deteriorating bone microarchitecture, significantly increasing fracture risk. Although it has long been considered predominantly a women’s health issue, osteoporosis is also highly prevalent in men. Globally, about 12% of men are affected by osteoporosis, compared to 23% of women. Notably, osteoporosis in men is underdiagnosed and undertreated due to lower screening rates, with most diagnoses occurring only after a fragility fracture.

In Europe, 6.5 million men suffer from osteoporosis, and the U.S. reports that around 10 million individuals over the age of 50 have the condition. Osteoporotic fractures in men are particularly concerning, as they are associated with higher mortality rates than those in women. Furthermore, fractures in elderly men, especially hip fractures, have a much higher mortality rate than in women.

Diagnosis is typically based on Bone Mineral Density (BMD) measurements using Dual-energy X-ray Absorptiometry (DXA), which is the gold standard. However, DXA has its limitations, such as the use of ionizing radiation, potential inaccuracies due to artifacts (e.g., bone deformities or calcifications), and lack of standardization between different devices.

Radiofrequency Echographic Multi-Spectrometry (REMS) is a non-ionizing technology that offers an alternative to DXA, using ultrasound waves to measure bone density. This study evaluates the diagnostic accuracy and precision of REMS for diagnosing osteoporosis in men, comparing its results with DXA.

Methods

Study Design

This study was a multicenter, cross-sectional observational study conducted across four clinical centers in Italy: Galateo Hospital (Lecce), Le Scotte University Hospital (Siena), Careggi University Hospital (Florence), and Borgo Roma Gianbattista Rossi University Hospital (Verona). A total of 603 male patients, aged between 30 and 90 years, participated in the study. These patients underwent lumbar spine and femoral neck BMD measurements using both DXA and REMS.

The study protocol was approved by the ethics review boards of all participating hospitals, and written informed consent was obtained from all participants.

Inclusion and Exclusion Criteria

• Inclusion Criteria: Male patients aged 30–90 years, Caucasian ethnicity, normal weight to obese, medical prescription for DXA examination of lumbar spine or femoral neck, no significant walking impairments.
• Exclusion Criteria: Secondary osteoporosis, significant comorbidities that could interfere with bone health, incomplete or inadequate scan data.

DXA Measurements

DXA scans were performed using a Hologic device according to standard procedures. BMD was measured at the lumbar spine (L1–L4) and femoral neck. The T-score values from DXA were used to classify patients as osteoporotic (T-score ≤ -2.5), osteopenic (-2.5 < T-score < -1.0), or healthy (T-score ≥ -1.0).

REMS Measurements

REMS scans were performed using the EchoStation device (Echolight Spa, Lecce, Italy), equipped with a 3.5 MHz convex transducer. The transducer was placed on the abdomen for lumbar spine scans and on the femoral neck for hip scans. The final BMD report was generated automatically based on unprocessed ultrasound signals.

Diagnostic Accuracy Evaluation

The diagnostic accuracy of REMS was assessed by comparing it to DXA results, calculating sensitivity, specificity, and diagnostic concordance. Pearson’s correlation coefficient was used to evaluate the relationship between DXA and REMS T-scores.

Results

Patient Characteristics

The demographic and clinical characteristics of the enrolled patients are summarized in Table 1 below:

Table 1: Demographic and Clinical Characteristics of the Study Population

Diagnostic Performance of REMS

The correlation between REMS and DXA T-scores for both lumbar spine and femoral neck was high, with Pearson’s correlation coefficients of r = 0.91 (lumbar spine) and r = 0.90 (femoral neck), both p < 0.0001. Figure 1 presents the scatterplot for the correlation between REMS and DXA T-scores.

Table 2 summarizes the diagnostic performance of REMS:

In all the calculations, DXA results obtained for the retained patients after the exclusion of medical reports containing errors were assumed as the reference ground truth.

Note: p < 0.0001 indicates statistical significance.

The Bland-Altman plots comparing T-score values from DXA and REMS for lumbar spine and femoral neck are shown in Figure 2, highlighting the minimal average differences: -0.06 ± 0.60 g/cm² for lumbar spine and -0.07 ± 0.44 g/cm² for femoral neck.

Repeatability and Precision

The short-term precision for REMS was calculated as 0.40% for lumbar spine and 0.34% for femoral neck. The Least Significant Change (LSC) was 1.11% for lumbar spine and 0.95% for femoral neck.

Scatterplot of DXA T-score vs REMS T-score for both lumbar spine and femoral neck.

Bland-Altman plots comparing the T-scores from DXA and REMS.

Discussion

This study demonstrates that REMS is a reliable non-ionizing alternative to DXA for diagnosing osteoporosis in men. The high correlation between REMS and DXA T-scores, along with excellent sensitivity and specificity (above 90%), suggests that REMS could be used as a standalone diagnostic tool. Additionally, REMS offers advantages over DXA, such as avoiding ionizing radiation and providing more precise measurements due to its ability to exclude artifacts from calcifications and bone deformities.

One notable strength of REMS is its ability to detect osteoporosis at both the lumbar spine and femoral neck with high diagnostic performance. Additionally, REMS technology provides short-term precision and inter-operator repeatability that are superior to DXA, making it an attractive option for routine clinical use.

Conclusion

REMS technology shows excellent diagnostic accuracy, precision, and repeatability in evaluating bone health in men. With its non-ionizing nature and high sensitivity and specificity, REMS presents a viable alternative to DXA for osteoporosis diagnosis in men. Its ability to overcome DXA limitations related to ionizing radiation and artifacts further supports its potential for clinical use. Further studies are necessary to confirm the clinical utility of REMS in predicting fracture risk and expanding its use in a broader population.