The sonographic quantitative assessment of the deltoid muscle to detect type 2 diabetes mellitus: a potential noninvasive and sensitive screening method?

BACKGROUND: In our previous published study, we demonstrated that a qualitatively assessed elevation in deltoid muscle echogenicity on ultrasound was both sensitive for and a strong predictor of a type 2 diabetes (T2DM) diagnosis. This study aims to evaluate if a sonographic quantitative assessment of the deltoid muscle can be used to detect T2DM. METHODS: Deltoid muscle ultrasound images from 124 patients were stored: 31 obese T2DM, 31 non-obese T2DM, 31 obese non-T2DM and 31 non-obese non-T2DM. Images were independently reviewed by 3 musculoskeletal radiologists, blinded to the patient's category. Each measured the grayscale pixel intensity of the deltoid muscle and humeral cortex to calculate a muscle/bone ratio for each patient. Following a 3-week delay, the 3 radiologists independently repeated measurements on a randomly selected 40 subjects. Ratios, age, gender, race, body mass index, insulin usage and hemoglobin A1c were analyzed. The difference among the 4 groups was compared using analysis of variance or chi-square tests. Both univariate and multivariate linear mixed models were performed. Multivariate mixed-effects regression models were used, adjusting for demographic and clinical variables. Post hoc comparisons were done with Bonferroni adjustments to identify any differences between groups. The sample size achieved 90% power. Sensitivity and specificity were calculated based on set threshold ratios. Both intra- and inter-radiologist variability or agreement were assessed. RESULTS: A statistically significant difference in muscle/bone ratios between the groups was identified with the average ratios as follows: obese T2DM, 0.54 (P < 0.001); non-obese T2DM, 0.48 (P < 0.001); obese non-T2DM, 0.42 (P = 0.03); and non-obese non-T2DM, 0.35. There was excellent inter-observer agreement (intraclass correlation coefficient 0.87) and excellent intra-observer agreements (intraclass correlation coefficient 0.92, 0.95 and 0.94). Using threshold ratios, the sensitivity for detecting T2DM was 80% (95% CI 67% to 88%) with a specificity of 63% (95% CI 50% to 75%). CONCLUSIONS: The sonographic quantitative assessment of the deltoid muscle by ultrasound is sensitive and accurate for the detection of T2DM. Following further studies, this process could translate into a dedicated, simple and noninvasive screening method to detect T2DM with the prospects of identifying even a fraction of the undiagnosed persons worldwide. This could prove especially beneficial in screening of underserved and underrepresented communities.

Sonographic evaluation of the association between calcific tendinopathy and rotator cuff tear: a case-controlled comparison.

OBJECTIVES: To compare the incidence of rotator cuff (RC) tears on shoulder ultrasounds of patients with RC calcific tendinopathy (CaT) to that of a control group without CaT. METHOD: In this retrospective case-control study, 50 shoulder ultrasounds of patients with CaT were compared independently by 2 musculoskeletal radiologists to 50 patients from a control group without CaT to catalog the number and type of RC tears. RC tears in the CaT group were further characterized based on location, into tears in the specific tendon(s) containing calcium versus all tendon tears. RESULTS: RC tears were diagnosed in 38% (19/50) of the control group (16 full-thickness) as compared to 22% (11/50) with CaT (6 full-thickness). The fewer full-thickness tears in the CaT group (12%, 6 of 50) compared to that in the control group (32%, 16 of 50) was statistically significant (P = 0.016, odds ratio 0.29). Only 7 of the 11 tears in the CaT group were in a calcium-containing tendon (3 full-thickness). The fewer calcium-containing tendon tears compared to tears in the control group was also statistically significant (P = 0.006, odds ratio 0.27). Furthermore, the fewer full-thickness calcium-containing tendon tears (6%, 3/50) compared to full-thickness tears in the control group (32%, 16/50) were yet more statistically significant (P = 0.001, odds ratio 0.14). CONCLUSIONS: In patients with shoulder pain and CaT, we observed a decreased number of RC tears and especially calcium-containing tendon tears, as compared to similar demographic patients with shoulder pain but without CaT. Key Points • Patients with rotator cuff calcific tendinopathy have few rotator cuff tears, especially full-thickness tears, compared to a control group without calcific tendinopathy. • The tendons containing the calcium hydroxyapatite deposition were the least likely to have a rotator cuff tear. • Future studies could evaluate if calcium hydroxyapatite deposition provides a protective mechanism against rotator cuff tears. • Musculoskeletal ultrasound is more sensitive than MRI in the evaluation of rotator cuff calcific tendinopathy.

The Hyperechoic Appearance of the Deltoid Muscle on Shoulder Ultrasound Imaging as a Predictor of Diabetes and Prediabetes.

OBJECTIVES: To evaluate whether the ultrasound appearance of the deltoid muscle in diabetic patients differs from that in obese nondiabetic patients. METHODS: Ultrasound images of the deltoid muscle from 137 type 2 diabetic patients (including 13 prediabetic patients) and 49 obese nondiabetic patients were blindly reviewed by 2 musculoskeletal radiologists, and by a third when arbitration was needed, to determine whether the appearance was "normal," "suspected diabetes," or "definite diabetes." Age, sex, race, body mass index (BMI), insulin use, and hemoglobin A1c were analyzed. This retrospective study included patients presenting between October 2005 and November 2017. Statistical analyses included a 2-sided sample t test or Wilcoxon rank sum test and a χ2 or Fisher exact test. Statistical significance was defined as P < .05. RESULTS: The type 2 diabetic patients included 98 women and 39 men aged 29 to 92 years, and the nondiabetic patients included 19 women and 30 men aged 18 to 75 years. A consensus diagnosis of definite diabetes by the musculoskeletal radiologists based on a hyperechoic deltoid was a powerful predictor of diabetes, with a positive predictive value of 89%. A hyperechoic deltoid was also a powerful predictor of prediabetes. Of the 13 prediabetic patients, all had the same hyperechoic appearance of the diabetic deltoid, regardless of BMI. Although obese diabetic patients more often had a diagnosis of definite diabetes, the BMI alone could not explain the increased echogenicity, as obese nondiabetic patients' deltoid muscles did not appear as hyperechoic and were correctly categorized as not having definite diabetes with 82% specificity. CONCLUSIONS: The characteristic hyperechoic deltoid appearance is a strong predictor of both diabetes and prediabetes and differs from that of obese nondiabetic patients.