Table 1. Demographic and Clinical Characteristics at Baseline for All Participants and Those Randomized to LMMS or Placebo.
| Characteristic | All participants (N = 50), median (IQR) [range] | Median (IQR) | P value | 95% CI for difference in group medians | |
|---|---|---|---|---|---|
| LMMS arm (n = 24) | Placebo arm (n = 26) | ||||
| Age, y | 16.3 (15.1 to 17.6) [11.2 to 26.1] | 16.9 (14.7 to 18.8) | 16.3 (15.2 to 17.2) | .41 | −0.68 to 1.86 |
| Height, cm | 161.7 (157.5 to 166.7) [139.3 to 181.9] | 161.3 (156.6 to 164.2) | 162.1 (157.8 to 166.8) | .52 | −4.30 to 2.40 |
| Weight, kg | 45.6 (43.3 to 50.8) [29.5 to 60.9] | 45.6 (39.1 to 50.7) | 46.1 (44.1 to 50.9) | .44 | −4.85 to 4.44 |
| BMI | 17.8 (16.4 to 18.7) [14.6 to 20.0] | 17.4 (16.1 to 18.6) | 18.2 (16.7 to 19.1) | .55 | −1.90 to 0.60 |
| Percentage of median BMI for age, % | 87.2 (81.0 to 91.6) [51.2 to 102.1] | 86.5 (80.1 to 92.0) | 87.9 (83.7 to 91.6) | .42 | −8.36 to 4.74 |
| Duration of AN, mo | 6.0 (3.0 to 12.0) [0 to 120.0] | 6.5 (3.0 to 32.5) | 6.0 (3.0 to 12.0) | .37 | −4.0 to 18.50 |
| Duration of amenorrhea, mo | 6.0 (3.0 to 11.8) [0 to 78.0] | 6.5 (3.0 to 15.0) | 6.0 (2.0 to 11.0) | .68 | −4.07 to 8.50 |
| Age at menarche, y | 12.0 (11.3 to 13.0) [10.0 to 15.0] | 12.5 (12.0 to 13.0) | 12.0 (11.0 to 13.0) | .41 | −0.50 to 1.00 |
| 25(OH)D, ng/mL | 36.9 (28.2 to 44.8) [18.3 to 68.1] | 33.6 (23.1 to 42.3) | 42.3 (33.3 to 49.6) | .04 | −18.68 to −2.70 |
| PTH, pg/mL | 17.0 (10.8 to 21.3) [8.0 to 36.0] | 17.0 (12.0 to 24.0) | 18.0 (10.8 to 21.3) | .33 | −6.50 to 6.00 |
| Race and ethnicity, No. (%) | |||||
| Asian | 3 (6.0) | 2 (8.3) | 1 (3.9) | .51 | −11.73 to 22.28 |
| Black | 1 (2.0) | 0 | 1 (3.9) | .33 | −10.26 to 18.97 |
| Hispanic | 3 (6.0) | 1 (4.2) | 2 (7.7) | .61 | −13.52 to 2.31 |
| Non-Hispanic | 47 (94.0) | 23 (95.8) | 24 (92.3) | .61 | −13.52 to 2.31 |
| White | 44 (88.0) | 20 (83.4) | 24 (92.2) | .33 | −10.28 to 28.95 |
| Othera | 2 (4.0) | 2 (8.3) | 0 | .14 | −5.90 to 25.81 |
| Total body z score | −0.5 (−1.1 to 0.4) [−3.3 to 2.9] | −0.4 (−1.2 to 0.0) | −0.5 (−1.1 to 0.7) | .64 | −1.15 to 0.60 |
| Spine z score | −0.7 (−1.2 to 0.0) [−2.8 to 2.0] | −0.7 (−1.1 to −0.1) | −0.7 (−1.6 to 0.0) | .95 | −0.60 to 0.75 |
| Total hip z score | −0.4 (−1.1 to 0.1) [−3.1 to 3.0] | −0.6 (−1.1 to 0.0) | −0.4 (−1.1 to 0.4) | .34 | −0.80 to 0.30 |
| DXA total body z score, No. (%) | |||||
| ≤–1 | 14 (28.0) | 7 (29.2) | 7 (28.0) | .93 | −22.71 to 25.35 |
| ≤–2 | 3 (6.0) | 2 (8.3) | 1 (3.9) | .52 | −11.82 to 22.20 |
| DXA spine z score, No. (%) | |||||
| ≤–1 | 18 (36.0) | 9 (37.5) | 9 (34.6) | .83 | −22.28 to 27.85 |
| ≤–2 | 4 (8.0) | 1 (4.2) | 3 (11.5) | .35 | −10.46 to 25.07 |
| DXA total hip z score, No. (%) | |||||
| ≤–1 | 15 (30.0) | 7 (29.2) | 8 (30.8) | .90 | −22.97 to 25.53 |
| ≤–2 | 2 (4.0) | 1 (4.2) | 1 (3.9) | .96 | −15.16 to 16.70 |
Abbreviations: 25(OH)D, 25-hydroxyvitamin D; AN, anorexia nervosa; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); DXA, dual energy x-ray absorptiometry; LMMS, low-magnitude mechanical signals; PTH, parathyroid hormone.
SI conversion factors: To convert 25(OH)D to nanomoles per liter, multiply by 2.4; PTH to nanograms per liter, multiply by 1.
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