Journal of Thyroid Research

Research Article

Bone Indices in Thyroidectomized Patients on Long-Term Substitution Therapy with Levothyroxine Assessed by DXA and HR-pQCT

Table 5

Bone indices as measured by HR-pQCT scans in patients on long-term treatment with levothyroxine and matched controls. Median with interquartile (25%–75% percentiles) range.
HR-pQCTPatientsControls value
Distal radius ( = 94)   
 Geometry   
  Total area (mm2)273.9 (248.1–344.5)282.2 (246.5–336.0)0.74
  Cortical area (mm2)57.7 (44.9–66.0)57.7 (49.7–67.8)0.35
  Trabecular area (mm2)221.0 (185.0–266.6)221.2 (189.2–253.7)0.87
 Volumetric BMD   
  Total bone density (mg HA/cm3)315.1 (261.7–360.7)330.3 (286.4–366.8)0.56
  Cortical bone density (mg HA/cm3)879.2 (848.8–935.7)899.6 (862.8–930.4)0.50
  Trabecular bone density (mg HA/cm3)152.8 (125.6–179.1)161.1 (124.4–176.4)0.60
  Meta trabecular bone density (mg HA/cm3)212.0 (190.1–227.8)219.8 (191.7–236.8)0.48
  Inner trabecular bone density (mg HA/cm3)111.0 (85.6–141.0)117.9 (83.7–136.2)0.73
 Microarchitecture   
   Cortical thickness (mm)0.78 (0.63–0.94)0.81 (0.69–0.97)0.41
  TbTh (µm)64 (54–69)61 (58–72)0.89
  Tb.N (mm−1)2.01 (1.77–2.20)2.00 (1.80–2.22)0.92
  Tb.Sp (mm)0.43 (0.38–0.50)0.43 (0.39–0.50)0.91
  TrBV/TV0.13 (0.11–0.15)0.13 (0.10–0.15)0.59
  Tb.N.SD (mm)0.17 (0.16–0.21)0.18 (0.15–0.22)0.53
 Estimated strength   
  Failure load (N)3903 (3166–4578)3985 (3315–4625)0.69
  Stiffness (kN/mm)82.6 (65.8–97.9)83.4 (71.8–96.1)0.58
Distal tibia ( = 98)   
 Geometry   
  Total area (mm2)733.4 (632.2–821.7)728.7 (661.3–814.5)0.83
  Cortical area (mm2)121.8 (99.3–137.6)123 (95.9–140.4)0.83
  Trabecular area (mm2)574.6 (510.3–702.5)614.9 (525.2–688.1)0.76
 Volumetric BMD   
  Total bone density (mg HA/cm3)290.9 (253.4–318.3)279.8 (239.7–326.7)0.98
  Cortical bone density (mg HA/cm3)852.7 (821.4–913.3)860.5 (826.6–910.9)0.94
  Trabecular bone density (mg HA/cm3)158.8 (135.5–182.1)167.9 (140.2–193.2)0.57
  Meta trabecular bone density (mg HA/cm3)228.0 (200.3–249.8)232.9 (202.2–254.0)0.61
  Inner trabecular bone density (mg HA/cm3)117.6 (91.5–141.8)123.2 (96.0–150.9)0.46
 Microarchitecture   
   Cortical thickness (mm)1.17 (0.93–1.31)1.07 (0.91–1.34)0.72
  TbTh (µm)70 (63–83)73 (64–81)0.92
  Tb.N (mm−1)1.80 (1.70–2.08)1.88 (1.70–2.12)0.36
  Tb.Sp (mm)0.45 (0.40–0.51)0.48 (0.41–0.53)0.39
  TrBV/TV0.13 (0.11–0.15)0.14 (0.12–0.16)0.58
  Tb.N.SD (mm)0.21 (0.17–0.24)0.20 (0.17–0.23)0.47
 Estimated strength   
  Failure load (N)10016 (8989–11713)10319 (8848–11867)0.80
  Stiffness (kN/mm)210.4 (188.1–248.1)215.6 (187.8–249.8)0.74
Tb.N: Trabecular numbers.
Tb.Sp: Trabecular separation.
Tb.N.SD: Standard deviation of 1/Tb.N.