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Table 2 Rates of change in bone mineral density and bone turnover markers

From: Bone turnover in elderly men: relationships to change in bone mineral density

  Symbol Estimated parameters ± standard error (SE) for
   Femoral neck BMD Lumbar spine BMD sPINP sICTP
Parameters      
Baselinea α 943.0 ± 13** 1288.0 ± 20.3** 40. 1 ± 1.3* 4.3 ± 0.12**
Rate of changeb β -3.5 ± 1.0** 7.4 ± 1.3** -0.4 ± 0.18* 0.08 ± 0.02*
Variance components      
Baseline σ α 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGae8xSdegabaGaeGOmaidaaaaa@312F@ 16650 ± 2453** 38968 ± 5883** 130.8 ± 25* 0.81 ± 0.22**
Rate of change σ β 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGae8NSdigabaGaeGOmaidaaaaa@3131@ 44 ± 6* 2 ± 30 0.4 ± 0.51 0.01 ± 0.05
Covariance σ α β 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGae8xSdeMae8NSdigabaGaeGOmaidaaaaa@32CB@ 43 ± 135 876 ± 283** -1.1 ± 2.7 0.07 ± 0.03**
Random error σ e 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGaemyzaugabaGaeGOmaidaaaaa@30E8@ 908 ± 131** 3234 ± 327** 52.6 ± 6.8** 0.84 ± 0.08**
  1. sICTP, serum C-terminal telopeptide of type I collagen; sPINP, serum N-terminal propeptide of type I collagen; BMD bone mineral density.
  2. Units of measurement: abaseline parameters were expressed in mg/cm2 (for bone mineral density) and μg/L (for sPINP and sICTP); brate of change: mg/cm2 per year (for bone mineral density) and μg/L per year (for sPINP and sICTP).
  3. Note of interpretation: For femoral neck BMD, the overall average baseline measurement was 943 mg/cm2, and the rate of change was -3.5 mg/cm2 per year. The standard deviation (SD) of baseline BMD among individuals was 16650 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaadaGcaaqaaiabigdaXiabiAda2iabiAda2iabiwda1iabicdaWaWcbeaaaaa@3191@ = 129 mg/cm2, and the SD of rates of change among individuals was 43 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaadaGcaaqaaiabisda0iabiodaZaWcbeaaaaa@2EB1@ = 6.6 mg/cm2. More importantly, the variance in BMD within individuals was 908 mg2/cm4. The covariance was not statistically significant, which suggests that there was no significant correlation between the baseline measurements and rates of change in BMD.
  4. Statistical significance is indicated by *p < 0.05; ** 0.001 < p < 0.05, and *** p < 0.0001.