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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.