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Table 3 Within-subject association between femoral neck BMD and bone turnover markers.

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

 

Symbol

Estimate ± SE

P-value

Analysis marker: sPINP

   

   Estimated parameters

   

Intercept (baseline)

α

944 ± 13

<0.0001

Rate of change

β

-3.7 ± 1.0

0.0004

sPINP

γ

-9.2 ± 4.4

0.022

   Variance components

   

Baseline

σ α 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGae8xSdegabaGaeGOmaidaaaaa@312F@

16428 ± 2425

<0.001

Rate of change

σ β 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGae8NSdigabaGaeGOmaidaaaaa@3131@

38 ± 16

0.009

Covariance

σ α β 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGae8xSdeMae8NSdigabaGaeGOmaidaaaaa@32CB@

72 ± 131

0.586

Random error

σ e 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGaemyzaugabaGaeGOmaidaaaaa@30E8@

903 ± 134

<0.001

Analysis marker: sICTP

   

   Estimated parameters

   

Intercept (baseline)

α

943 ± 13

<0.0001

Rate of change

β

-3.4 ± 1.0

0.0013

sICTP

γ

-0.7 ± 3.6

0.8425

   Variance components

   

Baseline

σ α 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGae8xSdegabaGaeGOmaidaaaaa@312F@

16677 ± 2462

<0.0001

Rate of change

σ β 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGae8NSdigabaGaeGOmaidaaaaa@3131@

44 ± 16

0.0041

Covariance

σ α β 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGae8xSdeMae8NSdigabaGaeGOmaidaaaaa@32CB@

43 ± 135

0.7526

Random error

σ e 2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFdpWCdaqhaaWcbaGaemyzaugabaGaeGOmaidaaaaa@30E8@

907 ± 130

<0.0001

  1. sICTP, serum C-terminal telopeptide of type I collagen; sPINP, serum N-terminal propeptide of type I collagen; BMD bone mineral density.
  2. Note of interpretation: Results in part (a) suggest that the BMD measurement (mg/cm2) for a subject at time t (denoted by BMD t ) can be represented by the equation: BMD t = 944 – 3.7*Year – 9.2* sPINP t , where "Year" is 0, 1, 2, ..., and sPINP t is the measurement of sPINP at time t for the subject. In other words, femoral neck BMD was decreased by -3.7 mg/cm2 per year. Furthermore, each 1 μg/L increase in sPINP was associated with a 9.2 mg/cm2 decrease in BMD. The interpretation of variance components is similar to that in Table 2. For example, the SD of baseline BMD among individuals was 16677 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaadaGcaaqaaiabigdaXiabiAda2iabiAda2iabiEda3iabiEda3aWcbeaaaaa@31A3@ = 129 mg/cm2, and the SD of rates of change among individuals was 44 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaadaGcaaqaaiabisda0iabisda0aWcbeaaaaa@2EB3@ = 6.6 mg/cm2. The within-individuals variance in BMD was 907 mg2/cm4, a slight reduction from 908 mg2/cm4 (Table 2), which suggests that including sPINP did not have a substantial effect on the within-subjects variance in BMD.