Determinants of Bone Strength Estimated by Calcaneal Ultrasonography in Inuit Women from Nuuk (Greenland)

Table 3

Predictors of QUS parameters at the second measurement (2002).

Model^a
𝑁=118
SOS (log)year 2002  (m/s)^b
𝑅^2=0.8306
Variables	𝑅^2 partial	𝛽 coefficient (SE)	𝑃 value
Intercept	—	1.19773 (0.32028)	0.0003
SOS (log)year 2000  (m/s)	0.7997	0.84241 (0.04380)	<0.0001
Smoking status (Yes/No)	0.0108	−0.00410 (0.00132)	0.0024
HRT use (Yes/No)	0.0102	0.00609 (0.00219)	0.0063
Height (cm)	0.0052	−0.00019 (0.00009)	0.0520
Age (years)	0.0047	−0.00027 (0.00015)	0.0805
BUAyear 2002 (dB/MHz)^c
𝑅^2=0.7092
Variables	𝑅^2 partial	𝛽 coefficient (SE)	𝑃 value
Intercept	—	19.77795 (7.15003)	0.0066
BUAyear 2000  (dB/MHz)	0.6517	0.82784 (0.05972)	<0.0001
Smoking status (Yes/No)	0.0178	−3.53459 (1.21960)	0.0045
Ratio omega-3/omega-6 PUFA	0.0199	4.29757 (1.45547)	0.0038
HRT use (Yes/No)	0.0090	4.28491 (2.01686)	0.0358
Menopausal status (Yes/No)	0.0108	−3.83486 (1.87776)	0.0435
SI (log)year 2002 (%)^d
𝑅^2=0.8410
Variables	𝑅^2 partial	𝛽 coefficient (SE)	𝑃 value
Intercept	—	0.75016 (0.23022)	0.0015
SI (log)year 2000  (%)	0.8005	0.85902 (0.04289)	<0.0001
Smoking status (Yes/No)	0.0140	−0.05410 (0.01377)	0.0001
Ratio omega-3/omega-6 PUFA	0.0119	0.05795 (0.01677)	0.0008
HRT use (Yes/No)	0.0092	0.05307 (0.02183)	0.0166
Age (years)	0.0055	−0.00313 (0.00160)	0.0523

aAutomatic selection of variables by the stepwise method (entry 𝑃 value of 0.10 and exit 𝑃 value of 0.15).
“Candidate” variables in the predictive model were QUS_{year 2000}, age, height, body weight, waist circumference/hip circumference ratio, ratio omega-3/omega-6 PUFA, DL-PCB 156, total breastfeeding duration, menopausal status, oral contraceptive use, HRT use, smoking status, calcium supplement use, sun exposure, and consumption of dairy products (“candidate” variables were measured at baseline, year 2000).
^bThe same predictive variables were identified in a predictive model that comprised a greater number of “candidate” variables: SOS (log)_{year 2000}, age, height, body weight, waist circumference/hip circumference ratio, % omega-6 PUFA, DL-PCB 156, total breastfeeding duration, menopausal status, oral contraceptive use, HRT use, smoking status, calcium supplement use, sun exposure, consumption of dairy products, and total cholesterol, total triglycerides, % omega-3 PUFA, personal history of fracture, LPA, CSO, parity, and alcohol intake. All “candidate” variables were measured at baseline (year 2000). This model included only 101 participants for whom dataset was complete.
^cThe same predictive variables were identified when all “candidate” variables were included in the predictive model (BUA_{year 2000} and the other variables listed in note^b; 𝑛=101).
When % omega-3 PUFA and % omega-6 PUFA were included as “candidate” variables instead of the omega-3/omega-6 PUFA ratio, the % omega-3 PUFA was significant (𝑃=0.0049; 𝑅² partial = 0.0202). The model (𝑅²=0.7080) was BUA_{year 2002} = 18.50058+0.82080BUA_{year 2000}  − 3.42455 smoking status + 0.33554% omega-3 PUFA + 4.17829HRT use − 3.61551 menopausal status.
^dThe same predictive variables were identified when all “candidate” variables for the predictive model [SI (log)_{year 2000} and the other variables given in note^b] were used (𝑛=101).
When % omega-3 PUFA and % omega-6 PUFA were included as “candidate” variables instead of the omega-3/omega-6 PUFA ratio, the % omega-3 PUFA was significant (𝑃=0.0013; 𝑅² partial = 0.0113). The model (𝑅²=0.8397) was SI (log)_{year 2002} = 0.75160 + 0.85030SI (log)_{year 2000}  − 0.05201 smoking status + 0.00441% omega-3 PUFA + 0.05289HRT use − 0.00290 age.