Table 3c.

Adjusted Associations between C-Terminal Telopeptide of Type I Collagen (CTX) Levels and Hip Fracture Risk after Exclusion of Controls who Experienced Hip Fractures during the Extension Study Period^*

	Model 1 (age adjusted, N = 632)		Model 2 (fully adjusted, N = 487)
	OR (95% CI)	p-trend*	OR (95% CI)	p-trend*
CTX Quartiles		0.02		0.04
Quartile 1 (0–25th percentile: 0–280 ng/L)	Reference		Reference
Quartile 2 (25th– 50th percentile: 280–390 ng/L)	1.10 (0.70, 1.75)		1.28 (0.69, 2.38)
Quartile 3 (50th– 75th percentile: 390–510 ng/L)	1.47 (0.92, 2.33)		1.94 (1.05, 3.59)
Quartile 4 (75th– Maximum: ≥510 ng/L)	1.61 (1.04, 2.50)		1.71 (0.94, 3.11)

^*Estimates are based on unconditional logistic regression models. The age adjusted model included only age and the bone turnover marker term. The fully adjusted model was adjusted for age, race/ethnicity, body mass index, years of education, season of blood draw, whether living with a partner, parity, smoking, fall history in past year, history of previous fracture, family history of hip fracture, past use of menopausal hormone therapy, Centers for the Epidemiologic Study of Depression score, use of antidepressant medication, frailty index, self-reported health status, RAND 36-item Health Survey score, and dietary and supplemental calcium and vitamin D intake. The bone turnover marker level was entered into the model as a categorical term in quartiles to obtain the odds ratios. The p-trend values were obtained by entering the bone-turnover markers quartile term as a continuous variable to determine if a significant linear trend exists across the quartiles.