Table 5. Association of urinary collagen fragments with serum biomarkers of collagen turnover.

Urinary marker (SD)	Collagen I		Urinary marker (SD)	Collagen III
Serum markers	Estimate (95% CI)	p	Serum markers	Estimate (95% CI)	p
p73697 (521)			p107460 (863)
PICP, μg/L	14.9 (12.0 to 17.8)	<0.0001	PICP, μg/L	–5.39 (–8.47 to –2.31)	0.0006
CITP, μg/L	0.31 (0.16 to 0.47)	<0.0001	CITP, μg/L	–0.62 (–0.76 to –0.47)	<0.0001
PIIINP, %	4.63 (1.77 to 7.50)	0.0016	TIMP-1, ng/mL	–30.9 (–43.9 to –18.0)	<0.0001
p77018 (1504)			p112106 (3149)
TIMP-1, ng/mL	21.4 (8.36 to 34.5)	0.0013	CITP, μg/L	–0.44 (–0.59 to –0.29)	<0.0001
p77763 (991)
TIMP-1, ng/mL	39.4 (26.5 to 52.2)	<0.0001

Abbreviations: CI, confidence interval; PICP, carboxyterminal propeptide of procollagen I; CITP, carboxyterminal telopeptide of collagen I; TIMP-1, tissue inhibitor of the matrix metalloproteinase type 1; PIIINP, aminoterminal propeptide of procollagen type III. Estimates express the change in the serum biomarkers per 1-SD increase in urinary collagen fragments. The urinary peptides were identified in the continuous analyses (S1 Fig and Table 3) with the exception of p77763, which was a marker of diastolic LV dysfunction in the PLS-DA analysis (Fig 2) and had an amino-acid sequence very similar to that of p77018 (one proline residue being replaced by hydroxyproline; S2 Table).