Table 4.

FGF-23 Trajectories and Risks for the KRT Outcome

	N		HR (95% CI)
FGF-23 Trajectory Groupa	Total	KRT	Unadj	Model 1	Model 2	Model 3	Model 4	Model 5
Stable	643	70	1.00 (reference)	1.00 (reference)	1.00 (reference)	1.00 (reference)	1.00 (reference)	1.00 (reference)
Slowly increasing	409	193	7.45 (5.54–10.03)	8.62 (6.22–11.93)	3.69 (2.50–5.46)	3.96 (2.65–5.90)	4.17 (2.73–6.38)	3.60 (2.35–5.53)
Rapidly increasing	111	91	43.80 (26.57–72.20)	52.25 (30.14–90.59)	19.77 (11.10–35.22)	23.54 (13.03–42.55)	27.68 (13.68–56.15)	21.41 (10.66–43.11)

Note: Up to 5 annual time points, median duration of subsequent follow-up time 3.2 years in 1,163 total participants at risk. Results are reported as HRs compared to the referent group. Covariate adjustments are for fifth annual study visit (time 0) covariate values except when stated. Model 1, stratified by center and adjusted for age, sex, race, and ethnicity. Model 2, model 1 plus eGFR, urinary protein-creatinine ratio, serum albumin, hemoglobin, C-reactive protein (baseline), and interleukin 6 (baseline) values. Model 3, model 2 plus diabetes, smoking, systolic blood pressure, body mass index, history of coronary artery disease, history of heart failure, history of stroke, history of peripheral vascular disease, number of hypertension medications, and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use. Model 4, model 3 plus calcium, phosphate, parathyroid hormone, ln(FGF-23), and baseline eGFR values. Model 5, model 4 plus eGFR trajectory.

Abbreviations: CI, confidence interval; eGFR, estimated glomerular filtration rate; FGF-23, fibroblast growth factor 23; HR, hazard ratio; KRT, kidney replacement therapy.

^aThe stable, slowly increasing, and rapidly increasing ln(FGF-23) groups increased by 0.03, 0.14, and 0.40 per year. Through algebraic transformation ((exp(mean group slope)-1) × 100), these mean group slopes can also be expressed as the following percent changes in mean FGF-23 levels per year: +3%, +15%, and +49.2%.