Table 4.

Frequency, incidence rates, HRs, and 95% CIs for incident CKD (hospitalizations and deaths) by quintile of serum levels of FGF-23 in the ARIC study (1990–2010; n=13,180)

RateQuintile of Serum Level of FGF-23 (pg/ml)P Value for Trenda
1 (<32.0)2 (32.0–38.5)3 (38.6–45.3)4 (45.4–54.6)5 (>54.6)
Participants (n)26782674266526492514
Eventsb303 (11.3)307 (11.5)338 (12.7)410 (15.5)460 (18.3)<0.001
Incidence ratec6.76 (6.04 to 7.57)6.81 (6.09 to 7.61)7.55 (6.79 to 8.40)9.49 (8.62 to 10.5)11.6 (10.6 to 12.7)<0.001
Modeld
 11 [Ref]1.01 (0.86 to 1.18)1.12 (0.96 to 1.31)1.42 (1.22 to 1.65)1.74 (1.51 to 2.02)<0.001
 21 [Ref]0.98 (0.84 to 1.15)1.08 (0.92 to 1.26)1.30 (1.12 to 1.51)1.59 (1.37 to 1.84)<0.001
 31 [Ref]0.92 (0.78 to 1.08)0.96 (0.82 to 1.12)1.07 (0.92 to 1.25)1.20 (1.03 to 1.39)0.001
 41 [Ref]0.94 (0.80 to 1.11)1.00 (0.86 to 1.18)1.06 (0.91 to 1.24)1.11 (0.95 to 1.29)0.05
 51 [Ref]0.95 (0.80 to 1.12)1.00 (0.85 to 1.18)1.07 (0.92 to 1.25)1.10 (0.94 to 1.29)0.06
  • Data are presented as n (%) or HR (95% CI) unless otherwise specified. Ref, reference group.

  • a Linear trend across the quintiles using the median of each quintile.

  • b Among all incident CKD patients, 20.5% (n=373) developed a eGFRCr<60 ml/min per 1.73 m2 and at least a 25% decline in eGFRCr, 7.9% (n=143) developed ESRD identified by the USRDS registry, and 71.6% (n=1302) had a CKD-related hospitalization or death.

  • c Unadjusted incidence rate (95% CIs) per 1000 person-years.

  • d Models are as follows: model 1 is unadjusted (no covariates included in the model); model 2 is adjusted for age, sex, and race; model 3 is adjusted for the variables in model 2 plus eGFRCr, eGFRCys, and eGFRCr-Cys; model 4 is adjusted for the variables in model 3 plus diabetes, systolic BP, antihypertensive medication, HDL cholesterol, body mass index, C-reactive protein, and β2-microglobulin; and model 5 is adjusted for variables in model 4 plus phosphate, calcium, and parathyroid hormone.