Table 1.

Baseline characteristics of the study population by quartiles of baseline fibroblast growth factor 23 concentrations in the random subcohort

CharacteristicsOverallQuartile 1 (<53 RU/ml)Quartile 2 (53–70 RU/ml)Quartile 3 (70.1–101 RU/ml)Quartile 4 (>101 RU/ml)
Weighted N27,9596874723867807067
Age, yr65.0 (64.5 to 65.6)62.2 (61.2 to 63.2)64.3 (63.3 to 65.3)66.4 (65.3 to 67.4)67.3 (66.3 to 68.4)
Male sex4558464630
Black4146374536
BMI, kg/m229.2 (28.7 to 29.6)28.4 (27.6 to 29.1)29.1 (28.3 to 29.9)29.7 (28.9 to 30.5)29.4 (28.5 to 30.4)
SBP, mm Hg127.2 (126.1 to 128.4)127.9 (125.2 to 130.6)126.6 (124.7 to 128.6)127.5 (125.0 to 129.9)126.7 (124.8 to 128.9)
DBP, mm Hg76.3 (75.7 to 76.9)77.8 (76.4 to 79.1)76.8 (75.5 to 78.1)76.2 (74.7 to 77.7)74.5 (73.3 to 75.7)
< HS graduate1211101216
Income <20K/yr1614111821
Smoking (current)141291421
Exercise (none)3431293143
Comorbidities
 Diabetes2117152228
 CHD1713111627
 COPD9491012
eGFR, ml/min per 1.73 m293.3 (91.1 to 95.6)87.1 (84.9 to 89.2)80.2 (77.8 to 82.6)69.1 (66.0 to 72.2)
 <60 ml/min per 1.73 m21025823
ACR, mg/g7.1 (4.5–14.4)6.4 (4.2–11.7)6.6 (4.2–11.3)7.6 (5.1–14.4)9.3 (4.9–26.6)
 ≥30 mg/g13881520
hsCRP, mg/L2.2 (0.9–4.9)1.6 (0.7–3.9)2.0 (0.9–4.1)2.4 (1.0–5.2)2.8 (1.1–6.3)
  • Values are presented as means (95% CIs), median (interquartile range), or proportions. BMI, body mass index; SBP, systolic BP; DBP, diastolic BP; HS, high school; CHD, coronary heart disease; COPD, chronic obstructive pulmonary disease; ACR, urine albumin-creatinine ratio; hsCRP, high-sensitivity C-reactive protein.