Table 1 Characteristics of the 300 study patients based on their phosphate levels

Sex, male [n (%)]

210 (70%)

126 (80%)

84 (60%)

 < 0.001

Age (year)

71 (56.5–79)

69 (57–77)

72 (56–81)

0.065

Body mass index (kg/m²)

24.1 (21.3–26.5)

24.5 (22.2–26.4)

24.0 (21–26.5)

0.119

Smoking [n (%)]

124 (42%)

75 (48%)

49 (35%)

0.023

Cancer [n (%)]

35 (12%)

12 (9%)

23 (16%)

0.02

Diabetes [n (%)]

92 (31%)

34 (22%)

58 (41%)

 < 0.001

Bone fracture [n (%)]

11 (4%)

5 (3%)

6 (4%)

0.24

Gastrointestinal bleeding [n (%)]

2(1%)

1 (1%)

1 (1%)

0.006

Creatinine (mg/dL)

1.54 (1.1–2.57)

1.29 (1.02–1.73)

2.21 (1.31–3.37)

 < 0.001

eGFR (mL/min per 1.73 m²)

34 (20–48)

40 (28–54)

23 (14–38)

 < 0.001

Urine protein (g/gCr)

0.7 (0.1–2.7)

0.3 (0.1–1.5)

1.6 (0.3–3.7)

 < 0.001

Alkaline phosphatase (U/L)

243.5 (190–299)

239 (186–298)

246 (198–299)

0.477

Lactic acid dehydrogenase (U/L)

206 (177–241)

200 (176–225)

220 (179–261)

0.003

Total protein (g/dL)

7.2 (6.8–7.5)

7.2 (6.9–7.6)

7.1 (6.6–7.5)

0.013

Albumin (g/dL)

4 (3.6–4.3)

4.1 (3.7–4.3)

3.8 (3.4–4.2)

 < 0.001

Sodium (mmol/L)

140 (138–141)

140 (139–142)

140 (138–141)

0.12

Potassium (mmol/L)

4.5 (4.2–4.9)

4.5 (4.1–4.8)

4.6 (4.2–5.0)

0.03

Urea nitrogen (mmol/L)

25 (18–37)

21 (16–27)

34 (21–47)

 < 0.001

Uric acid (mg/dL)

6.3 ± 1.5

6 ± 1.4

6.6 ± 1.5

 < 0.001

Calcium (mg/dL)

9.1 (8.7–9.4)

9.2 (8.8–9.4)

8 (8.3–9.3)

 < 0.001

Phosphate (mg/dL)

3.3 (3–3.8)

3 (2.7–3.1)

3.8 (3.6–4.2)

 < 0.001

Serum iron (μg/dL)

78 (62–103)

85 (66–111)

72 (58–96)

0.003

TIBC (μg/dL)

298 (264–337)

306 (273–339)

290 (252–328)

0.01

Ferritin (ng/mL)

135.6 (62.4–261.1)

141.2 (65–268.4)

130.5 (57.6–261.1)

0.676

Magnesium (mg/dL)

2.1 (1.9–2.3)

2 (1.9–2.2)

2.1 (1.9–2.3)

0.1

C-reactive protein (mg/dL)

0.09 (0.03–026)

0.07 (0.02–0.24)

0.11 (0.03–0.27)

0.334

White blood cell (× 1,000/μL)

6.1 (5.2–7.6)

6.1 (5.3–7.3)

6.3 (5.2–8)

0.311

Red blood cell (× 1,000,000/μL)

4.22 ± 0.79

4.46 ± 0.69

3.96 ± 0.81

 < 0.001

Hemoglobin (g/dL)

12.7 ± 2.3

13.6 ± 2

11.8 ± 2.3

 < 0.001

Hematocrit (%)

38.9 (34–42.6.)

41.4 (37.2–43.6)

35.2 (31.2–40.6)

 < 0.001

Mean corpuscular volume (fL)

91.4 (88.2–93.4)

91.5 (88.8–94.5)

91.2 (87.9–94)

0.236

MCHC (g/dL)

33.2 (32.6–33.8)

33.3 (32.7–33.9)

33.2 (32.4–33.7)

0.063

Platelet (× 1,000/μL)

216 (183–259)

210 (175–248)

228 (187–265)

0.043

Reticulocytes (%)

1.15 (0.9–1.49)

1.1 (0.9–1.47)

1.21 (0.94–1.51)

0.255

Hydrogen carbonate (mmol/L)

23.2 (21.5–24.7)

23.9 (22.3–25.2)

22.4 (20.2–24.5)

 < 0.001