Table 1.

Baseline participant characteristics stratified by baseline eGFR (n=550)

Baseline factorObservations, neGFR(CKD-EPI)<60 ml/min per 1.73 m2 (n=85)eGFR (CKD-EPI) 60–89 ml/min per 1.73 m2 (n=125)eGFR (CKD-EPI)≥90 ml/min per 1.73 m2 (n=340)Participants with Follow-up Blood Samples (n=550)Participants without Follow-up Blood Samples (n=46)P Valuea
Age, yr55060.1 (50.0–68.5)53.7 (44.1–63.5)39.6 (30.3–49.5)46.3 (34.8–56.5)32.4 (22.3–41.9)<0.001
Men55036 (42.4)47 (37.6)117 (34.4)200 (36.4)21 (45.7)0.21
Weight, kg54876.4 (63.4–92.0)83.9 (71.6–98.0)82.7 (69.7–98.3)82.1 (68.8–97.4)73.6 (62.2–87.6)0.02
BMI, kg/m254627.8 (23.8–32.1)30.2 (26.6–34.5)30.0 (25.4–35.1)29.6 (25.3–34.8)25.7 (21.9–29.9)0.01
Waist circumference, cm524101.1 (93.5–112.9)103.3 (95.0–113.3)100.3 (88.4–111.8)101.6 (90.9–112.2)89.6 (77.5–101.7)<0.001
Waist-to-hip ratio5201.00 (0.93–1.05)0.95 (0.90–1.03)0.93 (0.85–0.99)0.95 (0.87–1.01)0.87 (0.83–0.94)<0.001
Body surface area, m2b5461.82 (1.68–2.00)1.93 (1.75–2.09)1.92 (1.75–2.08)1.90 (1.74–2.08)1.86 (1.72–2.00)0.10
Diabetes55057 (67.1)59 (47.2)125 (36.8)241 (43.8)6 (13.3)<0.001
Current smoker53916 (19.8)32 (26.4)169 (50.1)217 (40.3)23 (51.1)0.16
Systolic BP, mmHg542120.0 (111.3–135.7)116.3 (106.0–129.7)114.2 (104.7–125.3)115.8 (106.0–128.0108.8 (98.2–119.8)0.02
Diastolic BP, mmHg54273.7 (67.7–79.0)73.7 (67.3–80.3)74.5 (67.3–82.0)74.0 (67.3–81.3)69.8 (61.7–78.0)0.01
HbA1c
 Measured as mmol/mol)c53647.5 (41.0–68.3)44.3 (39.9–57.4)42.1 (37.7–53.0)43.2 (37.7–56.3)38.3 (35.5–41.0)<0.001
 Measured as percentage5366.5 (5.9–8.4)6.2 (5.8–7.4)6.0 (5.6–7.0)6.1 (5.6–7.3)5.7 (5.4–5.9)<0.001
Cholesterol
 Measured as mg/dl530166.0 (142.8–189.1)173.7 (154.4–208.4)187.2 (162.1–216.2)181.4 (154.4–212.3)189.1 (158.3–220.0)0.10
 Measured as mmol/L5304.3 (3.7–4.9)4.5 (4.0–5.4)4.9 (4.2–5.6)4.7 (4.0–5.5)4.9 (4.1–5.7)0.10
HDL cholesterol
 Measured as mg/dl51934.7 (30.9–44.4)38.9 (34.7–46.3)38.6 (34.7–48.6)38.6 (33.6–46.3)46.3 (38.6–54.0)0.01
 Measured as mmol/L5190.9 (0.8–1.2)1.0 (0.9–1.2)1.0 (0.9–1.3)1.0 (0.9–1.2)1.2 (1.0–1.4)0.01
Cholesterol-to-HDL ratio5194.2 (3.6–5.9)4.5 (3.7–5.7)4.6 (3.6–5.8)4.5 (3.6–5.8)4.2 (3.3–5.0)0.08
Enzymatic creatinine
 Measured as mg/dl5321.70 (1.38–2.25)0.90 (0.81–1.05)0.68 (0.59–0.82)0.81 (0.64–0.99)0.79 (0.67–0.95)0.23
 Measured as µmol/La532150 (122–199)80 (72–93)60 (52–73)72 (57–88)70 (59–84)0.23
CKD-EPI eGFR, ml/min per 1.73 m254437.7 (24.4–48.7)82.0 (74.5–90.7)107.6 (99.2–116.9)97.9 (79.3–111.7)111.8 (98.2–121.0)<0.001
Measured GFR, ml/min per 1.73 m251646.2 (31.4–56.2)86.9 (73.8–98.4)114.2 (100.2–127.3)102.4 (82.6–120.8)112.5 (100.2–123.50.02
CRP, mg/L5275.0 (2.5–12.5)5.2 (3.0–10.0)6.0 (3.0–11.0)5.8 (3.0–11.0)5.0 (2.5–9.5)0.23
Bilirubin
 Measured as mg/dl )5430.29 (0.18–0.41)0.41 (0.29–0.53)0.35 (0.29–0.58)0.35 (0.23–0.53)0.47 (0.32–0.67)0.06
 Measured as µmol/L5435.0 (3.0–7.0)7.0 (5.0–9.0)6.0 (5.0–10.0)6.0 (4.0–9.0)8.0 (5.5–11.5)0.06
ACR
 Measured as mg/g520650.0 (146.9–1894.8)19.0 (7.1–122.1)12.4 (5.8–43.4)18.1 (6.2–151.8)4.4 (2.7–12.4)<0.01
 Measured as mg/mmol52073.5 (16.6–214.1)2.2 (0.8–13.8)1.4 (0.7–4.9)2.1 (0.7–17.2)0.5 (0.3–1.4)<0.001
ACR category520
 A16 (7.7)67 (56.8)224 (69.1)297 (57.1)34 (82.9)0.01
 A221 (26.9)26 (22.0)67 (20.7)114 (21.9)4 (9.8)
 A351 (65.4)25 (21.2)33 (10.2)109 (21.0)3 (7.3)
Use of ACE inhibitors55051 (60.0)45 (36.0)69 (20.3)165 (30.0)2 (4.3)<0.001
Use of ARB55023 (27.1)14 (11.2)19 (5.6)56 (10.2)3 (6.5)0.42
Housing
 Housing tenure5410.66
 Rent or other tenure77 (93.9)95 (77.9)296 (87.8)468 (86.5)4 (8.9)
 Own/being purchased5 (6.1)27 (22.1)41 (12.2)73 (13.5)41 (91.1)
Education
 Highest level of school completed5340.04
 Less than year 10/never went to school47 (58.8)50 (42.0)106 (31.6)203 (38.0)9 (20.0)
 Year 10/equivalent19 (23.8)52 (43.7)142 (42.4)213 (39.9)21 (46.7)
 Year 12/equivalent14 (17.5)17 (14.3)87 (26.0)118 (22.1)15 (33.3)
  • Data are median (IQR) or n (%). CKD-EPI, CKD-Epidemiology Collaboration; BMI, body mass index; HbA1c, hemoglobin A1c; CRP, C-reactive protein; ACR, urine albumin-to-creatinine ratio; A1, albuminuria <27 mg/g (3 mg/mmol); A2, albuminuria, 27–265 mg/g (3–30 mg/mmol); A3, albuminuria>265 mg/g (30 mg/mmol); ACE, angiotensin-converting enzyme; ARB, angiotensin-receptor blockade.

  • a The P value compares the group with follow-up blood samples to the group without follow-up blood samples and was calculated using ANOVA for continuous variables and chi-squared test between categorical variables. The difference between serum creatinine in the two participant groups was tested on the log serum creatinine level.

  • b Calculated using the Dubois formula.

  • c The difference between hemoglobin A1c (HbA1c) levels in the two participant groups was tested on the log HbA1c level.

  • 2 For difference between participants with a follow-up blood sample and participants without a follow-up blood sample. Calculated using ANOVA for continuous variables and chi-squared test between categorical variables.