Table 1.
Characteristics of 1338 participants by quartiles of eGFR
| Characteristic | Low | Medium low | Medium high | High | P-value |
|---|---|---|---|---|---|
| Limits (mL/min/1.73 m2) | <69.89 | 69.89–79.73 | 79.73–90.77 | ≥90.77 | |
| Participants in category, n | 335 | 334 | 334 | 334 | |
| Women, n (%) | 200 (59.7) | 172 (51.5)* | 176 (52.5) | 132 (39.5)‡ | 0.08 |
| Smokers, n (%) | 34 (10.2) | 50 (15.0) | 58 (17.3)* | 81 (24.3)§ | 0.02 |
| Hypertension, n (%) | 180 (53.7) | 107 (32.0)§ | 94 (28.1) | 62 (18.6)† | 0.050 |
| Antihypertensive treatment, n (%) | 163 (48.7) | 76 (22.8)§ | 61 (18.2) | 24 (7.2)§ | 0.052 |
| Lipid-lowering treatment, n (%) | 101 (30.2) | 65 (19.5)† | 40 (11.9)† | 16 (4.8)‡ | 0.01 |
| Diabetes mellitus, n (%) | 23 (6.9) | 13 (3.9) | 12 (3.6) | 7 (2.1) | 0.056 |
| Age (years), mean (SD) | 66.0 (10.9) | 55.4 (12.3)§ | 48.2 (12.6)§ | 37.0 (12.5)§ | 0.003 |
| Body mass index (kg/m2), mean (SD) | 28.0 (4.6) | 26.9 (4.5)† | 26.2 (4.2)* | 25.2 (4.0)† | 0.003 |
| Waist:hip ratio, mean (SD) | 0.90 (0.08) | 0.89 (0.08) | 0.87 (0.08)† | 0.85 (0.08)† | 0.001 |
| Office blood pressure (mmHg), mean (SD) | |||||
| Systolic pressure | 139.1 (18.3) | 131.7 (15.7)§ | 128.2 (16.7)† | 122.9 (14.2)§ | 0.01 |
| Diastolic pressure | 81.0 (9.8) | 82.2 (9.3) | 82.3 (9.6) | 77.8 (9.6)§ | 0.42 |
| Mean arterial pressure | 100.3 (10.2) | 98.7 (10.0)* | 97.6 (11.0) | 92.8 (10.1)§ | 0.057 |
| Heart rate (beats/min), mean (SD) | 63.7 (9.3) | 63.1 (9.4) | 64.7 (9.8)* | 63.9 (9.3) | 0.57 |
| Biochemical data, mean (SD) | |||||
| Serum creatinine (μmol/L) | 98.3 (16.8) | 87.4 (11.4)§ | 82.1 (11.0)§ | 78.1 (10.3)§ | 0.03 |
| 24-h microalbuminuria (mg) | 6.0 (4.5–8.3) | 6.2 (4.5–8.1) | 5.7 (4.2–8.1) | 5.6 (3.9–7.6) | 0.20 |
| Total cholesterol (mmol/L) | 5.14 (0.99) | 5.17 (0.93) | 5.07 (0.91) | 4.81 (0.95)† | 0.14 |
| HDL cholesterol (mmol/L) | 1.45 (0.40) | 1.47 (0.40) | 1.50 (0.39) | 1.45 (0.35) | 0.84 |
| Total:HDL cholesterol ratio | 3.75 (1.06) | 3.71 (1.03) | 3.59 (1.07) | 3.49 (1.03) | 0.02 |
| Plasma glucose (mmol/L) | 5.04 (0.90) | 4.85 (0.81)† | 4.80 (0.67) | 4.64 (0.52)‡ | 0.02 |
| γ-glutamyltransferase (units/L) | 22 (15–31) | 21 (15–33) | 19 (13–28)* | 18 (13–27) | 0.01 |
eGFR according to the CKD-EPI formula [22]. Office blood pressure was the average of five consecutive auscultatory readings. Hypertension was a blood pressure ≥ 140 mmHg systolic or ≥ 90 mmHg diastolic or the use of antihypertensive drugs. For 24-h microalbuminuria and γ-glutamyltransferase, values are geometric mean (interquartile range). P-values are for linear trend across eGFR categories. Significance of the difference with the adjacent lower fourth: *P ≤ 0.05, †P ≤ 0.01, ‡P ≤ 0.001, §P ≤ 0.0001.