Table 1.
General characteristics of the study population.
| FT3 quartiles (pmol/L) | |||||
|---|---|---|---|---|---|
| Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | P for trend | |
| (n = 839) | (n = 843) | (n = 845) | (n = 819) | ||
| Male | 275 (32.8) | 293 (34.8) | 329 (38.9) | 439 (53.6) | <0.0001 |
| Age (years) | 63.6 ± 11.1 | 61.0 ± 10.1 | 60.1 ± 9.5 | 58.4 ± 8.3 | <0.0001 |
| BMI (kg/m2) | 24.9 ± 3.7 | 25.3 ± 3.7 | 25.3 ± 3.8 | 25.7 ± 3.5 | <0.0001 |
| Current smokers | 120 (14.3) | 154 (18.3) | 163 (19.3) | 251 (30.7) | <0.0001 |
| Current drinkers | 111 (13.2) | 125 (14.8) | 129 (15.3) | 160 (19.5) | 0.0006 |
| Use of ACEI/ARB drugs | 33 (3.93) | 32 (3.80) | 31 (3.67) | 33 (4.03) | 0.98 |
| SBP (mmHg) | 139.5 ± 23.5 | 137.6 ± 22.2 | 138.6 ± 21.2 | 138.9 ± 20.4 | 0.77 |
| DBP (mmHg) | 76.3 ± 10.1 | 77.8 ± 10.2 | 78.6 ± 9.6 | 81.0 ± 10.5 | <0.0001 |
| FPG (mmol/L) | 5.2 (4.7–6.1) | 5.2 (4.8–6.1) | 5.2 (4.8–5.8) | 5.3 (4.8–6.0) | 0.08 |
| OGTT-2 h PG (mmol/L) | 8.5 (6.3–14.4) | 7.8 (6.1–12.5) | 7.6 (6.1–11.4) | 7.7 (6.3–11.4) | <0.0001 |
| Triglycerides (mmol/L) | 1.28 (0.89–1.89) | 1.40 (1.00–2.02) | 1.46 (1.01–2.14) | 1.61 (1.10–2.34) | <0.0001 |
| TC (mmol/L) | 5.07 ± 1.04 | 5.15 ± 0.98 | 5.21 ± 0.93 | 5.17 ± 0.99 | 0.02 |
| HDL-C (mmol/L) | 1.37 ± 0.33 | 1.36 ± 0.29 | 1.37 ± 0.32 | 1.32 ± 0.29 | 0.01 |
| LDL-C (mmol/L) | 2.34 ± 0.71 | 2.41 ± 0.70 | 2.39 ± 0.66 | 2.42 ± 0.68 | 0.03 |
| FT3 (pmol/L) | 4.05 (3.84–4.18) | 4.45 (4.37–4.53) | 4.76 (4.68–4.85) | 5.18 (5.05–5.38) | — |
| FT4 (pmol/L) | 13.7 (12.7–14.9) | 14.1 (13.2–15.1) | 14.2 (13.3–15.3) | 14.8 (13.8–15.8) | <0.0001 |
| TSH (μIU/mL) | 1.59 (1.07–2.33) | 1.50 (1.02–2.18) | 1.44 (1.01–2.160 | 1.35 (0.92–1.99) | <0.0001 |
| TPOAb (IU/mL) | 0.30 (0.17–0.74) | 0.31 (0.17–0.77) | 0.30 (0.16–0.72) | 0.34 (0.18–0.81) | 0.93 |
| TgAb (IU/mL) | 1.09 (0.70–2.73) | 1.08 (0.70–2.95) | 1.02 (0.71–2.27) | 1.05 (0.72–2.25) | 0.08 |
| eGFR (mL/min/1.73 m2) | 107.5 ± 28.6 | 112.6 ± 24.4 | 112.8 ± 24.9 | 115.8 ± 22.9 | <0.0001 |
| UACR (mg/g) | 6.08 (2.86–12.86) | 5.93 (2.70–12.39) | 5.93 (2.79–12.48) | 5.28 (2.65–12.12) | 0.03 |
| Hs-CRP (mg/g) | 0.21 (0.05–1.13) | 0.18 (0.06–0.85) | 0.18 (0.07–0.61) | 0.24 (0.08–0.82) | 0.58 |
Data were means ± SD or medians (interquartile range) or numbers (proportions). BMI, body mass index; ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; SBP, systolic blood pressure; DBP, diastolic blood pressure; TC, total cholesterol; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein; FPG, fasting plasma glucose; OGTT-2 h PG, OGTT 2-hour plasma glucose; FT3, free triiodothyronine; FT4, free thyroxine; TSH, thyroid stimulating hormone; TPOAb, thyroid peroxidase antibody; TgAb, thyroglobulin antibody; eGFR, estimate glomerular filtration rate; UACR, urinary albumin-to-creatinine ratio.
FT3 quartiles were as follows: quartile 1, ≤4.28 pmol/L; quartile 2, 4.29–4.60 pmol/L; quartile 3, 4.61–4.93 pmol/L; quartile 4, >4.94 pmol/L.