Table 1.
Baseline characteristics of the 6,054 participants according to sex-stratified quartiles of FT4
| Sex-stratified quartiles of FT4 | |||||||
|---|---|---|---|---|---|---|---|
| I | II | III | IV | Ptrend | |||
| Male | <14.5 | 14.5–15.8 | 15.9–17.2 | >17.2 | |||
| Female | <14.1 | 14.1–15.4 | 15.5–16.7 | >16.7 | |||
| All participants (N = 6,054) | Male | 788 | 787 | 787 | 787 | ||
| FT4, pmol/L | Female | 727 | 726 | 726 | 726 | ||
| Sociodemographic characteristics | |||||||
| Age | 53.3 (12.0) | 54.0 (11.4) | 53.5 (11.6) | 52.7 (12.1) | 52.9 (12.6) | 0.002 | |
| Race | |||||||
| Caucasian | 5766 (95.2) | 1452 (95.8) | 1445 (95.5) | 1439 (95.1) | 1430 (94.5) | 0.02 | |
| Negroid | 60 (1.0) | 18 (1.2) | 18 (1.2) | 13 (0.9) | 11 (0.7) | ||
| Asian | 116 (1.9) | 19 (1.3) | 28 (1.9) | 36 (2.4) | 33 (2.2) | ||
| Other | 66 (1.1) | 14 (0.9) | 14 (0.9) | 17 (1.1) | 21 (1.4) | ||
| Unknown | 46 (0.8) | 12 (0.8) | 8 (0.5) | 8 (0.5) | 18 (1.2) | ||
| Education | |||||||
| Low | 2612 (43.1) | 693 (45.7) | 677 (44.7) | 638 (42.3) | 604 (39.9) | 0.001 | |
| Middle | 1543 (25.5) | 385 (25.4) | 360 (23.8) | 388 (25.6) | 410 (27.1) | ||
| High | 1899 (31.4) | 437 (28.8) | 476 (31.5) | 487 (32.2) | 499 (33.0) | ||
| Current smoking | 1749 (28.9) | 385 (25.4) | 416 (27.5) | 464 (30.7) | 484 (32.0) | <0.001 | |
| Drinking alcohol, ≥10 g/day | 1638 (27.1) | 404 (26.7) | 414 (27.4) | 419 (27.7) | 401 (26.5) | 0.98 | |
| Type 2 diabetes | 363 (6.0) | 94 (6.2) | 106 (7.0) | 83 (5.5) | 80 (5.3) | 0.12 | |
| History of CVD | 389 (6.4) | 80 (5.3) | 107 (7.1) | 113 (7.5) | 89 (5.9) | 0.43 | |
| Thyroid function | |||||||
| TSH, mIU/L | 1.72 (0.82) | 1.89 (0.87) | 1.75 (0.83) | 1.68 (0.78) | 1.57 (0.75) | <0.001 | |
| FT3, pmol/L | 4.8 (4.5–5.2) | 4.7 (4.3–5.0) | 4.8 (4.5–5.1) | 4.9 (4.6–5.2) | 5.0 (4.7–5.4) | <0.001 | |
| Anti-TPO, kIU/L | 10.3 (8.1–13.8) | 10.2 (8.0–13.9) | 10.3 (7.9–13.5) | 10.3 (8.1–13.7) | 10.5 (8.3–14.1) | 0.09 | |
| Body composition | |||||||
| BMI, kg/m2 | 26.6 (4.3) | 27.3 (4.5) | 26.7 (4.3) | 26.5 (4.3) | 26.1 (4.1) | <0.001 | |
| Haemodynamics | |||||||
| SBP, mmHg | 126.2 (18.7) | 126.2 (18.4) | 125.9 (18.3) | 126.1 (18.9) | 126.5 (19.2) | 0.62 | |
| DBP, mmHg | 73.5 (9.2) | 73.6 (9.4) | 73.7 (9.1) | 73.4 (9.1) | 73.2 (9.1) | 0.22 | |
| Lipid spectrum | |||||||
| Total cholesterol, mmol/L | 5.4 (1.0) | 5.5 (1.1) | 5.4 (1.0) | 5.4 (1.0) | 5.4 (1.1) | <0.001 | |
| HDL cholesterol, mmol/L | 1.25 (0.31) | 1.24 (0.32) | 1.25 (0.31) | 1.25 (0.31) | 1.26 (0.30) | 0.09 | |
| Total cholesterol/HDL | 4.6 (1.3) | 4.7 (1.4) | 4.6 (1.3) | 4.5 (1.3) | 4.5 (1.3) | <0.001 | |
| Triglycerides, mmol/L | 1.12 (0.81–1.61) | 1.19 (0.83–1.71) | 1.13 (0.81–1.67) | 1.10 (0.80–1.56) | 1.06 (0.79–1.50) | <0.001 | |
| Inflammation | |||||||
| Hs-CRP, mg/L | 1.36 (0.62–3.11) | 1.46 (0.67–3.25) | 1.30 (0.61–3.08) | 1.41 (0.63–3.14) | 1.26 (0.56–3.00) | 0.01 | |
| Kidney function parameters | |||||||
| eGFRSCr-CysC, mL/min/1.73 m2 | 90.8 (20.7) | 91.2 (20.7) | 91.3 (20.7) | 91.2 (21.0) | 89.5 (20.6) | 0.02 | |
| UAE, mg/day | 8.7 (6.1–15.8) | 8.9 (6.1–17.2) | 8.7 (6.0–15.6) | 8.8 (6.1–15.3) | 8.3 (6.0–15.6) | 0.05 | |
| UAE categories | |||||||
| <15 mg/day | 4436 (73.3) | 1080 (71.3) | 1114 (73.6) | 1126 (74.4) | 1116 (73.8) | 0.10 | |
| 15–29.9 mg/day | 818 (13.5) | 206 (13.6) | 217 (14.3) | 201 (13.3) | 194 (12.8) | ||
| 30–300 mg/day | 707 (11.7) | 199 (13.1) | 166 (11.0) | 160 (10.6) | 182 (12.0) | ||
| >300 mg/day | 93 (1.5) | 30 (2.0) | 16 (1.1) | 26 (1.7) | 21 (1.4) | ||
| Medication | |||||||
| Antihypertensive drugs | 1264 (20.9) | 291 (19.2) | 297 (19.6) | 325 (21.5) | 351 (23.2) | 0.003 | |
| Lipid-lowering drugs | 560 (9.3) | 146 (9.6) | 148 (9.8) | 140 (9.3) | 126 (8.3) | 0.18 | |
Data are mean (SD), median (IQR), or n (%)
BMI body-mass index, CVD cardiovascular disease, CysC serum cystatin C, DBP diastolic blood pressure, eGFR estimated glomerular filtration rate, FT3 triiodothyronine, FT4 free thyroxine, HDL high-density lipoprotein, Hs-CRP high-sensitive C-reactive protein, SBP systolic blood pressure, SCr serum creatinine, TPO thyroid peroxidase, TSH thyrotropin, UAE urinary albumin concentration