Table 1.
Baseline characteristics by thyroid function category
| Subclinical hyperthyroid (n = 41) | Euthyroid (n = 1387) | Subclinical hypothyroid, TSH <10 (n = 116) | Subclinical hypothyroid, TSH ≥ 10 (n = 8) | P valuea | |
|---|---|---|---|---|---|
| Age (yr) | 74.1 (5.9) | 73.6 (5.8) | 76.4 (6.4)b | 78.1 (7.5) | <0.01 |
| White race | 36 (87.8) | 1244 (89.7) | 106 (91.4) | 8 (100) | 0.8 |
| Smoking status | 0.5 | ||||
| Never | 15 (36.6) | 499 (36) | 48 (41.4) | 5 (62.5) | |
| Past | 26 (63.4) | 835 (60) | 66 (56.9) | 3 (37.5) | |
| Current | 0 | 53 (3.8) | 2 (1.7) | 0 | |
| BMI (kg/m2) | 27.9 (4.4) | 27.4 (3.7) | 27.3 (3.5) | 24.5 (4.0) | 0.12 |
| Systolic BP (mm Hg) | 136.7 (18.7) | 141.8 (19.3) | 143.6 (19.7) | 145.3 (17.9) | 0.25 |
| TSH (mIU/liter) | 0.32 (0.16)b | 2.14 (0.97) | 6.12 (1.25)b | 13.19 (2.46)b | <0.01 |
| FT4 (ng/dl) | 1.16 (0.21)b | 1.00 (0.14) | 0.92 (0.14)b | 0.87 (0.10)b | <0.01 |
| Total cholesterol (mg/dl) | 195.2 (42.7) | 192.9 (32.9) | 190.5 (31.0) | 205.1 (37.4) | 0.61 |
| LDL cholesterol (mg/dl) | 112.9 (36.7) | 114.0 (29.8) | 111.0 (29.1) | 109.1 (35.5) | 0.8 |
| HDL cholesterol (mg/dl) | 55.8 (18.5)b | 49.2 (14.5) | 48.8 (15.4) | 60.5 (19.4) | 0.01 |
| Triglycerides (mg/dl) | 132.2 (66.8) | 148.7 (91.2) | 153.5 (96.2) | 177.5 (232.0) | 0.4 |
| Baseline history of | |||||
| Diabetes | 4 (9.8) | 153 (11.0) | 17 (14.7) | 1 (12.5) | 0.6 |
| CHD | 7 (17.1) | 320 (23.1) | 37 (31.9) | 2 (25.0) | 0.1 |
| Non-skin cancer | 5 (12.2) | 240 (17.3) | 21 (18.1) | 2 (25.0) | 0.7 |
| Stroke | 2 (4.9) | 83 (6.0) | 7 (6.0) | 1 (12.5) | 0.7 |
| CHF | 3 (7.3) | 61 (4.4) | 8 (6.9) | 1 (12.5) | 0.2 |
| Hypertension | 16 (39.0) | 617 (44.5) | 52 (44.8) | 1 (12.5) | 0.3 |
| High thyroid or Graves' disease | 3 (7.3) | 19 (1.4) | 4 (3.5) | 1 (12.5) | <0.01 |
| Low thyroid or hypothyroid | 15 (36.6) | 83 (6.0) | 20 (17.2) | 2 (25.0) | <0.01 |
| Self-reported health (good/excellent) | 36 (87.8) | 1189 (85.8) | 98 (84.5) | 5 (62.5) | 0.3 |
| Thyroid hormone use | 15 (36.6) | 80 (6.0) | 22 (19.8) | 2 (25.0) | <0.01 |
| Statin use | 11 (26.8) | 376 (28.3) | 29 (26.1) | 1 (12.5) | 0.7 |
Results are mean (sd) or n (%). BP, Blood pressure; HDL, high-density lipoprotein; LDL, low-density lipoprotein.
a
P value for overall χ2, one-way ANOVA, or Kruskall-Wallis test.
b
P < 0.05 vs. euthyroid using t test or Wilcoxon rank sum test.