Table 2.
End-of-Study Energy Expenditure and Body Composition Measures for Each Arm by Intention to Treat
| Measurea | Arm 1 (Low-Normal TSH; n = 46) | Arm 2 (High-Normal TSH; n = 47) | Arm 3 (Mildly Elevated TSH; n = 45) | Arm 2 vs Arm 1b | Arm 3 vs Arm 1b | Arm 3 vs Arm 2b | |||
|---|---|---|---|---|---|---|---|---|---|
| Difference (95% CI) | P Valuec | Difference (95% CI) | P Valuec | Difference (95% CI) | P Valuec | ||||
| TEE, kcal/d | 2239 ± 57 | 2361 ± 155 | 2201 ± 71 | −31.9 (−243.0 to 179.2) | 0.93 | −21.6 (−234.7 to 191.4) | 0.97 | 10.3 (−185.8 to 206.4) | > 0.99 |
| TEE/LBM, kcal/kg/d | 51.1 ± 1.5 | 53.0 ± 1.6 | 50.6 ± 1.1 | −0.07 (−4.39 to 4.25) | > 0.99 | −0.83 (−5.16 to 3.50) | 0.89 | −0.76 (−4.75 to 3.23) | 0.89 |
| REE, kcal/d | 1397 ± 36 | 1333 ± 33 | 1298 ± 33 | −17.8 (−80.8 to 45.2) | 0.78 | −31.7 (−99.0 to 35.6) | 0.51 | −13.9 (−76.9 to 49.1) | 0.86 |
| REE/LBM, kcal/kg/d | 30.3 ± 0.4 | 30.0 ± 0.4 | 30.0 ± 0.5 | −0.51 (−1.79 to 0.76) | 0.61 | −0.69 (−2.06 to 0.67) | 0.45 | −0.18 (−1.46 to 1.09) | 0.94 |
| CHO oxidation, g/d | 133 ± 11 | 137 ± 12 | 149 ± 11 | 8.9 (−34.6 to 52.3) | 0.88 | 31.5 (−14.6 to 77.5) | 0.24 | 22.6 (−19.1 to 64.4) | 0.41 |
| Fat oxidation, g/d | 66.9 ± 4.4 | 63.1 ± 5.6 | 50.0 ± 4.5 | −0.97 (−19.52 to 17.57) | > 0.99 | −17.3 (−37.4 to 2.8) | 0.11 | −16.3 (−35.0 to 2.4) | 0.10 |
| Protein oxidation, g/d | 62.6 ± 3.3 | 54.2 ± 2.8 | 55.6 ± 2.7 | −8.1 (−16.9 to 0.7) | 0.08 | −2.6 (−11.9 to 6.7) | 0.79 | 5.5 (−3.2 to 14.2) | 0.29 |
| TEF, kcal/d | 136 ± 13 | 147 ± 28 | 125 ± 12 | 23.1 (−42.7 to 88.8) | 0.68 | −11.6 (−74.8 to 51.5) | 0.90 | −34.7 (−91.3 to 21.9) | 0.31 |
| TEF peak energy, kcal | 34.7 ± 1.0 | 34.0 ± 1.6 | 33.1 ± 1.1 | 0.65 (−1.76 to 3.05) | 0.80 | −0.35 (−2.67 to 1.98) | 0.93 | −0.99 (−3.05 to 1.07) | 0.48 |
| TEF time to peak, h | 1.4 ± 0.2 | 1.7 ± 0.2 | 1.8 ± 0.2 | −0.01 (−0.90 to 0.87) | > 0.99 | 0.30 (−0.55 to 1.15) | 0.67 | 0.32 (−0.45 to 1.08) | 0.58 |
| LBM, kg | 46.2 ± 1.1 | 45.0 ± 1.4 | 43.8 ± 1.3 | 0.57 (−0.15 to 1.28) | 0.15 | 0.66 (−0.11 to 1.42) | 0.11 | 0.09 (−0.63 to 0.81) | 0.95 |
| Fat mass, kg | 31.0 ± 1.6 | 27.9 ± 1.6 | 30. 0 ± 2.0 | −0.15 (−1.45 to 1.14) | 0.96 | 0.61 (−0.77 to 1.99) | 0.54 | 0.77 (−0.52 to 2.06) | 0.34 |
| BMI, kg/m2 | 28.6 ± 0.8 | 27.3 ± 0.8 | 27.6 ± 1.0 | 0.09 (−0.52 to 0.70) | 0.93 | 0.42 (−0.23 to 1.08) | 0.28 | 0.33 (−0.28 to 0.94) | 0.40 |
| Fat mass, % | 38.2 ± 1.0 | 36.4 ± 1.2 | 38.1 ± 1.1 | −0.55 (−1.54 to 0.44) | 0.39 | 0.14 (−0.92 to 1.20) | 0.95 | 0.69 (−0.30 to 1.68) | 0.23 |
| Visceral fat, g in abdominal ROI | 584 ± 49 | 491 ± 46 | 489 ± 43 | 7.9 (−42.5 to 58.3) | 0.93 | 23.9 (−30.0 to 77.9) | 0.55 | 16.0 (−34.0 to 66.0) | 0.73 |
Data presented as unadjusted mean ± SEM.
Abbreviations: CHO, carbohydrate; ROI, region of interest.
TEE values were available for 19 subjects in the low-normal, 23 in the high-normal, and 23 in the mildly elevated arms; REE values were available for all subjects; substrate oxidation values were available for all subjects, except for 4 missing CHO values and 1 missing fat value in the low-normal arm, 1 missing CHO and 1 missing fat value in the high-normal arm, and 1 missing fat value in the mildly elevated arm; TEF values were available for 23 in the low-normal, 26 in the high-normal, and 31 in the mildly elevated arm; and body composition values were available for all subjects.
Multiple linear regression models were adjusted for age, estrogen status, baseline TSH (low normal vs high normal), SD of TSH values at all but first visit, baseline LT4 dose, duration of LT4, duration of LT4 dose, and baseline value of outcome. The TEF models were also adjusted for end of study LBM, fat percentage, and meal size.
P values were adjusted using Tukey multiple comparison procedure for pairwise comparisons between arms.