ECE2018 Poster Presentations: Thyroid Thyroid (non-cancer) (105 abstracts)
National Taiwan University Hospital, Taipei City, Taiwan.
Background: Graves disease (GD) is associated with accelerated bone turnover and elevated fibroblast growth factor 23 (FGF23). FGF23 is involved in the mineral homeostasis, especially the regulation of serum phosphate. Literatures showed that FGF23 decreased along with treatment of GD. It remains unclear whether FGF23 becomes normal after euthyroid status achieved.
Methods: A total of 64 patients with euthyroid GD and 64 healthy control subjects were enrolled. Endocrine profiles including thyroid autoimmune profiles, FGF23 and bone turnover markers were obtained and compared between two groups and within each group.
Results: Euthyroid GD patients have significantly higher FGF23 and phosphate, and lower 25-hydroxyvitamin D (25OH-VitD) and intact parathyroid hormone (iPTH) levels than the control group. FGF23 was significantly and negatively correlated with phosphate level after adjusted for age, gender, calcium, iPTH and 25OH-VitD in euthyroid GD group.
Euthyroid GD | Control | P | |
N | 64 | 64 | |
Age (years) | 47.6±10.9 | 48.0±10.8 | 0.8523 |
Gender (female: male) | 51:13 | 50:14 | 0.828 |
Corrected calcium (mg/dl) | 9.12±0.48 | 9.23±0.29 | 0.1874 |
Phosphate (mg/dl) | 4.24±0.78 | 3.84±0.51 | 0.0044 |
25-OH Vitamin D (ng/dl) | 16.40±5.52 | 23.20±5.24 | <0.0001 |
iPTH (pg/ml) | 15.39±8.82 | 25.79±11.25 | <0.0001 |
FGF23 (pg/ml) | 59.10 (45.1895.09) | 46.00 (27.2160.55) | 0.0003 |
PINP (ng/ml)* | 49.70±19.65 | 54.12±20.65 | 0.5293 |
CTX (ng/ml)* | 0.21±0.12 | 0.23±0.09 | 0.5995 |
*Data of PINP and CTX were analyzed in 23 euthyroid GD subjects and 13 control subjects. |
Euthyroid Graves disease group | Control group | |
Crude | ||
Regression coefficient | −31.6 | 8.5 |
p value | 0.015 | 0.260 |
Adjusted for age, gender, calcium, parathyroid hormone and 25-OH vitamin D | ||
Regression coefficient | −34.9 | 16.9 |
P value | 0.045 | 0.306 |
Conclusion: Serum FGF23 levels remain higher than normal in GD patients even after euthyroid status achieved. Underlying mechanisms warrant further investigations. Data are presented as mean±S.D. if the continuous variable is normally distributed, and as median (interquartile range) if not normally distributed. Corrected calcium was calculated as follows: serum calcium (mg/dL) +0.8 * (four albumin). P values were calculated by t-test for continuous variables and by chi-squared test for categorical variables. FGF23 was log-transformed to become normally distributed for t-test.