Prolactin and thyroid hormones in patients with systemic sclerosis: correlations with disease manifestations and activity

Summary.

Objective: To determine serum levels of prolactin (PRL) and thyroid hormones and to investigate the correlation between these hormones and different disease manifestations in patients with systemic sclerosis (SSc). Methods: Twenty four patients with SSc (23 women, mean age 37.7±12.7) were subjected to thyroid hormones assessment. Prolactin (PRL) was assessed in 23female patients. The patients were evaluated regarding different disease manifestations. Fifteen normal female volunteers were involved as controls. Results: Serum levels of PRL in all patients was significantly higher than controls (16.75±9.06 for patients vs. 11.6±4.5 for controls with p<0.001). Eight patients out of 23 (34.8%) showed hyperprolactinemia. In patients with diffuse SSc (dSSc), PRL levels showed significant correlation with the rate of skin tethering (r=+0.72, p<0.01) and abnormal left ventricular filling pattern (↓E/A ratio), i.e., occurrence of diastolic dysfunction (r=+0.65, p<0.05). Hyperprolactinemia in all patients correlated significantly with disease duration (r=–0.42, p<0.05).     Mean serum levels of free thyroxin (FT4) in all patients were significantly lower than the control group(7.46±2.7 for patients vs 10.47±2.5 with p<0.001). Eight out of all 24 patients (33.3%) showed hypothyroidism. In groupA (duration<3years); FT4 levels correlated significantly with Dlco% (r=+0.90, p<0.01). While in groupB (duration>3years), T4 hypothyroidism correlated significantly with hand joint restriction of motion (r=+0.66, p<0.01).    Serum levels of triiodothironine (FT3) in all patients were nonsignificantly lower than the control group (4.8±2.3 for patients vs 5.3±1.9 for controls, P=NS). Three patients out of 24 (12.5%) showed T3 thyrotoxicosis. Serum levels of T3 correlated significantly with liver enzyme elevations (r=+0.46, p<0.05) and ESR (r=+0.41, p<0.05). Conclusion: This study demonstrates the close association between PRL or thyroid hormones and some organ involvement in SSc.