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

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 23 female 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 (down arrowE/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 group A (duration < 3 years); FT4 levels correlated significantly with Dlco% (r = + 0.90, p < 0.01). While in group B (duration > 3 years), 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 = + 0.4 1, p < 0.05). Conclusion This study demonstrates the close association between PRL or thyroid hormones and some organ involvement in SSc.