FST and Huntington disease: HD patients were categorized into a low-AAC-score group (AAC score < 4) and a high-AAC-score group (AAC score ≥ 4).<h4>Results</h4>HD patients had higher serum follistatin levels than the controls (1.25 ± 0.53 ng/ml vs. 0.88 ± 0.30 ng/ml, p < 0.001).