Table 4.

Correlations between serum Cys-C levels and clinical indicators

Serum Cys-C (mg/L)	FVC	ALSFRS-R	Disease duration	Age at onset	Site of onset	Rate of ALS disease progression
r-values	-0.237	-0.355	0.068	-0.065	0.274	0.098
p-values	0.078	0.007	0.618	0.636	0.041	0.474

Abbreviations: ALS, amyotrophic lateral sclerosis; ALSFRS-R, the ALS functioning rating scale-revised; FVC, forced vital capacity.