Table 1.

Demographic characteristics of subjects enrolled in the present study.

Groups	Number (%)	Gender Male:Female	P-value	P-value	Age (years) (mean ± SD)	P-value	P-value
HC	318(33.1)	178:140	Ref		67.61 ± 8.93	Ref
PD	312(32.4)	176:136	NS	Ref	67.47 ± 9.56	NS	Ref
NDC	332(34.5)	188:144	NS	NS	67.6 ± 10.2	NS	NS

Chi-square test and Student’s t-test. SD, standard deviation; Ref, reference; NS, not significant; HC, healthy controls; PD, Parkinson’s disease; NDC, neurological disease control.