Serum 5-hydroxytryptamine levels as biomarkers for motor dysfunction and depression in Parkinson’s disease patients

Table 1 A comparison of the clinically relevant variables between non-dyskinesia and dyskinesia groups, mean ± SD

Variable	Non-dyskinesia (n = 37)	Dyskinesia (n = 33)	t/χ2	P value
Gender (male/female)	19/18	15/18	χ2 = 0.31	0.578
Age (years)	69.00 ± 8.86	63.03 ± 10.34	t = 2.56	0.013a
Height (cm)	163.64 ± 7.55	162.46 ± 7.66	t = 0.65	0.520
Weight (kg)	63.11 ± 10.32	60.76 ± 11.47	t = 0.90	0.373
MMSE	22.97 ± 6.29	21.79 ± 6.98	t = 0.74	0.462
Age of onset (years)	63.43 ± 8.63	55.12 ± 10.72	t = 3.50	0.001b
Course of disease (years)	5.16 ± 3.61	7.97 ± 3.97	t = -2.96	0.004b
UPDRS I (off phase)	2.70 ± 2.83	4.39 ± 3.94	t = -2.00	0.050a
UPDRS III (off phase)	42.62 ± 19.85	52.06 ± 20.87	t = -1.95	0.056
H-Y stage (off phase)	2.41 ± 0.90	2.97 ± 0.98	t = -2.45	0.017a
Duration of dopaminergic treatment (years)	3.12 ± 3.22	7.33 ± 4.14	t = -4.74	< 0.001c
Onset-to-treatment interval (years)	1.37 ± 2.79	0.53 ± 1.22	t = 1.59	0.117
Duration of wearing-off (months)	1.78 ± 6.46	19.70 ± 21.21	t = -4.45	< 0.001c
Duration of on-off (months)	1.46 ± 4.78	21.49 ± 29.21	t = -3.69	< 0.001c
Equivalent dose for wearing-off (mg)	40.54 ± 132.73	428.03 ± 326.96	t = -6.23	< 0.001c
Equivalent dose for on-off (mg)	47.30 ± 149.98	393.94 ± 306.12	t = -5.92	< 0.001c
Maximum daily levodopa (mg)	409.67 ± 294.09	735.39 ± 277.80	t = -4.78	< 0.001c

^aP < 0.05.

^bP < 0.01.

^cP < 0.001.

MMSE: Mini-Mental State Examination; UPDRS: Unified Parkinson’s Disease Rating Scale; H-Y: Hoehn-Yahr.