Table 2.

Pearson correlations between proprioceptive and olfactory sensitivity and age across the three groups

Measures	JNDT for passive motion sense		JNDT for limb position sense		Smell identification		Smell discrimination
	r	p values	r	p values	r	p values	r	p values
Healthy group
Age	− 0.11	0.95	− 0.24	0.20	0.05	0.79	− 0.08	0.67
PD group
Age	0.22	0.23	0.20	0.28	− 0.14	0.44	0.12	0.51
Disease duration	< 0.001	1.00	− 0.15	0.41	− 0.52	0.002**	0.06	0.76
UPDRS motor	− 0.03	0.88	− 0.09	0.65	− 0.30	0.13	0.24	0.22
UPDRS total	− 0.08	0.68	− 0.19	0.34	− 0.50	0.008**	0.18	0.36
Levodopa equivalent dose	− 0.14	0.43	− 0.01	0.96	− 0.13	0.49	0.31	0.09
MCI group
Age	0.39	0.07	0.17	0.46	− 0.19	0.39	0.05	0.82
MoCA	− 0.43	0.05	0.06	0.78	0.44	0.04*	− 0.40	0.07

JNDT Just noticeable difference threshold, UPDRS Unified Parkinson’s Disease Rating Scale, PD Parkinson’s disease, MCI mild cognitive impairment, MoCA Montreal Cognitive Assessment.

*: p-value < 0.05; **: p-value < 0.01