Association between sebum secretion and cardiac sympathetic dysfunction in Parkinson's disease

Patients with Parkinson's disease (PD) have α-synuclein (α-Syn) deposition in the skin, and decreased sebum secretion due to epidermal dysfunction. However, the relationship between sebum secretion and autonomic neuropathies is unknown.

Using the medical records in our facility, we identified patients newly diagnosed with PD on admission from August 2020 to December 2023. We analyzed whether sebum secretory ability at multiple sites was associated with cardiac sympathetic nerve function that was assessed by cardiac ¹²³I-metaiodobenzylguanidine scintigraphy.

Forty patients were included. Their sebum secretion ability positively correlated with the ratio of the average pixel count in the heart to that in the mediastinum (H/M ratio) in the posterior neck, the anterior chest, the arms, and the abdomen. In the multiple regression analysis, those in the arms (β, 8.8; 95 % CI, 4.4-13.2; P < 0.001) and abdomen (β, 1.3; 95 % CI, 0.1-2.5; P = 0.032) were associated with the H/M ratio after controlling for age, sex, and UPDRS part III.

This study revealed an association between sebum secretion in the arms and the abdomen, and cardiac sympathetic nerve function in PD patients. The site of the sebum secretory disturbance associated with cardiac sympathetic nerves closely resembled the gradient of α-Syn deposition in the skin, corroborating its deposition pattern. Our findings suggest that noninvasive sebum measurement may serve as an adjunctive diagnostic tool of α-Syn deposition in the skin for PD and provide insights into sympathetic nerve damage alongside cardiac sympathetic nerve assessments.