Cases and Controls

Forty-two AS outpatients (32 male, 10 female), aged 38.12 ± 12.37 years who took part in the research were all from the Division of Allergy, Immunology and Rheumatology in Chung Shan Medical University Hospital. All the patients satisfied the modified New York criteria for AS.¹⁵ Patients with a history of arrhythmia, systemic hypertension, diabetes mellitus, thyroid disease, or other rheumatic diseases were excluded. We also recruited 230 healthy subjects, sex and age matched (175 male and 57 female, aged 38.08 ± 13.57), as control group who were free of physical illness and were not taking any medications at the time of the study. All the subjects were totally symptom free for ANS involvement and had normal neurological examination findings.