Objective: We determine the comorbid conditions associated with syncope in women. In addition, we hypothesize a higher proportion of autonomic comorbid conditions during the female reproductive age.
Methods: We identified a cohort of patients admitted to US hospitals with the principal diagnosis of syncope. We compare patient demographics stratified by gender as well as syncope associated comorbidities. We compared these comorbidities in female of reproductive age (15-45) to men as control.
Results: From a total sample of 305,932, females constituted 56.7% (n = 173,434). Females were slightly older (mean age 70.9 +/- 17.9 vs. 66.7 +/- 17.3; P < 0.0001); with similar racial distribution (white 57.8 vs. 57.5%), and similar length of hospital stay (mean 2.66 +/- 2.63 vs. 2.68 +/- 2.72 days; P > 0.05). Females had higher proportion of migraine (1.65 vs. 1.29%; odds ratio 'OR' 1.29; 95% confidence interval 'CI' 1.21, 1.36); chronic fatigue syndrome (1.73 vs. 1.3%; OR 1.32; 95% CI 1.25, 1.4); gastroparesis (0.2 vs. 0.12%; OR 1.64; 95% CI 1.35, 1.98); interstitial cystitis (0.07 vs. 0.01%; OR 7.44; 95% CI 4.10, 13.5); and postural tachycardia syndrome (0.49 vs. 0.44%; OR 1.1; 95% CI 1.001, 1.23). Orthostatic hypotension was not different between the groups (P = 0.24). When the sample was stratified by age category, the odds ratio for gastroparesis, orthostatic hypotension, and postural tachycardia syndrome was increased (P < 0.05).
Interpretation: A higher proportion of autonomic dysfunction was present in women compared to men. In addition, these comorbid autonomic conditions were especially prominent during the female reproductive age.