Sex differences in age at onset of symptoms in patients with hypertrophic cardiomyopathy

Abstract

Background: We hypothesized that, in hypertrophic cardiomyopathy, endogenous estrogen may delay the development of symptoms in females as compared with males by several cardiovascular protective mechanisms. We examined this by assessing the sex distribution in relation to age at onset of symptoms in patients with hypertrophic cardiomyopathy.

Methods: The study population of 94 patients (55 men and 39 women) was subdivided into four groups according to age at onset of symptoms; < 15 years, 15-29 years, 30-39 years and > 40 years. In the first group, comprising the youngest patients, all the girls were pre-menarche. The age of 40 years was chosen as the lower limit for the last group because of the possible influence of pre- and perimenopausal decrease in estrogen levels on the onset of symptoms in women in their fifth decade of life.

Results: In general, females with hypertrophic cardiomyopathy developed symptoms later than did males (31.3 +/- 11.9 compared with 26.7 +/- 9.9 years; P < 0.05). Among adolescents, similar percentages of girls and boys developed the condition. Among young adult patients (between 15 and 29 years of age), it was predominantly men who developed symptoms. Men predominated, albeit insignificantly, among patients with onset of symptoms in the fourth decade of life, but there was a significant dominance of women over men in the group who became symptomatic after 40 years of age.

Conclusion: Delayed onset of symptoms in women with hypertrophic cardiomyopathy compared with men resulted in nearly one-third of women remaining asymptomatic until 40 years of age, symptoms developing in the fifth decade of life.