Kinetic epidemiological model for elucidating sexual difference of hypertension (KCIS no.20)

Background Woman have lower rate of hypertension than man but it is still elusive how such gender difference can be explained by kinetic epidemiological curves. Objective The aim of this paper was to develop a multi-state model for delineating the kinetic epidemiology of hypertension according to the Seventh Report of the Joint National Committee (JNC 7) classification criteria by gender, and to derive gender-specific kinetic curves. Methods We used data from a population-based screening programme with 42 027 participants to fit a four-state Markov model corresponding to the classification of hypertension from the JNC 7. Results The young man had higher progression rate but lower regression rate for the movement between normal and pre-hypertension than the young woman. Such gender difference disappeared after 50 years old. The mean sojourn time of pre- and stage 1 hypertension for man and stage 1 for woman was approximately 5 years. However, the corresponding figure for pre-hypertension for woman was 25 years at age 30, 10 years at age 40 and 5 years afterwards. Conclusion Elucidating the kinetic epidemiological curves of hypertension explains higher prevalence rate in young man than woman. These findings fit with the role of sex hormones regulating blood pressure demonstrated in the animal model.