Hypertension prevalence in Japan projected to 2040 using a Bayesian Lee-Carter model

Accurate projections of future hypertension prevalence are essential for planning effective public health strategies to prevent cardiovascular mortality. This study aimed to project the future prevalence of hypertension in Japan through 2040. Prevalence estimates of hypertension and untreated/uncontrolled hypertension stratified by sex and age groups were obtained from the National Health and Nutrition Survey from 1986 to 2019. Hypertension was defined as systolic blood pressure (BP) ≥ 140 mmHg, diastolic BP ≥ 90 mmHg, or use of antihypertensive medication, and untreated/uncontrolled hypertension as systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg. Three approaches were compared: a Bayesian Lee-Carter model, a model assuming monotonic prevalence change, and a constant-prevalence model. The projected prevalence estimates were applied to the population projections from the Vital Statistics of Japan. The Bayesian Lee-Carter model demonstrated the best predictive accuracy among the three models. The model projected that hypertension prevalence remained stable among men from 47.1% (95% credible interval [CI], 45.6-48.6%) in 2020 to 48.2% (44.6-52.4%) in 2040, and among women from 36.7% (35.5-37.8%) to 35.6% (32.8-38.3%). In contrast, untreated/uncontrolled hypertension prevalence would decline among men from 31.9% (28.6-34.6%) to 26.7% (18.0-38.4%), and among women from 23.1% (21.3-24.8%) to 17.2% (13.1-22.6%). The prevalence of hypertension in Japan is projected to remain largely unchanged through 2040, while the prevalence of untreated/uncontrolled hypertension is projected to decline. The findings suggest that public health policies and clinical efforts for BP control should be maintained and further strengthened to sustain and accelerate the trend.