From progress to plateau: 50-year trends in hypertension and salt intake in Finland

Abstract Background This study aimed to assess trends and changes in the prevalence of hypertension and salt intake in the Finnish population throughout its 50-year history of population health studies, and to discuss the current state and future directions of sodium reduction policies. Materials and methods Twelve independent cross-sectional study samples from 1972 to 2023 were used to assess changes in mean blood pressure, use of antihypertensive medication, and salt intake based on health examinations and 24-hour urine collections conducted in population-based surveys in selected geographical areas. The study population (n = 77418) consisted of adults aged 25-64 years who had participated in a health examination. A 24-hour urine subset included those subjects who completed a 24-hour urine collection (n = 5035). Year-to-year changes in the prevalence of hypertension and mean salt intake were assessed using logistic regression, with year included as a categorical independent variable. The prevalence of hypertension, defined by having systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥90 mmHg or current use of antihypertensive medication, was used as the main outcome variable. Results From 1972 to 2012, hypertension prevalence significantly decreased from 78% to 50% in men (p < 0.001) and from 73% to 36% in women (p < 0.001). After 2012, no statistically significant changes were observed in year-to-year comparisons, using 2023 as a reference. Based on year-to-year comparisons, there has been no statistically significant changes in mean salt intake from the 2000s onwards on either men or women. Conclusions The longstanding decline in hypertension prevalence and salt intake, observed until the late 20th century, have now both plateaued. Based on current situation, actions aimed at further developing early identification and treatment of hypertension, and reducing salt intake should therefore be reintroduced into Finland's public health discourse. Key messages • Based on Finnish population health studies, the favorable trend in the prevalence of hypertension and salt intake is threatening to stop. • Reducing population salt intake requires active political public health measures and cooperation with the food industry to prevent a new increase in the prevalence of hypertension.