Association of low diastolic blood pressure with all‐cause death among US adults with normal systolic blood pressure

Although the effect of intensive systolic blood pressure lowering is widely recognized, treatment‐related low diastolic blood pressure still worrisome. This was a prospective cohort study based on the National Health and Nutrition Examination Survey. Adults (≥20 years old) with guideline‐recommended blood pressure were included and pregnant women were excluded. Survey‐weighted logistic regression and cox models were used for analysis. A total of 25 858 participants were included in this study. After weighted, the overall mean age of the participants was 43.17 (16.03) years, including 53.7% women and 68.1% non‐Hispanic white. Numerous factors were associated with low DBP (<60 mmHg), including advanced age, heart failure, myocardial infarction, and diabetes. The use of antihypertensive drugs was also associated with lower DBP (OR, 1.52; 95% CI, 1.26–1.83). DBP of less than 60 mmHg were associated with a higher risk of all‐cause death (HR, 1.30; 95% CI, 1.12–1.51) and cardiovascular death (HR, 1.34; 95% CI, 1.00–1.79) compared to those with DBP between 70 and 80 mmHg. After regrouping, DBP <60 mmHg (no antihypertensive drugs) was associated with a higher risk of all‐cause death (HR, 1.46; 95% CI, 1.21–1.75). DBP <60 mmHg after taking antihypertensive drugs was not associated with a higher risk of all‐cause death (HR, 0.99; 95% CI, 0.73–1.36). Antihypertensive drug is an important factor contributing to DBP below 60 mmHg. But the pre‐existing risk does not increase further with an additional reduction of DBP after antihypertensive drugs treatment.