Objective: To explore the prevalence of isolated diastolic hypertension and associated cardiovascular risk and blood pressure changes during follow up.
Methods: This cohort study screened 101 510 participants who were employees of the Kailuan Group, a state-run coal mining company in 2006 and 2007. Among them, 6 778 subjects were diagnosed with isolated diastolic hypertension (IDH). IDH subjects without history of cardiovascular disease and not treated with antihypertensive drugs were included in this analysis. Participants without health examination between 2008 to 2009 or 2010 to 2011 were excluded. A total of 4 600 participants were included in the final analysis. At the end of the third health examination, the conversion rate of different blood pressure turnover was calculated after standardizing age and gender according to demographic data of China in 2006. Multivariate logistic regression analysis was applied to analyze the risk factors of blood pressure turnover in IDH population.
Results: (1) Participants were followed up for (4.03 ± 0.26) years and the rates of turnover from IDH to normotension, isolated systolic hypertension (ISH) and systolic diastolic hypertension (SDH) were 51.4%, 3.5%, 18.3%, respectively (45.6%, 3.6%, 22.0% in male, 57.4%, 3.3%, 14.7% in female). (2) Multivariate logistic regression analysis showed that low baseline age, low diastolic pressure, low body mass index, low uric acid, physical exercise and low alcohol intake were associated with turnover from IDH to normotension; the risk factors of turnover from IDH to ISH were older age at baseline, higher systolic pressure and higher sensitivity C-reactive protein; the risk factors of turnover from IDH to SDH were older baseline age, high systolic pressure and excessive salt intake.
Conclusions: Untreated subjects with IDH can transform from IDH to normotension,ISH, SDH, and the rate of turnover from IDH to normotension is higher than others during follow up. Aging, higher systolic pressure, higher sensitivity C-reactive protein and excessive salt intake are risk factors for IDH subjects to suffer from ISH and SDH.