A study in this week’s issue of THE LANCET highlights how people with normal or high-normal (slightly raised, but not high) blood pressure can progress to high blood pressure (hypertension) over a four-year period, which is positively associated with advancing age and weight increase. Authors of the study suggest that blood pressure should be monitored every year for people with high-normal blood pressure, and possibly every two years for people with normal blood pressure.
Patients with optimum (less than 120/80 mm Hg), normal (120-129/80-84 mm Hg), and high normal (130-139/85-89 mm Hg) blood pressure (BP) may progress to high blood pressure (hypertension, 140/90 mm Hg or greater) over time. Ramachandran Vasan and colleagues from the Framingham Heart Study Group, USA, aimed to establish the best frequency of BP screening by assessing the rates and determinants of progression to high blood pressure.
The investigators assessed repeated BP measurements in individuals who did not have high blood pressure (BP less than 140/90 mm Hg) from the Framingham Study (which totalled 4200 men and 5645 women). The average age of the participants was 52 years of age, and BP examination was done between 1978 and 1994. The incidence of high blood pressure (or use of antihypertensive treatment) and its determinants were studied.
Around 5% of participants with optimum BP, 18% with normal, and 37% with high normal BP aged below 65 years progressed to high blood pressure over 4 years. Corresponding four-year rates of progression for patients 65 years and older were 16%, 26%, and 50%, respectively. Obesity and weight gain also contributed to progression; a 5% weight gain on follow-up was associated with 20-30% increased odds of hypertension.
In an accompanying Commentary (p 1659), Sven-Olof Isacsson from the University of Lund, Sweden, states: “The key features that influence a rise in blood pressure are still not completely known. [Future] research should focus on mechanisms involved in the increase of blood pressure and the transition to hypertension. Identifying specific pathways, and susceptible subgroups of people, would also provide new opportunities for intervention. Research also has to address the major issue of how new insights from research are used to achieve effects in the population involving all sectors of the society. Other topics for attention include prevention of unhealthy lifestyles in childhood and adolescence, the role of physical activity in the prevention of high blood pressure and the maintenance of normal body weight, and strategies for the incorporation of preventive activities in primary care practice.”
Contact: Dr Ramachandran S Vasan, c/o NHLBI Communications Office, Room 4A21/Building 31, 31 Center Street, MSC 2480, Bethesda, Maryland 20892-2480 USA; T) +1 301 496 4236; F) +1 301 402 2405; E) vasan@fram.nhlbi.nih.gov
Professor Sven-Olof Isacsson, Department of Community Medicine, Samhällsmedicinska institutionen, University of Lund, 20502 Malmo, Sweden; T) +46 40 332661; E) Sven-Olof.Isacsson@smi.mas.lu.se
Journal
The Lancet