Hypertension Control as an Indicator of the Geographical Variation of Stroke
To the Editor:
An interesting article in the Stroke1 recently reported a correlation between the prevalence of high blood pressure (HBP) and the stroke attack rate in men (r=0.42, P=.09) and women (r=0.56, P=.016) aged 35 to 64 years across centers in the MONICA Project. These findings have prompted us to examine the relation between HBP control and stroke attack and mortality rates using data from the published reports of the MONICA project.1 2 3
HBP control is defined as the proportion of actual hypertensives with systolic and diastolic blood pressures under 160 and 95 mm Hg, respectively. Data on age-adjusted HBP control are obtained from the first MONICA surveys in the mid-1980s,2 while data on age-adjusted stroke attack and mortality rates correspond to the late 1980s.3 Finally, we have used data for the same MONICA centers as Stegmayr et al,1 with the exception of the Novosibirsk control and the Gothenburg centers, because we could not extract the data from the MONICA reports.
Pearson correlation coefficients between HBP control and stroke attack rates were −0.29 (P=.28) for men and −0.18 (P=.51) for women. Correlations between HBP control and stroke mortality were −0.59 (P=.01) and −0.25 (P=.34) for men and women, respectively. From the perspective of the strategies of stroke prevention through HBP control, it is reassuring that this variable contributes modestly, although significantly among men, to the geographical variation of stroke across centers from very diverse countries.
- Copyright © 1998 by American Heart Association
Stegmayr B, Asplund K, Kuulasmaa K, Rajakangas A, Thorvaldsen P, Tuomilehto J. Stroke Incidence and Mortality Correlated to Stroke Risk Factors in the WHO MONICA Project: an Ecological Study of 18 Populations. Stroke.. 1997;28:1367–1374.
Keil U, Kuulasmaa K, for the WHO MONICA PROJECT. WHO MONICA Project: risk factors. Int J Epidemiol. 1989;18(suppl 1):S46–S55.
Thorvaldsen P, Kuulasmaa K, Rajakangas A, Rastenyte D, Sarti C, Wilhelmsen L. Stroke Trends in the WHO MONICA Project. Stroke.. 1997;28:500–506.