Miura and colleagues1 add persuasively to the small number of studies that illustrate that even moderately elevated blood pressure (BP) in early life increases cardiovascular disease risk. The authors state that the only prospective studies of the association between BP in young adulthood and cardiovascular disease mortality are nested case-control investigations and analyses of life insurance data. However, in the "Comment" section they cite our study of this issue among male former students attending Glasgow University, Scotland, from 1948 to 1968. This is a large prospective cohort study in which BP was measured at a mean age of 20.5 years—on average more than 9 years earlier than in the Chicago study. As noted by the authors, we found a positive association between systolic BP and coronary heart disease mortality.2 In addition, our findings provide evidence that both systolic and diastolic BP are positively associated with cardiovascular disease and coronary heart disease mortality, while for stroke there was evidence of a strong association between diastolic BP and stroke mortality. Miura and colleagues point out that we did not supply detailed relations by BP strata, but such analyses do not materially alter the results or the recommendations they support, although they may allow the findings to be more readily interpreted by both the public and physicians. For comparison, in Table 1 we provide mortality associations by BP strata as defined by the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-VI).3 The findings are similar to those for the Chicago men, although the relative risks in the highest BP categories are lower. This may be related to the small proportion of persons with severe hypertension among our younger and, on average, more affluent participants, leading to considerable imprecision in estimating relative risks. Another possibility is that there may be greater dilution of effects due to measurement error in our data, given the unstandardized manner in which BP was measured and the large number of people carrying out the measurements. We are currently investigating this issue among men who had BP measured on more than one occasion.