Day 253 - 21 May 96 - Page 31
1 about which you should take some sort of action.
2
3 Q. Again, we see that not by very much perhaps, I do not know
4 what the significance of the units is, but the French
5 exceed us in both the middle pink and the dark pink, do
6 they not?
7 A. Yes.
8
9 MR. JUSTICE BELL: Let me catch up a moment, please, Mr.
10 Rampton.
11
12 MR. RAMPTON: I am sorry, my Lord.
13
14 MR. JUSTICE BELL: What are the figures at figure 2.22?
15 A. They are millimetres of mercury which is the
16 traditional way of measuring blood pressure.
17
18 Q. Yes, but those must be diastolic unless I have just got my
19 terms all the way round. The systolic blood pressure is
20 when the heart is pumping?
21 A. Yes.
22
23 Q. And the diastolic is when it is not pumping?
24 A. Yes. It is the return if you like. The major one is
25 the exertion that the heart has to make in order to push
26 blood around the circulation, and that is the systolic
27 measurement, so the higher that is, the harder the work the
28 heart has to do to push blood through the circulation and
29 if blood vessels are obstructed.
30
31 MR. JUSTICE BELL: I understand now. The pale blue is between
32 140 and white is less than 140, I am just catching up. The
33 figures along the bottom are not actually levels of
34 mercury. They are percentages, are they not?
35 A. Percentage of the total, yes.
36
37 Q. Yes, that is right. I understand now. I was thrown. The
38 irony is that if a healthy young man might expect his blood
39 pressure to be something like 120 over 80, the figures
40 along the bottom could be diastolic figures and would fall
41 into place quite nicely, that is what completely threw me,
42 but I see now. I understand. Thank you.
43
44 MR. RAMPTON: Then?
45 A. Could I just make one point about these figures for
46 blood pressure; this is to put them into perspective. One
47 is looking at values here 140, 150 for a substantial part
48 of the population; what we were looking at yesterday was
49 the possible effects of diet modification and the proposal
50 that if we could reduce our salt intake to 6 grammes a day
51 it is calculated that this might reduce systolic blood
52 pressure on average by 2 or 3 milligrams. Now, in relation
53 to 140 and 150, that is really not very much, and a much
54 more effective way of treating hypertension of, course, is
55 the use of drugs which have a much more dramatic effect
56 than the avoidance of salt. I do not mean by that that
57 I think people should try and reduce the salt intake, but
58 the idea that if we make such modifications in our diet we
59 are going to see dramatic changes in blood pressure as a
60 result of falling salt is just not the case. It really is
