“In addition to reporting average responses in groups of individuals, some trials have also reported the blood pressure responses of individual participants (Table 6-5). An apparent rise in blood pressure in some individuals when sodium intake is reduced has been interpreted as a pressor response, potentially as a result of an over-active renin-angiotensin-aldosterone system. However, an alternative explanation is that an apparent rise in blood pressure reflects intrinsic blood pressure variability or imprecision in blood pressure measurement. This phenomenon is illustrated by analyses of the Dietary Approaches to Stop Hypertension (DASH)-Sodium trial, which assessed blood pressure change across two points in time, separated by at least a month, when there was no change in diet or sodium level (Figure 6-2a), as well as blood pressure change when sodium was markedly reduced (Figure 6-2b) (Obarzanek et al., 2003). In both situations, there was a wide, Gaussian distribution of blood pressure change. Furthermore, the standard deviation of the distribution of change in blood pressure was similar, 8.4 versus 8.6 mm Hg, respectively, suggesting that much of the variability in blood pressure response to a reduced sodium intake (including an apparent increase in blood pressure in some individuals) results from random factors unrelated to sodium intake. A similar distribution of blood pressure changes was likewise evident in an intervention study (Miller et al., 1987) that measured blood pressure carefully and on multiple occasions pre- and postintervention (see Figure 6-3), as well as in other trials (Ruppert et al., 1991). In such studies, reports that certain individuals experienced a rise in blood pressure (Table 6-5) must be interpreted very carefully. Nonetheless, the group of individuals whose blood pressure apparently rises likely differs, on average, from the group of individuals whose blood pressure falls. Specifically, those individuals with an apparent rise in blood pressure experience a greater activation of the renin-angiotensin-aldosterone axis than those whose blood pressure falls (Egan et al., 1994; Weinberger et al., 1993a).
Ruppert and colleagues (1991) reported that while a rise in plasma renin activity and aldosterone concentration were observed in all subjects placed on a reduced sodium diet, the largest increases were observed in those whose blood pressure increased. Those who have the greatest reduction in blood pressure as a result of a reduced sodium intake appear to have a less responsive renin-angiotensin-aldosterone system (Cappuccio et al. 1997; He et al., 1998, 2001; Weinberger et al., 1993a).
Given the above considerations, an apparent rise in blood pressure in response to a reduced sodium intake cannot be used as an indicator of adequate sodium intake.
National Academies of Sciences, Engineering, and Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. https://doi.org/10.17226/10925.”
This is the first time I’ve found anything on the topic of people who experience a blood pressure rise like I have when reducing salt. It was quite a relief because I knew it worked but it seemed I was the only one.
