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. Author manuscript; available in PMC: 2012 Apr 15.
Published in final edited form as: Circ Res. 2011 Apr 7;108(8):980–984. doi: 10.1161/CIRCRESAHA.110.233668

Figure 3. Endogenous circadian variation in blood pressure during the constant routine protocol is out of phase with circadian variations in other measured variables.

Figure 3

Shown are data from the constant routine protocol. lnHF is a marker of cardiac vagal tone (see legend to Figure 2 for other abbreviations and explanations). The phase of peak SBP is shown in each panel by a dashed vertical line close to 251° which was similar to the timing of the circadian peak in DBP, but quite distinct from the circadian peaks or troughs in other relevant physiological variables shown above in the other panels. Very similar circadian rhythms occurred in the two forced desynchrony protocols (Figure 2; Supplemental Material Online Figure I and Online Table I).