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7-Day ambulatory monitoring for adults with hypertension and diabetes
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CORRESPONDENCE REFERENCES
l. Coulson R, Scheinman SJ: Xanthine effect on renal proximal tubular function and cyclic AMP metabolism. J Pharmacol Exp Ther 248:589-595, 1989 2. Passmore AP, Kondowe GB, Johnston GD: Renal and cardiovascular effects of caffeine: A dose-response study. Clin Sci 72:749-756, 1987 3. Gates GF: Glomemlar filtration rate: Estimation from fractional renal accumulation of 99mTc-DTPA (stannous). AJRAm J Roentgenol 138:565-570, 1982 4. Disler PB, Lunch SR, Charlton RW, Torrance JD, Bothwell TH, Walker RB, Mayet F: The effect of tea on iron absorption. Gut 16:193-200, 1975 5. Serafin WE: Methylxanthines, in Hardman JG, Limbird LE, Mofinoff PB, Ruddon RW, Goodman Gilman A (eds): The Pharmacological Basis of Therapeutics. New York, McGraw-Hill, 1996, pp 672-678 © 2001 by the National Kidney Foundation, Inc. doi: lO. 1053/ajkd.2001.24124
7-DAY AMBULATORY MONITORING FOR ADULTS WITH HYPERTENSION AND DIABETES To the Editor: Patients with diabetes are in double jeopardy if an elevated blood pressure complicates their condition1; it seems desirable to detect yet another separate blood pressurerelated risk of nephropathy, namely a systolic and/or diastolic pressure that over swings along the 24-hour scale, dubbed CHAT, for circadian _hyper-_amplitude-_tension.2 CHAT, an above-threshold variability of blood pressure, can be accompanied by a below-threshold variability of heart rate. This occurrence further increases the risk of a catastrophic event, including a myocardial infarction, cerebral ischemia, and nephropathy. The 7-day/24-hour monitoring is required for the diagnosis of CHAT. Indeed, high blood pressures can be detected much more reliably with the 7-day/24-hour approach, which shows that many measurements below 140/90 rnm Hg are found during office hours in the absence of antihypertensive treatment in patients conventionally diagnosed as hypertensive. A few patients have over 50% of their values below the 140/90 mm Hg limit during office hours. 3 The merit of week-long automatic monitoring of those who may be on medication they do not need also has been reported. 3 During office hours, normotensives can have occasional hypertensive values and vice versa. Even a 24hour ambulatory blood pressure average can be high for several days and normal for months or years of ambulatory monitoring thereafter. 2 While it has not been shown as yet that treating CHAT lowers the risk of nephropathy, the possibility of eliminating CHAT by autogenic treatment or drugs is documented. 2,4 Diastolic CHAT significantly increases the risk of nephropathy by 590%, even when the 24-hour average of systolic/ diastolic blood pressure is below 130/80 mm Hg (by comparison, a decreased heart rate variability significantly increases
the risk of nephropathy by 440%)? CHAT may be transient; hence, a 7-day span of ambulatory monitoring has been recommended by an international consensus meeting. 4 For the reliable diagnosis of an abnormality such as an overall blood pressure elevation as well as for detecting CHAT, monitoring for 1 week is advisable because of the variability long known to characterize swings in blood pressure. 2,5 Seven-day automatic ambulatory monitoring is practical, because instruments for clinical use are available at a 90% price reduction through the Chronobiology Center at the University of Minnesota. Analyses based on reference standards from normal subjects specified by clock-hour as well as gender and age are also available. Interested parties can contact the University of Minnesota Chronobiology Center by e-mail (come001 @tc.urrm.edu) or by phone (612-624-6976). Germaine Cornglissen, PhD Othild Schwartzkopff, MD Franz Halberg, MD Halberg Chronobiology Center University of Minnesota Minneapolis, Minnesota Kuniaki Otsuka, MD Yoshihiko Watanabe, MD, PhD Department of Medicine 1 Division of Neurocardiology Tokyo Women's Medical University Tokyo, Japan
REFERENCES 1. Bakris GI, Williams M, Dworkin L, Elliott WJ, Epstein M, Toto R, Tuttle K, Douglas J, Hsueh W, Sowers J, for the National Kidney Foundation Hypertension and Diabetes Executive Committees Working Group: Preserving renal function in adults with hypertension and diabetes: A consensus approach. Am J Kidney Dis 36:646-661, 2000 2. Halberg E Cornrlissen G, Halberg J, Fink H, Chert C-H, Otsuka K, Watanabe Y, Kumagal Y, Syutldna EV, Kawasaki T, Uezono K, Zhao ZY, Schwartzkopff O: Circadian Hyper-Amplitude-Tension, CHAT: A disease risk syndrome of anti-aging medicine. J Anti-Aging Med 1:239-259, 1998 (Editor's Note by M. Fossel, p 239) 3. Cornrlissen G, Otsuka K, Chen C-H, Kumagai Y, Watanabe Y, Halberg F, Siegelova J, Dusek J: Nonlinear relation of the circadian blood pressure amplitude to cardiovascular disease risk. Scripta Medica (Brno) 73:85-94, 2000 4. Halberg F, Cornrlissen G, International Womb-toTomb Chronome Initiative Group: Resolution from a meeting of the International Society for Research on Civilization Diseases and the Environment (New SIRMCE Confederation), Brussels, Belgium, March 17-18, 1995: Fairy tale or reality? Medtronic Chronobiology Seminar #8, April 1995. http://revilla.mac.cie.uva.es/chrono 5. Janeway TC: The Clinical Study of Blood Pressure. New York, NY, Appleton & Co., 1904 © 0 by the National Kidney Foundation, Inc. doi: l O.l O53/ajkd.2001.2 4166
CORRESPONDENCE REFERENCES
l. Coulson R, Scheinman SJ: Xanthine effect on renal proximal tubular function and cyclic AMP metabolism. J Pharmacol Exp Ther 248:589-595, 1989 2. Passmore AP, Kondowe GB, Johnston GD: Renal and cardiovascular effects of caffeine: A dose-response study. Clin Sci 72:749-756, 1987 3. Gates GF: Glomemlar filtration rate: Estimation from fractional renal accumulation of 99mTc-DTPA (stannous). AJRAm J Roentgenol 138:565-570, 1982 4. Disler PB, Lunch SR, Charlton RW, Torrance JD, Bothwell TH, Walker RB, Mayet F: The effect of tea on iron absorption. Gut 16:193-200, 1975 5. Serafin WE: Methylxanthines, in Hardman JG, Limbird LE, Mofinoff PB, Ruddon RW, Goodman Gilman A (eds): The Pharmacological Basis of Therapeutics. New York, McGraw-Hill, 1996, pp 672-678 © 2001 by the National Kidney Foundation, Inc. doi: lO. 1053/ajkd.2001.24124
7-DAY AMBULATORY MONITORING FOR ADULTS WITH HYPERTENSION AND DIABETES To the Editor: Patients with diabetes are in double jeopardy if an elevated blood pressure complicates their condition1; it seems desirable to detect yet another separate blood pressurerelated risk of nephropathy, namely a systolic and/or diastolic pressure that over swings along the 24-hour scale, dubbed CHAT, for circadian _hyper-_amplitude-_tension.2 CHAT, an above-threshold variability of blood pressure, can be accompanied by a below-threshold variability of heart rate. This occurrence further increases the risk of a catastrophic event, including a myocardial infarction, cerebral ischemia, and nephropathy. The 7-day/24-hour monitoring is required for the diagnosis of CHAT. Indeed, high blood pressures can be detected much more reliably with the 7-day/24-hour approach, which shows that many measurements below 140/90 rnm Hg are found during office hours in the absence of antihypertensive treatment in patients conventionally diagnosed as hypertensive. A few patients have over 50% of their values below the 140/90 mm Hg limit during office hours. 3 The merit of week-long automatic monitoring of those who may be on medication they do not need also has been reported. 3 During office hours, normotensives can have occasional hypertensive values and vice versa. Even a 24hour ambulatory blood pressure average can be high for several days and normal for months or years of ambulatory monitoring thereafter. 2 While it has not been shown as yet that treating CHAT lowers the risk of nephropathy, the possibility of eliminating CHAT by autogenic treatment or drugs is documented. 2,4 Diastolic CHAT significantly increases the risk of nephropathy by 590%, even when the 24-hour average of systolic/ diastolic blood pressure is below 130/80 mm Hg (by comparison, a decreased heart rate variability significantly increases
the risk of nephropathy by 440%)? CHAT may be transient; hence, a 7-day span of ambulatory monitoring has been recommended by an international consensus meeting. 4 For the reliable diagnosis of an abnormality such as an overall blood pressure elevation as well as for detecting CHAT, monitoring for 1 week is advisable because of the variability long known to characterize swings in blood pressure. 2,5 Seven-day automatic ambulatory monitoring is practical, because instruments for clinical use are available at a 90% price reduction through the Chronobiology Center at the University of Minnesota. Analyses based on reference standards from normal subjects specified by clock-hour as well as gender and age are also available. Interested parties can contact the University of Minnesota Chronobiology Center by e-mail (come001 @tc.urrm.edu) or by phone (612-624-6976). Germaine Cornglissen, PhD Othild Schwartzkopff, MD Franz Halberg, MD Halberg Chronobiology Center University of Minnesota Minneapolis, Minnesota Kuniaki Otsuka, MD Yoshihiko Watanabe, MD, PhD Department of Medicine 1 Division of Neurocardiology Tokyo Women's Medical University Tokyo, Japan
REFERENCES 1. Bakris GI, Williams M, Dworkin L, Elliott WJ, Epstein M, Toto R, Tuttle K, Douglas J, Hsueh W, Sowers J, for the National Kidney Foundation Hypertension and Diabetes Executive Committees Working Group: Preserving renal function in adults with hypertension and diabetes: A consensus approach. Am J Kidney Dis 36:646-661, 2000 2. Halberg E Cornrlissen G, Halberg J, Fink H, Chert C-H, Otsuka K, Watanabe Y, Kumagal Y, Syutldna EV, Kawasaki T, Uezono K, Zhao ZY, Schwartzkopff O: Circadian Hyper-Amplitude-Tension, CHAT: A disease risk syndrome of anti-aging medicine. J Anti-Aging Med 1:239-259, 1998 (Editor's Note by M. Fossel, p 239) 3. Cornrlissen G, Otsuka K, Chen C-H, Kumagai Y, Watanabe Y, Halberg F, Siegelova J, Dusek J: Nonlinear relation of the circadian blood pressure amplitude to cardiovascular disease risk. Scripta Medica (Brno) 73:85-94, 2000 4. Halberg F, Cornrlissen G, International Womb-toTomb Chronome Initiative Group: Resolution from a meeting of the International Society for Research on Civilization Diseases and the Environment (New SIRMCE Confederation), Brussels, Belgium, March 17-18, 1995: Fairy tale or reality? Medtronic Chronobiology Seminar #8, April 1995. http://revilla.mac.cie.uva.es/chrono 5. Janeway TC: The Clinical Study of Blood Pressure. New York, NY, Appleton & Co., 1904 © 0 by the National Kidney Foundation, Inc. doi: l O.l O53/ajkd.2001.2 4166