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Gender, day-night blood pressure changes, and left ventricular mass in essential hypertension
AJH 1995; 8:I93-196
Gender, Day-Night Blood Pressure Changes, and Left Ventricular Mass in Essential Hypertension Dippers and Peakers Paolo Verdecchia, Giuseppe Schillaci, Claudia Borgioni, Antonella Ciucci, Nicola Sacchi, Massimo Battistelli, Massimo Guerrieri, Elio Comparato, and Carlo Porcellati
The finding of increased left ventricular (LV) mass in hypertensive subjects with blunted nocturnal fall in blood pressure (BP) might be an artifact of matching patients for daytime BP, with resulting higher 24-h BP in nondippers. Therefore, we compared a large number (n = 1048) of hypertensive dippers and nondippers in their LV mass at echocardiography before and after adjustment for 24-h, daytime, and nighttime ambulatory BP. In men, the difference between dippers and nondippers was not significant before and after adjustment for 24-h BP, but after adjustment for nighttime BP LV mass was greater in dippers (more properly "'peakers"). In women, LV mass was greater in nondip-
pers than in dippers both before and after adjustment for 24-h BP, while the difference between the two groups disappeared after adjustment for nighttime BP. Thus, for any given level of mean 24-h BP, a flattened diurnal BP profile is associated with a greater LV mass in hypertensive women. Daytime hypertension, either associated or not with a blunted nocturnal fall in BP, may be a sufficient determinant of LV wall thickening in men. Am J Hypertens 1995;8:193-196
mbulatory blood pressure (BP) readings obtained using semiautomatic recorders during day are better predictors of cardiovascular morbidity than standard BP mea-
surements obtained in the physician's office. 1 The recent development of fully automated devices has facilitated ambulatory BP monitoring over the entire 24-h period and several reports indicate that left ventricular (LV) hypertrophy and other measures of target organ damage in hypertension are more closely related to the average 24-h BP than to clinic BP. 2 In addition to the mean levels of BP, the characteristics of the 24-h BP profile might be a further determinant of target organ damage in essential hypertension. Patients with a reduced or absent nocturnal fall of BP ( " n o n d i p p e r s " ) have a more frequent history of stroke 3 and may be at increased risk of target organ damage 4-8 and, perhaps, of cardiovascular complications over the subsequent years 9'1° than those with a normal day-night BP rhythm. However, an important methodologic problem in this area is that when hypertensive "dippers" and "nondippers" are matched
A
Received June 30, 1994. Accepted September 26, 1994. From the Unita Organica di Malattie Cardiovascolari e Medicina Interna, Ospedale Generale Regionale "R. Silvestrini," Perugia (PV, CB, AC, MB, CP); Divisione Medicina, Ospedale "Beato G. Villa," Citta della Pieve (GS, NS); and Divisione Medicina, Ospedale S. Agostino, Castiglione del Lago (MG, EC). This work was presented in part at the Ninth Annual Scientific Meeting of the American Society of Hypertension, New York, NY, May 11-14, 1994. This study was supported in part by the Associazione Umbra Cuore e Ipertensione, Perugia, Italy. Address correspondence and reprint requests to Dr. Paolo Verdecchia, Unita Organica di Malattie Cardiovascolari e Medicina Interna, Ospedale Generale Regionale "R. Silvestrini", 06100 Perugia PG (Italy).
© 1995 by the American Journal of Hypertension, Ltd.
KEY WORDS: Ambulatory blood pressure monitoring, circadian blood pressure rhythm, left ventricular hypertrophy, hypertension.
0895-7061/95/$9.50 0895-7061(94)00187-G
194
VERDECCHIA ET AL
for daytime ambulatory BP, the latter may have greater target organ damage in relation to the higher mean BP levels over the 24 h, and not necessarily as a result of the altered diurnal BP rhythm per se. ~1 Consequently, the present study was designed to investigate the effects of an altered diurnal BP rhythm, through the comparison between dippers and nondippers in either gender, on LV mass determined at echocardiography, before and after correction for daytime, nighttime, and mean 24-h ambulatory BP. PATIENTS A N D METHODS
We e x a m i n e d 1048 h y p e r t e n s i v e patients (519 women, age 51 -+ 12 years, range 18 to 93) referred to our centers by a group of general practitioners. All patients had clinic BP --- 140/90 mm Hg on at least three visits at 1-week intervals, and fulfilled all the following inclusion criteria: 1) no previous treatment for hypertension (70% of subjects), or withdrawal from antihypertensive drugs at least 4 weeks prior to the study; 2) no clinic or laboratory evidence of heart failure, coronary heart disease, valvular defects, or secondary causes of hypertension; 3) good quality echocardiographic tracings; 4) at least one valid BP measurement per hour throughout the 24 h. Ambulatory BP was recorded using the automatic units SpaceLabs 5200, 90202, and 90207 (SpaceLabs, Redmond, WA), one reading every 15 rain throughout the 24 h. The reading, editing, and analysis of data were done as previously described. 5 Patients were classified as dippers if their daytime (0600 to 2200 h) systolic or diastolic BP decreased by at least 10% during night (2200 to 0600 h) and all the other subjects were classified as nondippers. The M-mode echocardiographic study of the left ventricle was performed under cross-sectional control using commercially available instruments. Measurements were taken according to the American Society of E c h o c a r d i o g r a p h y r e c o m m e n d a t i o n s . 12 Only frames with optimal visualization of interfaces and showing simultaneous visualization of septum, LV internal diameter, and posterior wall were used for reading. The mean value from at least five measurements of the left ventricle per observer was computed. LV mass was calculated using the formula introduced by Devereux et a113 on the basis of necropsy validation studies. Data were analyzed using the SPSS/PC+ V2.0 package (SPSS Inc., Chicago, IL). Standard descriptive analysis was used to assess differences of variables between groups. Linear correlation coefficients were used w h e n indicated, and compared by means of the z statistics. Mean BP was defined as diastolic BP + (systolic BP - diastolic BP)/3. Dippers and nondippers were compared in their left ventricular mass index by means of an analysis of covariance (ANCOVA), considering as source of variability the aver-
AJH-FEBRUARY 1995-VOL. 8, NO. 2
age values of mean BP during daytime, nighttime, and over 24 h. Further simultaneous covariates were age, body mass index, and, in the analysis of the whole population, sex. RESULTS
Twenty-three percent of subjects (n = 238) were classified as nondippers, and the remaining 77% (n = 810) as dippers. As shown in Table 1, nondippers were slightly older and showed, only among women, a greater body mass index than dippers (all P < .01). In the whole population, LV mass index was greater in nondippers (119 - 31 g/m 2) than in dippers (105 -+ 33 g/m 2, P < .0001). This difference persisted after adjustment for daytime mean BP (115 v 107 g/m 2, P < .0001) but was no more significant after adjustment for 24-h mean BP (111 v 108, P = .11). Separate results for men and w o m e n are reported in Table 1. In men, the difference between dippers and nondippers was small and not significant before (115 v 121 g/m 2) and after adjustment for daytime (117 v 118 g/m 2) and mean 24-h BP (118 v 114 g/m2), but after adjustment for nighttime BP LV mass was greater in dippers (more properly "peakers ''n) than in nondippers ("nonpeakers") (120 v 107 g/m 2, P < .01). In women, LV mass was greater in nondippers than in dippers before (116 v 96 g/m 2) and after adjustment for daytime (112 v 97 g/m 2) and mean 24-h BP (109 v 98 g/m2), while the difference between the two groups disappeared after adjustment for nighttime BP (101 v 100 g/m2). The percent reduction in BP from day to night was inversely related to left ventricular mass index in w o m e n (r = - 0 . 2 9 for systolic BP and - 0 . 2 8 for diastolic BP, P < .001) and men (both r = -0.12, P < .01), but the correlation was closer in women than in men (P < .05 for systolic and diastolic BP, z score). DISCUSSION A blunted or absent nocturnal fall in BP has been associated with a greater LV mass in hypertensive women, but not in men. 7'14 Several other studies 4-s showed an association between target organ damage and altered diurnal BP profile in subjects with essential hypertension, but this finding could be an artifact of matching dippers and nondippers for daytime ambulatory BP, with resulting higher 24-h BP in nondippers. 11 The new finding in this study is that, even after adjustment for mean 24-h BP, a constant pressure overload was associated with greater LV mass, and a normal circadian BP profile with lesser LV mass, in hypertensive women. In contrast, daytime hypertension, either associated or not with a blunted nocturnal BP fall, was a sufficient determinant of LV wall thickening in men. The persistence of high BP levels during night was therefore an additional deter-
LEFT VENTRICULAR HYPERTROPHY: DIPPERS A N D PEAKERS 195
AJH-FEBRUARY 1995-VOL. 8, NO. 2
TABLE
1. CLINICAL AND ECHOCARDIOGRAPHIC CHARACTERISTICS OF HYPERTENSIVE PATIENTS BY GENDER A N D D I P P I N G PATTERN Men Dippers (n = 397)
Age, years Body mass index (kg/m2) Clinic systolic/diastolic BP 24-h systolic/diastolic BP Daytime systolic/diastolic BP Nighttime systolic/diastolic BP Echocardiographic LVH (%) Left ventricular mass index (g/m2): Unadjusted Adjusted for daytime mean BP Adjusted for 24-h mean BP Adjusted for nighttime mean BP
Women Nondippers (n = 132)
Dippers (n = 413)
Nondippers (n = 106)
49 (12) 27.4 (4) 154/97 (18/9) 138/88 (14/10) 143/93 (14/10) 125/77 (14/10) 24
54* (11) 27.3 (4) 160"/98 (19/11) 146"/92"(15/10) 148"/94 (16/10) 143"/89"(16/10) 29
51 (11) 25.7 (4) 157/97 (18/10) 134/85 (14/9) 139/89 (15/10) 121/73 (15/9) 22
56* (13) 26.9* (5) 165"/96 (19/11) 144"/88" (17/11) 145"/89 (17/11) 143"/85" (18/11) 52*
115 (34) 117 118 120
121 (32) 118 114 107"
96 (25) 97 98 100
116" (33) 112" 109" 101
BP, blood pressure; L VH, left ventricular hypertrophy. In the analysis of covariance, age and body mass index were further simultaneous covariates. Data are expressed as mean (SD). BP data are expressed in mmHg. *P < .01 v dippers.
m i n a n t of LV mass in h y p e r t e n s i v e w o m e n , but not in men. These findings e x t e n d p r e v i o u s observations 7"14 and provide further evidence of an i m p o r t a n t difference b e t w e e n the g e n d e r s in the possible p a t h o p h y s iologic implications of an altered diurnal BP profile in h y p e r t e n s i o n , b u t d o not clarify the basic mechanisms involved. Male animals are more susceptible than female animals to develop cardiac h y p e r t r o p h y in r e s p o n s e to pressure is or h o r m o n a l 16 triggers, possibly because of the concomitant trophic effect of and r o g e n h o r m o n e s o n myocites. 17 Progression of LV h y p e r t r o p h y in essential h y p e r t e n s i o n could therefore be slower in w o m e n than in men, with w o m e n requiring a longer duration of exposure to increased BP over the 24 h to develop LV h y p e r t r o p h y . These data m a y h a v e i m p o r t a n t p r o g n o s t i c implications since a b l u n t e d nocturnal fall in BP has been s h o w n to be more f r e q u e n t in h y p e r t e n s i v e w o m e n , but not in men, with future cardiovascular complications. 9 REFERENCES 1. Perloff D, Sokolow M, Cowan R: The prognostic value of ambulatory blood pressure. JAMA 1983;249:27922798. 2.
3.
Devereux RB, Pickering TG: Relationship between ambulatory or exercise blood pressure and left ventricular structure: prognostic implications. J Hypertens 1990;8(suppl 6):$125-$134.
O'Brien E, Sheridan J, O'Malley K: Dippers and nondippers. Lancet 1988;2:397. 4. Kobrin I, Oigman W, Kumar A, et ah Diurnal variation of blood pressure in elderly patients with essential hypertension. J Am Geriatr Soc 1984;32:896-899.
5. Verdecchia P, Schillaci G, Guerrieri M, et al: Circadian blood pressure changes and left ventricular hypertrophy in essential hypertension. Circulation 1990;81: 528-536. 6. Palatini P, Penzo M, Racioppa A, et al: Clinical relevance of nighttime blood pressure and of daytime blood pressure variability. Arch Intern Med 1992;152: 1855-1860. 7. Verdecchia P, Schillaci G, Boldrini F, et al: Sex, cardiac hypertrophy and diurnal blood pressure variations in essential hypertension. J Hypertens 1992;10:683-692. 8. Shimada K, Kawamoto A, Matsubayashi K, et al: Diurnal blood pressure variations and silent cerebrovascular damage in elderly patients with hypertension. J Hypertens 1992;10:875-878. 9. Verdecchia P, Schillaci G, Gatteschi C, et al: Blunted nocturnal fall in blood pressure in hypertensive women with future cardiovascular morbid events. Circulation 1993;88:986-992. 10. Kuwajima I, Araki A, Suzuki Y, et al: Prognostic value of 24-hour ambulatory blood pressure: a prospective study in the elderly (abst). J Hypertens 1994;12(suppl 3):$13. 11. Pickering TG, James GD: Determinants and consequences of the diurnal rhythm of blood pressure. Am J Hypertens 1993;6:166S--169S. 12. Sahn DJ, DeMaria A, Kisslo J, Weyman A, for the Committee on M-Mode Standardization of the American Society of Echocardiography: Recommendations regarding quantitation in M-mode echocardiography: results of a survey of echocardiographic measurements. Circulation 1978;58:1072-1083. 13. Devereux RB, Alonso DR, Lutas EM, et al: Echocardiographic assessment of left ventricular hypertrophy: comparison to necropsy findings. Am J Cardiol 1986; 57:450M58. 14. Rockstroh JK, Schmieder RE, Gatzka C, Messerli FH:
196
15.
VERDECCHIA ET AL
Relation of circadian blood pressure changes to left ventricular hypertrophy in essential hypertension. Am J Hypertens 1992;5:26A. Grindlay Moore L, McMurty IF, Reeves JT: Effects of sex hormones on cardiovascular and haematological responses to chronic hypoxia in rats. Proc Soc Exp Biol Med 1978;158:658-662.
AJH-FEBRUARY 1995-VOL. 8, NO. 2
16.
17.
Baker PJ, Ramey ER, Rammwell PW: Androgenmediated sex differences of cardiovascular responses in rats. Am J Physiol 1978;235:H242-H246. Koenig H, Goldstone A, Lu CY: Testosteronemediated sexual dimorphism of the rodent heart. Ventricular lysosomes, mitochondria, and cell growth are modulated by androgens. Circ Res 1982;50:782-787.
Gender, Day-Night Blood Pressure Changes, and Left Ventricular Mass in Essential Hypertension Dippers and Peakers Paolo Verdecchia, Giuseppe Schillaci, Claudia Borgioni, Antonella Ciucci, Nicola Sacchi, Massimo Battistelli, Massimo Guerrieri, Elio Comparato, and Carlo Porcellati
The finding of increased left ventricular (LV) mass in hypertensive subjects with blunted nocturnal fall in blood pressure (BP) might be an artifact of matching patients for daytime BP, with resulting higher 24-h BP in nondippers. Therefore, we compared a large number (n = 1048) of hypertensive dippers and nondippers in their LV mass at echocardiography before and after adjustment for 24-h, daytime, and nighttime ambulatory BP. In men, the difference between dippers and nondippers was not significant before and after adjustment for 24-h BP, but after adjustment for nighttime BP LV mass was greater in dippers (more properly "'peakers"). In women, LV mass was greater in nondip-
pers than in dippers both before and after adjustment for 24-h BP, while the difference between the two groups disappeared after adjustment for nighttime BP. Thus, for any given level of mean 24-h BP, a flattened diurnal BP profile is associated with a greater LV mass in hypertensive women. Daytime hypertension, either associated or not with a blunted nocturnal fall in BP, may be a sufficient determinant of LV wall thickening in men. Am J Hypertens 1995;8:193-196
mbulatory blood pressure (BP) readings obtained using semiautomatic recorders during day are better predictors of cardiovascular morbidity than standard BP mea-
surements obtained in the physician's office. 1 The recent development of fully automated devices has facilitated ambulatory BP monitoring over the entire 24-h period and several reports indicate that left ventricular (LV) hypertrophy and other measures of target organ damage in hypertension are more closely related to the average 24-h BP than to clinic BP. 2 In addition to the mean levels of BP, the characteristics of the 24-h BP profile might be a further determinant of target organ damage in essential hypertension. Patients with a reduced or absent nocturnal fall of BP ( " n o n d i p p e r s " ) have a more frequent history of stroke 3 and may be at increased risk of target organ damage 4-8 and, perhaps, of cardiovascular complications over the subsequent years 9'1° than those with a normal day-night BP rhythm. However, an important methodologic problem in this area is that when hypertensive "dippers" and "nondippers" are matched
A
Received June 30, 1994. Accepted September 26, 1994. From the Unita Organica di Malattie Cardiovascolari e Medicina Interna, Ospedale Generale Regionale "R. Silvestrini," Perugia (PV, CB, AC, MB, CP); Divisione Medicina, Ospedale "Beato G. Villa," Citta della Pieve (GS, NS); and Divisione Medicina, Ospedale S. Agostino, Castiglione del Lago (MG, EC). This work was presented in part at the Ninth Annual Scientific Meeting of the American Society of Hypertension, New York, NY, May 11-14, 1994. This study was supported in part by the Associazione Umbra Cuore e Ipertensione, Perugia, Italy. Address correspondence and reprint requests to Dr. Paolo Verdecchia, Unita Organica di Malattie Cardiovascolari e Medicina Interna, Ospedale Generale Regionale "R. Silvestrini", 06100 Perugia PG (Italy).
© 1995 by the American Journal of Hypertension, Ltd.
KEY WORDS: Ambulatory blood pressure monitoring, circadian blood pressure rhythm, left ventricular hypertrophy, hypertension.
0895-7061/95/$9.50 0895-7061(94)00187-G
194
VERDECCHIA ET AL
for daytime ambulatory BP, the latter may have greater target organ damage in relation to the higher mean BP levels over the 24 h, and not necessarily as a result of the altered diurnal BP rhythm per se. ~1 Consequently, the present study was designed to investigate the effects of an altered diurnal BP rhythm, through the comparison between dippers and nondippers in either gender, on LV mass determined at echocardiography, before and after correction for daytime, nighttime, and mean 24-h ambulatory BP. PATIENTS A N D METHODS
We e x a m i n e d 1048 h y p e r t e n s i v e patients (519 women, age 51 -+ 12 years, range 18 to 93) referred to our centers by a group of general practitioners. All patients had clinic BP --- 140/90 mm Hg on at least three visits at 1-week intervals, and fulfilled all the following inclusion criteria: 1) no previous treatment for hypertension (70% of subjects), or withdrawal from antihypertensive drugs at least 4 weeks prior to the study; 2) no clinic or laboratory evidence of heart failure, coronary heart disease, valvular defects, or secondary causes of hypertension; 3) good quality echocardiographic tracings; 4) at least one valid BP measurement per hour throughout the 24 h. Ambulatory BP was recorded using the automatic units SpaceLabs 5200, 90202, and 90207 (SpaceLabs, Redmond, WA), one reading every 15 rain throughout the 24 h. The reading, editing, and analysis of data were done as previously described. 5 Patients were classified as dippers if their daytime (0600 to 2200 h) systolic or diastolic BP decreased by at least 10% during night (2200 to 0600 h) and all the other subjects were classified as nondippers. The M-mode echocardiographic study of the left ventricle was performed under cross-sectional control using commercially available instruments. Measurements were taken according to the American Society of E c h o c a r d i o g r a p h y r e c o m m e n d a t i o n s . 12 Only frames with optimal visualization of interfaces and showing simultaneous visualization of septum, LV internal diameter, and posterior wall were used for reading. The mean value from at least five measurements of the left ventricle per observer was computed. LV mass was calculated using the formula introduced by Devereux et a113 on the basis of necropsy validation studies. Data were analyzed using the SPSS/PC+ V2.0 package (SPSS Inc., Chicago, IL). Standard descriptive analysis was used to assess differences of variables between groups. Linear correlation coefficients were used w h e n indicated, and compared by means of the z statistics. Mean BP was defined as diastolic BP + (systolic BP - diastolic BP)/3. Dippers and nondippers were compared in their left ventricular mass index by means of an analysis of covariance (ANCOVA), considering as source of variability the aver-
AJH-FEBRUARY 1995-VOL. 8, NO. 2
age values of mean BP during daytime, nighttime, and over 24 h. Further simultaneous covariates were age, body mass index, and, in the analysis of the whole population, sex. RESULTS
Twenty-three percent of subjects (n = 238) were classified as nondippers, and the remaining 77% (n = 810) as dippers. As shown in Table 1, nondippers were slightly older and showed, only among women, a greater body mass index than dippers (all P < .01). In the whole population, LV mass index was greater in nondippers (119 - 31 g/m 2) than in dippers (105 -+ 33 g/m 2, P < .0001). This difference persisted after adjustment for daytime mean BP (115 v 107 g/m 2, P < .0001) but was no more significant after adjustment for 24-h mean BP (111 v 108, P = .11). Separate results for men and w o m e n are reported in Table 1. In men, the difference between dippers and nondippers was small and not significant before (115 v 121 g/m 2) and after adjustment for daytime (117 v 118 g/m 2) and mean 24-h BP (118 v 114 g/m2), but after adjustment for nighttime BP LV mass was greater in dippers (more properly "peakers ''n) than in nondippers ("nonpeakers") (120 v 107 g/m 2, P < .01). In women, LV mass was greater in nondippers than in dippers before (116 v 96 g/m 2) and after adjustment for daytime (112 v 97 g/m 2) and mean 24-h BP (109 v 98 g/m2), while the difference between the two groups disappeared after adjustment for nighttime BP (101 v 100 g/m2). The percent reduction in BP from day to night was inversely related to left ventricular mass index in w o m e n (r = - 0 . 2 9 for systolic BP and - 0 . 2 8 for diastolic BP, P < .001) and men (both r = -0.12, P < .01), but the correlation was closer in women than in men (P < .05 for systolic and diastolic BP, z score). DISCUSSION A blunted or absent nocturnal fall in BP has been associated with a greater LV mass in hypertensive women, but not in men. 7'14 Several other studies 4-s showed an association between target organ damage and altered diurnal BP profile in subjects with essential hypertension, but this finding could be an artifact of matching dippers and nondippers for daytime ambulatory BP, with resulting higher 24-h BP in nondippers. 11 The new finding in this study is that, even after adjustment for mean 24-h BP, a constant pressure overload was associated with greater LV mass, and a normal circadian BP profile with lesser LV mass, in hypertensive women. In contrast, daytime hypertension, either associated or not with a blunted nocturnal BP fall, was a sufficient determinant of LV wall thickening in men. The persistence of high BP levels during night was therefore an additional deter-
LEFT VENTRICULAR HYPERTROPHY: DIPPERS A N D PEAKERS 195
AJH-FEBRUARY 1995-VOL. 8, NO. 2
TABLE
1. CLINICAL AND ECHOCARDIOGRAPHIC CHARACTERISTICS OF HYPERTENSIVE PATIENTS BY GENDER A N D D I P P I N G PATTERN Men Dippers (n = 397)
Age, years Body mass index (kg/m2) Clinic systolic/diastolic BP 24-h systolic/diastolic BP Daytime systolic/diastolic BP Nighttime systolic/diastolic BP Echocardiographic LVH (%) Left ventricular mass index (g/m2): Unadjusted Adjusted for daytime mean BP Adjusted for 24-h mean BP Adjusted for nighttime mean BP
Women Nondippers (n = 132)
Dippers (n = 413)
Nondippers (n = 106)
49 (12) 27.4 (4) 154/97 (18/9) 138/88 (14/10) 143/93 (14/10) 125/77 (14/10) 24
54* (11) 27.3 (4) 160"/98 (19/11) 146"/92"(15/10) 148"/94 (16/10) 143"/89"(16/10) 29
51 (11) 25.7 (4) 157/97 (18/10) 134/85 (14/9) 139/89 (15/10) 121/73 (15/9) 22
56* (13) 26.9* (5) 165"/96 (19/11) 144"/88" (17/11) 145"/89 (17/11) 143"/85" (18/11) 52*
115 (34) 117 118 120
121 (32) 118 114 107"
96 (25) 97 98 100
116" (33) 112" 109" 101
BP, blood pressure; L VH, left ventricular hypertrophy. In the analysis of covariance, age and body mass index were further simultaneous covariates. Data are expressed as mean (SD). BP data are expressed in mmHg. *P < .01 v dippers.
m i n a n t of LV mass in h y p e r t e n s i v e w o m e n , but not in men. These findings e x t e n d p r e v i o u s observations 7"14 and provide further evidence of an i m p o r t a n t difference b e t w e e n the g e n d e r s in the possible p a t h o p h y s iologic implications of an altered diurnal BP profile in h y p e r t e n s i o n , b u t d o not clarify the basic mechanisms involved. Male animals are more susceptible than female animals to develop cardiac h y p e r t r o p h y in r e s p o n s e to pressure is or h o r m o n a l 16 triggers, possibly because of the concomitant trophic effect of and r o g e n h o r m o n e s o n myocites. 17 Progression of LV h y p e r t r o p h y in essential h y p e r t e n s i o n could therefore be slower in w o m e n than in men, with w o m e n requiring a longer duration of exposure to increased BP over the 24 h to develop LV h y p e r t r o p h y . These data m a y h a v e i m p o r t a n t p r o g n o s t i c implications since a b l u n t e d nocturnal fall in BP has been s h o w n to be more f r e q u e n t in h y p e r t e n s i v e w o m e n , but not in men, with future cardiovascular complications. 9 REFERENCES 1. Perloff D, Sokolow M, Cowan R: The prognostic value of ambulatory blood pressure. JAMA 1983;249:27922798. 2.
3.
Devereux RB, Pickering TG: Relationship between ambulatory or exercise blood pressure and left ventricular structure: prognostic implications. J Hypertens 1990;8(suppl 6):$125-$134.
O'Brien E, Sheridan J, O'Malley K: Dippers and nondippers. Lancet 1988;2:397. 4. Kobrin I, Oigman W, Kumar A, et ah Diurnal variation of blood pressure in elderly patients with essential hypertension. J Am Geriatr Soc 1984;32:896-899.
5. Verdecchia P, Schillaci G, Guerrieri M, et al: Circadian blood pressure changes and left ventricular hypertrophy in essential hypertension. Circulation 1990;81: 528-536. 6. Palatini P, Penzo M, Racioppa A, et al: Clinical relevance of nighttime blood pressure and of daytime blood pressure variability. Arch Intern Med 1992;152: 1855-1860. 7. Verdecchia P, Schillaci G, Boldrini F, et al: Sex, cardiac hypertrophy and diurnal blood pressure variations in essential hypertension. J Hypertens 1992;10:683-692. 8. Shimada K, Kawamoto A, Matsubayashi K, et al: Diurnal blood pressure variations and silent cerebrovascular damage in elderly patients with hypertension. J Hypertens 1992;10:875-878. 9. Verdecchia P, Schillaci G, Gatteschi C, et al: Blunted nocturnal fall in blood pressure in hypertensive women with future cardiovascular morbid events. Circulation 1993;88:986-992. 10. Kuwajima I, Araki A, Suzuki Y, et al: Prognostic value of 24-hour ambulatory blood pressure: a prospective study in the elderly (abst). J Hypertens 1994;12(suppl 3):$13. 11. Pickering TG, James GD: Determinants and consequences of the diurnal rhythm of blood pressure. Am J Hypertens 1993;6:166S--169S. 12. Sahn DJ, DeMaria A, Kisslo J, Weyman A, for the Committee on M-Mode Standardization of the American Society of Echocardiography: Recommendations regarding quantitation in M-mode echocardiography: results of a survey of echocardiographic measurements. Circulation 1978;58:1072-1083. 13. Devereux RB, Alonso DR, Lutas EM, et al: Echocardiographic assessment of left ventricular hypertrophy: comparison to necropsy findings. Am J Cardiol 1986; 57:450M58. 14. Rockstroh JK, Schmieder RE, Gatzka C, Messerli FH:
196
15.
VERDECCHIA ET AL
Relation of circadian blood pressure changes to left ventricular hypertrophy in essential hypertension. Am J Hypertens 1992;5:26A. Grindlay Moore L, McMurty IF, Reeves JT: Effects of sex hormones on cardiovascular and haematological responses to chronic hypoxia in rats. Proc Soc Exp Biol Med 1978;158:658-662.
AJH-FEBRUARY 1995-VOL. 8, NO. 2
16.
17.
Baker PJ, Ramey ER, Rammwell PW: Androgenmediated sex differences of cardiovascular responses in rats. Am J Physiol 1978;235:H242-H246. Koenig H, Goldstone A, Lu CY: Testosteronemediated sexual dimorphism of the rodent heart. Ventricular lysosomes, mitochondria, and cell growth are modulated by androgens. Circ Res 1982;50:782-787.