A possible relationship of nocturnal blood pressure variability with coronary artery disease in diabetic nephropathy.
Evidence suggests a relationship between short-term blood pressure (BP) variability and cardiovascular target-organ damage. Although a blunted nocturnal decrease in BP and reduced heart rate variability have been shown to be associated with cardiovascular morbidity in diabetic patients, little information is available on short-term BP variability. In this study, short-term BP variability was assessed in 36 subjects with type 2 diabetes and overt nephropathy who underwent ambulatory BP monitoring, and the factors that correlated with short-term BP variability were examined. The incidence of coronary artery disease (CAD) was significantly greater in the patients with increased 24-h systolic BP variability (67% versus 11%; p < 0.0005), while that of cerebrovascular disease was not significantly affected (61% versus 50%). Multiple stepwise regression analysis revealed that serum cholesterol (cholesterol) and plasma norepinephrine (p-NE) were significant and independent contributors to nighttime systolic BP variability (partial R2 = 0.490, p < 0.001; partial R2 = 0.470, p < 0.001) and demonstrated that body mass index and p-NE were primary determinants of nighttime diastolic BP variability (partial R2 = 0.539, p < 0.0005; partial R2 = 0.304, p < 0.05). Diabetic nephropathy patients with CAD had significantly increased daytime systolic (17.8 mmHg versus 13.1 mmHg, p < 0.0005), nighttime systolic (17.4 mmHg versus 10.5 mmHg, p < 0.0001), and nighttime diastolic (10.4 mmHg versus 7.2 mmHg, p < 0.05) BP variability. Furthermore, logistic regression analysis demonstrated that nighttime systolic BP variability was an independent risk factor for CAD (odds ratio 3.13 [95% CI 1.02-9.61]; p < 0.05). The increase in nighttime BP variability is associated with a proportional sympathetic activation in diabetic nephropathy. Elevated short-term BP variability combined with relative sympathetic prevalence during the night might represent an important risk factor for cardiovascular events in the diabetic population.
Tamura
Kouichi
K
Department of Medicine II, Yokohama City University School of Medicine, Yokohama, Japan. tamukou@med.yokohama-cu.ac.jp
Tsurumi
Yuko
Y
Sakai
Masashi
M
Tanaka
Yutaka
Y
Okano
Yasuko
Y
Yamauchi
Junji
J
Ishigami
Tomoaki
T
Kihara
Minoru
M
Hirawa
Nobuhito
N
Toya
Yoshiyuki
Y
Yabana
Machiko
M
Tokita
Yasuo
Y
Ohnishi
Toshimasa
T
Umemura
Satoshi
S
D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D003327:Coronary Disease / Q000209:etiology / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012307:Risk Factors; D013564:Sympathetic Nervous System / Q000502:physiology