Abstract: ObjectiveTo investigate the conditions of night blood pressure in patients with chronic kidney disease (CKD) by normal blood pressure and the incidence of nocturnal hypertension. MethodsA total of 236 CKD patients with normal blood pressure were selected， 69 cases male， 167 cases female， the average age (55.8±15.1)  years old. The patients were divided into CKD1 grade (1 194 cases)， GFR≥90 ml/(min·1.73 m2)，CKD2 grade (73 cases)， GFR 6089 ml/(min·1.73 m2)，CKD 35 grade (44 cases)， GFR 3059 ml/(min·1.73 m2)，1529  ml/(min·1.73 m2)，<15  ml/(min·1.73 m2)，respectively，according to the glomerular filtration rate. Fifty healthy subjects were enrolled as control group.  24 h ambulatory blood pressure was monitored in these patients by Spacelab noninvasive ambulatory blood pressure instrument made in the United States. ResultsNocturnal ambulatory blood pressure(mean)  increased in 79 cases， 33.5%(79/236 cases). But in control group，there was  no nocturnal hypertension. Mainly night time diastolic blood pressure increased，others were either systolic or diastolic blood pressure increased. Fortysix patients had hypertension only in the night. The night time systolic blood pressure of CKD patients were also corresponding increased by the increased CKD stage， but only the CKD35 phase group and CKD1 group showed significant differences(P<0.05). The night time diastolic blood pressure were no significant differences in three groups. The incidence of nocturnal hypertension in three groups were also corresponding increased by the increased CKD stage，31.1%，35.6%，36.4%，respectively. ConclusionThe incidence of nocturnal hypertension was higher in CKD patients with normal blood pressure， so ambulatory blood pressure monitoring should be performed in CKD patients， in order to find  the  nocturnal  hypertension  and other abnormal situations as well as  the evidence for clinical diagnosis and treatment.

Key words: nephritis, blood pressure, hypertension