Hypertension is one of the most important independent risk factors for the prognosis of continous ambulatory peritoneal dialysis patients. The incident rate is high and the control rate is low. Nocturnal hypertension has been paid more attention in recent years. Compared to daytime blood pressure, nocturnal blood pressure is an independent and efficient prognostic indicator of hypertensive deaths and cardiovascular events, but it is lack of evidence about its impact on prognosis in peritoneal dialysis patients and the effective treatment program. Our previous cohort study suggests that the incidence of nocturnal hypertension in patients with chronic kidney disease is up to 71.22%, with a significant increase as the decline of renal function, and more severe target organ damage in patients with nocturnal hypertension: the decrease of glomerular filtration rate, left ventricular hypertrophy, and the increase of all cause death and cardiovascular death. Our small sample size study show that night time antihypertensive drugs can better control blood pressure and delay the development of left ventricular hypertrophy. These preliminary results suggest that nocturnal hypertension is closely related to the prognosis of chronic renal disease. Taking antihypertensive drugs at night is one of the options for controlling nocturnal hypertension. However, it is not clear whether taking antihypertensive drugs at night can improve the prognosis of maintenance peritoneal dialysis patients with nocturnal hypertension. To this end, the investigators collect continous ambulatory peritoneal dialysis patients with nocturnal hypertension, and propose a time selective use of losartan to intervene in nocturnal hypertension. By comparing the difference in the effects of losartan on the prognosis of maintenance peritoneal dialysis patients during the day or night, to further clarify the role of nocturnal hypertension in the prognosis of maintenance peritoneal dialysis patients, whether controlling nocturnal hypertension can improve the prognosis of maintenance peritoneal dialysis patients. The completion of study will optimize the prevention and treatment of hypertension in maintenance peritoneal dialysis patients, and provide an evidence for precise prevention and treatment of nocturnal hypertension in maintenance peritoneal dialysis patients.

Inclusion Criteria:

1. Age over 18 years old and <75 years.
2. Diagnosed as chronic kidney disease 5th stage in accordance with the KDIGO guide 2012 (egfr < 15 ml/ (min 1.73m2)).
3. Accept 3-5 bags daily, continous ambulatory peritoneal dialysis for >3 months.
4. Ambulatory blood pressure monitoring indicates nighttime systolic blood pressure (SBP) > 120mmHg and / or diastolic blood pressure (DBP) > 70mmHg.

Exclusion Criteria:

1. Night learning or work, irregular rest for a long time.
2. Moderate and severe edema in difficult to correct
3. Persistent atrial fibrillation.
4. Severe anemia and severe dystrophy.
5. Patients with postural hypotension or symptomatic hypotension.
6. Severe side effects or contraindications of valsartan treatment.
7. Treatment of corticosteroids or other hormones at present.
8. Unable to cooperate or unable to tolerate ambulatory blood pressure monitoring.
9. Ineffective ambulatory blood pressure data.
10. The clinical data were incomplete during the treatment period; end-point events occurred within 6 months or follow-up time was less than 6 months.
11. In the first 3 months before admission, there were obvious cardiovascular and cerebrovascular diseases such as coronary syndrome, myocardial infarction or stroke.
12. There were complications such as vascular disease, infection and bleeding within 1 months.