Tehran University Medical Journal

Background: Blood pressure decreases during sleep and is markedly increased in the morning in healthy individuals. Lack of nocturnal blood pressure fall (non-dipping) has been associated with cardiovascular morbidity, mortality and other organ damage. However, their importance in chronic renal failure is unclear. This study aimed to investigate relationship between circadian rhythm of blood pressure and renal failure severity in patients with chronic kidney disease.
Methods: This cross-section study was done in April 2016. The study population was 95 patients, more than 30 year old with hypertension and chronic renal failure. Patients were selected from clinics of two private and university hospitals affiliated to Qom University of Medical Sciences Shahid Beheshti Hospital and Vali-e-Asr Hospital, Iran. Checklist containing data such as age, sex, duration of renal failure and cause of renal failure were filled. Serum creatinine and serum urea levels were measured and entered in the checklist. The circadian rhythm of blood pressure in all patients was assessed by Holter monitoring. patients who had less than 10% decrease in blood pressure overnight were considered non-dipper and those who had 10% or more decrease in blood pressure overnight were considered dipper.
Results: Average (SD) 24-hour ambulatory systolic and diastolic of blood pressure was 136.56 (16.66) and 84.84 (10.86) mmHg, respectively. 70 patients (73.7%) had non-dipper blood pressure pattern and 25 patients (26.3%) had dipper blood pressure pattern. There was no significant difference between two groups (dipper and non-dipper) based on distribution of gender (P=0.744), age (P=0.407), serum creatinine (P=0.569), serum urea (P=0.689) and renal failure duration (P=0.812). Mean of glomerular filtration rate in dipper group was 68.64±4.13 and in non-dipper group was 65.09±16.27 (P=0.337).
Conclusion: The results of this study did not show a significant relationship between circadian rhythm of blood pressure and renal failure severity. In addition, patients with chronic renal failure showed higher rates of non-dipping pattern of blood pressure.

Background: Asymptomatic hypotension is a common complication in patients undergoing hemodialysis, which can lead to serious consequences. Troponin I, as a biochemical marker for myocardial injury, may play a role in the diagnosis and management of this complication. This study aimed to investigate the relationship between serum troponin I level changes and asymptomatic hypotension in patients with advanced kidney failure undergoing hemodialysis.
Methods: In this cross-sectional study, 120 adult ESRD patients (aged 30–80 years) with an ejection fraction (EF) >50% who attended the hemodialysis unit of Shohada Tajrish Hospital over a 6-month period starting 15 January 2024 were enrolled. Demographic and clinical data were collected using a checklist. Serum troponin I levels were measured before and after dialysis, and patients' blood pressure was recorded throughout dialysis sessions. For quantitative variables, mean and standard deviation were reported; for qualitative variables, absolute and relative frequencies were presented. Statistical analysis was performed using the Paired t-test, Independent t-test, Pearson correlation coefficient, and their non-parametric equivalents as appropriate. A significance level of p < 0.05 was considered statistically significant.
.Results: A total of 120 patients were examined, with a mean age of 57.6 ± 7.1 years. The gender distribution was 67 males (55.8%) and 53 females (44.2%). The mean body mass index was 20.73 ± 0.98. Significant differences were found in mean blood pressure, heart rate, body weight, and changes before and after dialysis (P<0.05). These differences included a decrease in blood pressure, and body weight, an increase in heart rate, and an increase in troponin levels. No significant relationship was found between troponin changes before and after dialysis with age, gender, height, weight, body mass index, heart rate, average duration of dialysis, and other laboratory variables (P>0.05). However, a significant correlation was found between troponin changes and blood pressure changes, indicating that as troponin levels increased, the mean blood pressure of patients decreased.
Conclusion: The findings of this study indicate a significant relationship between increased serum troponin I levels and asymptomatic hypotension in patients with advanced kidney failure undergoing hemodialysis. These results may be useful in identifying at-risk patients and improving therapeutic management. Further research is needed to confirm this relationship and explore its underlying mechanisms.