Relationship Between Electrolyte Levels and Dipping Blood Pressure Pattern in Hypertensive Patients: A Single Center Cross-Sectional Study in Shanghai

Background: Few studies have explored the link between body fluid ion levels (sodium, calcium, magnesium, phosphorus) and blood pressure circadian rhythm. This study investigates these ions' relationship with the dipping blood pressure pattern in hypertensive patients, highlighting their potential for monitoring electrolyte levels in hypertension management. Methods: According to 2018 Chinese guidelines for hypertension management, hypertensive patients were classified into dipping/super-dipping and non-dipping/reverse-dipping groups based on nocturnal blood pressure decline. Clinical data and serum/24-hour urine electrolyte levels were then collected from these patients. Logistic regression and advanced statistical modeling were used to identify influencing factors. Results: Age and alpha-blockers negatively correlate with the likelihood of dipping blood pressure in hypertensive patients (P<0.05). Highest chance of dipping occurs at age 54 years, with serum sodium at 139.55 mmol/L and 24-hour urinary calcium at 5.34 mmol (P<0.05). The lowest likelihood is at a 24-hour urinary calcium level of 1.65 mmol (P<0.05). The largest nocturnal systolic drop is at age 57 years, serum calcium at 2.41 mmol/L, and 24-hour urinary calcium at 5.34 mmol (P<0.05). The largest diastolic drop is at age 54 years, with serum sodium at 139.03 mmol/L, serum calcium at 2.42 mmol/L, and serum magnesium at 0.95 mmol/L (P<0.05). A serum calcium level over 2.20 mmol/L significantly boosts the chance of dipping and nocturnal diastolic drop (P<0.05). Conclusion: In hypertensive patients, the chance of a dipping blood pressure pattern declines with age, possibly peaking between 54-57 years. Optimal serum sodium for dipping is 139 mmol/L, and higher serum calcium (peaking at 2.41 mmol/L) increases this likelihood. Alpha-blockers may negatively affect the dipping blood pressure pattern.