Factors associated with moderate-to-severe hypokalemia in hospitalized hypertensive patients with thiazide-containing single-pill combination-induced hypokalemia

Objective To explore the risk-factors for moderate to severe hypokalemia in hospitalized hypertensive patients with hypokalemia who are taking single-pill combination (SPC) containing thiazide diuretics.

Methods A retrospective analysis was conducted. Data were collected from patients with essential hypertension who were hospitalized for hypokalemia at Huai'an First People's Hospital, Nanjing Medical University, between January 1, 2013, and December 31, 2023, and who were taking thiazide-containing SPC. Based on serum potassium levels, the subjects were divided into a mild hypokalemia group (serum potassium level: 3.0 to ＜3.5 mmol/L) and a moderate-to-severe hypokalemia group (serum potassium leve: < 3.0 mmol/L). Multivariate logistic model was used to analyze the factors related to moderate-to-severe hypokalemia.

Results A total of 261 subjects were included, with a mean age of (66.62 ± 11.13) years, and 54.79% (143 cases) were female. Among them, 165 were in the mild hypokalemia group, and 96 were in the moderate-to-severe hypokalemia group. Compared with patients in the mild hypokalemia group, patients in the moderate-to-severe hypokalemia group had a significantly higher proportion of taking traditional SPC (51.04% 49/96 vs 34.55% 57/165, χ² = 6.847, P = 0.009), smokers (χ²= 3.977, P = 0.046), and alcohol consumers (χ²= 4.072, P = 0.044). Additionally, serum chloride (Z = –2.707, P = 0.007), calcium (Z = –2.025, P = 0.043), and phosphorus (Z = –3.097, P = 0.002) levels were significantly lower in the moderate-to-severe hypokalemia group. Multivariate logistic regression analysis showed that taking traditional SPC (OR = 1.917, 95%CI: 1.102 to 3.333, P = 0.021) and serum chloride levels (OR = 0.940, 95%CI: 0.900 to 0.981, P = 0.004) were influencing factors for moderate-to-severe hypokalemia. Subgroup analysis results showed that, the interactions between factors such as age, sex, comorbid diabetes, comorbid coronary heart disease, smoking, alcohol consumption, and estimated glomerular filtration rate (eGFR) level with the type of SPC containing thiazide diuretics were not statistically significant (all P for interaction ＞ 0.05).

Conclusion The traditional SPC and serum chloride levels are influencing factors for the moderate-to-severe hypokalemia in hospitalized hypertensive patients taking SPC containing thiazide diuretics.