SUMMARY OBJECTIVE: The aim of our study was to determine the role of serum glucose–potassium ratio in predicting inhospital mortality in coronary care unit patients. METHODS: This study used data from the MORtality in CORonary Care Units in Turkey study, a national, observational, multicenter study that included all patients admitted to coronary care units between September 1, 2022, and September 30, 2022. Statistical analyses assessed the independent predictors of mortality. Two models were created. Model 1 included age, history of heart failure, chronic kidney disease, hypertension, diabetes mellitus, and coronary artery disease. Model 2 included glucose–potassium ratio in addition to these variables. Multivariate regression and receiver operating characteristic analysis were performed to compare Model 1 and Model 2 to identify if the glucose–potassium ratio is an independent predictor of inhospital mortality. RESULTS: In a study of 3,157 patients, the mortality rate was 4.3% (n=137). Age (p=0.002), female gender (p=0.004), mean blood pressure (p<0.001), serum creatinine (p<0.001), C-reactive protein (p=0.002), white blood cell (p=0.002), and glucose–potassium ratio (p<0.001) were identified as independent predictors of mortality through multivariate regression analysis. The receiver operating characteristic analysis indicated that Model 2 had a statistically higher area under the curve than Model 1 (area under the curve 0.842 vs area under the curve 0.835; p<0.001). A statistically significant correlation was found between the inhospital mortality and glucose–potassium ratio (OR 1.015, 95%CI 1.006–1.024, p<0.001). CONCLUSION: Our study showed that the glucose–potassium ratio may be a significant predictor of inhospital mortality in coronary care unit patients. OBJECTIVE glucosepotassium glucose potassium METHODS national observational 2022 30 created age failure disease hypertension mellitus variables RESULTS 3157 3 157 3,15 43 4 4.3 n=137. n137 n n=137 . 137 (n=137) p=0.002, p0002 p p=0.002 , 0 002 (p=0.002) p=0.004, p0004 p=0.004 004 (p=0.004) p<0.001, p0001 p<0.001 001 Creactive C reactive (p<0.001 0842 842 0.84 0.835 0835 835 p<0.001. p<0.001) OR 1015 015 1.015 95CI CI 95 10061024 006 024 1.006–1.024 CONCLUSION 202 315 15 3,1 4. n13 n=13 13 (n=137 p000 p=0.00 00 (p=0.002 (p=0.004 p<0.00 (p<0.00 084 84 0.8 0.83 083 83 101 01 1.01 9 1006102 02 1.006–1.02 20 31 3, n1 n=1 (n=13 p00 p=0.0 (p=0.00 p<0.0 (p<0.0 08 8 0. 10 1.0 100610 1.006–1.0 n= (n=1 p0 p=0. (p=0.0 p<0. (p<0. 1. 10061 1.006–1. (n= p=0 (p=0. p<0 (p<0 1006 1.006–1 (n p= (p=0 p< (p< 100 1.006– (p= (p 1.006 1.00

Resumen Fundamento: se ha demostrado que la deficiencia de vitamina B12, que puede causar trastornos hematológicos y neuropsiquiátricos, también puede estar asociada con disfunción autonómica cardíaca, variabilidad de la frecuencia cardíaca, disfunción endotelial y disminución de la deformación miocárdica. Objetivos: el objetivo de nuestro estudio es evaluar la relación entre los niveles de vitamina B12 y los trastornos de repolarización electrocardiográfica que son indicadores de predisposición arritmogénica en individuos sanos. Métodos: la población del estudio fue de 214 adultos sanos. Considerando la distribución de los niveles de vitamina B12 y aceptando los percentiles del 25 % y 75 % como valores de corte, los participantes se dividieron en 3 grupos. Se compararon las mediciones de laboratorio, ecocardiografía y electrocardiografía (ECG) entre tres grupos. Las mediciones del ECG se realizaron manualmente y se calcularon los intervalos Tpeak-Tend (Tp-e), Tp-e corregido (Tp-ec), QT y QT corregido (QTc). Resultados: se encontró que los pacientes del grupo 1 (vitamina B12 < 253 pg/ml) tenían dispersiones QT y QTc, intervalo Tp-e, cocientes Tp-e/QT y Tp-e/QTc significativamente más altos cuando se compararon con los del grupo 2 (253 pg/ml < vitamina B12 > 436 pg/ml) y el grupo 3 (vitamina B12 > 436 pg/ml). Por otro lado, se detectó una correlación significativa negativa entre los niveles de vitamina B12 y las relaciones Tp-e, Tp-e/QT, Tp-e/QTc, dispersiones QT y QTc. Conclusión: el bajo nivel de vitamina B12 en los individuos sanos puede ser un indicador significativo de susceptibilidad arritmogénica. Un seguimiento estrecho de estos sujetos en términos de predisposición arritmogénica podría ser útil.

Abstract Background: it has been shown that vitamin B12 deficiency, which can cause hematological and neuropsychiatric disorders, may also be associated with cardiac autonomic dysfunction, heart rate variability, endothelial dysfunction, and a decrease in myocardial deformation. Aims: the aim of our study is to evaluate the relationship between vitamin B12 levels and electrocardiographic repolarization disorders, which are indicators of arrhythmogenic predisposition in healthy individuals. Methods: our study population consisted of 214 healthy adults. Considering the distribution of vitamin B12 levels and accepting 25 % and 75 % percentiles as the cut-off values, the participants were divided into 3 groups. Laboratory, echocardiography and electrocardiography (ECG) measurements were compared between three groups. ECG measurements were performed manually and Tpeak-Tend (Tp-e), Tp-e corrected (Tp-ec), QT and QT corrected (QTc) intervals were calculated. Results: the patients in Group 1 (vitamin B12 < 253 pg/ml) were found to have significantly higher QT and QTc dispersions, Tp-e interval, Tp-e/QT and Tp-e/QTc ratios when compared to those in Group 2 (253 pg/ml < vitamin B12 > 436 pg/ml) and Group 3 (vitamin B12 > 436 pg/ml). On the other hand, a negative significant correlation was detected between vitamin B12 levels and Tp-e, Tp-e/QT, Tp-e/QTc ratios, QT and QTc dispersions. Conclusion: a low level of vitamin B12 in healthy individuals can be a significant indicator of arrhythmogenic susceptibility. A close follow-up of these subjects in terms of arrhythmogenic predisposition can be useful.