Urinary Sodium and Potassium, and Risk of Ischemic and Hemorrhagic Stroke (INTERSTROKE): A Case–Control Study

• Published in: American journal of hypertension 2021-04, Vol.34 (4), p.414-425
• Main Authors: Judge, Conor, O’Donnell, Martin J, Hankey, Graeme J, Rangarajan, Sumathy, Chin, Siu Lim, Rao-Melacini, Purnima, Ferguson, John, Smyth, Andrew, Xavier, Denis, Lisheng, Liu, Zhang, Hongye, Lopez-Jaramillo, Patricio, Damasceno, Albertino, Langhorne, Peter, Rosengren, Annika, Dans, Antonio L, Elsayed, Ahmed, Avezum, Alvaro, Mondo, Charles, Ryglewicz, Danuta, Czlonkowska, Anna, Pogosova, Nana, Weimar, Christian, Diaz, Rafael, Yusoff, Khalid, Yusufali, Afzalhussein, Oguz, Aytekin, Wang, Xingyu, Lanas, Fernando, Ogah, Okechukwu S, Ogunniyi, Adesola, Iversen, Helle K, Malaga, German, Rumboldt, Zvonko, Oveisgharan, Shahram, Al Hussain, Fawaz, Yusuf, Salim
• Format: Article
• Language: English
• Subjects: blood pressure; Case-Control Studies; Clinical Medicine; Hemorrhagic Stroke - epidemiology; Humans; hypertension; intracerebral hemorrhage; ischemic stroke; Ischemic Stroke - epidemiology; Klinisk medicin; Original Contributions; potassium; Potassium - urine; Potassium, Dietary - administration & dosage; Risk Assessment; sodium; Sodium - urine; Sodium, Dietary - administration & dosage; Sodium, Dietary - adverse effects; stroke
• ISSN: 0895-7061; 1941-7225
• DOI: 10.1093/ajh/hpaa176

Abstract BACKGROUND Although low sodium intake (3.5 g/day) are proposed as public health interventions to reduce stroke risk, there is uncertainty about the benefit and feasibility of this combined recommendation on prevention of stroke. METHODS We obtained random urine samples from 9,275 cases of acute first stroke and 9,726 matched controls from 27 countries and estimated the 24-hour sodium and potassium excretion, a surrogate for intake, using the Tanaka formula. Using multivariable conditional logistic regression, we determined the associations of estimated 24-hour urinary sodium and potassium excretion with stroke and its subtypes. RESULTS Compared with an estimated urinary sodium excretion of 2.8–3.5 g/day (reference), higher (>4.26 g/day) (odds ratio [OR] 1.81; 95% confidence interval [CI], 1.65–2.00) and lower (4.26 g/day) was significantly greater (P < 0.001) for intracerebral hemorrhage (ICH) (OR 2.38; 95% CI, 1.93–2.92) than for ischemic stroke (OR 1.67; 95% CI, 1.50–1.87). Urinary potassium was inversely and linearly associated with risk of stroke, and stronger for ischemic stroke than ICH (P = 0.026). In an analysis of combined sodium and potassium excretion, the combination of high potassium intake (>1.58 g/day) and moderate sodium intake (2.8–3.5 g/day) was associated with the lowest risk of stroke. CONCLUSIONS The association of sodium intake and stroke is J-shaped, with high sodium intake a stronger risk factor for ICH than ischemic stroke. Our data suggest that moderate sodium intake—rather than low sodium intake—combined with high potassium intake may be associated with the lowest risk of stroke and expected to be a more feasible combined dietary target. Graphical Abstract Graphical Abstract