Supplementary Material for: Racial and Ethnic Differences in Mortality Associated with Serum Potassium in a Large Hemodialysis Cohort
Kim T.
Rhee C.M.
Streja E.
Soohoo M.
Obi Y.
Chou J.A.
Tortorici A.R.
Ravel V.A.
Kovesdy C.P.
Kalantar-Zadeh K.
10.6084/m9.figshare.5024477.v1
https://karger.figshare.com/articles/journal_contribution/Supplementary_Material_for_Racial_and_Ethnic_Differences_in_Mortality_Associated_with_Serum_Potassium_in_a_Large_Hemodialysis_Cohort/5024477
<p><b><i>Background:</i></b> Hyperkalemia is observed in chronic kidney
disease patients and may be a risk factor for life-threatening
arrhythmias and death. Race/ethnicity may be important modifiers of the
potassium-mortality relationship in maintenance hemodialysis (MHD)
patients given that potassium intake and excretion vary among
minorities. <b><i>Methods:</i></b> We examined racial/ethnic differences
in baseline serum potassium levels and all-cause and cardiovascular
mortality using Cox proportional hazard models and restricted cubic
splines in a cohort of 102,241 incident MHD patients. Serum potassium
was categorized into 6 groups: ≤3.6, >3.6 to ≤4.0, >4.0 to ≤4.5
(reference), >4.5 to ≤5.0, >5.0 to ≤5.5, and >5.5 mEq/L. Models
were adjusted for case-mix and malnutrition-inflammation cachexia
syndrome (MICS) covariates. <b><i>Results:</i></b> The cohort was
composed of 50% whites, 34% African-Americans, and 16% Hispanics.
Hispanics tended to have the highest baseline serum potassium levels
(mean ± SD: 4.58 ± 0.55 mEq/L). Patients in our cohort were followed for
a median of 1.3 years (interquartile range 0.6-2.5). In our cohort,
associations between higher potassium (>5.5 mEq/L) and higher
mortality risk were observed in African-American and whites, but not
Hispanic patients in models adjusted for case-mix and MICS covariates.
While in Hispanics only, lower serum potassium (<3.6 mEq/L) levels
were associated with higher mortality risk. Similar trends were observed
for cardiovascular mortality. <b><i>Conclusions:</i></b> Higher
potassium levels were associated with higher mortality risk in white and
African-American MHD patients, whereas lower potassium levels were
associated with higher death risk in Hispanics. Further studies are
needed to determine the underlying mechanisms for the differential
association between potassium and mortality across race/ethnicity.</p>
2017-05-19 08:35:17
Potassium
Hemodialysis
Chronic kidney disease
Mortality