Cholesterol impacts CV mortality risk in patients with chronic kidney disease

CHICAGO — Low serum cholesterol may increase CV mortality risk across chronic kidney disease stages, according to data from a cohort of older veterans presented at American Heart Association Scientific Sessions.

Higher serum cholesterol correlated with CV mortality risk in patients without CKD, although these correlations “were attenuated across strata of CKD,” according to the study findings.

“High serum cholesterol concentration has long been associated with higher risk of morbidity and mortality in adults, yet this has been recently challenged in elderly patients,” the researchers wrote. “Among CKD patients, where a majority are older, the relationship between serum cholesterol level and mortality is still unclear, especially in the context of the severity of disease. We hypothesize that CKD stage impacts the relationship between cholesterol with all-cause and CV mortality risk.”

Melissa Soohoo, MPH, of the Tibor Rubin VA Medical Center in Long Beach, CA, and colleagues analyzed serum cholesterol and creatinine data collected between 2004 and 2006 among 2,132,346 U.S. veterans. Patients in the study were older (65±14 years); 5% of patients were women, 15% were black and 22% had diabetes.

The researchers analyzed the relationship between baseline serum cholesterol and all-cause and CV mortality using Cox models that considered various clinical characteristics, including smoking, statin use and other lipid values. They also grouped patients according to CKD stage at the time of cholesterol measurement. Patients were followed for a median of 9 years (range, 6-10).

The median cholesterol level was 177 mg/dL (range, 152-206 mg/dL). Stages 1 and 2 CKD, which was classified as non-CKD, was noted in most patients (76%); 31% of individuals were taking a statin.

Low cholesterol (<120 mg/dL) correlated with higher all-cause and CV mortality across CKD stages when compared with cholesterol between 160 and 180 mg/dL. High cholesterol (200 mg/dL) was associated with lower or no risk for all-cause mortality at any stage of CKD.

In patients with stage 5 CDK, cholesterol 180 mg/dL correlated with a lower risk for death. High cholesterol (200 mg/dL) pointed to a higher risk for CV mortality across all CKD strata except for stage 5. The protective relationship between high cholesterol and all-cause mortality among patients with stage 5 CKD was not found for CV mortality.

“In this veteran cohort, low serum cholesterol level is associated with higher CV mortality risk across CKD stages,” the researchers wrote. “Higher serum cholesterol was associated with CV mortality risk in [patients without CKD], but these associations were attenuated across strata of CKD. Future studies with considerations for lipid therapy and time-varying covariates are needed to evaluate this seemingly paradoxical relationship among CKD patients.” – by Scott Buzby

Reference:

Soohoo M, et al. Abstract Sa1197/1197. Presented at: American Heart Association Scientific Sessions; Nov. 10-12, 2018; Chicago.

Disclosure: Soohoo reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.