SAN DIEGO – Among incident hemodialysis patients, high-density lipoprotein cholesterol levels remained stable over time in men but mildly decreased over time in women, regardless of age.
In addition, larger deviations in HDL cholesterol in the first 6 months of incident hemodialysis were associated with a higher risk of 5-year all-cause mortality.
Those are key findings from a large analysis of patients who received hemodialysis care over a 4-year period, which was presented at the meeting sponsored by the American Society of Nephrology.
“Elevated high-density lipoprotein cholesterol levels, although protective in the general population, can be associated with higher mortality in hemodialysis patients,” Dr. Kamyar Kalantar-Zadeh and his colleagues wrote in an abstract of the study. “Association of HDL change over time with mortality has yet to be examined.”
Dr. Kalantar-Zadeh of the division of nephrology and hypertension at the University of California, Irvine, and his associates examined changes in HDL cholesterol levels over time in 24,400 incident hemodialysis patients who received care from facilities affiliated with DaVita HealthCare Partners between 2007 and 2011.
They examined the association of delta HDL (HDL cholesterol change between the first and second 91-day interval from dialysis start) and HDL cholesterol trajectory with all-cause mortality, using mixed effect and Cox regression models and adjusted for demographics, comorbidities, and baseline HDL cholesterol. Delta HDL was treated both as a continuous variable using restricted cubic splines and in five categories ranging from less than –6 mg/dL to 6 mg/dL or greater.
The mean age of patients was 65 years, 44% were female, 31% were black, and 66% had diabetes.
Mean baseline HDL cholesterol was 40.5 mg/dL, with an HDL cholesterol change of 1.7 mg/dL. The researchers found that while male patients had no significant change in HDL cholesterol over time, females had a significant decrease in HDL cholesterol (a mean of –0.6mg/dL per year). At the same time, a 6 mg/dL or greater increase or decrease in delta HDL was associated with a 7% and 37% increase in all-cause mortality, respectively, compared with the reference group. Delta HDL mortality associations did not differ across gender.
“Patients who have a greater than 6 mg/dL change in HDL between the first and second patient [tests] have a higher risk of 5-year all-cause mortality,” the researchers concluded. “Change in HDL exhibits a reverse J-shaped association with mortality in hemodialysis patients. Further studies are needed to examine the underlying causes of these HDL changes and pathophysiology leading to higher risk of all-cause mortality.”
The study was supported by funding from the National Institute of Diabetes and Digestive and Kidney Diseases. The researchers reported having no financial disclosures.