High, low atherogenic index of plasma tied to all-cause mortality
Both high and low values of the atherogenic index of plasma (AIP) are independently associated with all-cause mortality, a new study reveals.
Laboratory, clinical and demographic information of 1,174 end-stage renal disease (ESRD) patients (mean age 55.4±14.2 years; 61.4 percent male) undergoing peritoneal dialysis (PD) or haemodialysis (HD) were retrieved from the electronic database of the Clinical Research Center for ESRD in Korea. Those with incomplete information and underwent dialysis for less than 3 months were excluded.
Using fasting blood measurements of plasma triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C), the investigators calculated the AIP of the participants. Death events and the corresponding causes were recorded until 30 September 2015, the end of the follow-up period.
With a median AIP of 0.47 (0.26 to 0.66), the 1,174 participants were further divided into quintiles according to AIP. For the first to fifth quintiles, the corresponding median AIP were 0.06, 0.31, 0.47, 0.62 and 0.84. HD was administered to 740 patients, while PD was administered to 434.
Univariate logistic regression showed that PD (β, 0.046; 95 percent CI, 0.01 to 10.082; p=0.01) was significantly associated with higher AP values compared with HD. Similarly, diabetes mellitus (β, 0.053; 0.017 to 0.088), higher BMI (β, 0.024; 0.019 to 0.029) and higher log high-sensitivity C-reactive protein (hs-CRP; β, 0.022; 0.001 to 0.043; p=0.04) were all significantly associated with higher AIP.
Multivariate logistic regression validated the significant, independent relationship between AIP and PD (β, 0.057; 0.022 to 0.093; p=0.002), diabetes mellitus (β,0.044; 0.008 to 0.0794; p=0.02), BMI (β, 0.024; 0.018 to 0.029; p<0.001) and hs-CRP (β, 0.026; 0.004 to 0.047; p=0.02).
There were 170 death and 55 cardiovascular death events recorded over the mean follow-up period of 33.2±18.2 months. Corresponding incidences were lowest in the third quintile (8.9 and 3.0 percent, respectively) and highest in the fifth quintile (17.1 and 6.8 percent, respectively).
Using the third quintile as a reference, Cox regression showed that the first (hazard ratio [HR], 1.76; 1.02 to 3.03) and fifth (HR, 2.15; 1.26 to 3.65) AIP quintiles were independently associated with all-cause mortality, resulting in a U-shaped plot of HRs against AIP quintiles.