Effect of low and high HDL-C levels on the prognosis of lupus nephritis patients: a prospective cohort study

Background: Few data has been available on the effect of serum HDL-C levels on the prognosis of lupus nephritis (LN) patients. The present study therefore aimed to explore the effect of serum HDL-C levels on LN patients. Methods: We included 775 patients with follow-up information registered in an LN database between 1 January 2006 and 31 December 2011. The patients were divided into groups with low, intermediate and high HDL-C, according to NCEP ATPIII criteria. Cox regression analyses were used to explore the effects of HDL-C levels on end-stage renal disease (ESRD), all-cause mortality and cardiovascular disease (CVD) mortality. Results: During a median follow-up of 56 months (3-206 months), 71 (9.2%) had ESRD. 84 (10.8%) deaths occurred, 17 (20.2%) of which were due to CVD. There was no statistically significant association of HDL-C category or continuous HDL-C levels with ESRD in the total cohort, but in subgroup analyses by eGFR, with each 0.1 mmol/L increase in HDL-C level, adjusted HRs for ESRD were 0.92 (95% CI: 0.83-1.04, P = 0.173) for eGFR >= 60 ml/min/1.73m(2) and 1.11 (95% CI: 1.01-1.23, P = 0.036) for eGFR <60 ml/min/1.73m(2). The effect of the interaction between eGFR category and serum HDL-C level on ESRD was statistically significant (beta = -1.738, P = 0.005). Low HDL-C was associated with all-cause mortality (HR = 2.16, 95% CI: 1.06-4.40, P = 0.033) with intermediate HDL-C as reference category after adjusting for several variables. Conclusions: Our results demonstrate that high HDL-C levels were associated with increased risk of ESRD in LN patients with advanced renal dysfunction. While low HDL-C levels were associated with increased risk of all-cause mortality in LN patients.