Association between high-density-lipoprotein cholesterol and postoperative recovery from lumbar disc herniation

The levels of high density lipoprotein cholesterol (HDL-C) correlate with lumbar spine degeneration, but their value for predicting the prognosis of the lumbar spine is unclear. This study was implemented to explore whether HDL-C levels were associated with postoperative recovery from lumbar disc herniation (LDH).

Patients with LDH who underwent posterior lumbar interbody fusion (PLIF) admitted between January 1st, 2018, and December 31st, 2022, were included in this study. The outcome was postoperative recovery as assessed by the economic-functional score. The primary exposure variable was the postoperative plasma HDL-C level. LASSO regression was used to screen for variables associated with outcome, and GAM modeling was used to determine cutoff values for HDL-C levels, with the adjusted model used to estimate the relative contribution of each variable. HDL-C levels were transformed into a dichotomous variable based on the cutoff values, and multifactorial logistic regression was used to assess OR.

A total of 967 patients with LDH were included 529 males (54.7%), 438 females (45.3%), mean age 49.63 ± 12.51 years, mean HDL-C level 1.14 ± 0.25 mmol/L. LASSO regression showed that HDL-C was associated with outcome, there was a risk-protecting effect in the GAM with a cutoff value of 1.15 mmol/L. According to the commonly used clinical classification method, logistic regression showed that normal levels of HDL-C were protective compared with abnormal levels (OR=1.553, 95% CI,1.017-2.372, P = 0.042). HDL-C had a U-shaped effect in patients without cerebral disease, with a range of 1.1-1.8 mmol/L promoting recovery,and in the subgroup without cerebral disease, HDL-C level ranked 6 out of 20 variables, whereas in the overall cohort it ranked 14th and showed no significant effect. Logistic regression showed a protective effect of normal levels of HDL-C over abnormal levels (OR=1.900, 95% CI,1.206-2.992, P = 0.006).

Postoperative HDL-C levels were not significantly associated with 1-year postoperative functional recovery in the overall cohort of patients undergoing PLIF for LDH. In a pre-specified subgroup of patients without cerebral disease, postoperative HDL-C levels exhibited a significant U-shaped association with recovery (optimal range 1.1-1.8 mmol/L). These findings are hypothesis-generating and require validation in future studies.