Association of non-HDL-C/HDL-C ratio and its dynamic changes with incident type 2 diabetes mellitus: The Rural Chinese Cohort Study

BACKGROUND We aimed to evaluate the association of the ratio of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol (non-HDL-C/HDL-C) and its dynamic changes with incident type 2 diabetes mellitus (T2DM). METHODS A total of 11,487 nondiabetic participants ≥18 years old in rural China were recruited in 2007-2008 and followed up in 2013-2014. A Cox proportional-hazards model was used to assess the risk of incident T2DM by quartiles of baseline non-HDL-C/HDL-C ratio and dynamic absolute and relative changes in non-HDL-C/HDL-C ratio, estimating hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS Risk of incident T2DM was increased with quartiles 2, 3, and 4 versus quartile 1 of baseline non-HDL-C/HDL-C ratio (HR 1.46 [95% CI 1.08-1.98], 1.51 [1.12-2.03], and 2.16 [1.62-2.88], Ptrend < 0.001). As compared with stable non-HDL-C/HDL-C ratio during follow-up, an absolute gain in non-HDL-C/HDL-C ratio was associated with increased risk of T2DM (HR 1.67 [95% CI 1.25-2.24] for quartile 3 and 2.00 [1.52-2.61] for quartile 4). A relative increase in non-HDL-C/HDL-C ratio was also associated with increased risk of T2DM (HR 1.56 [95% CI 1.19-2.04] for quartile 3 and 1.97 [1.49-2.60] for quartile 4). Subgroup analyses showed that the association of non-HDL-C/HDL-C ratio with T2DM risk remained consistent. CONCLUSIONS Increased non-HDL-C/HDL-C ratio is associated with increased risk of incident T2DM among rural Chinese adults, so the index may be an important indicator for identifying individuals at T2DM risk.