Introduction:
The role of triglyceride-rich lipoproteins in atherogenesis is insufficiently recognized and often underestimated. We aimed to evaluate the distribution of serum triglyceride (TG), remnant cholesterol (RC), and small dense LDL cholesterol (sdLDL-C) levels and their interrelationships in participants of the NATPOL 2011 survey.

Material and methods:
In approximately 2,000 NATPOL participants, serum TG was measured, and serum RC and sdLDL-C were calculated and compared between women and men, across age groups, and in relation to overweight/obesity and plasma glucose. RC/sdLDL-C levels were also compared across serum TG intervals (< 100, 100–149, and 150–499 mg/dl), and their percentile distributions were analyzed.

Results:
Serum TG, RC and sdLDL-C were higher in overweight/obese participants and in those with prediabetes. In subjects with serum TG levels < 100, 100–149, and 150–499 mg/dl, RC and sdLDL-C levels were successively higher, with values exceeding the cutoffs used to indicate high atherosclerotic cardiovascular disease (ASCVD) risk observed in both TG intervals > 100 mg/dl. Participants with serum RC and sdLDL-C above these cutoffs had higher TG. Serum TG levels of 100 mg/dl and 150 mg/dl corresponded to the 55.9th and 88.2nd percentiles, respectively; serum RC of 24 mg/dl corresponded to the 73.8th percentile; and serum sdLDL-C of 30 mg/dl (adopted cutoff) corresponded to the 38th percentile of the respective distributions.

Conclusions:
We found an association between serum RC and sdLDL-C, and TG levels > 100 mg/dl indicating that serum TG levels of 100–150 mg/dl may already be associated with TRL remnants and sdLDL accumulation. Calculated serum RC and sdLDL-C may be considered useful supplements to the lipid profile.