Remnant cholesterol in obesity phenotypes: results from NHANES

The association between remnant cholesterol (RC) with obesity phenotypes remains unclear.

This study designed to evaluate the association between RC and obesity phenotypes using data from the National Health and Nutrition Examination Survey (NHANES). The classification systems for obesity phenotypes encompassed both preclinical/clinical obesity and obesity stages, which were assessed based on two authoritative obesity guidelines: the 2025 clinical obesity guideline, and the 2016 obesity guideline established by the American Association of Clinical Endocrinologists and the American College of Endocrinology (AACE/ACE). Participants were selected according to the diagnostic criteria for obesity proposed in the 2025 clinical obesity guideline and were categorized into tertiles based on their RC levels. Their obesity phenotypes, obesity-related clinical manifestations, obesity-related comorbidities, and characteristics were then described. Logistic regression analyses and restricted cubic spline (RCS) models were used to analyze the relationship between RC and adverse obesity phenotypes. Sensitivity analyses were conducted in patients not receiving lipid-lowering drugs.

This study comprised 3,207 adult participants, revealing distinct prevalence patterns: 47.80% exhibited preclinical obesity and 17.81% showed clinical obesity, while obesity stage stratification demonstrated 0%, 12.76%, and 21.63% prevalence for stage 0, 1, and 2, respectively. Multivariable regression analyses demonstrated dose-response relationship between RC levels and adverse obesity phenotypes, with individuals in the highest RC tertile showing significantly elevated risks of clinical obesity (OR 1.95, 95% CI 1.19-3.19) and obesity stage progression (OR 1.96, 95% CI 1.06-3.62) compared to the lowest tertile reference group. RCS analyses further revealed similar "J"-shaped association between RC levels and adverse obesity phenotypes (P for nonlinearity < 0.001), sharing a common inflection point at 0.51 mmol/L. The sensitivity analyses confirmed the consistency of the results among patients who were not receiving lipid-lowering therapy.

RC was found to be positively and independently associated with adverse obesity phenotypes, particularly when RC levels exceeded 0.51 mmol/L, demonstrating a similar "J"-shaped association. It is recommended that clinicians monitor RC levels for obese patients as a primary screening indicator for adverse phenotypes of obesity.