Association of Platelet-to-HDL Cholesterol Ratio with Metabolic Syndrome in a Japanese Health Check-up Population

The platelet-to-high-density lipoprotein cholesterol (HDL-C) ratio (PHR) has been proposed as a composite biomarker reflecting both thrombogenic and lipid-related mechanisms. However, its relationship with metabolic syndrome (MetS) has not been extensively evaluated in the general Japanese population.

We conducted a cross-sectional analysis of 17,581 adults (7,400 women) who underwent health check-ups between 2007 and 2024. PHR was calculated as the platelet count divided by HDL-C. MetS was defined according to the Japanese criteria. The association between PHR and MetS and its components was assessed using multivariable linear and logistic regression. Receiver operating characteristic (ROC) analysis was used to evaluate the discriminatory ability of PHR compared to other simple markers.

PHR was significantly higher in participants with MetS (p < 0.001) and correlated with key components, including waist circumference, triglycerides (TG), and fasting plasma glucose. In multivariable logistic regression, PHR was independently associated with MetS in both sexes. The area under the curve (AUC) for PHR was 0.687 (95% confidence interval [CI]: 0.674 - 0.700) in men and 0.724 (95% CI: 0.700 - 0.748) in women. These values were modestly lower than those for TG and TG/HDL-C, but PHR showed utility as a non-redundant marker.

PHR is independently associated with MetS and its components in the Japanese population. Although its discriminatory performance is modest, PHR may serve as a supplementary marker in health check-up settings for identifying individuals at risk of metabolic disorders.