The association of the platelet/high-density lipoprotein cholesterol ratio with self-reported stroke and cardiovascular mortality: a population-based observational study

BACKGROUND

Previous studies have shown that the relationship between high-density lipoprotein cholesterol (HDL-C) and stroke is controversial, and the association between the platelet/high-density lipoprotein cholesterol ratio (PHR), a novel marker for inflammation and hypercoagulability states, and stroke has not been established.

METHODS

This study presents an analysis of cross-sectional data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES). Stroke history, HDL-C levels, and platelet counts were obtained during cross-sectional surveys. The PHR was calculated as the ratio of the number of platelets to HDL-C concentration. Weighted logistic regression was used to assess the associations of HDL-C and the PHR with stroke. Nonlinearity of this relationship was determined through restricted cubic splines (RCSs) and two-piecewise linear regression for identifying inflection points. Furthermore, Cox regression was utilized to prospectively analyze the associations of the PHR and HDL-C concentration with cardiovascular disease (CVD) mortality in stroke survivors.

RESULTS

A total of 27,301 eligible participants were included in the study; mean age, 47.28 years and 50.57% were female, among whom 1,040 had a history of stroke. After full adjustment, the odds ratio (OR) of stroke associated with a per standard deviation (SD) increase in the PHR was estimated at 1.13 (95% confidence interval (CI): 1.03 - 1.24, P = 0.01), and the OR of stroke associated with a per SD increase in HDL-C was 0.95 (95% CI: 0.86-1.05, P = 0.30). The RCS indicated a nonlinear relationship for both variables (PPHR = 0.018 and PHDL-C = 0.003), and further piecewise linear regression identified inflection points at PHR = 223.684 and HDL-C = 1.4 mmol/L. Segmental regression indicated that in the PHR ≥ 223.684 segment, the estimated OR of stroke associated with a per-SD increase in the PHR was 1.20 (95% CI: 1.09 - 1.31, P < 0.001), while the association of stroke with HDL-C was not significant before or after the inflection point (P > 0.05). Furthermore, Cox regression and RCS showed that a per-SD increase in the PHR was linearly associated with a greater risk of CVD mortality among stroke survivors (HR: 1.14, 95% CI: 1.06 - 1.22, P < 0.001; nonlinear, P = 0.956), while HDL-C was not significantly associated with CVD mortality.

CONCLUSION

The association between the PHR and stroke incidence exhibited a significant threshold effect, with an inflection point at 223.684. A PHR exceeding 223.684 was positively associated with stroke, while the association between HDL-C and stroke was not significant. Additionally, the PHR was positively and linearly associated with CVD mortality among stroke survivors.

Association between the platelet/high-density lipoprotein cholesterol ratio and nonalcoholic fatty liver disease: results from NHANES 2017-2020

The platelet/high-density lipoprotein cholesterol ratio (PHR) is a novel inflammatory and hypercoagulability marker that represents the severity of metabolic syndrome. Liver metabolic syndrome is manifested by nonalcoholic fatty liver disease (NAFLD), which is associated with inflammation and hypercoagulability. This cross-sectional investigation aimed to identify the relationship between PHR and NAFLD. Participants in the National Health and Nutrition Examination Survey (NHANES) 2017-2020 were evaluated for hepatic steatosis and fibrosis using vibration-controlled transient elastography. The PHR was calculated as the ratio of platelets to high-density lipoprotein cholesterol. Increased PHR was associated with an increased incidence of NAFLD and hepatic fibrosis. Compared with patients in the first PHR quartile, after adjustment for clinical variables, the corresponding odds ratio (OR) for NAFLD in the fourth quartile was 2.36 (95% CI, 1.76 to 3.18) (p < 0.05); however, the OR for hepatic fibrosis was not statistically significant (p > 0.05). Furthermore, restricted cubic spline analyses showed an S-shaped association between PHR and NAFLD and an L-shaped relationship between PHR and hepatic fibrosis. The results support the effectiveness of PHR as a marker for NAFLD and hepatic fibrosis. Therefore, interventions to improve the PHR may be of benefit in reducing the incidence of both hepatic steatosis and fibrosis.