Association of the triglyceride-glucose index with elevated somatic symptoms: a cross-sectional study in patients with hypertension

Background Insulin resistance is a key component of cardiometabolic dysfunction and has been associated with adverse health outcomes. The triglyceride–glucose (TyG) index is a surrogate marker of insulin resistance. Elevated somatic symptoms are common but may be underrecognized among patients with hypertension. However, the association between TyG and elevated somatic symptoms remains unclear. Methods Patients with hypertension were consecutively recruited from the Affiliated Cardiovascular Hospital of Qingdao University between 2022 and 2023. Elevated somatic symptoms were assessed using the Chinese version of the Somatic Self-rating Scale (SSS-CN), with an SSS-CN score ≥30 defining elevated somatic symptoms. Multivariable regression models were used to evaluate the associations of TyG with elevated somatic symptoms. The incremental value of TyG beyond traditional clinical variables was assessed using model discrimination, reclassification, calibration, and decision curve analysis. Additive interaction analyses were performed to evaluate the joint effects of TyG with anxiety and depression. Sensitivity analyses were conducted to assess the robustness of the findings. Results Among 2,422 participants, 540 (22.3%) were classified as having elevated somatic symptoms. In fully adjusted models, TyG was positively associated with elevated somatic symptoms. Compared with Q1, the adjusted odds ratios for Q2–Q4 were 1.21 (95% CI: 0.89–1.64), 1.54 (95% CI: 1.15–2.08), and 1.87 (95% CI: 1.38–2.54), respectively. Adding TyG to traditional clinical variables improved model performance, with the area under the curve increasing from 0.704 (95% CI: 0.678–0.729) to 0.717 (95% CI: 0.692–0.742; DeLong test, P = 0.004). The addition of TyG also improved reclassification and discrimination (NRI = 0.3057, 95% CI: 0.2149–0.3955; IDI = 0.0143, 95% CI: 0.0080–0.0213; both P < 0.001). Statistically significant additive interactions were observed between elevated TyG and anxiety or depression in relation to elevated somatic symptoms. Sensitivity analyses yielded consistent results. Conclusions TyG was associated with elevated somatic symptoms among patients with hypertension, with additive interactions observed between TyG and anxiety or depression. TyG may provide additional information for assessing elevated somatic symptoms beyond traditional clinical variables.