Association of the Triglyceride–Glucose Index with Systolic and Diastolic Blood Pressure Among Patients With Type 2 Diabetes Mellitus

Background Hypertension and type 2 diabetes mellitus (T2DM) frequently coexist, substantially increasing cardiovascular morbidity and mortality. Insulin resistance is a key mechanism linking these conditions. The triglyceride-glucose (TyG) index, derived from fasting triglyceride and glucose levels, has emerged as a simple surrogate marker of insulin resistance. While TyG has been associated with blood pressure in non‑diabetic populations, its relationship with systolic blood pressure (SBP) and diastolic blood pressure (DBP) among patients with established T2DM remains less clearly defined. Methods A cross‑sectional study was conducted among 219 patients with T2DM (149 [68.0%] males, 70 [32.0%] females) attending a tertiary care hospital in Kerala, India. Of these, 109 (49.8%) had good glycemic control and 110 (50.2%) had poor glycemic control. Demographic, anthropometric, and biochemical data were collected using standardized procedures. SBP and DBP were measured using a standardized protocol. The TyG index was derived from fasting triglyceride and glucose values. Pearson's correlation and multiple linear regression analyses (adjusted for age, gender, and BMI) were performed to examine associations between TyG and blood pressure components. Results A total of 219 patients with T2DM (149 [68.0%] males, 70 [32.0%] females) were included, of whom 109 (49.8%) had good glycemic control and 110 (50.2%) had poor glycemic control. The mean SBP was 140.0 ± 18.0 mmHg, and the mean DBP was 97.1 ± 11.4 mmHg. The mean TyG index was 10.10 ± 0.44. Pearson's correlation analysis demonstrated a weak but statistically significant positive association between TyG and DBP (r = 0.149, p = 0.027), while no significant correlation was observed with SBP (r = 0.035, p = 0.612). In regression analysis adjusted for age, gender, and BMI, TyG remained independently associated with DBP (B = 3.52, p = 0.047) but not with SBP. Conclusion In patients with T2DM, the TyG index demonstrated a weak but significant association with diastolic blood pressure, whereas no relationship was observed with SBP. These findings suggest that TyG may provide complementary insights into the metabolic determinants of diastolic hypertension. However, given the modest strength of association and low explanatory power, larger prospective studies are required to validate its predictive utility.