Association Between the Aggregate Index of Systemic Inflammation and Non-Dipper Blood Pressure Pattern in Hypertensive Patients with Type 2 Diabetes Mellitus

Purpose: This study aimed to investigate the association between the Aggregate Index of Systemic Inflammation (AISI) and non-dipper blood pressure (BP) pattern in hypertensive (HT) patients with type 2 diabetes mellitus (DM). Given the well-established role of systemic inflammation in circadian BP regulation, we hypothesized that elevated AISI levels would be associated with impaired nocturnal BP decline. Patients and Methods: A total of 356 newly diagnosed HT patients with type 2 DM and 170 normotensive control subjects were included in this observational study. HT patients were further classified as dipper (n=186) or non-dipper (n=170) based on 24-hour ambulatory blood pressure monitoring (ABPM). AISI was calculated using neutrophil, lymphocyte, platelet, and monocyte counts. Correlation analyses were performed to evaluate the relationship between AISI and ambulatory BP parameters. Multivariate logistic regression analysis with a backward stepwise method was conducted to determine independent predictors of non-dipper status. Receiver operating characteristic (ROC) curve analysis was used to assess the discriminative performance of AISI and other inflammatory indices. Results: AISI and ln(AISI) levels were significantly higher in non-dipper HT patients than in dipper HT patients and normotensive controls (p< 0.001 for all). Ln(AISI) was positively correlated with nighttime systolic and diastolic BP (p< 0.05). In multivariate logistic regression analysis, ln(AISI) emerged as the strongest independent predictor of non-dipper blood pressure pattern (OR: 14.13, 95% CI: 3.68– 54.32, p< 0.001). In ROC analysis, ln(AISI) showed the highest discriminative performance for identifying non-dipper status, with a sensitivity of 71.0% and specificity of 74.1% at a cutoff value of 5.80 (AUC: 0.757, p< 0.001), outperforming NLR, PLR, SII, and SIRI. Conclusion: Elevated AISI levels were independently associated with non-dipper blood pressure pattern in hypertensive patients with type 2 diabetes mellitus. These findings suggest that AISI may serve as a practical and integrative biomarker for identifying high-risk patients with impaired circadian blood pressure regulation.