A new longitudinal analysis of the China Health and Retirement Longitudinal Study (CHARLS) reports that three related measures—the stress-hyperglycemia ratio, the frailty index, and a composite combining the two—are each associated with the later development of cardiometabolic multimorbidity, the co-occurrence of diabetes, heart disease, and stroke. The study, published in Cardiovascular Diabetology, was a prospective analysis of 6,096 participants from the China Health and Retirement Longitudinal Study who were free of cardiometabolic multimorbidity at baseline, and examined whether baseline and repeated measures of these indices were associated with incident cardiometabolic multimorbidity.
The stress-hyperglycemia ratio captures glycemic dysregulation relative to long-term glycemic exposure, offering a way to distinguish acute stress-related hyperglycemia from sustained high blood sugar. The frailty index, by contrast, quantifies accumulated health deficits across multiple domains, providing a summary of overall biological vulnerability. The researchers also constructed a composite product of the two measures, termed SHR-FI, to test whether combining glycemic stress with frailty status would improve risk identification beyond either measure alone.
During follow-up anchored at Wave 1 of the survey, 527 participants developed cardiometabolic multimorbidity. In fully adjusted Cox models, each standard deviation increase in baseline stress-hyperglycemia ratio was associated with a hazard ratio of 1.09 (95% confidence interval, 1.01–1.18) for incident cardiometabolic multimorbidity. The corresponding hazard ratios were 1.36 (1.26–1.48) for the baseline frailty index and 1.35 (1.26–1.45) for the baseline SHR-FI product, indicating that the frailty-related measures carried a substantially stronger association than the glycemic measure alone.
The associations grew notably stronger when the researchers used cumulative summaries computed across two survey waves. Each standard deviation increase in cumulative frailty index was associated with a hazard ratio of 1.60 (1.48–1.73), while cumulative SHR-FI showed a hazard ratio of 1.55 (1.44–1.66) per standard deviation increase. These two-wave summaries, assessed with Wave 3 as a landmark, suggest that repeated measurement of accumulated health deficits over time may capture risk information that a single baseline snapshot misses.
Predictive discrimination, measured by the area under the receiver operating characteristic curve, told a similar story. The baseline frailty index and SHR-FI each achieved an AUC of 0.68, while the cumulative versions reached 0.72 and 0.73, respectively. Importantly, the frailty index accounted for most of this observed discrimination, and the SHR-FI composite showed only a modest complementary signal, offering limited additional information in this cohort beyond what the frailty index alone provided.
The analysis went beyond standard Cox regression, incorporating restricted cubic spline analyses to examine dose-response patterns, subgroup analyses, decision-curve analyses, joint models, and a range of sensitivity checks. Landmark analyses beginning at Wave 3 produced directionally consistent associations for cumulative frailty index and cumulative SHR-FI, reinforcing the robustness of the two-wave cumulative findings across different analytical starting points.
Cardiometabolic multimorbidity, encompassing the co-occurrence of diabetes, heart disease, and stroke, is a major source of disability and premature mortality in ageing populations.
The authors are careful about the practical implications. They conclude that two-wave cumulative summaries and longitudinal patterns of these indices may support research-oriented risk stratification, but that their clinical value requires calibration, internal validation, and external validation before any application beyond research settings. The findings are observational associations from a single national cohort, and the reported hazard ratios describe group-level risk differences rather than individual predictions.
Within those limits, the study adds to a growing body of CHARLS-based work examining combined metabolic and frailty indices in relation to incident cardiometabolic multimorbidity, including recent analyses of composite triglyceride-glucose and estimated glucose disposal rate measures paired with the frailty index.
Subject of Research: Associations of the stress-hyperglycemia ratio, frailty index, and their product with incident cardiometabolic multimorbidity in the China Health and Retirement Longitudinal Study
Article Title: Stress-hyperglycemia ratio, frailty index, and their product in relation to incident cardiometabolic multimorbidity comprising diabetes, heart disease, and stroke: a longitudinal analysis of CHARLS
Article References: Liu, S., Xie, G., Lei, Y., & Xin, W. (2026). Stress-hyperglycemia ratio, frailty index, and their product in relation to incident cardiometabolic multimorbidity comprising diabetes, heart disease, and stroke: a longitudinal analysis of CHARLS. Cardiovascular Diabetology. https://doi.org/10.1186/s12933-026-03414-7
Image Credits: AI Generated
DOI: 10.1186/s12933-026-03414-7
Keywords: stress-hyperglycemia ratio, frailty index, cardiometabolic multimorbidity, CHARLS, diabetes, heart disease, stroke, prospective cohort, risk prediction, aging, hazard ratios, China
News Source: Beatrice Stafford. (October 29, 2026). Frailty Index Outperforms Stress-Hyperglycemia Ratio in Predicting Cardiometabolic Multimorbidity. Scienmag.
