Single point insulin sensitivity estimator index and incident impaired fasting glucose in Chinese adults: a...

Insulin resistance is the core pathophysiological mechanism underlying the development of impaired fasting glucose (IFG) and diabetes mellitus. The SPISE index is a novel, simple surrogate marker of insulin sensitivity that does not require insulin measurement. However, the predictive value of the SPISE index for IFG remains to be further elucidated. This study aimed to investigate the association between the baseline SPISE index and the risk of incident IFG using retrospective longitudinal cohort data from Chinese adults.

A total of 100494 Chinese adults with normal fasting plasma glucose at baseline were included. The exposure was the SPISE index, and the primary outcome was incident IFG during follow-up. Multivariable Cox proportional hazards regression models and logistic regression models were employed to assess the associations. RCS was used to explore the relationship between the SPISE index and incident IFG. Extensive subgroup and sensitivity analyses were performed to verify the robustness of the results.

During a median follow-up of 2.99 years, the incidence of IFG in the overall study population was 12.33%. A higher SPISE index was independently associated with a lower risk of IFG. In the fully adjusted Cox model, each one-unit increase in the SPISE index was associated with a hazard ratio of 0.91 for incident IFG. Participants in the Q4 had an approximately 40% lower risk of developing IFG compared to those in the Q1, showing a significant dose-response relationship. RCS analysis indicated a linear inverse association between the SPISE index and IFG risk. Subgroup and sensitivity analyses confirmed the consistency and robustness of this association across different population characteristics and data handling approaches.

In a community-based Chinese adult population with normal baseline blood glucose, a lower SPISE index is an independent risk factor for future incident IFG, with a linear inverse dose-response relationship. Our findings suggest that the SPISE index could potentially be implemented in routine clinical practice as a simple and cost-effective tool for identifying individuals at high risk for IFG, serving as an effective tool for the early identification of high-risk individuals for IFG and for implementing targeted primary prevention strategies for diabetes.