The impact of prediabetes and diabetes on endothelial function in a large population-based cohort.

Background: Diabetes and prediabetes are well-recognized risk factors for cardiovascular disease (CVD) and are marked by vascular endothelial dysfunction (ED). However, there is a scarcity of thorough population-based studies examining ED in individuals with diabetes/prediabetes free from manifest CVD. Here, we examined the association between ED assessed by reactive hyperaemia index (RHI) in the finger and diabetes/prediabetes in a large middle-aged population cohort.

Methods: Within the Malmö Offspring Study, following the exclusion of participants <30 years and participants with prevalent CVD, 1384 participants had complete data on all covariates. The RHI was calculated using pulse amplitude tonometry. ED was defined as RHI < 1.67. Multivariable logistic and linear regression models were conducted to investigate associations between ED and RHI with diabetes and prediabetes.

Results: The study population had a mean age of 53.6 ± 7.6 years (53% women). In study participants with manifest diabetes (n = 121) and prediabetes (n = 514), ED was present in 42% and 25% respectively, compared to 23% in those with normal glucometabolic status. In multivariable logistic regression analyses, prevalent diabetes was significantly associated with ED (OR 1.95; 95%CI 1.57-3.39; p = 0.002), as well as with lower RHI (β-coeff. -0.087; p = 0.002). However, prediabetes showed no association with neither ED nor RHI.

Conclusion: In a population free from CVD, vascular endothelial dysfunction was primarily associated with manifest diabetes, but not with prediabetes, implying that finger ED may develop when diabetes is established, rather than being an early sign of glucose intolerance. Further research is needed to explore whether addressing glucose intolerance could potentially delay or prevent vascular ED onset.