Associations between cardiac adipose tissue volume, measures of coronary calcification, myocardial microvascular function and systemic inflammation in individuals with type 2 diabetes free of overt cardiovascular disease.

BACKGROUND: Peri- and epicardial adipose tissue (PEAT) is a metabolically active fat depot surrounding the heart and coronary arteries that may contribute to vascular dysfunction and inflammation in type 2 diabetes (T2D). We examined associations between PEAT volume, coronary calcification (CACS), myocardial flow reserve (MFR), and systemic inflammation (hsCRP).

METHODS: Cross-sectional analysis of adults with T2D without overt CVD recruited 2020-2023. PEAT was quantified on non-contrast CT; CACS was calculated by the Agatston method; MFR was measured by rubidium-82 PET/CT; hsCRP assessed systemic inflammation. Associations were tested using multivariable regression adjusting for cardiovascular risk factors.

RESULTS: Among 887 participants (mean age 65 years; 70% male; mean BMI 30 kg/m2; median PEAT 199 mL [IQR 133-283]), higher PEAT (per 100 mL) was associated with lower MFR (β - 0.04; 95% CI - 0.09 to 0.00; p = 0.041) and higher hsCRP, corresponding to a 38% increase (95% CI 28% to 48%; p < 0.001) in age- and sex-adjusted models, but not with CACS > 300 (OR 1.01; 95% CI 0.89-1.15). After further adjustment for diabetes duration, BMI, LDL cholesterol, systolic blood pressure, HbA1c, kidney function, smoking, and albuminuria, only the association with hsCRP remained significant at 14% (95%; CI 4% to 25%; p = 0.005).

CONCLUSION: In individuals with T2D without overt CVD, PEAT volume was not independently associated with CACS or MFR after multivariable adjustment. Higher PEAT volume was associated with higher hsCRP, suggesting a relationship with systemic inflammation; however, this exploratory finding should be interpreted in the context of established links between adiposity and inflammatory burden.