Impact of glycemic optimization on myocardial steatosis and cardiac remodeling in patients with newly diagnosed type 2 diabetes: a longitudinal study.

BACKGROUND

Cardiac remodeling is common in individuals with type 2 diabetes (T2D) and is influenced by glycemic and metabolic factors. However, myocardial steatosis, a proposed contributor to diabetic cardiomyopathy, has been inconsistently related to glycemic control. This study aimed to characterize longitudinal changes in myocardial triglyceride content (MTGC) and cardiac remodeling following glycemic optimization in newly diagnosed T2D.

METHODS

In this uncontrolled, exploratory longitudinal study, twenty adults with newly diagnosed T2D underwent a 12-month standardized glycemic optimization protocol including insulin, metformin, and empagliflozin, in addition to nutritional and lifestyle counseling. Cardiac magnetic resonance imaging (CMR) and proton magnetic resonance spectroscopy (¹H-MRS) were performed at baseline and after 12 months to assess cardiac structure, function, and MTGC. Longitudinal changes and associations between clinical, biochemical, and imaging parameters were assessed.

RESULTS

Participants (mean age 54.8 ± 9 years, 72.3% male) achieved significant reductions in HbA1c levels, body mass index (BMI) and waist circumference (WC). No significant changes in MTGC were found at follow-up (p = 0.23). CMR evaluation revealed increases in left ventricle (LV) ejection fraction (59.0% [54.8-61.5] vs. 63.1% [56.9-66.3], p = 0.01) and decreases in ventricular volumes: (LV) end-systolic volume (29.9 mL/m2 [26.4-35.1] vs. 27.3 mL/m2 [22.5-31.7]; p = 0.007), right ventricular (RV) end-systolic volume (30.6 mL/m2 [25.9-35.7] vs. 28.7 mL/m2 [25.5-32.6], p = 0.02) and RV end-diastolic volume (76.5 mL/m2 [64.6-82.4] vs. 72.4 mL/m2 [66.1-77.7], p = 0.03). The indexed LV mass increased (46.1 g/m2 [35.1-54.2] vs. 49.5 [39.5-54.3], p = 0.006). No associations were found between HbA1c improvement and the MTGC or CMR parameters. Reductions in BMI and WC were associated with greater left atrial strain (ρ = - 0.78 and - 0.77; p < 0.001), whereas reductions in WC were also associated with greater LV end-diastolic volume (ρ = -0.59; p = 0.024).

CONCLUSIONS

In patients with newly diagnosed T2D, 12 months of glycemic optimization was associated with changes in cardiac remodeling parameters despite no detectable changes in myocardial steatosis. The observed cardiac changes were more closely associated with concurrent reductions in adiposity markers than with changes in HbA1c, emphasizing weight management as a key target for early prevention of diabetic cardiomyopathy.