Clarke GD, et al. – Myocardial insulin sensitivity and left ventricular (LV) function were assessed in type 2 diabetes (T2D) patients who were treated with pioglitazone. In these subjects, treatment with pioglitazone resulted in improvements in whole–body and myocardial insulin sensitivity, LV diastolic function, and systolic function. Additionally, data indicated a strong correlation between improved myocardial insulin sensitivity and diastolic function.

Methods

• In this study, twelve subjects with T2D and 12 with normal glucose tolerance received a euglycemic insulin clamp.
• Researchers measured myocardial glucose uptake (MGU) and myocardial perfusion with [¹⁸F]fluoro-2-deoxy-d-glucose and [¹⁵O]H₂O positron emission tomography before and after 24 weeks of pioglitazone treatment.
• They also measured myocardial function and transmitral early diastolic relation/atrial contraction (E/A) flow ratio with magnetic resonance imaging.

Results

• Findings demonstrated that pioglitazone reduced HbA_1c by 0.9%; decreased systolic and diastolic blood pressure by 7 ± 2 and 7 ± 2 mmHg, respectively (P < 0.05); and increased whole-body insulin-stimulated glucose uptake by 71% (3.4 ± 1.3 to 5.8 ± 2.1 mg/kg · min; P < 0.01) in subjects with T2D.
• Researchers observed that pioglitazone enhanced MGU by 75% (0.24 ± 0.14 to 0.42 ± 0.13 μmol/min · g; P < 0.01) and myocardial perfusion by 16% (0.95 ± 0.16 to 1.10 ± 0.25 mL/min · g; P< 0.05).
• In addition, data revealed that measures of diastolic function, E/A ratio (1.04 ± 0.3 to 1.25 ± 0.4) and peak LV filling rate (349 ± 107 to 433 ± 99 mL/min), both increased (P< 0.01).
• It was also reported that end-systolic volume, end-diastolic volume, peak LV ejection rate, and cardiac output trended to increase (P not significant), whereas the ejection fraction (61 ± 6 to 66 ± 7%) and stroke volume increased significantly (71 ± 20 to 80 ± 20 L/min; both P < 0.05).