Conclusions
Whilst VLCDs result in dramatic improvements in insulin resistance, they are associated with transient but significant cardiovascular functional decline, which may have an impact on those with the coexisting cardiac disease. However, after 8 weeks, the diet was associated with normalisation of cardiac function, suggesting they may form a potential therapeutic intervention for diastolic dysfunction in obesity and diabetes.
Methods
25 obese volunteers (BMI 36.8 ± 5.8 kg/m2) underwent magnetic resonance imaging, echocardiography, metabolic profiling, and bio-impedance analysis before 1 and 8 weeks following a VLCD (800 kcal/day).
Results
After 1 week of VLCD, despite only modest weight loss, significant drops occurred in liver fat and insulin resistance (HOMA-IR; by 14-50%, all p < 0.01). In contrast, myocardial triglyceride content (MTGC) increased (by 48%, p = 0.030), and was associated with deterioration in both systolic (LVEF by 4%, p = 0.041) and diastolic function (e/e' 8.6 ± 1.4 to 9.4 ± 1.7, p = 0.019). Aortic stiffness also increased by 35% (p = 0.015). At 8 weeks, liver steatosis and visceral fat were lower than baseline (by 20-55%, p < 0.001), and peripheral metabolic improvements continued. MTGC also fell to below baseline (1.5 ± 0.6 vs 2.1 ± 1%, p = 0.05) with improved myocardial function (e/e' 8.6 ± 1.4 to 7.5 ± 1.5, p = 0.003). Conclusions: Whilst VLCDs result in dramatic improvements in insulin resistance, they are associated with transient but significant cardiovascular functional decline, which may have an impact on those with the coexisting cardiac disease. However, after 8 weeks, the diet was associated with normalisation of cardiac function, suggesting they may form a potential therapeutic intervention for diastolic dysfunction in obesity and diabetes.