Myocardial glucose uptake in patients with the m.3243A G mutation in mitochondrial DNA

Autor: Juhani Knuuti, Markku Taittonen, Kari Majamaa, Ilmo E. Hassinen, Patricia Iozzo, Mikko Kärppä, Pirjo Nuutila, Jussi P. Pärkkä, Markus M. Lindroos
Rok vydání: 2015
Předmět:
Zdroj: Journal of inherited metabolic disease. 39(1)
ISSN: 1573-2665
Popis: Mitochondrial mutations impair glucose oxidation and increase glucose uptake in cell cultures and lead to cardiomyopathy in patients. Here we characterize cardiac glucose uptake in 14 patients with the m.3243A G mutation in mitochondrial DNA. The 14 patients with m.3243A G and 13 controls were similar in age, physical activity and body mass index. Ten patients had diabetes. Left ventricular glucose uptake per tissue mass (LVGU) was measured with 2-[(18) F]fluoro-2-deoxyglucose positron emission tomography during euglycemic hyperinsulinemia. Cardiac morphology and function were assessed with magnetic resonance imaging. We found that the LVGU was 25% lower in the patients than that in the controls (P = 0.029). LVGU was inversely correlated with mutation heteroplasmy, glycated haemoglobin and fasting lactate in patients. The seven patients with mutation heteroplasmy ≥ 49% had 44% lower LVGU than the seven patients with heteroplasmy 49%. This difference remained significant after adjustment for concurrent free fatty acid concentration or glycated haemoglobin or glucose uptake in skeletal muscle or all (p 0.048 [All]). Patients with m.3243A G had a lower stroke volume and a higher heart rate than the controls, whereas cardiac output and work were similar. Myocardial glucose uptake is not increased but decreased with a threshold effect pattern in patients with the m.3243A G mutation. The glucose hypometabolism adds to the impaired cardiac energetics and likely contributes to the progression of the mitochondrial cardiomyopathy.
Databáze: OpenAIRE