Impaired insulin stimulation of muscular ATP production in patients with type 1 diabetes.
J Intern Med, 2011/2;269(2):189-99.
Kacerovsky M[1], Brehm A, Chmelik M, Schmid AI, Szendroedi J, Kacerovsky-Bielesz G, Nowotny P, Lettner A, Wolzt M, Jones JG, Roden M
Affiliations
PMID: 21205021DOI: 10.1111/j.1365-2796.2010.02298.x
Impact factor: 13.068
Abstract
objective: in type 2 diabetic patients and their first-degree relatives, insulin resistance (IR) is associated with impairment of insulin-stimulated myocellular glucose-6-phosphate (g6p) and unidirectional flux through ATP synthase (fATP), suggesting the presence of inherited abnormal mitochondrial oxidative fitness. We hypothesized that patients with long-standing type 1 diabetes may also exhibit insulin resistance as well as lower fATP.
design: this single-centre trial was registered at ClinicalTrials.gov (NCT00481598).
subjects: we included eight nonobese type 1 diabetic patients (mean diabetes duration: 17 years) with near-target glycaemic control [haemoglobin A1c (HbA1c): 6.8 ± 0.4%] during treatment with continuous subcutaneous insulin infusion pumps and eight healthy volunteers (HbA1c: 5.4 ± 0.2%) of comparable age, body mass and level of physical activity.
outcome measures: myocellular fATP, g6p and intramyocellular lipid content (IMCL) were measured with (1) H/(31) P magnetic resonance spectroscopy during fasting and hyperinsulinaemic-euglycaemic clamp tests.
results: fasting fATP, g6p and IMCL did not differ between groups. During stimulation by insulin, type 1 diabetic patients exhibited approximately 50% (P < 0.001) lower whole-body glucose disposal along with approximately 42% (P = 0.003) lower intramyocellular g6p and approximately25% (P = 0.024) lower fATP. Insulin-stimulated fATP correlated positively with whole-body insulin sensitivity (R = 0.706, P = 0.002) and negatively with HbA1c (R = -0.675, P = 0.004).
conclusions: despite documented near-target glycaemic control for 1 year, nonobese patients with long-standing type 1 diabetes can exhibit insulin resistance. This associates with lower insulin-stimulated flux through muscular ATP synthase which could result from glucose toxicity.
MeSH terms
Adenosine Triphosphate; Adult; Anthropometry; Blood Glucose; Diabetes Mellitus, Type 1; Fasting; Female; Glucose Clamp Technique; Humans; Hypoglycemic Agents; Infusions, Subcutaneous; Insulin; Insulin Resistance; Magnetic Resonance Spectroscopy; Male; Middle Aged; Muscle, Skeletal; Young Adult
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