Skeletal Muscle Energy Metabolism Of Type2Diabetes Offsprings With Normal Blood Glucose

ObjectiveTo evaluate the energy metabolism and mitochondrial function of skeletal musclein offspring of type2diabetes patients and healthy volunteers using dynamic3.0teslaPhosphorus Magnetic Resonance Spectroscopy(31P-MRS).MethodsWe performed dynamic31P-MRS studies in21young offspring of patients withtype2diabetes and18no diabetic family history control subjects matches withage,sex,BMI. Spectra of quadricep muscles were acquired while subjects were instates of rest(2spectrums),exercise(several spectrums) and recovery(10spectrums).All spectrums were analyzed using jMRUI and Matlabsoftware.Concentration of inorganic phosphate(Pi), phosphocreatine(PCr) andadenosine triphosphate(ATP) was measured from area under the peak. Concentrationof adenosine diphosphate(ADP) and intracellular pH value was calculated from thebiochemistry reaction equilibrium. The time constant and recovery rates of PCr, andADP were analyzed using exponential curve fitting.ResultsThe characterize of skeletal muscle was prominent high energy phosphate, socould produce high PCr and ATP peaks. When exercised, the Pi peak increased andthe PCr peak significantly decreased to the half of rest. During the recovery phase, thePi gradually decreased and returned to the resting phase value.(1)The concentration ofPi,PCr,ADP, β-ATP and the ratio of Pi/PCr were no significance difference betweenthe two groups in status of rest.（2）The concentration of β-ATP is significantly lowerin offsprings of diabetes than healthy subjects at the end of exercise（P=0.03）.（3） At recovery phase,the offsprings’ concentration of PCr is significantly lower thanhealthy sebjects at the second,third,5th,7th,8th10thspectrums(p=0.02,0.02,0.04,0.03,0.045,0.04).The concentration of β-ATP is significantly lowerat the5th,6th,8thspectrums(P=0.03,0.02,0.02) and the pH value is significantly lowerat7thand9thspectrums(P=0.045,0.03) than control group.The ratio of Pi/PCr ofoffspring is significantly higher than heathy subjects at the third spectrum of recoveryphase(P=0.019).(4)The mean PCr recovery rate of offspring was8.83mmol/s, whichis significantly slower than that for healthy subjects(14.31mmol/s,P=0.01).ConclusionThe non-invasive31P-MRS is an effective method to quantitatively evaluatemitochondrial function. This in vivo technique could be used to detect the imparedenergy metabolism and mitochondrial disfunction in high risk population of type2diabetes patients, prior to manifestation of diabetes, could be used at clinical practice.