Location: Children's Nutrition Research CenterTitle: Relationship of cardiac structure and function to cardiorespiratory fitness and lean body mass in adolescents and young adults with Type 2 Diabetes
|BACHA, FIDA - Children'S Nutrition Research Center (CNRC)|
|GIDDING, SAMUEL - Nemours Children'S Clinic|
|PYLE, LAURA - University Of Colorado|
|KATZ, LORRAINE - Children'S Hospital - Philadelphia, Pennsylvania|
|KRISKA, ANDREA - University Of Pittsburgh|
|NADEAU, KRISTEN - University Of Colorado|
|LIMA, JOAO - Johns Hopkins University|
Submitted to: Journal of Pediatrics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/13/2016
Publication Date: 10/1/2016
Citation: Bacha, F., Gidding, S.S., Pyle, L., Katz, L.L., Kriska, A., Nadeau, K.J., Lima, J.A. 2016. Relationship of cardiac structure and function to cardiorespiratory fitness and lean body mass in adolescents and young adults with Type 2 Diabetes. Journal of Pediatrics. 177:159-166.
Interpretive Summary: The relationship of heart structure and function to body composition and fitness level in youth with obesity and type 2 diabetes has not been well studied. We examined these relationships in 233 youth with type 2 diabetes who participated in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study. We found that in obese 12-24 year old youth with type 2 diabetes, the heart size was partly related to the lean body mass and fitness level and, therefore, part of the larger heart size in these youth appears to be related to the need to accommodate the needs of a lager body size. Although fat mass was related to subtle functional changes, overall heart function was within normal limits. Fitness level counteracted the effect of blood sugar on the function of the right side of the heart. We conclude that fitness level and greater lean body mass account for some of the increase in heart in obese youth with type 2 diabetes, and fitness seems to counteract the effect of elevated sugar on the heart.
Technical Abstract: To investigate the relationships of cardiac structure and function with body composition and cardiorespiratory fitness (CRF) among adolescents with type 2 diabetes in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) Study Group. Cross-sectional evaluation of 233 participants (median age 18.3 [min-max 12.4-24.2] years, 63% females, median hemoglobin A1c 6.8%) who had echocardiography measurements of left ventricular (LV) mass, ejection fraction, left atrial dimensions, LV diastolic function (early transmitral flow velocity to early mitral annular velocity ratio from tissue Doppler imaging), and right ventricular function (tricuspid annular plane systolic excursion [TAPSE]) and body composition (dual-energy x-ray absorptiometry) and CRF (cycle ergometry determination of physical work capacity at heart rate of 170 beats per minute). LV mass correlated positively with CRF (r=0.5, P<.0001), lean body mass (LBM) (r=0.7, P<.0001), and fat mass (FM) (r=0.2, P=.00047); LV ejection fraction did not. Early transmitral flow velocity to early mitral annular velocity was positively related to FM (r=0.14, P=.03) and % body fat (r=0.18, P=.007), and left atrial internal diameter correlated with FM (r=0.4, P<.0001), LBM (r=0.3, P<.001), and CRF (r=0.2, P=.0033). TAPSE weakly correlated with CRF (r=0.2, P=.0014) and LBM (r=0.13, P<.05) but not with FM. In multivariable regression analyses, LBM (beta=2.13, P<.0001) and CRF (beta=0.023, P=.008) were related to LV mass independent of race, sex, age, hemoglobin A1c, hypertension, smoking, and diabetes medications. CRF (beta=0.0002, P=.0187) and hemoglobin A1c (beta=-0.022, P=.0142) were associated with TAPSE. In youth with type 2 diabetes, LV size is related to physical fitness. LV ejection fraction is within normal limits. LV diastolic function is inversely related to FM. Greater fitness may counteract adverse effects of poor glycemic control on right ventricular function.