Effects of insulin on left ventricular function during dynamic exercise in overweight and obese subjects.
OBJECTIVE
We designed this study in order to determine the effect of insulin on cardiac function in overweight and obese subjects during exercise.


RESULTS
The cardiac function of 62 normal glucose tolerant subjects, aged 30-40 and divided into normal weight (group 1, n=22, BMI 20-24.9 kg/m(2)), overweight (group 2, n=20, BMI 25-29.9 kg/m(2)), and obesity (group 3, n=20, BMI 30-35 kg/m(2)) was evaluated at rest and during dynamic exercise through angiocardioscintigraphy, when on hyperinsulinaemic euglycaemic clamp (test A) and when on normal saline infusion (test B). Left ventricular function at rest was statistically greater (P<0.05) in both tests in overweight and obese subjects compared with normal weight controls, with no statistical difference (P=0.057) within groups between insulin and normal saline infusion. During exercise, cardiac function improved in all the subjects in both tests. The increase was lower in overweight and obese patients, even if statistically significant only in obese vs. control subjects in both tests (P<0.05). Insulin sensitivity showed a significant correlation (P< or =0.001) with left ventricular ejection fraction (LVEF) at rest and with change in LVEF during clamp.


CONCLUSIONS
Our findings suggest a metabolic pathogenesis for the impaired LV function in obesity.
Sasso
Ferdinando C
FC
Department of Geriatrics and Metabolic Diseases, Second University of Naples, Naples, Italy. ferdinando.sasso@unina2.it
Carbonara
Ornella
O
Nasti
Rodolfo
R
Marfella
Raffaele
R
Esposito
Katherine
K
Rambaldi
Pierfrancesco
P
Mansi
Luigi
L
Salvatore
Teresa
T
Torella
Roberto
R
Cozzolino
Domenico
D
D000328:Adult; D000704:Analysis of Variance; D015992:Body Mass Index; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D009765:Obesity / Q000503:physiopathology*; D013318:Stroke Volume / Q000187:drug effects; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000187:drug effects*
D007004:Hypoglycemic Agents; D007328:Insulin