Compared to controls , participants randomized to the IET group presented a significant decrease in apnea-hypopnea index ( AHI ) ( 40.619.4 vs. 28.019.3 ; P < 0.001 ) , oxygen desaturation index ( ODI ) , and arousal index , which occurred in conjunction with significant decrease in body mass index ( BMI ) , neck circumference , fat mass , fasting glucose , and diastolic blood pressure .