CARDIORESPIRATORY CAPACITY OF INDIVIDUALS WITH MENTAL-RETARDATION INCLUDING DOWN-SYNDROME

This study evaluated the cardiorespiratory capacity of persons with MR with and without Down syndrome. Analyses of individual data records o f maximal exercise tests with metabolic analyses were conducted on tes ts of 111 subjects (31 men and 16 women with DS; 35 men and 29 women w ithout DS) from six participating centers. All centers used a walking treadmill protocol previously shown to produce valid and reliable maxi mal tests with this population. Peak oxygen uptake and peak minute ven tilation were higher in men than in women (P < 0.006), and in subjects without DS (P < 0.006). Peak heart rate was also higher in subjects w ithout DS (P < 0.006). Peak respiratory exchange ratio (RER) was highe r in subjects without DS (P < 0.006). Using: peak RER as a covariate d id not change the results. An analysis of peak minute ventilation, hea rt rate and VO2 of subjects with a peak RER above 1.1 revealed the sam e results. These data show that individuals with mental retardation ha ve low levels of peak VO2, consistent with low levels of cardiovascula r fitness. Individuals with Down syndrome have even lower levels of pe ak VO2 than their peers without Down syndrome, a finding that is possi bly miti gated by the lower peak heart rates of the individuals with D own syndrome.