Cardiorespiratory capacity of individuals with mental retardation including Down syndrome

Abstract

This study evaluated the cardiorespiratory capacity of persons with MR with and without Down syndrome. Analyses of individual data records of maximal exercise tests with metabolic analyses were conducted on tests of 111 subjects (31 men and 16 women with DS; 35 men and 29 women without DS) from six participating centers. All centers used a walking treadmill protocol previously shown to produce valid and reliable maximal tests with this population. Peak oxygen uptake and peak minute ventilation 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 without DS (P < 0.006). Peak respiratory exchange ratio (RER) was higher in subjects without DS (P < 0.006). Using peak RER as a covariate did not change the results. An analysis of peak minute ventilation, heart rate and VO2 of subjects with a peak RER above 1.1 revealed the same results. These data show that individuals with mental retardation have low levels of peak VO2, consistent with low levels of cardiovascular fitness. Individuals with Down syndrome have even lower levels of peak VO2 than their peers without Down syndrome, a finding that is possibly mitigated by the lower peak heart rates of the individuals with Down syndrome.

Health‐promoting physical activity of adults with mental retardation

“…Since there is sufficient evidence that some impairments associated with Down syndrome (e.g., joint hypermobility, obesity, low bone mass) negatively impact health factors such as physical fitness [Fernhall et al, 1996], specific diagnosis must be considered when studying physical activity in people with MR.…”

The functional fitness capacity of adults with Down syndrome in South Africa

“…When controlling for thyroid dysfunction, resting metabolic rate in obese DS individuals is not reduced, implying that when children with DS have low resting metabolic rates, it may predispose them to obesity as adults . The high incidence of obesity in DS individuals is mainly attributed to sedentary lifestyle (Dodd et al, 2005;Rimmer et al, 2004;Tsimaras et al, 2003;Carmeli et al, 2002 b ;Fernhall et al, 1996;Fernhall et al, 1993;Pitetti et al, 1993 andPitetti et al, 1991). The problem is exacerbated by the fact that adults with DS face considerable barriers to participation in health promotion programs .…”

“…The physiological characteristics of the Down's syndrome individual provide potential limitations and restrictions to both cardiovascular and resistance based exercise tolerance (Shields et al, 2008;Rimmer et al, 2004;Tsimaras et al, 2003;Varela et al, 2001;Millar et al, 1993), with heart abnormalities, poor skeletal muscle development and chronotropic incompetence (CI) being the primary constraints (Fernhall et al, 1996). Additionaly, Barnhart et al (2007) found that lower lean muscle mass and higher incidences of obesity could also be contributory to the lower cardiovascular capacity of DS individuals.…”

“…Moreover, numerous researchers have shown that individuals with intellectual disabilities have low aerobic capacities and low maximum heart rates (Guerra et al, 2003;Fernhall et al, 2000;Pitetti et al, 1993), while individuals with DS have even lower aerobic capacities and maximum heart rates than their ID peers (Baynard et al, 2004;Fernhall et al, 2001 a ;Fernhall et al, 1996;Millar et al, 1993;Pitetti et al, 1992 a andFernhall et al, 1989). In fact, DS individuals have a 30 beat/minute less than normal maximum heart rate compared to the general population Fernhall et al, 2001 a ).…”

“…In fact, DS individuals have a 30 beat/minute less than normal maximum heart rate compared to the general population Fernhall et al, 2001 a ). When statistically controlling for peak heart rate, Fernhall et al (1996) established that there is no change in peak VO 2 (volume of oxygen consumption).…”