Blood Flow in Individuals With Down Syndrome

University of Illinois

Status: Terminated

Conditions: Down Syndrome

Treatments: Other: Hand grip exercise and lower body negative pressure

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT03590665

2017-0642

1K99HD092606-01 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

This study focuses on physiological explanations of difficulties with physical activity and exercise in individuals with Down syndrome, by non-invasively examining cardiac output and the regulation of blood flow to working muscles during exercise.

Full description

Work capacity is an important predictor of declining health or physical function, and of mortality, and is commonly measured as peak oxygen consumption. Peak oxygen consumption is very low in individuals with Down syndrome, the most prevalent genetic cause of intellectual disability. Previous research suggests individuals with Down syndrome may experience a double disadvantage when they are exercising: they may not be able to increase cardiac output sufficiently and they may not be able to allocate adequate blood flow to the working muscles.

The aim of this research study is therefore to determine the impact of limitations in central and peripheral regulation of blood flow on work capacity in individuals with DS. The results of this project will aid our understanding of the underlying mechanisms and determine the potential to improve health across the lifespan of individuals with Down syndrome by tailoring exercise interventions.

Enrollment: 21 patients

Sex: All

Ages: 18 to 45 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Between 18 and 45 years old

• generally healthy

• sedentary or low-active (defined as being involved in less than 30 minutes of moderately-intense physical activity per day)

• additionally for the participants with Down syndrome:

  • diagnosis of Down syndrome trisomy 21 and
  • normal thyroid function or stable thyroid function (and medications) for at least 6 months.

Exclusion criteria

• atherosclerotic or other vascular disease;
• asthma or other pulmonary disease;
• hypertension (defined BP >140/90 mmHg);
• blood pressure below 90/60 mmHg;
• history of pre-syncope or syncope;
• diabetes (defined as Hba1c of >7.5% or use of glucose lowering medication);
• severe obesity (defined as BMI >40);
• medications affecting heart rate, blood pressure or arterial function;
• anti-inflammatory medication including NSAIDS;
• current smoking and
• pregnancy.

Trial design

Primary purpose: Screening

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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21 participants in 2 patient groups

Individuals with Down syndrome

Other group

Description:

For participants with Down syndrome, the first visit includes baseline measures and familiarization with the graded maximal exercise test protocol. If necessary, additional familiarization sessions will be scheduled for people with Down syndrome. The second visit, we perform the graded maximal exercise test and familiarize the participant with the procedures for the third visit: the hand grip exercise protocol and the lower body negative pressure (LBNP) box. The third visit we assess the peripheral blood flow during the hand grip exercise protocol without and with the LBNP. For control subjects, the first and second visit are combined. Their second visit is the same as the third visit for individuals with Down syndrome.

Treatment:

Other: Hand grip exercise and lower body negative pressure

Individuals without Down syndrome

Other group

Description:

For participants with Down syndrome, the first visit includes baseline measures and familiarization with the graded maximal exercise test protocol. The second visit, we perform the graded maximal exercise test and familiarize the participant with the procedures for the third visit: the hand grip exercise protocol and the lower body negative pressure (LBNP) box. The third visit we assess the peripheral blood flow during the hand grip exercise protocol without and with the LBNP. For control subjects, the first and second visit are combined. Their second visit is the same as the third visit for individuals with Down syndrome.

Treatment:

Other: Hand grip exercise and lower body negative pressure