Clinical trial NCT02468817: PTH And Calcium Responses to Exercise (PACE) in Older Adults
Official title: PTH And Calcium Responses to Exercise (PACE) in Older Adults
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Osteoporosis
Keywords: parathyroid hormone (PTH)
bone mineral density (BMD)
Lead sponsor: University of Colorado, Denver
Sponsor class: OTHER
First posted: 2015-06-11
Enrollment: 12
Sex: ALL
Minimum age (years): 60
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: PREVENTION

Brief summary: Exercise that causes a decline in serum Calcium (Ca) as a result of dermal Ca loss stimulates bone resorption via an increase in Parathyroid Hormone (PTH).

Detailed description: Determine whether the magnitude of dermal Ca loss (i.e., sweating) during exercise is a determinant of the decline in iCa and increases in PTH and carboxy-terminal collagen crosslinks (CTX; marker of bone resorption). The proposed experiment will address this by manipulating the rate of dermal Ca loss (moderate vs high sweating rate) to determine whether this is the trigger for the cascade described in Figure 1. This will be achieved by having participants perform two identical exercise bouts under different thermal conditions (warm vs cool).

Eligibility criteria: Inclusion Criteria:

* Healthy adults aged 60-80 y

Exclusion Criteria:

* Use of medications in the past 6 months known to affect bone metabolism (e.g., bisphosphonates, thiazide diuretics, oral glucocorticoids)
* BMD t score \< -2.5 at the total hip or lumbar spine
* Known disease or condition associated with intestinal malabsorption
* Moderate or severe renal impairment defined as an estimated glomerular filtration rate of \<60 mL/min/1.73m2 based on the MDRD equation
* Chronic hepatobiliary disease, defined as liver function tests (AST, ALT) \>1.5 times the upper limit of normal; if such values are obtained on initial screening and thought to be transient in nature, repeated testing will be allowed
* Thyroid dysfunction, defined as an ultrasensitive TSH \<0.5 or \>5.0 mU/L; volunteers with abnormal TSH values will be re-considered for participation in the study after follow-up evaluation by the PCP with initiation or adjustment of thyroid hormone replacement
* Serum calcium \<8.5 or \>10.3 mg/dL
* Serum 25(OH)D \<20 ng/mL; volunteers with abnormal serum 25(OH)D values may be re-considered for participation in the study if serum 25(OH)D is \>20 ng/mL after vitamin D supplementation
* Uncontrolled hypertension defined as resting systolic BP \>150 mmHg or diastolic BP\>90 mmHg; participants who do not meet these criteria at first screening will be re-evaluated, including after follow-up evaluation by the PCP with initiation or adjustment of anti-hypertensive medications
* History of type 1 or type 2 diabetes
* Cardiovascular disease; subjective or objective indicators of ischemic heart disease (e.g., angina, ST segment depression) or serious arrhythmias at rest or during the graded exercise test (GXT) without follow-up evaluation will be cause for exclusion; follow-up evaluation must include diagnostic testing (e.g., stress echocardiogram or thallium stress test) with interpretation by a cardiologist
* Diagnosis or history of asthma

Primary outcomes:
measure: Change in Parathyroid Hormone (PTH)
timeFrame: 60 minutes of exercise and 2 hours of recovery
measure: Change C-Telopeptide (CTX)
timeFrame: 60 minutes of exercise and 2 hours of recovery
measure: Change in Serum Ionized Calcium (iCa)
timeFrame: 60 minutes of exercise
measure: Change in Total Ca
timeFrame: 60 minutes of exercise
Secondary outcomes:
Other outcomes:
Locations:
city: Aurora
country: United States
facility: University of Colorado Hospital
state: Colorado
Study officials:
affiliation: University of Colorado, Denver
name: Sarah J Wherry, PhD
role: PRINCIPAL_INVESTIGATOR
References: