Nitrites, Skeletal Muscle Mitochondrial Bioenergetics, and Physical Activity in Old Age (Nitrite)

This 2-site randomized double blinded controlled trial is to confirm and more definitively clarify the impact of a 12-week course of nitrite versus placebo on mitochondrial bioenergetics in older sedentary adults. This investigator will take an integrative physiology approach to determine the effect of nitrite therapy on a comprehensive assessment of mitochondrial energetics, skeletal muscle vascular function, and whole body physical function (cardiorespiratory function, exercise endurance, strength, balance, and physical activity) and fatigability.

Study Overview

• Status: Completed
• Conditions: Sedentary Lifestyle; Frailty; Aging
• Intervention / Treatment: Drug: 20mg sodium nitrite tid; Drug: Placebos

Detailed Description

Old age is associated with declining skeletal muscle mitochondrial bioenergetics with related decrements in cardiorespiratory fitness (CRF) and physical function that predispose to frailty, disability, and diminished quality of life. While exercise training may moderate and possibly even reverse declines in mitochondrial bioenergetics, potential for such benefit is typically confounded by exercise intolerance with early fatigability that results from the same age-related mitochondrial declines. Consequently, sedentariness is endemic and insidious among the growing population of older adults. This trial is to study the utility of inorganic nitrite salts as a novel means to modify this detrimental pattern. Classic studies demonstrate that nitrite facilitates hypoxic vasodilation in muscle. This investigator's preliminary data suggests that nitrite treatment also augments skeletal muscle mitochondrial bioenergetics in older adults. This investigator proposes improving mitochondrial function will also be reflected in clinical parameters, including CRF as well as broader functional attributes (endurance, strength, and balance) that enable physical activity (PA) and opportunity to mitigate frailty and disability. As such, this application is in line with the National Institute on Aging's mission to develop targeted interventions to prevent and treat age-associated conditions. This multi-disciplinary team has published seminal work indicating that mitochondrial bioenergetics and CRF are significant determinants of physical function in older adults. In parallel efforts, this investigative team showed efficacy of chronic nitrite therapy to improve mitochondrial bioenergetics in older sedentary adults. Only one month of nitrite therapy significantly improved ex vivo assessments of mitochondrial energetics in skeletal muscle biopsies, concomitant with increased skeletal muscle sirtuin-3 expression, a nicotinamide adenine dinucleotide (NAD) dependent lysine deacetylase and key regulator of mitochondrial metabolism. These key data reinforce the premise that nitrite enhances vital mitochondrial metabolism in older adults. Moreover, improvement in muscle energetics in nitrite-treated older adults was linked with increased exercise efficiency as evidenced by reduced oxygen consumption (VO2) during submaximal steady-state walking. This data supports the hypothesis that nitrite will make physical function easier such that physical activity will increase.

• Study Type: Interventional
• Enrollment (Actual): 64
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15213
      • University of Pittsburgh

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 70 years and older (Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥70 years
• Sedentary (<1 hour/week of volitional exercise activity)
• Clinically stable (euvolemic; baseline HR <100 bpm) and without hospitalization or invasive cardiac procedure for 6 weeks

Exclusion Criteria:

• Blood pressure <110 or >160/95 mmHg
• Orthopedic or other chronic condition which limits physical activity or exercise testing assessments
• If valve replacement has been performed, patient may not be enrolled for 12 months after this procedure
• Severe peripheral or pulmonary artery disease
• Anemia: Hgb <11.0 (♂),10.0 (♀) gm/dl
• Participants with diabetes whose HgbA1c >10.0%
• Chronic alcohol (>14 drinks ETOH a week) or drug (any cocaine, methamphetamine, and cannabis ≥4 x week) dependency
• Allergy to lidocaine and red dye
• Chronic use of oral corticosteroids or other medications that affect muscle function
• Current use of organic nitrates or phosphodiesterase type 5 (PDE5) inhibitors
• Unable to hold warfarin, direct-acting oral anticoagulants (DOACs), non-steroidal anti-inflammatory medications (NSAIDs) or aspirin for 3 days prior to muscle biopsy, or to hold thienopyridine medications for 5 days prior to muscle biopsy. Participants unable or unwilling to hold will follow the modified ASA hold plan
• Any bleeding disorder that would contraindicate biopsy such as history of clinically significant bleeding diathesis (e.g., Hemophilia A or B, Von Willebrand's Disease or congenital Factor VII deficiency)
• Unstable psychiatric diagnosis that would affect adherence and ability to complete the protocol
• Dementia or inability to give informed consent or follow study protocol
• End-stage disease
• Other chronic unstable disease such as active neoplasm, end stage chronic kidney, liver or other organ disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 20 mg Sodium Nitrite TID Arm; Subject is to receive active study drug three times per day during treatment (12 weeks +/- 5 days) period and then after the treatment period (up to 16 weeks total).	Drug: 20mg sodium nitrite tid; Oral, inorganic sodium nitrite capsule at a dose of 20 mg administered three times per day, during the day.
Placebo Comparator: Placebo Control Arm; Subject is to receive placebo three times per day during treatment period (12 weeks +/- 5 days) and then after the treatment testing period (up to 16 weeks total).	Drug: Placebos; Oral placebo capsule at a dose of 20 mg administered three times per day, during the day.; Other Names: Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skeletal Muscle Mitochondrial Respiration State 3; Baseline to 12-week Change.	High resolution respirometry via Oroboros Oxygraph 2k is used to assess the effects of 12 weeks of inorganic nitrite vs placebo on skeletal muscle mitochondrial respiration from samples obtained via vastus lateralis muscle biopsy.	12-week course of study drug supplementation, up to 16 weeks total

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skeletal Muscle Adenosine Triphosphate (ATP) Production, Baseline to 12-week Change	Using phosphorus-magnetic resonance spectroscopy, we will measure ATPmax (recovery rate) and how it will change after 12 weeks (up to 16 weeks) of inorganic nitrite supplementation vs placebo	12-week course of study drug supplementation, up to 16 weeks total

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cardiorespiratory Fitness Measured as Peak Oxygen Uptake (Non-weight Normalized VO2) During a Progressive Resistance Cycle Ergometer Exercise Test; Baseline to 12-week Change	Cardiorespiratory fitness is measured as peak oxygen utilization (non-weight normalized VO2) during a progressive resistance cycle ergometer exercise test that is symptom-limited (maximum). This is assessed before and after 12 weeks (16 weeks total) of oral inorganic nitrite supplementation vs placebo.	12-week course of study drug supplementation, up to 16 weeks total
Oxygen Utilization (Non-weight Normalized VO2) During a Slow (1.5 Mph) Fixed Rate Walking Speed Test; Baseline to 12-week Change	Oxygen utilization (non-weight normalized VO2) is measured during slow walking during the last minute of a 5-minute slow (1.5 mph) fixed rate walking speed test. This is assessed before and after 12 weeks (16 weeks total) of oral inorganic nitrite supplementation vs placebo.	12-week course of study drug supplementation, up to 16 weeks total
Endurance During a Submaximal Constant Workload Cycle Ergometer Exercise Test; Baseline to 12-week Change.	Endurance is measured as duration (minutes) of exercise during a constant submaximal workload cycle ergometer exercise (i.e., calibrated at 75-80% of the maximum resistance [watts] achieved in a prior maximum cycle ergometer exercise test). This is assessed before and after 12 weeks (16 weeks total) of oral inorganic nitrite supplementation vs placebo.	12-week course of study drug supplementation, up to 16 weeks total
Time to Complete a Fast-paced 400 m Corridor Walk; Baseline to 12-week Change	Time to complete a fast-paced 400 m corridor walk is assessed This is assessed before and after 12 weeks (16 weeks total) of oral inorganic nitrite supplementation vs placebo.	12-week course of study drug supplementation, up to 16 weeks total
Borg Rating of Perceived Exertion During a 5-minute Slow (1.5 Mph) Fixed Rate Walking Speed Test; Baseline to 12-week Change	Fatigability is assessed using the Borg Rating of Perceived Exertion during minute 5 of a 5-minute fixed rate (1.5 mph) slow walking test. Borg Rating of Perceived Exertion is scored on a scale from 6 to 20 with 6 being the least difficult or intense (better) and 20 being the most difficult or intense (worse). This is assessed before and after 12 weeks (up to 16-weeks) of inorganic nitrite supplementation vs placebo.	12-week course of study drug supplementation, up to 16 weeks total
Short Physical Performance Battery; Baseline to 12-week Change	The Short Physical Performance Battery is assessed before and after 12-weeks (up to 16-weeks) of inorganic nitrite supplementation vs placebo. The Short Physical Performance Battery score is the aggregate of three sub-scales for balance, gait speed and repeated sit to stand performance. Each of the three sub-scales is scored from 0 to 4 with 0 being the poorest performance and 4 being the best performance. The scores for balance, gait speed, and repeated sit to stand performance are add for a total score ranging from 0 (worst) to 12 (best).	12-week course of study drug supplementation, up to 16 weeks total
Grip Strength; Baseline to 12-week Change	Maximum grip strength is assessed before and after 12 weeks (up to 16-weeks) of inorganic nitrite supplementation vs placebo.	12-week course of study drug supplementation, up to 16 weeks total
Physical Activity (Accelerometry), Measured as Daily Step Count; Baseline to 12-week Change	Physical activity is measured as daily step count (assessed using an Actigraph accelerometry device on the participant's wrist), before and after 12 weeks (up to 16-weeks) of inorganic nitrite supplementation vs placebo.	12-week course of study drug supplementation, up to 16 weeks total

Collaborators and Investigators

• Sponsor: Gladwin, Mark, MD
• Collaborators: National Institutes of Health (NIH); National Institute on Aging (NIA)

Study record dates

Study Major Dates

• Study Start (Actual): April 23, 2021
• Primary Completion (Actual): July 14, 2023
• Study Completion (Actual): July 14, 2023

Study Registration Dates

• First Submitted: April 15, 2019
• First Submitted That Met QC Criteria: May 26, 2020
• First Posted (Actual): May 28, 2020

Study Record Updates

• Last Update Posted (Actual): October 10, 2024
• Last Update Submitted That Met QC Criteria: October 8, 2024
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Keywords: Frailty; Bioenergetics; 70 and Older
• Additional Relevant MeSH Terms: Pathologic Processes; Frailty
• Other Study ID Numbers: STUDY20110334; R01AG058883 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-Identified data may be shared with other future investigators as research questions arise.
• IPD Sharing Time Frame: A limit in time frame of sharing has not been defined.
• IPD Sharing Access Criteria: Only de-identified data approved for sharing by PI.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No