Iron Absorption in The Low Oxygen Exposure and Weight Status (LOWS) Study

NCT07542873 | Recruiting DMC

• 2 other identifiers: 2022-046-PBRCU24DK132740
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Declines in iron status are common in those with obesity and may be due to obesity-related chronic inflammation; however, the effects of reducing inflammation following diet-induced weight loss on iron metabolism are poorly understood. Low environmental oxygen exposure increases dietary iron absorption and availability to supply iron for erythropoiesis but has not yet been tested in the context of weight loss. This study is designed to investigate diet-induced weight loss (inflammation reduction) and overnight low oxygen exposure (erythropoiesis stimulating agent) as strategies to improve dietary iron absorption in obesity.

Conditions

Obesity (Disorder)

Keywords

Body weight; Normobaric hypoxia; Negative energy balance; Energy intake; Energy expenditure; Iron absorption; Iron metabolism

Outcome Measures

Primary Outcomes (1)

• Change in iron absorption

  Fractional iron absorption will be measured during the baseline weight maintenance phase (day -7) and at the end of the study (day 42). Change in fractional iron absorption will be calculated as: fractional iron absorption on day 42 - fractional iron absorption on day -7.

  7 weeks

Study Arms (2)

Normobaric hypoxia (NH)

EXPERIMENTAL

8 weeks of overnight exposure (8 hrs/night) to NH conditions (\~15% oxygen; achieved with nitrogen dilution, equivalent to \~8500 feet elevation) using a commercially available tent and generator system (Hypoxico, Inc., New York, NY).

Other: Normobaric hypoxia (NH)

Normobaric normoxia (NN)

SHAM COMPARATOR

8 weeks of overnight exposure (8 hrs/night) to NN conditions (\~21% oxygen; sea level) using a commercially available tent and generator system (Hypoxico, Inc., New York, NY).

Other: Normobaric normoxia (NN)

Interventions

Normobaric hypoxia (NH) OTHER

Low oxygen exposure to mimic \~8500 feet elevation (experimental)

Normobaric hypoxia (NH)

Normobaric normoxia (NN) OTHER

Normal oxygen exposure to mimic sea level conditions (sham comparator).

Normobaric normoxia (NN)

Eligibility Criteria

• Age: 22 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Obese (BMI between 30-39.9 kg/m2)
• Born at altitudes below 2,100 meters (\~7,000 feet)
• Currently residing in Baton Rouge, Louisiana or surrounding area
• Not taking any medication(s) that interfere with oxygen delivery/transport for 4 weeks prior to and throughout the entire study (e.g., includes sedatives, sleeping aids, tranquilizers and/or any medication that depresses ventilation, diuretics, alpha and beta blockers).
• Willing to refrain from smoking, vaping, chewing tobacco, and dietary supplement use throughout the entire study.
• Willing to have a hypoxic tent set-up in their home and spend 8 consecutive hours per night in the tent for 8 weeks

You may not qualify if:

• Living in areas that are more than 1,200 m (\~4,000 feet), or have traveled to areas that are more than 1,200 m for five days or more within the last 2 months
• Cardiovascular abnormalities, gastrointestinal disorders, or any condition that interferes with oxygen delivery/transport (e.g., kidney disease, cardiovascular disease, etc.)
• Oxygen saturation \< 95% while awake or oxygen saturation dips below 88% for a total of ≥ 10 min overnight in normoxic conditions
• Evidence of apnea or other sleeping disorders
• Evidence of prior high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE) diagnosis
• Diagnosis or family history of sickle cell anemia/trait
• Hematocrit \<42% for males, \<36% for females
• Hemoglobin \<13 g/dL for males, \<12 g/dL for females
• Blood donation within 8 weeks of beginning the study
• Present condition of alcoholism, anabolic steroids, or other substance abuse issues
• Women who are pregnant, lactating, planning to become pregnant, or who have had an irregular menstrual cycle in the past 6 mo.
• Weight gain or loss \> 10% of body weight during the past 6 months
• Adults unable to consent

Sponsors & Collaborators

• Pennington Biomedical Research Center: lead
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): collaborator

Study Sites (1)

Pennington Biomedical Research Center

Baton Rouge, Louisiana, 70808, United States

RECRUITING

Related Publications (1)

• Riley TM, Weschenfelder C, Ravussin E, Rood JC, Greenway F, Taff S, Hickner RC, Cao H, Sutin AR, Todd G, Hennigar SR, Berryman CE. Effects of daily low oxygen exposure on weight status, body composition, and metabolic health in adults with obesity: protocol for a randomized, double-blind, controlled-feeding study. Contemp Clin Trials. 2026 Jan;160:108167. doi: 10.1016/j.cct.2025.108167. Epub 2025 Nov 26.

  PMID: 41314599 BACKGROUND

MeSH Terms

Conditions

Obesity; Body Weight

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Camila Weschenfelder, PhD

  Pennington Biomedical Research Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Recruitment Core

CONTACT

225-763-3000; clinicaltrials@pbrc.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 14, 2026
• First Posted: April 21, 2026
• Study Start: April 21, 2025
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): June 30, 2026
• Last Updated: April 21, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)