Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT02482519 |
Other study ID # |
2015P000624 |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
November 2015 |
Est. completion date |
April 2018 |
Study information
Verified date |
December 2022 |
Source |
Massachusetts General Hospital |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Marrow adipocytes have been identified as a component of the bone marrow micro-environment.
Evidence exists suggesting that marrow fat plays an important physiologic role in both bone
mineral and energy metabolism in humans. The investigators will study the effects of acute
weight gain and acute nutritional deprivation on energy homeostasis and bone mineral
metabolism by examining marrow adiposity, peripheral fat depots and bone microarchitecture.
The study will include two ten day inpatient study visits. Participants will eat a high
calorie diet for 10 days, followed by a 13-18 day stabilization period at home, and then
return for a ten day fast.
Description:
Marrow adipocytes have been identified as a component of the bone marrow micro-environment.
Evidence exists suggesting that marrow fat plays an important physiologic role in both bone
mineral and energy metabolism in humans. Studies have shown that nutritional status,
particularly body fat distribution, may be important in marrow fat. For example, anorexia
nervosa, a state of low body fat, is associated with elevated marrow adiposity and low bone
mineral density. However, it is not known whether this is in direct response to nutritional
deprivation or other hormonal changes that occur in anorexia nervosa. Drugs known to cause
adipose redistribution and associated with low bone mass, such as the thiazolidinediones and
glucocorticoids, have also been shown to stimulate the accumulation of marrow adipocytes.
Therefore, the relationship between bone marrow fat, bone mass, body fat depots and their
hormone regulators is a dynamic one and not yet well understood. Although studies have shown
an inverse relationship between high marrow adiposity and low bone mineral density (BMD), the
physiologic role of marrow adipose tissue has not been defined nor its relationship to
hormonal factors in humans. A role for marrow adipose tissue (MAT) in mineral and energy
metabolism is further supported by the fact that a number of pathologic states are associated
with increased marrow adiposity. Visceral adipose tissue, intramyocellular lipids (IMCL),
intrahepatic lipids (IHL) and serum triglycerides, all of which are elevated in obesity, are
also positive predictors of MAT, but whether acute weight gain in humans results in elevated
marrow adiposity is unknown. Therefore observing changes in marrow fat during acute weight
gain and acute nutritional deprivation will further the understanding of the role of marrow
adiposity in energy homeostasis. While it is known that markers of bone formation
dramatically decrease after only 4 days of fasting, it is not known how quickly marrow fat
can change in response to physiologic cues. In a rat model, increases in marrow fat were
observed after 14 days in space suggesting that changes in marrow adiposity may occur acutely
in the human model as well.