Bone marrow fat unsaturation in young adults is not affected by present or childhood obesity, but increases with age: A pilot study

ObjectivesObesity increases bone marrow fat (BMF) content. The association between early obesity and bone marrow fatty acid composition is unknown. We measured BMF unsaturation index (UI) in normal-weight and overweight young adults with a known weight status in early childhood and tested the relationship between BMF UI and exercise history, glycemic state, and other clinical characteristics.MethodsThe study included 18 normal-weight (BMI < 25 kg/m2; 2 males, 16 females) and 17 overweight (BMI ≥ 25 kg/m2; 9 males, 8 females) young adults aged 15–27 years. BMF UI was assessed with magnetic resonance proton spectroscopy optimized to reduce water interference. Exercise information was obtained with a pedometer accompanied with the history of recent physical activity. Blood samples (insulin, glucose, HbA1c) and body characteristics (BMI, waist-to-hip ratio, body fat composition) were assessed.ResultsBMF UI was not affected by obesity at the time of study or before age 7 years. BMF UI increased with age in normal-weight and overweight subjects (R = 0.408, p = 0.015) but did not associate with gender, physical activity or body fat composition; a suggestive association was observed with glucose (R = − 0.289, p = 0.10).ConclusionsThe association of BMF UI with age in early adulthood may represent normal maturation of bone marrow. There was a trend toward an association with blood glucose, warranting further studies.