Obese Versus Normal-Weight Late-Adolescent Females have Inferior Trabecular Bone Microarchitecture: A Pilot Case-Control Study

Abstract

Though still a topic of debate, the position that skeletal health is compromised with obesity has received support in the pediatric and adult literature. The limited data relating specifically to trabecular bone microarchitecture, however, have been relatively inconsistent. The aim of this pilot cross-sectional case-control study was to compare trabecular bone microarchitecture between obese (OB) and normal-weight (NW) late-adolescent females. A secondary aim was to compare diaphyseal cortical bone outcomes between these two groups. Twenty-four non-Hispanic white females, ages 18–19 years, were recruited into OB (n = 12) or NW (n = 12) groups based on pre-specified criteria for percent body fat (≥32 vs. <30, respectively), body mass index (>90th vs. 20th–79th, respectively), and waist circumference (≥90th vs. 25th–75th, respectively). Participants were also individually matched on age, height, and oral contraceptive use. Using magnetic resonance imaging, trabecular bone microarchitecture was assessed at the distal radius and proximal tibia metaphysis, and cortical bone architecture was assessed at the mid-radius and mid-tibia diaphysis. OB versus NW had lower apparent trabecular thickness (radius and tibia), higher apparent trabecular separation (radius), and lower apparent bone volume to total volume (radius; all P < 0.050). Some differences in radius and tibia trabecular bone microarchitecture were retained after adjusting for insulin resistance or age at menarche. Mid-radius and mid-tibia cortical bone volume and estimated strength were lower in the OB compared to NW after adjusting for fat-free soft tissue mass (all P <0.050). These trabecular and cortical bone deficits might contribute to the increased fracture risk in obese youth.

Survey of MRI Usefulness for the Clinical Assessment of Bone Microstructure

“…Liu et al also reported 3T MR images (pixel size 0.180 mm × 0.180 mm, acq. time 9:18 min) of 92 distal femurs divided in three groups (without osteoarthritis, mild osteoarthritis, and severe osteoarthritis) reporting progressively lower BVF and higher erosion index from healthy patients to those affected by severe osteoarthritis [ 108 ], extending previous results [ 109 , 110 , 111 ].…”

“…The MRI potential for the bone microstructure has also been assessed in vivo in anatomical regions more affected by osteoporosis, i.e., tibiae and radii, vertebrae [ 65 , 117 , 118 ], distal [ 18 , 108 , 109 , 111 , 119 ], and proximal femurs [ 60 , 71 , 72 ]. Microarchitectural parameters extrapolated from 3T MRI (0.156 mm × 0.156 mm × 0.5 mm) and compared to HR-pQCT of tibiae and radii of 11 healthy volunteers showed good correlation for BVF (r = 0.83) and Tb.Sp (r = 0.7) in tibiae and good correlation for all the microarchitecture parameters investigated in radii (r = 0.65, 0.95, 0.83, and 0.63 for BVF, Tb.N, Tb.Sp, and Tb.Th respectively) [ 77 ].…”

Bone health in diabetes and prediabetes

“…In a cross-sectional analysis of nondiabetic postmenopausal women, higher levels of insulin resistance were associated with lower cortical bone volume, independent of age and weight[172]. Consistently, female obese late-adolescents had worse trabecular bone microarchitecture at the radius and tibia as compared with non-obese controls, as well as lower bone volume and estimated bone strength[173]. T2D diabetes and insulin resistance are almost invariably associated with obesity and increased central adiposity, which reflects increased VAT.…”

The “Fat but Fit” Paradigm and Bone Health in Young Adults: A Cluster Analysis

“…A complex relationship has been described between adiposity and bone development. Numerous studies have proposed that fat mass has a substantial effect on bone, not only due to increased mechanical loading [ 10 ] but also due to the metabolic action of bone–related hormones that are secreted or regulated by adipocytes [ 11 ]. However, excessive fat mass may negatively influence bone remodeling through the action of inflammatory cytokines that are released from visceral adipocytes [ 12 ].…”

“…However, excessive fat mass may negatively influence bone remodeling through the action of inflammatory cytokines that are released from visceral adipocytes [ 12 ]. In this sense, after accounting for lean mass, adiposity seems to be a negative predictor of bone mass in youth [ 10 , 13 ]. Moreover, from a nutritional point of view, dietary intake is an important modifiable factor for both fat mass and bone health, accordingly normal bone metabolism requires a sufficient amount of nutrients, such as magnesium, calcium, phosphorus, vitamin D, potassium and proteins [ 14 ] also, nutrients such as calcium may play a significant role in decreasing fat mass [ 15 ].…”