Relationships among biological sex, body composition, and bone mineral density in young persons with and without diabetes

Abstract

Objectives: Bone mineral density (BMD) is influenced by factors including age, sex, body composition, and diabetes. However, data regarding these relationships in young individuals is limited. The objective of this study was to address this gap in the literature.

Methods: We conducted a post-hoc analysis of participants from six cross-sectional cohort studies, encompassing individuals with type 1 diabetes (T1D) and type 2 diabetes (T2D), as well as controls of healthy weight (HWC) and with obesity (OC). Whole-body dual-energy X-ray absorptiometry (DXA) was employed to measure BMD and body composition. Multiple linear regression models assessed sexual dimorphism in BMD, adjusting for age and exploring effect modification by group and sex.

Results: A total of 325 participants were included (T1D [n=123, mean age 22.4 years, 50 % male], T2D [n=72, mean age 16.2 years, 33 % male], HWC [n=79, mean age 16.6 years, 41 % male], and OC [n=51, mean age 13.8 years, 53 % male]). Sexual dimorphism in BMD was evident only in T1D and HWC, with males having higher BMD than females (p=0.021; p<0.001, respectively). BMI was positively correlated with BMD in all groups (p<0.001 for HWC; p=0.001 for OC; p<0.001 for T1D; p=0.008 for T2D). Body fat percentage was inversely correlated with BMD in HWC and T1D (p<0.001; p=0.011, respectively), but not in OC or T2D. Additionally, lean mass percentage was significantly associated with higher BMD in HWC and OC (p<0.001; p=0.023, respectively), but not in groups with diabetes.

Conclusions: Our study documents sexual dimorphism in BMD in youth, with varied associations between body composition metrics and BMD across groups with diabetes and in controls without diabetes, underscoring the importance of understanding these relationships for optimizing bone health during adolescence.

Keywords: body composition; body fat percentage; bone mineral density; diabetes; lean mass percentage; obesity.

Figure 1:

Sexual dimorphism in bone mineral density. The LSMeans and 95 % confidence intervals are shown stratified by group and sex which were generated from a multiple linear regression model, adjusting for the effects of age. The p-values displayed above each grouped pair of lines indicate the significance of the LSMean differences between sexes within each group.

Figure 2:

Associations between body mass index and bone mineral density by group and sex. (A) The relationship between body mass index (BMI) and bone mineral density (BMD) is depicted for each group, revealing a positive correlation across all groups. The HWC group exhibited the strongest association between BMI and BMD, while the T2D group demonstrated the weakest association. Effect modification by group*BMI was evaluated. Age is indicated by dot size, with smaller dots representing younger participants. While the legend uses age values of 10, 20, and 30 to demonstrate changes in dot size, the dots reflect a continuous range of participant ages across the cohort. (B) The relationship between BMI and BMD is depicted for each group and sex, revealing a positive correlation across all groups. Overall, males exhibited similar or stronger associations between BMI and BMD compared to females across all groups. Effect modification by sex*BMI was evaluated for each group. Age is indicated by dot size, with smaller dots representing younger participants. While the legend uses age values of 10, 20, and 30 to demonstrate changes in dot size, the dots reflect a continuous range of participant ages across the cohort.

Figure 3:

Associations between body fat percentage and bone mineral density by group and sex. (A) The relationship between body fat percentage and bone mineral density (BMD) is depicted for each group, revealing a negative correlation across all groups. The HWC group exhibited the strongest association between body fat percentage and BMD, while the T2D group demonstrated the weakest association. Effect modification by group*body fat percentage was evaluated. Age is indicated by dot size, with smaller dots representing younger participants. While the legend uses age values of 10, 20, and 30 to demonstrate changes in dot size, the dots reflect a continuous range of participant ages across the cohort. (B) The relationship between body fat percentage and BMD is depicted for each group and sex, revealing mixed correlation directions across all groups. Overall, males exhibited inverse relationships between body fat percentage and BMD across all groups, although this was only statistically significant in HWC and OC groups, while females exhibited positive (but not statistically significant) relationships across all groups. Effect modification by sex*body fat percentage was evaluated for each group. Age is indicated by dot size, with smaller dots representing younger participants. While the legend uses age values of 10, 20, and 30 to demonstrate changes in dot size, the dots reflect a continuous range of participant ages across the cohort.

Figure 4:

Associations between lean mass percentage and bone mineral density by group and sex. (A)The relationship between lean mass percentage and bone mineral density (BMD) is depicted for each group. There was a positive correlation between lean mass percentage and BMD in all groups, however this was only statistically significant in HWC and OC groups. The controls with no diabetes exhibited a stronger association between lean mass percentage and BMD compared to the groups with either T1D or T2D. Effect modification by group*lean mass percentage was evaluated. Age is indicated by dot size, with smaller dots representing younger participants. While the legend uses age values of 10, 20, and 30 to demonstrate changes in dot size, the dots reflect a continuous range of participant ages across the cohort. (B) The relationship between lean mass percentage and BMD is depicted for each group and sex, revealing mixed correlation directions across all groups. Overall, males exhibited positive relationships between lean mass percentage and BMD across all groups except in the T1D group, however this relationship was not significant for the male T2D group. Females exhibited inverse relationships across all groups except in the HWC, however none of these relationships were statistically significant. Effect modification by sex*lean mass percentage was evaluated for each group. Age is indicated by dot size, with smaller dots representing younger participants. While the legend uses age values of 10, 20, and 30 to demonstrate changes in dot size, the dots reflect a continuous range of participant ages across the cohort.