Bone mass and sex steroids in postmenarcheal adolescents and adult women with Type 1 diabetes mellitus☆

Abstract 

Objective

The aim of this study was to compare the bone mass in young adolescents and adult women with Type 1 diabetes mellitus (T1DM) and determine its relationship with sex steroid and sex hormone-binding globulin (SHBG) levels.

Design

Cross-sectional study.

Patients

We studied a group of adolescents and adult women with T1DM (n=45) and 50 healthy controls (C) matched by gynecological age and body mass index in a case-control study. Girls with menarche within the last 18–40 months (n=17 T1DM and 32 C) and adult women (age=30.4+1.4 years; n=28 T1DM and 18 C) were recruited.

Measurements

Bone mass was evaluated with a GE Lunar Prodigy densitometer. Sex steroid levels were measured by radioimmunoassay.

Results

Bone mass was lower in adolescents with T1DM than in control adolescents, but was similar in both groups of postmenarcheal girls after adjusting for age, lean, and fat mass. However, adult T1DM women exhibited lower adjusted and unadjusted (P<.05) Z-femoral neck (−0.2±0.2 vs. 0.4±0.2) and bone mineral content (BMC) (2306±61 vs. 2645±79 g) than adult controls. Adult controls and T1DM adults showed higher whole body BMC than adolescent controls and T1DM adolescents, respectively. Bone mass in T1DM did not correlate with estradiol, free estradiol, testosterone, SHBG, or HbA1c levels.

Conclusions

The diminished bone mass observed in adult T1DM women does not appear to be related to sex steroid levels. In young adolescents with T1DM, the observed decrease in bone mass appears to be related to differences in body composition and age.

Keywords: Diabetes mellitus, Type 1, osteopenia, estradiol, sex hormone-binding globulin