A comparison of bone mineral density in normal weight and obese adolescents with polycystic ovary syndrome.

STUDY OBJECTIVE

To evaluate whether there are any differences in bone mineral density (BMD) between normal weight and obese adolescents suffering from polycystic ovary syndrome (PCOS) with oligo/amenorrhea.

DESIGN

Prospective cohort study.

SETTING

Adolescent gynecology clinic in a general service hospital.

PARTICIPANTS

Subjects consisted of adolescents between 16 to 18 years of age presenting with oligo/ amenorrhea with ultrasound morphology of polycystic ovaries ± evidence of hyperandrogenism over 24 months. Controls consisted of consecutive eumenorrheic patients within the same age group.

INTERVENTIONS

All underwent full hormonal profile assessment, and dual energy X-ray absorptiometry and peripheral quantitative computed tomography scans.

MAIN OUTCOME MEASURES

Areal and volumetric BMD parameters.

RESULTS

Of 37 adolescents with PCOS, 12 (32%) were obese with BMI ≥25, of which 9/12 (75%) were hyperandrogenic. The control group consisted of 40 normal weight eumenorrheic girls. The PCOS group overall had lower lumbar spine BMD values as compared to the controls (0.91 vs 0.97 g/ cm(2), P = 0.033). The normal weight PCOS group had lower BMD at the spine (0.90 vs 0.97 g/ cm(2), P = 0.027), trochanter (0.66 vs 0.71 g/ cm(2), P = 0.039) as well as volumetric distal tibial core sites (268 vs 296 mg/ cm(3)) as compared to eumenorrheic controls, but there were no significant BMD differences between the obese PCOS group and the eumenorrheic controls.

CONCLUSIONS

Normal weight PCOS adolescents with oligo/amenorrhea have marginally lower BMD values than controls, but obese PCOS adolescents have BMD values compatible with eumenorrheic adolescents.