Diabetes and premature menopause: is their co-existence detrimental to the skeleton?

OBJECTIVE Premature menopause is a known risk factor for osteoporosis, whilst the influence of type 2 diabetes on bone mineral density (BMD) is still controversial. DESIGN AND METHODS BMD values assessed by dual-energy X-ray absorptiometry (DXA) in L2-L4 vertebrae and the femoral neck (FN) of 40 diabetic women with premature menopause (D-EMP) were compared with those of 60 non-diabetic, prematurely menopausal women (EMP) and 60 diabetic women with normal menopause (D-NMP) who had been matched by age and body mass index (BMI). In all women, the time elapsed since menopause ranged between 10 and 25 years and the duration of diabetes exceeded 75% of the postmenopausal time period. The age of D-EMP women was 58.7+/-5 years (mean+/-1 s.d.), age at menopause 39.5+/-2.7, years since menopause 18.6+/-4.9, BMI 27.8+/-4.3 kg/m(2) and duration of diabetes 13.9+/-3.9 years. RESULTS Vertebral BMD values of D-EMP women were significantly higher than those of EMP women (0.908+/-0.135 vs. 0.817+/-0.14 g/cm(2), P = 0.002), although there was no significant difference between D-EMP and D-NMP women (0.886+/-0.15 g/cm(2)). No significant differences were observed in FN BMD values between all groups. Age-adjusted BMD values (Z scores) of D-EMP women were higher than EMP women in both anatomic sites (P < 0.01), but did not differ from D-NMP women. In contrast to the other two groups, no statistically significant correlation was observed in D-EMP women between the BMD values of either anatomic area and the time elapsed since menopause. HbA(1c) values were positively correlated only to vertebral BMD values of the D-EMP group (P < 0.05). No correlation was observed between the BMD values and the duration of diabetes either in D-EMP or in D-NMP women. CONCLUSIONS Type 2 diabetes seems to positively affect the mineral density of the trabecular bone in women with premature menopause. The duration of diabetes does not appear to influence bone mass.