High bone mineral density among perimenopausal women

Abstract

Studies regarding high bone mineral density (HBMD) are few. In the population-based Kuopio Osteoporosis Risk Factor and Prevention Study, BMDs of women were measured from 1990-1991 and 1995-1997. The mean age of the 1,873 women studied was 53.5 years at baseline (range 48.0-59.6). In all, 248 women were excluded because of BMD measurement errors or artifacts: 41 from the HBMD group (20.6%) and 207 (12.4%) from the control group. The final study group consisted of 1,551 women, 168 in the HBMD group (baseline lumbar BMD >1.23 g/cm2; femoral BMD >1.01 g/cm2, and 5-year follow-up lumbar BMD >1.21 g/cm2; femoral BMD >0.98 g/cm2, respectively) and 1,383 in the control group. The predictors for HBMD in the multivariate regression analysis were as follows: hormone therapy (HT) during the follow-up from 0.5 to 2 years and for over 2 years (OR 2.06, CI: 1.11-3.81 and OR 2.16, CI 1.43-3.26) and being overweight (BMI from 25 kg/m2 to 30 kg/m2, and BMI >30 kg/m2) at baseline (OR 2.84, CI: 1.82-4.42; OR 5.94, CI: 3.47-10.16, respectively). High physical activity while 11-18 years of age was associated with HBMD (OR 1.69, CI: 1.17-2.45). Parity predicted HBMD so that after one to two births the OR was 2.66 (CI: 1.03-6.88) and 3.03 (CI: 1.16-7.90) after three or more births. Menopause was negatively associated with HBMD (OR 0.57, CI 0.38-0.85). There were more premenopausal women in the HBMD group (53.9 vs. 34.6%, P <0.001). The HBMD group showed fewer fractures. In conclusion, being overweight, parity, HT use, premenopause and high physical activity in adolescence seemed to be predictors for persistently high BMD in early postmenopausal women. We suggest that the fracture risk is low in these women, and thus they are neither primary candidates for BMD screening nor for osteoporosis medication.