Factors influencing bone mineral density in postpartum women

Abstract

Background: Osteopenia is a common condition. Therefore, identification of groups for prevention of osteoporosis and restoration of bone mineral density (BMD) remains relevant.
 Aim: to assess the factors contributing to development of osteopenia in puerperas.
 Methods: prospective cross-sectional study. We examined 112 patients aged 20-35, 3-5 days after delivery. To assess possible factors for BMD decrease, we analyzed medical history, lifestyle, nutrition, anthropometric data, obstetric and gynecological history, and pregnancy course. We also assessed serum levels of 25-hydroxycalciferol (25-OH-D) and PTH. BMD was measured by dual energy x-ray osteodensitometry. We considered Z-score from -1 to -2.5SD as osteopenia, below -2.5 SD-as osteoporosis.
 Results: based on Z-score values, two groups were formed: 1 (n=70) - puerperas with osteopenia, 2 (n=42) - puerperas with normal BMD. In the first group, osteopenia in the distal radius was observed in 48%, in the lumbar spine in 16% and in the proximal femur in 36%. Influence of the following possible factors in group 1 was established: BMI in 15-20 years ≤ 18 kg/m2 (p<0.013), BMI ≥ 25 kg/m2 (p<0.018), 25-OH-D less than 25 ng / ml (p < 0.0018), calcium intake less than 800 mg/day (p<0.041). Menstrual disorders (p<0.052) and preeclapsia (p < 0.042) affected lumbar spine BMD. In group 1, vitamin D deficiency was detected in 82% of women, 18% showed vitamin D insufficiency; in group 2, vitamin D deficiency was found in 16%, deficiency in 70%, in 14% vitamin D was normal. In women with a combination of factors such as BMI≤ 18 kg/m; calcium intake lower than 800 mg/day, menstrual cycle disorders, vitamin D deficiency - osteopenia in the distal radius occured 11 times more often (OR=11,47059; CI 95%=[4,0326; 32,627]).
 Conclusion: most significant impact on BMD decrease in puerperas can be expected if patient has the following risk factors: BMI≤18 kg/m2; 25-OH- D<25 ng/ml ; nutrition with calcium intake <800 mg per day, preeclampsia. Combination of these factors may increase the risk of osteopenia in the distal radius.