Mìžnarodnij Endokrinologìčnij Žurnal (Apr 2020)
25(ОН)D level, 10-year probability of major osteoporotic fractures, bone mineral density and quality, fat and lean mass in pre- and postmenopausal women
Abstract
Background. Postmenopausal osteoporosis is an issue of great concern as it results in an elevated risk of fractures with a further negative impact on the elderly women’s health. The osteoporosis may be diagnosed based on the low-energy fractures occurring with no major trauma, or based on the low bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA). The purpose of study is to examine 25(ОН)D level, 10-year probability of major osteoporotic fractures, bone mineral density and quality, fat and lean mass and to analyze their associations in the pre- and postmenopausal women. Materials and methods. Three hundred and two women aged 45–80 years (mean age — 61.3 ± 7.7 years) were examined and divided into 6 groups according to the pre- and postmenopausal period duration: group I — premenopausal women (n = 36; mean age — 50.1 ± 3.4 years); groups II–VI — postmenopausal women (n = 266; mean age — 62.8 ± 6.8 years). All the examined patients were subjected to bone mineral density measurement by the DXA on Prodigy system (GE Medical Systems, model 8743, 2005) according to the standard protocol. BMD and T-score of the lumbar spine, femoral neck and total skeleton were evaluated. Trabecular bone score of lumbar spine was measured by TBS iNsight (Med-Imaps, Pessac, France). Total 25(ОН)D was assessed by electrochemoluminescent method using Еlecsys 2010 analyzer (Roche Diagnostics, Germany) and Cobas test systems. The 10-year probability of major osteoporotic fractures and hip fractures was calculated by the Ukrainian FRAX model without DXA results considered. Total body fat and lean mass was assayed by the dual-energy X-ray absorptiometry (Prodigy, GE). Results. We found a significant association between the pre- and postmenopausal period duration and bone density and quality variables (trabecular bone score (F = 6.85; p < 0.001), BMD of lumbar spine (F = 5.53; p < 0.001), BMD of femoral neck (F = 10.25; p < 0.001), BMD of total skeleton (F = 12.28; p < 0.001)). Among 266 postmenopausal women examined, 90 (33.8 %) had osteoporosis diagnosed at the lumbar spine, 108 (40.6 %) had osteopenia, 68 (25.6 %) — normal bones; 47 (17.7 %) people had osteoporosis diagnosed at the femoral neck, 187 (70.3 %) women had osteopenia, 32 (12.0 %) had normal bones. The 10-year probability of major osteoporotic fractures significantly increased compared with a premenopausal age during the following postmenopausal stages: 5–9 years — 3.58 ± 1.97 and 6.72 ± 3.23, p < 0.0001; 10–14 years — 3.58 ± 1.97 and 6.90 ± 2.78, p < 0.0001; 15–19 years — 3.58 ± 1.97 and 7.19 ± 3.23, p < 0.0001; 20–24 years — 3.58 ± 1.97 and 8.03 ± 2.45, p < 0.0001. Vitamin D deficiency was observed in 39.7 % (n = 120) of cases, insufficiency — in 30.4 % (n = 92), 29.9 % of women had normal bones (n = 90). We didn’t register any seasonal or monthly impact as far as 25(ОН)D is concerned (F = 0.51; p = 0.89). The 25(ОН)D level had a negative correlation with body weight, body mass index, fat mass indices, and positive — with a 10-year probability of major osteoporotic fractures. Conclusions. The obtained results indicate a significant negative impact of pre- and postmenopause duration on bone mineral density and quality variability, and a positive one — on the 10-year probability of major osteoporotic fractures and hip fractures. For the postmenopausal women, obesity is a protective factor against bone loss and developing osteoporosis, which is likely due to the elevated adipocyte rate. According to the regression analysis, there is a confirmed negative correlation between body weight, body mass index, total fat mass and 25(ОН)D concentration in the blood serum. The above-mentioned fact requires elaboration of an adequate therapeutic approach when the vitamin D deficiency is associated with obesity.
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