Investigation Of Factors, Dongcheng District, Han Nationality Postmenopausal Women Vitamin D Nutritional Status And Influence

Background and purpose:Osteoporosis is a kind of general bone metabolic disease. Primary osteoporosis is bone degeneration that caused by menostasis or aging. The disease incidence is rising in our country. Vitamin D deficiency is one of the most important risk factors of primary osteoporosis and is very common. There are lots of factors that may influence vitamin D levels. More studies have been focused on the investigation of vitamin D status in postmenopausal women and the influence factors. But there are still lots of problems in recent studies, including lack of recent studies from Chinese, small sample size, and the inconsistent conclusions about relationships between vitamin D states and PTH level, BMD. We conduct this study in order to assess the vitamin D status of the Han group postmenopausal women in Dongcheng District, Beijing during May and June, and to examine its relationship with serum parathyroid hormone (PTH) and biochemical markers of bone turnover. In addition, the determinants of summier serum25-hydroxyvitamin D levels in these women were investigated.We investigated their life style(diet, sport status and so on), the codition of their bone health, medical history, etc. We intended to get an overview of the circumstances of the Vitamin D defeciency in postmenopausal women in this district. Furthermore, we will analyses the conspicuous and potentional factors that may influence the level of Vitamin D and bone health. We hope to provide some useful information for the precaution and therapy.Methods:This is A cross-sectional observational study seting in Beijing,China.614healthy Han group free-living postmenopausal women, aged between45and81in Dongcheng District, were randomly selected from participants of a population-based study. BMD was measured at the lumbar spine and hip by dual X-ray absorption-metry. Fasting serums were collected and Serum25(OH)D, parathyroid hormone (PTH), calcium, phosphorus, alkaline phosphatases, glucose and creatinine were measured. The analysis for25(OH) D and parathyroid hormone (PTH) is by enzyme immunoassays. PTH was logarithmically transformed (LnPTH). Later we apply SPSS11.0to perform the the statistics analysis.Linear regression models were developed to determine the association between serum25(OH)D and BMD at different sites. Also the association between other observed factors. Other methods including ANOVA, chisquare, independent t-test and so on were also performed.Results:In614women,mean25(OH)D level was12.49±5.43ng/ml;92.3%(n=567) had25(OH)D<20ng/ml and7%(n=43) had25(OH)D between20and30ng/ml,0.65%(n=4) had25(OH)D≥30ng/ml. In614objects, mean PTH was 47.47±20.24pg/ml, range from6.9to142pg/ml. According to the T score of L2-L4BMD, we divide the591objects into3groups.9.8%(n=58) in the osteoporosis group,37.1%(n=219) are osteopenic,53.1%(n=314) have normal L2-L4BMD.25(OH) D correlated inversely with PTH (r=-0.211, p<0.01). In the multivariate analyses, no association was found between25(OH) D level and BMD at any of the skeletal sites after adjusting for age, duration of menopause, body mass index, calcium, and LnPTH. BMD was associated inversely with LnPTH only in femoral neck and L2-L4but not in the other sites. This study nearly shows no association between25(OH)D and BMD in free living Dongcheng District postmenopausal women.Conclusion:1、A high proportion of postmenopausal women living in Dongcheng District, Beijing had low vitamin D status(<20ng/ml) even during summertime. The propotion of Vitamin D deficiency is92.3%, and vitamin D insufficiency is7%.2、25(OH) D correlated inversely with PTH (r=-0.211, p<0.01)and Calcium (r=0.09, P<0.05).3、According to the T score of L2-L4BMD, we divide the591objects into3groups,9.8%(n=58) in the osteoporosis group,37.1%(n=219) are osteopenic,53.1%(n=314) have normal L2-L4BMD. According to the T score of femoral neck BMD, we divide the597objects into3groups,5.3%(n=31) in the osteoporosis group,48.5%(n=290) are osteopenic,46.2%(n=276) have normal femoral neck BMD.4、There was negative correlation between Femoral neck BMD and PTH level in total group、osteopenic group and osteopenic+osteoporosis group women respectively.(r=-0.189, P<0.01; r=-0.15, P<0.05; r=-0.15,P<0.05)。 L2-L4and Femoral neck BMDcorrelated inversely with LnPTH, L2-L4(r=-0.12, P<0.01), Femoral neck (r=-0.19, P<0.01).5、Influencing factors of Vitamin D level are:activities and exercise。Increasing activities is an important factor that could help maintain adequate vitamin D levels during summer in these women.6、Height、weight、BMI and the age of menopause are factors that correlated positively with BMD, age、duration of menopause and the age of menarche are factors that correlated negatively with BMD. The level of activities correlated positively with BMD.