Objective To explore the association between 25-hydroxyvitamin D (25OHD) level and risk of the onset of metabolic syndrome (MS) in people in Chengdu. Methods In total, 474 participants were selected randomly by cluster sampling from one urban district and two rural villages in Longquanyi district of Chengdu. The data of sociodemographic information, lifestyle and family history were collected by questionnaires. Binary logistic regression was performed to assess the relationship between baseline 25OHD level and incident of MS, while multiple linear regression was conducted to analyze the relationship between baseline 25OHD level and insulin resistance. Results Four hundred seventy-four people were enrolled in the cohort study, 39 of them developed MS, with the incidences of 20.8 events per 1 000 person years. Among women, low 25OHD status was significantly associated with the risk of developing MS (OR=4.29, 95%CI 1.05 to 29.50, P=0.044) after adjustment for multiple potential confounders. In a multiple linear regression analysis, low 25OHD level of baseline was independently associated with the increased HOMA-IR over a 4-year period among Chengdu individuals (P<0.05) and was independently related to the decreased ISIcomp over a 4-year period in female (P<0.05). Conclusions The current prospective study suggests that low 25OHD level may contribute to increase insulin resistance in Chengdu population. Furthermore, low 25OHD level may increase the risk of MS among women in Chengdu.
Objective The research was performed to investigate the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and the risk of adverse pregnancy outcomes. Methods We enrolled females who were in the first trimester of pregnancy and had arranged antenatal care at the Weifang Maternal and Child Health Hospital between January 2017 and December 2019. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used to detect serum concentrations of 25(OH)D. The health status of the expectant mothers and fetuses and the incidence of adverse pregnancy outcomes of newborns were monitored through the outpatient, prenatal, and delivery stages in the hospital. Results An initial total of 6 770 females were signed up, while 4 997 females were eventually included. The median value of 25(OH)D concentration was 15.40 ng/mL, and the incidence rate of vitamin D deficiency [25(OH)D < 20 ng/mL] was 71.26%. The occurrence rates of gestational diabetes mellitus (GDM), pre-eclampsia, premature rupture of membranes (PROM), oligohydramnios, polyhydramnios, cesarean delivery, spontaneous abortion or stillborn fetus, fetal malformation, premature delivery, fetal macrosomia, low birth weight, small for gestational age infant, and asphyxia of newborn were 28.31%, 2.27%, 23.47%, 12.68%, 0.51%, 45.71%, 1.44%, 0.93%, 9.26%, 5.05%, 11.68%, 2.68%, 3.18%, and 1.16%, respectively. After adjusting for age, parity, season, pre-existing hypertension, pre-existing diabetes, and vitamin D supplementation, no relationship between 25(OH)D levels and adverse pregnancy outcomes was found (P>0.05). Conclusions Levels of 25(OH)D do not affect the risk of adverse pregnancy outcomes in females during the first trimester of pregnancy.