Through the past decade of research, the correlation between depression and metabolic diseases has been noticed. More and more studies have confirmed that depression is comorbid with a variety of metabolic diseases, such as obesity, diabetes, metabolic syndrome and so on. Studies showed that the underlying mechanisms of both depression and metabolic diseases include chronic inflammatory state, which is significantly related to the severity. In addition, they also involve endocrine, immune systems. At present, the effects of clinical treatments of depression is limited. Therefore, exploring the co-disease mechanism of depression and metabolic diseases is helpful to find a new clinical therapeutic intervention strategy. Herein, focusing on the relationship between depression and metabolic diseases, this manuscript aims to provide an overview of the comorbidity of depression and metabolic.

IntroductionPolycystic ovary syndrome (PCOS) is one of the leading causes of female infertility, affecting around 5% of women of childbearing age in China. Vitamin D insufficiency is common in women with PCOS and is associated with lower live birth rates. However, evidence regarding the effectiveness of vitamin D supplementation in women with PCOS is inconclusive. This multicentre randomised, double-blinded, placebo-controlled trial aims to evaluate the effectiveness of vitamin D supplementation prior to in vitro fertilisation (IVF) on the live birth rate in women with PCOS.Methods and analysisWe plan to enrol women with PCOS scheduled for IVF. After informed consent, eligible participants will be randomised in a 1:1 ratio to receive oral capsules of 4000 IU vitamin D per day or placebo for around 12 weeks until the day of triggering. All IVF procedures will be carried out routinely in each centre. The primary outcome is live birth after the first embryo transfer. The primary analysis will be by intention-to-treat analysis. To demonstrate or refute that treatment with vitamin D results in a 10% higher live birth rate than treatment with placebo, we need to recruit 860 women (48% vs 38% difference, anticipating 10% loss to follow-up and non-compliance, significance level 0.05 and power 80%).Ethics and disseminationThis study has been approved by the Ethics Committee in Women’s Hospital of Zhejiang University on 2 March 2020 (reference number: IRB-20200035-R). All participants will provide written informed consent before randomisation. The results of the study will be submitted to scientific conferences and a peer-reviewed journal.Trial registration numberNCT04082650.

Background There is no definitive evidence about the suitable timing to transfer blastocysts formed and cryopreserved on day 6 (D6 blastocysts) in frozen-thawed embryo transfer (FET) cycles. This study aimed to investigate the suitable timing to transfer D6 blastocysts in FET cycles and to identify factors affecting clinical pregnancy rate (CPR) and early miscarriage rate (EMR) in FET cycles with blastocysts. Methods This retrospective cohort study included 1788 FET cycles with blastocysts. There were 518 cycles with D6 blastocysts, and 1270 cycles with blastocysts formed and cryopreserved on day 5 (D5 blastocysts) (D5 group). According to the blastocyst transfer timing, the cycles with D6 blastocysts were divided into cycles with D6 blastocysts transferred on day 5 (D6-on-D5 group, 103 cycles) and cycles with D6 blastocysts transferred on day 6 (D6-on-D6 group, 415 cycles). The chi-square test, independent t-test or Mann-Whitney test, and logistic regression analysis were used for data analysis. Results The CPR and implantation rate (IR) were significantly higher in the D6-on-D5 group than in the D6-on-D6 group (55.3% vs. 37.3%, 44.8% vs. 32.6%, P < 0.01). The CPR and IR were significantly higher in the D5 group than in the D6-on-D5 group (66.0% vs. 55.3%, 62.1% vs. 44.8%, P < 0.05), and the EMR was significantly lower in the D5 group than in the D6-on-D5 group (11.2% vs. 21.1%, P < 0.05). Logistic regression analysis demonstrated that transfer D6 blastocysts on day 5, instead of day 6, could significantly increase the CPR (odds ratio[OR]: 2.031, 95% confidence interval (CI): 1.296–3.182, P = 0.002). FET cycles with D6 blastocysts transferred on day 5 had a higher EMR than those with D5 blastocysts (OR: 2.165, 95% CI: 1.040–4.506, P = 0.039). Hormone replacement therapy (HRT) cycles exhibited a higher EMR than natural cycles (OR: 1.953, 95% CI: 1.254–3.043, P = 0.003), while no difference was observed in the CPR (P > 0.05). Conclusions These results indicate that the suitable timing to transfer D6 blastocysts in FET cycles may be day 5, and D6 blastocyst transfer on day 6 in FET cycles should be avoided. D6 blastocysts transfer and HRT cycles may be associated with a higher EMR.

OBJECTIVE: To investigate effects of vitamin .D(Vit.D) administration in patients with polycystic ovary syndrome(PCOS) DESIGN: Experimental animal study. MATERIALS AND METHODS: Forty female pre-pubertal mice were randomly divided into 4 groups: the control, PCOS, PCOS+low dose Vit.D and PCOS+high dose Vit.D groups(N¼10 per group). The PCOS mouse model was developed by 6mg/kg/day dehydroepiandrosterone(DHEA) administration with subcutaneously injections and high fat diet feeding. After 30 days, Vit.D was administrated by intraperitoneal injection in the following 40 days, 130ng/100g/week 1,25(OH)2D3 in low dose Vit.D group, and 1300ng/100g/week 1,25(OH)2D3 in high dose Vit.D group. Controls were injected with vehicle alone and fed with normal diet. At the end of the 70 days, blood samples were collected and the ovarian and liver tissues were taken.RESULTS: All the mice in PCOS+high dose Vit.D group died in two weeks after Vit.D administration. In the other three group, the weight of the PCOS mice was significantly higher than the weight of the controls before Vit.D administration( 31.10AE2.52, 31.76AE2.54 VS 28.82AE1.83g, PCOS group, PCOS+low dose Vit.D group VS control group, P¼0.022). However, at the end of the study, the weight of the mice in PCOS group was significantly higher than those in control group and PCOS+low dose Vit.D group (41.41AE3.90 VS 35.50AE2.50, 34.55AE2.31 g, P¼0.000). The serum 25(OH) D concentration was significantly higher in PCOS+low dose Vit.D group than in control group and PCOS group (99.29AE18.31 VS 19.55AE4.10,18.04AE6.51 ng/ml,P¼0.000). The testosterone levels in PCOS group were significantly higher than those of control group and PCOS+low dose Vit.D group (1.27AE0.27 VS 0.95AE0.15 ,0.90AE0.17 ng/ml, P¼0.001). Furthermore, total cholesterol levels in control group were lower than in PCOS and PCOS+low dose Vit.D group (3.08AE0.44 VS 4.55AE0.47, 4.42AE0.45mmol/L, P¼0.011). Moreover, the ratio of liver weight to body weight was significantly different among the three groups (0.045AE0.0046 VS 0.036AE0.0043 VS 0.041AE0.0031, control group VS PCOS group VS PCOS+low dose Vit.D group, P¼0.000). CONCLUSIONS: Our results indicate that low dose Vit.D has positive effects on the hormonal changes and obesity observed in PCOS, maybe through liver metabolism regulation, and high dose Vit.D administration may be harmful.