Causal association between telomere length and female reproductive endocrine diseases: a univariable and multivariable Mendelian randomization analysis.

BACKGROUND: The relationship between leukocyte telomere length (LTL) and female reproductive endocrine diseases has gained significant attention and research interest in recent years. However, there is still limited understanding of the exact impacts of LTL on these diseases. Therefore, the primary objective of this study was to investigate the genetic causal association between LTL and female reproductive endocrine diseases by employing Mendelian randomization (MR) analysis. METHODS: Instruments for assessing genetic variation associated with exposure and outcome were derived from summary data of published genome-wide association studies (GWAS). Inverse-variance weighted (IVW) was utilized as the main analysis method to investigate the causal relationship between LTL and female reproductive endocrine diseases. The exposure data were obtained from the UK Biobanks GWAS dataset, comprising 472,174 participants of European ancestry. The outcome data were acquired from the FinnGen consortium, including abnormal uterine bleeding (menorrhagia and oligomenorrhea), endometriosis (ovarian endometrioma and adenomyosis), infertility, polycystic ovary syndrome (PCOS), premature ovarian insufficiency (POI) and premenstrual syndrome (PMS). Furthermore, to account for potential confounding factors such as smoking, alcohol consumption, insomnia, body mass index (BMI) and a history of pelvic inflammatory disease (PID), multivariable MR (MVMR) analysis was also conducted. Lastly, a series of pleiotropy tests and sensitivity analyses were performed to ensure the reliability and robustness of our findings. P < 0.0063 was considered to indicate statistically significant causality following Bonferroni correction. RESULTS: Our univariable MR analysis demonstrated that longer LTL was causally associated with an increased risk of menorrhagia (IVW: odds ratio [OR]: 1.1803; 95% confidence interval [CI]: 1.0880-1.2804; P = 0.0001) and ovarian endometrioma (IVW: OR: 1.2946; 95%CI: 1.0970-1.5278; P = 0.0022) at the Bonferroni significance level. However, no significant correlation was observed between LTL and oligomenorrhea (IVW: OR: 1.0124; 95%CI: 0.7350-1.3946; P = 0.9398), adenomyosis (IVW: OR: 1.1978; 95%CI: 0.9983-1.4372; P = 0.0522), infertility (IVW: OR: 1.0735; 95%CI: 0.9671-1.1915; P = 0.1828), PCOS (IVW: OR: 1.0633; 95%CI: 0.7919-1.4278; P = 0.6829), POI (IVW: OR: 0.8971; 95%CI: 0.5644-1.4257; P = 0.6459) or PMS (IVW: OR: 0.7749; 95%CI: 0.4137-1.4513; P = 0.4256). Reverse MR analysis indicated that female reproductive endocrine diseases have no causal effect on LTL. MVMR analysis suggested that the causal effect of LTL on menorrhagia and ovarian endometrioma remained significant after accounting for smoking, alcohol consumption, insomnia, BMI and a history of PID. Pleiotropic and sensitivity analyses also showed robustness of our results. CONCLUSION: The results of our bidirectional two-sample MR analysis revealed that genetically predicted longer LTL significantly increased the risk of menorrhagia and ovarian endometrioma, which is consistent with the findings from MVMR studies. However, we did not notice any significant effects of LTL on oligomenorrhea, adenomyosis, infertility, PCOS, POI or PMS. Additionally, reproductive endocrine disorders were found to have no impact on LTL. To enhance our understanding of the effect and underlying mechanism of LTL on female reproductive endocrine diseases, further large-scale studies are warranted in the future.

Association between depression and infertility risk among American women aged 18-45 years: the mediating effect of the NHHR.

BACKGROUND/OBJECTIVE: Depression and infertility are major medical and social problems. The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) serves as an innovative and reliable lipid marker for cardiovascular disease risk assessment. Previous research has indicated a potential correlation among lipid metabolism, depression, and infertility. Nonetheless, the exact involvement of lipid metabolism in modulating the pathological mechanisms associated with depression-induced infertility remains to be fully elucidated. The aim of this study was to explore the connection between depression and infertility and to assess whether the NHHR mediates this association. METHODS: A cross-sectional analysis was performed utilizing data from there cycles (2013-2018) of the National Health and Nutrition Examination Survey (NHANES) database. Female infertility was assessed according to the responses to the RHQ074 question in the reproductive health questionnaire module. Depression states were evaluated using the Patient Health Questionnaire-9 and classified into three grades based on the total scores: no depression (0-4 points), minimal-to-mild depression (5-9 points) and moderate-to-severe depression (10 or more points). The NHHR was calculated from laboratory cholesterol test results. Baseline population characteristics were compared, and subgroup analyses were carried out based on the stratification of age and body mass index (BMI). Weighted multivariable logistic regression and linear regression models, with adjustments for various covariables, were employed to examine the associations among depression, infertility and the NHHR. Finally, mediation analysis was utilized to explore the NHHR's potential mediating role in depression states and female infertility. RESULTS: Within this cross-sectional study, 2,668 women aged 18 to 45 years residing in the United States were recruited, 305 (11.43%) of whom experienced infertility. The study revealed a markedly higher prevalence of depression (P = 0.040) and elevated NHHR (P < 0.001) among infertile women compared to the control cohort. Furthermore, moderate-to-severe depression states independently correlated with increased infertility risk, irrespective of adjustments for various covariables. Subgroup analysis indicated a positive association between depression and infertility risk within certain age categories, although no such relationship was observed within subgroups stratified by BMI. The findings from the weighted logistic regression analysis demonstrated that the elevated NHHR is positively associated with heightened infertility risk. Additionally, the weighted linear regression analysis indicated that moderate-to-severe depression is positively linked to the NHHR levels as well. Finally, the association between depression states and female infertility was partially mediated by the NHHR, with the mediation proportion estimated at 6.57%. CONCLUSION: In the United States, depression is strongly correlated with an increased likelihood of infertility among women of childbearing age, with evidence suggesting that this relationship is mediated by the NHHR. Subsequent research efforts should further explore the underlying mechanisms connecting depression and infertility.

Protective effect of unsaturated fatty acids on cognitive impairment in CKD patients: Results from the National Health and Nutrition Examination Survey (2011-2014).

BACKGROUND: It is still unknown whether unsaturated fatty acids (UFA) have the same effect on preventing cognitive impairment in chronic kidney disease (CKD) patients as in healthy people. OBJECTIVE: To investigate the protective effect of dietary UFA intake and proportion on cognitive impairment in patients with CKD. METHODS: We extracted data from the National Health and Nutrition Examination Survey (NHANES, 2011-2014) on participants with a previous diagnosis of CKD and at least one complete cognitive assessment (Consortium to Establish a Registry for Alzheimer's Disease test, Animal Fluency Test and Digit Symbol Substitution Test). We used the lower quartile of the total scores of these three tests as the cut-off point, and divided the participants into two groups of normal cognitive performance and low cognitive performance to extract participants' intake of various UFA from the NHANES dietary module.