Identification of two lipid phosphatases that regulate sphingosine-1-phosphate cellular uptake and recycling

Sphingosine-1-phosphate (S1P) is a sphingolipid metabolite that serves as a potent extracellular signaling molecule. Metabolic regulation of extracellular S1P levels impacts key cellular activities through altered S1P receptor signaling. Although the pathway through which S1P is degraded within the cell and thereby eliminated from reuse has been previously described, the mechanism used for S1P cellular uptake and the subsequent recycling of its sphingoid base into the sphingolipid synthesis pathway is not completely understood. To identify the genes within this S1P uptake and recycling pathway, we performed a genome-wide CRISPR/Cas9 KO screen using a positive-selection scheme with Shiga toxin, which binds a cell-surface glycosphingolipid receptor, globotriaosylceramide (Gb3), and causes lethality upon internalization. The screen was performed in HeLa cells with their sphingolipid de novo pathway disabled so that Gb3 cell-surface expression was dependent on salvage of the sphingoid base of S1P taken up from the medium. The screen identified a suite of genes necessary for S1P uptake and the recycling of its sphingoid base to synthesize Gb3, including two lipid phosphatases, PLPP3 (phospholipid phosphatase 3) and SGPP1 (S1P phosphatase 1). The results delineate a pathway in which plasma membrane–bound PLPP3 dephosphorylates extracellular S1P to sphingosine, which then enters cells and is rephosphorylated to S1P by the sphingosine kinases. This rephosphorylation step is important to regenerate intracellular S1P as a branch-point substrate that can be routed either for dephosphorylation to salvage sphingosine for recycling into complex sphingolipid synthesis or for degradation to remove it from the sphingolipid synthesis pathway.     

Tracking the Stability of Clinically Relevant Blood Plasma Proteins with Delta-S-Cys-Albumin—A Dilute-and-Shoot LC/MS-Based Marker of Specimen Exposure to Thawed Conditions

Biomolecular integrity can be compromised when blood plasma/serum (P/S) specimens are improperly handled. Compromised analytes can subsequently produce erroneous results—without any indication of having done so. We recently introduced an LC/MS-based marker of P/S exposure to thawed conditions called ΔS-Cys-Albumin which, aided by an established rate law, quantitatively tracks exposure of P/S to temperatures greater than their freezing point of ?30 °C. The purposes of this study were to (1) evaluate ΔS-Cys-Albumin baseline values in gastrointestinal cancer patients and cancer-free control donors, (2) empirically assess the kinetic profiles of ΔS-Cys-Albumin at 23 °C, 4 °C, and ?20 °C, and (3) empirically link ΔS-Cys-Albumin to the stability of clinically relevant proteins. ΔS-Cys-Albumin was measured at ≥ 9 different time points per exposure temperature in serum and K₂EDTA plasma samples from 24 separate donors in aliquots kept separately at 23 °C, 4 °C, and ?20 °C. Twenty-one clinically relevant plasma proteins were measured at four time points per temperature via a multiplexed immunoassay on the Luminex platform. Protein stability was assessed by mixed effects models. Coordinated shifts in stability between ΔS-Cys-Albumin and the unstable proteins were documented by repeated measures and Pearson correlations. Plasma ΔS-Cys-Albumin dropped from approximately 20% to under 5% within 96 h at 23 °C, 28 days at 4 °C, and 65 days at ?20 °C. On average, 22% of the 21 proteins significantly changed in apparent concentration at each exposure temperature (p < 0.0008 with >10% shift). A linear inverse relationship was found between the percentage of proteins destabilized and ΔS-Cys-Albumin (r = ?0.61; p < 0.0001)—regardless of the specific time/temperature of exposure. ΔS-Cys-Albumin tracks cumulative thawed-state exposure. These results now enable ΔS-Cys-Albumin to approximate the percentage of clinically relevant proteins that have been compromised by incidental plasma exposure to thawed-state conditions.     

Cardiovascular Disease in Women Update: Ischemia,Diagnostic Testing,and Menopause Hormone Therapy

ObjectiveThis update will address 3 areas specifically that are essential to improving cardiovascular outcomes for women.MethodsThe current literature has been reviewed and three important areas of cardiovascular care in women are highlighted. First is that even though women and men share many traditional risk factors for ischemic heart disease, several of these risk factors affect women disproportionately when it comes to CVD risk and events. There are also unique sex-specific risk factors for women and risk factors that are more common in women than in men. Adverse outcomes of pregnancy and hypertensive disorders of pregnancy are associated with an increased long-term risk of CVD and events. At menopause, cardiovascular risks increase, and lipids become unfavorable. Second is that diagnostic testing for ischemic heart disease presents different specificities and sensitivities between men and women and testing should be determined according to what is best and safest for women. Third is that currently, menopause hormone therapy is approved by the U.S. Food and Drug Administration for the treatment of vasomotor and genitourinary symptoms, prevention of osteoporosis, and estrogen replacement in the setting of surgical menopause, hypogonadism, or premature ovarian insufficiency. It is not recommended for the primary or secondary prevention of CVD and not recommended for women with high atherosclerotic CVD risk.ResultsCardiovascular disease (CVD) remains the most common cause of death in women in the United States despite tremendous improvements in cardiovascular care for men and women. The prevention of CVD in women with early detection and implementation of preventive therapies before atherosclerotic CVD develops is critical to improving outcomes for women.     

Preconception Vitamin D Level and In Vitro Fertilization: Pregnancy Outcome

ObjectiveVitamin D deficiency impairs female fertility and the success of in vitro fertilization (IVF). The recommended serum 25-hydroxyvitamin D (25(OH)D) level in IVF-conceived pregnancies is still debated. We aimed to explore the relationship of the preconception serum 25(OH)D level with pregnancy outcome following IVF treatment. We also explored the utility of the currently recommended serum 25(OH)D cutoff of ≥50 nmol/L for women undergoing IVF therapy.MethodsRetrospective cohort of women who had undergone IVF therapy. Of the women who started IVF therapy (n = 354), 218 completed the study. They were divided into 2 groups: (1) women who achieved a successful pregnancy (pregnant group, n = 160) and (2) those who did not achieve a successful pregnancy (nonpregnant group, n = 58). Preconception serum samples were analyzed for reproductive hormones, fasting glucose, insulin, and 25(OH)D levels.ResultsOverall, the median (interquartile range) age, body mass index, and hemoglobin A1c level were 32 (6) years, 25.7 (7.4) kg/m², and 5.2% (0.6%), respectively. The 25(OH)D level was significantly higher at preconception in the pregnant group (56.4 [21.4] vs 47.9 [29.16] for nonpregnant, P = .001). The preconception 25(OH)D level was a significant predictor of IVF outcome (B = 0.04; 95% CI, 1.01-1.06; P = .001), with greater IVF success associated with a serum 25(OH)D level of ≥50 nmol/L (odds ratio, 0.46; P = .01).ConclusionPreconception 25(OH)D sufficiency (≥50 nmol/L) is associated with successful pregnancy outcome following IVF therapy.     

Bioactive lipid mediators in plasma are predictors of preeclampsia irrespective of aspirin therapy

There are few early biomarkers to identify pregnancies at risk of preeclampsia (PE) and abnormal placental function. In this cross-sectional study, we utilized targeted ultra-performance liquid chromatography-ESI MS/MS and a linear regression model to identify specific bioactive lipids that serve as early predictors of PE. Plasma samples were collected from 57 pregnant women prior to 24-weeks of gestation with outcomes of either PE (n = 26) or uncomplicated term pregnancies (n = 31), and the profiles of eicosanoids and sphingolipids were evaluated. Significant differences were revealed in the eicosanoid, (±)11,12 DHET, as well as multiple classes of sphingolipids; ceramides, ceramide-1-phosphate, sphingomyelin, and monohexosylceramides; all of which were associated with the subsequent development of PE regardless of aspirin therapy. Profiles of these bioactive lipids were found to vary based on self-designated race. Additional analyses demonstrated that PE patients can be stratified based on the lipid profile as to PE with a preterm birth linked to significant differences in the levels of 12-HETE, 15-HETE, and resolvin D1. Furthermore, subjects referred to a high-risk OB/GYN clinic had higher levels of 20-HETE, arachidonic acid, and Resolvin D1 versus subjects recruited from a routine, general OB/GYN clinic. Overall, this study shows that quantitative changes in plasma bioactive lipids detected by ultra-performance liquid chromatography-ESI-MS/MS can serve as an early predictor of PE and stratify pregnant people for PE type and risk.     

A high-throughput platform for the rapid screening of vitamin D status by direct infusion-MS/MS

Vitamin D is an important fat-soluble prohormone with pleiotropic effects on human health, such as immunomodulation of the innate and adaptive immune system. There is an unmet clinical need for a rapid screening platform for 25-hydroxyvitamin D (25OH-D) determination without chromatographic separation that offers better precision and accuracy than immunoassays. Here, we introduce a high-throughput method for assessing vitamin D status from blood specimens based on direct infusion-MS/MS (DI-MS/MS) following click derivatization using 2-nitrosopyridine. We developed an optimized liquid-phase extraction protocol to minimize ion suppression when directly infusing serum or plasma extracts via a capillary electrophoresis system for quantitative determination of 25OH-D. Acceptable reproducibility (mean coefficient of variation = 10.9%, n = 412), recovery (mean = 102% at 15, 30, and 45 nmol/l), and linearity (R² > 0.998) were achieved for 25OH-D with lower detection limits (limit of detection ～1.2 nmol/l, S/N ～ 3), greater throughput (～3 min/sample), and less bias than a commercial chemiluminescence immunoassay prone to batch effects. There was mutual agreement in 25OH-D concentrations from reference blood samples measured by DI-MS/MS as compared with LC-MS/MS (mean bias = 7.8%, n = 18). We also demonstrate that this method could reduce immunoassay misclassification of vitamin D deficiency in a cohort of critically ill children (n = 30). In conclusion, DI-MS/MS offers a viable alternative to LC-MS/MS for assessment of vitamin D status in support of large-scale studies in nutritional epidemiology as well as clinical trials to rapidly screen individual patients who may benefit from vitamin D supplementation.     

Postpartum Levothyroxine Adjustment and Its Impact Factors in Women With Hypothyroidism in Pregnancy

ObjectiveWomen with hypothyroidism need to increase exogenous thyroid hormone levels during pregnancy to reduce adverse outcomes. Few studies have reported the effect of gestational levothyroxine (LT4) variations on postpartum LT4 treatment.MethodsWomen were classified as having subclinical hypothyroidism (SCH) (n = 101), overt hypothyroidism (OH) caused by autoimmune thyroiditis (AIT-OH), OH following thyroidectomy for benign thyroid disease (BA-OH) (n = 66), and OH after surgery for papillary thyroid cancer (PTC-OH) (n = 46). Thyroid function was monitored, and LT4 therapy was adjusted accordingly.ResultsAfter delivery, all women with SCH stopped LT4 treatment, and 57.4% of them restarted LT4 treatment in the following 1 year, independently of the gestational LT4 variations. Among patients with OH, after adjusted by gestational body weight, 49.1% of them had LT4 doses less than the prepregnancy dose (baseline) in late pregnancy, leading to LT4 reduction in postpartum. The LT4 dose was reduced to approximately 50% baseline for women with AIT-OH and BA-OH and reduced by 27% for women with PTC-OH. The reduction reasons for AIT-OH and BA-OH were thyroid-stimulating hormone levels of <2.5 mU/L during pregnancy and postpartum thyrotoxicosis occurrence (39.4%), and for PTC-OH, the reason was thyroid-stimulating hormone overinhibition (<1.0 mU/L) before delivery.ConclusionFor patients with SCH, postpartum LT4 treatment could initially be suspended. For women with OH, if the LT4 dose in late pregnancy was less than baseline, a prepregnancy dose reduced by 50%, 50%, and 27% should be applied after delivery for women with AIT-OH, BA-OH, and PTC-OH, respectively.     

The Impact of COVID-19 Viral Infection on the Hypothalamic-Pituitary-Adrenal Axis

ObjectiveTo study the adrenocortical response to an acute coronavirus disease-2019 (COVID-19) infection.MethodsMorning plasma cortisol, adrenocorticotropic hormone (ACTH), and dehydroepiandrosterone sulfate levels were measured in 28 consecutive patients with COVID-19 (16 men, 12 women, median age 45.5 years, range 25-69 years) on day 1 to 2 of hospital admission. These tests were repeated twice in 20 patients and thrice in 15 patients on different days. The hormone levels were correlated with severity of the disease.ResultsThe median morning cortisol level was 196 (31-587) nmol/L. It was <100 nmol/L in 8 patients (28.6%), <200 nmol/L in 14 patients (50%), and <300 nmol/L in 18 patients (64.3%). The corresponding ACTH values had a median of 18.5 ng/L (range 4-38 ng/L), and the ACTH level was <10 ng/L in 7 patients (26.9%), <20 ng/L in 17 patients (60.7%), and <30 ng/L in 23 patients (82.1%). The repeated testing on different days showed a similar pattern. Overall, if a cutoff level of <300 nmol/L is considered abnormal in the setting of acute disease, 9 patients (32%) had cortisol levels below this limit, regardless of whether the test was done only once (3 patients) or 3 times (6 patients). When the disease was more severe, the patients had lower cortisol and ACTH levels, suggesting a direct link between the COVID-19 infection and impaired glucocorticoid response.ConclusionUnexpectedly, the adrenocortical response in patients with COVID-19 infection was impaired, and a significant percentage of the patients had plasma cortisol and ACTH levels consistent with central adrenal insufficiency.     

A simple,highly sensitive,and facile method to quantify ceramide at the plasma membrane

The role of ceramide in biological functions is typically based on the elevation of cellular ceramide, measured by LC-MS in the total cell lysate. However, it has become increasingly appreciated that ceramide in different subcellular organelles regulates specific functions. In the plasma membrane, changes in ceramide levels might represent a small percentage of the total cellular ceramide, evading MS detection but playing a critical role in cell signaling. Importantly, there are currently no efficient techniques to quantify ceramide in the plasma membrane. Here, we developed a method to measure the mass of ceramide in the plasma membrane using a short protocol that is based on the hydrolysis of plasma membrane ceramide into sphingosine by the action of exogenously applied bacterial recombinant neutral ceramidase. Plasma membrane ceramide content can then be determined by measuring the newly generated sphingosine at a stoichiometry of 1:1. A key step of this protocol is the chemical fixation of cells to block cellular sphingolipid metabolism, especially of sphingosine to sphingosine 1-phosphate. We confirmed that chemical fixation does not disrupt the lipid composition at the plasma membrane, which remains intact during the time of the assay. We illustrate the power of the approach by applying this protocol to interrogate the effects of the chemotherapeutic compound doxorubicin. Here we distinguished two pools of ceramide, depending on the doxorubicin concentration, consolidating different reports. In summary, we have developed the first approach to quantify ceramide in the plasma membrane, allowing the study of new avenues in sphingolipid compartmentalization and function.     

Direct Proteomic Detection and Prioritization of 19 Onchocerciasis Biomarker Candidates in Humans

Onchocerca volvulus, the causative agent of onchocerciasis, infects over 20 million people and can cause severe dermatitis and ocular conditions including blindness. Current treatments employed in mass drug administration programs do not kill adult female worms, and common diagnostic tests cannot reliably assess viability of adult worms. There is an urgent need for better diagnostic tests to facilitate monitoring the efficacy of new treatments and disease elimination efforts. Here, eight plasma samples collected from individuals infected with O. volvulus and seven from uninfected individuals were analyzed by MS/MS spectrometry to directly identify O. volvulus proteins present in infected but absent in uninfected control samples. This direct proteomic approach for biomarker discovery had not been previously employed for onchocerciasis. Among all detected proteins, 19 biomarker candidates were supported by two or more unique peptides, identified in the plasma of at least three O. volvulus-infected human samples and absent in all control samples. Comprehensive analysis and ranking of these candidates included detailed functional annotation and a review of RNA-seq gene expression profiles. Isotope-labeled standard peptides were run in parallel and validated MS/MS peptide identifications for 15 peptides from 11 of the 19 proteins, and two infected urine and one uninfected urine sample was used for additional validation. A major antigen/OVOC11613 was identified as the most promising candidate with eight unique peptides across five plasma samples and one urine sample. Additional strong candidates included OVOC1523/ATP synthase, OVOC247/laminin and OVOC11626/PLK5, and along with OVOC11613, and were also detected in urine samples from onchocerciasis patients. This study has identified a promising novel set of proteins that will be carried forward to develop assays that can be used for diagnosis of O. volvulus infections and for monitoring treatment efficacy.     

Cytochrome P450-soluble epoxide hydrolase derived linoleic acid oxylipins and cognitive performance in type 2 diabetes

Type 2 diabetes mellitus (T2DM) increases the risk of cognitive decline and dementia. Disruptions in the cytochrome P450-soluble epoxide hydrolase (CYP450-sEH) pathway have been reported in T2DM, obesity and cognitive impairment. We examine linoleic acid (LA)-derived CYP450-sEH oxylipins and cognition in T2DM and explore potential differences between obese and nonobese individuals. The study included 51 obese and 57 nonobese participants (mean age 63.0 ± 9.9, 49% women) with T2DM. Executive function was assessed using the Stroop Color-Word Interference Test, FAS-Verbal Fluency Test, Digit Symbol Substitution Test, and Trails Making Test-Part B. Verbal memory was assessed using the California Verbal Learning Test, second Edition. Four LA-derived oxylipins were analyzed by ultra-high-pressure–LC/MS, and the 12,13-dihydroxyoctadecamonoenoic acid (12,13-DiHOME) considered the main species of interest. Models controlled for age, sex, BMI, glycosylated hemoglobin A1c, diabetes duration, depression, hypertension, and education. The sEH-derived 12,13-DiHOME was associated with poorer executive function scores (F_1,98 = 7.513, P = 0.007). The CYP450-derived 12(13)-epoxyoctadecamonoenoic acid (12(13)-EpOME) was associated with poorer executive function and verbal memory scores (F_1,98 = 7.222, P = 0.008 and F_1,98 = 4.621, P = 0.034, respectively). There were interactions between obesity and the 12,13-DiHOME/12(13)-EpOME ratio (F_1,97 = 5.498, P = 0.021) and between obesity and 9(10)-epoxyoctadecamonoenoic acid (9(10)-EpOME) concentrations (F_1,97 = 4.126, P = 0.045), predicting executive function such that relationships were stronger in obese individuals. These findings suggest that the CYP450-sEH pathway as a potential therapeutic target for cognitive decline in T2DM. For some markers, relationships may be obesity dependent.     

Association of Thyroid Function During Pregnancy With the Risk of Pre-eclampsia and Gestational Diabetes Mellitus

ObjectiveTo estimate the association of maternal thyroid dysfunction with the risk of gestational hypertension and diabetes. Whether the association was affected by gestational age at diagnosis and thyroid autoimmunity was further explored.MethodsA cohort study of 41 647 participants was conducted. Thyroid function (ie, thyroid-stimulating hormone [TSH] and free thyroxine [FT4]) was measured by electrochemiluminescence immunoassay. Thyroid antibody positivity (eg, thyroperoxidase, thyroglobulin, and TSH receptor antibody) was indicated if the values of these antibodies exceeded the upper targets of the reference range. The relationship between maternal thyroid dysfunction and the risk of pre-eclampsia (PE) and gestational diabetes mellitus (GDM) was assessed by multivariate logistic regression.ResultsIsolated hypothyroxinemia (defined as 5th ≤ TSH ≤ 95th percentile, FT4 < 5th percentile) was associated with the risk of PE (odds ratio [OR], 1.32; 95% CI, 1.10-1.58). Overt hypothyroidism (TSH > 95th percentile; FT4 < 5th percentile) was related to the risk of severe PE (OR, 2.59; 95% CI, 1.05-6.37). Being positive for TSH receptor antibody was associated with a decreased risk of GDM (OR, 0.49; 95% CI, 0.35-0.70). A marginally significant association between overt hypothyroidism detected at the first trimester and the risk of GDM was found (OR, 1.60; 95% CI, 1.00-2.83). The association of thyroid dysfunction with the risk of PE and GDM was stronger among pregnant women who were negative for autoantibodies.ConclusionSome types of thyroid dysfunction during pregnancy were associated with the risk of PE and GDM. The associations varied by gestational age at diagnosis and by thyroid autoantibody status.     

Relationship between hepatic and mitochondrial ceramides: a novel in vivo method to track ceramide synthesis

Ceramides (CERs) are key intermediate sphingolipids implicated in contributing to mitochondrial dysfunction and the development of multiple metabolic conditions. Despite the growing evidence of CER role in disease risk, kinetic methods to measure CER turnover are lacking, particularly using in vivo models. The utility of orally administered ¹³C₃, ¹⁵N l-serine, dissolved in drinking water, was tested to quantify CER 18:1/16:0 synthesis in 10-week-old male and female C57Bl/6 mice. To generate isotopic labeling curves, animals consumed either a control diet or high-fat diet (HFD; n = 24/diet) for 2 weeks and varied in the duration of the consumption of serine-labeled water (0, 1, 2, 4, 7, or 12 days; n = 4 animals/day/diet). Unlabeled and labeled hepatic and mitochondrial CERs were quantified using liquid chromatography tandem MS. Total hepatic CER content did not differ between the two diet groups, whereas total mitochondrial CERs increased with HFD feeding (60%, P < 0.001). Within hepatic and mitochondrial pools, HFD induced greater saturated CER concentrations (P < 0.05) and significantly elevated absolute turnover of 16:0 mitochondrial CER (mitochondria: 59%, P < 0.001 vs. liver: 15%, P = 0.256). The data suggest cellular redistribution of CERs because of the HFD. These data demonstrate that a 2-week HFD alters the turnover and content of mitochondrial CERs. Given the growing data on CERs contributing to hepatic mitochondrial dysfunction and the progression of multiple metabolic diseases, this method may now be used to investigate how CER turnover is altered in these conditions.     

Albuminuria,Disease Duration,and Glycated Hemoglobin Are Related With Bone Mineral Density in Type 1 Diabetes: A Cross-sectional Study

ObjectiveStudies have found a significant decrease in bone mineral density (BMD) in individuals with type 1 diabetes (T1D) compared to healthy controls. Factors associated with this phenomenon have yet to be defined; therefore, this study aimed to explore the association of glycated hemoglobin (HbA1c), disease duration, albuminuria, and glomerular filtration rate with BMD in adults with T1D.MethodsA cross-sectional study was carried out in tertiary care center. BMD analysis was performed by dual x-ray absorptiometry. Linear models were constructed considering variables associated with BMD. Approval from the ethics committees and informed consent were obtained.ResultsWe included 128 participants, of whom 59% were women, and 16% had menopause. The median age was 33 (26-42) years. The average age of diabetes diagnosis was 15.3 ± 6.3 years, and the median disease duration was 19.5 (12-27) years. In the adjusted analysis, higher albuminuria (P < .01) and disease duration (P < .05) were associated with a lower BMD in the femoral neck and total hip, independently of age, sex, and body mass index (BMI). Higher HbA1c (P < .01) was associated with a lower spine BMD after adjustment for age, sex, and BMI.ConclusionStudied factors specific to T1D, including albuminuria, disease duration, and HbA1c have an association with BMD regardless of BMI, age, and sex.     

Association of Angiotensin-Converting Enzyme gene polymorphism in Pakistani women with the atypical steroidogenesis in Polycystic ovarian syndrome: A case-control study

BackgroundPolymorphism in the angiotensin-converting enzyme gene (ACE) is responsible for elevated ACE concentrations in plasma. High ACE levels induce insulin resistance and hyperandrogenism, which are the main attributes of polycystic ovary syndrome (PCOS). Therefore, it was hypothesized that I/D polymorphism plays a role in the pathogenesis of PCOS.ObjectiveA case-control study was designed to investigate the association of I/D polymorphism of the ACE gene with PCOS in Pakistani women of reproductive age.MethodsACE I/D polymorphism was assessed in 252 women of age group 16–40 years. For genotypic analysis, PCR amplification of genomic DNA was carried out. Statistical analysis was performed to interpret the results using SPSS software.ResultsOur study showed that PCOS women were more likely to have a high body mass index and waist circumferences. Most PCOS patients had menstrual irregularities 99.3%, hirsutism 75.2% and cysts in ovaries 66.6%, along with other hyperandrogenic conditions (P-value = 0.001). The genotypic and allelic frequencies were significantly different between patients and controls. There was a significant association of three genotypes with the ratio of LH: FSH among PCOS patients (P = 0.05). Anthropometric characters, comorbidities, clinical symptoms, and PCOS conditions showed no statistical significance with ACE polymorphism.ConclusionsACE I/D polymorphism was not found associated with clinical conditions of PCOS in women of reproductive age. However, it was associated with atypical steroidogenesis. So, it indicates that ACE I/D polymorphism aggravates the pathogenesis of PCOS.     

Association of Early Pregnancy Free and Total Triiodothyronine With the Subsequent Risk of Gestational Diabetes Mellitus

ObjectiveTo estimate the association of free triiodothyronine (FT3) and total triiodothyronine (TT3) in early pregnancy and subsequent gestational diabetes mellitus (GDM) risk and define appropriate TT3 thresholds for GDM screening.MethodsThis investigation is a hospital-based cohort study of pregnant women submitted to a universal thyroid function test before 24 weeks of gestation. GDM was diagnosed according to a 75-g oral glucose tolerance test. The association of maternal high FT3 and TT3 levels in early pregnancy with the risk of GDM was estimated using logistic regression. The potential nonlinear association was probed by the restricted cubic spline curve method.ResultsA total of 27 184 pregnant women and 3073 GDM cases were included in the analysis. FT3 and TT3 were associated with an increased subsequent risk of GDM in a nonlinear fashion. The adjusted odds ratios were 1.59 (95% confidence interval, 1.50-1.68) and 2.80 (95% confidence interval, 2.46-3.18) for FT3 and TT3 continuous levels, respectively. Associations were strong in euthyroid women, showed heterogeneity in women with mild thyroid dysfunction, and lacked in patients with overt hypothyroidism and hyperthyroidism. The TT3 thresholds of 1.5 and 2.0 ng/mL between 7 and 12 weeks of gestation and 1.6 and 2.1 ng/mL for 13 to 23 weeks of gestation effectively distinguished the subsequent risk of GDM.ConclusionThe increased FT3 and TT3 levels in early pregnancy were associated with a subsequent higher risk of GDM. These findings provide measures for early detection and potential prevention of GDM.     

Pulmonary surfactant protein B carried by HDL predicts incident CVD in patients with type 1 diabetes

Atherosclerotic CVD is the major cause of death in patients with type 1 diabetes mellitus (T1DM). Alterations in the HDL proteome have been shown to associate with prevalent CVD in T1DM. We therefore sought to determine which proteins carried by HDL might predict incident CVD in patients with T1DM. Using targeted MS/MS, we quantified 50 proteins in HDL from 181 T1DM subjects enrolled in the prospective Coronary Artery Calcification in Type 1 Diabetes study. We used Cox proportional regression analysis and a case-cohort design to test associations of HDL proteins with incident CVD (myocardial infarction, coronary artery bypass grafting, angioplasty, or death from coronary heart disease). We found that only one HDL protein—SFTPB (pulmonary surfactant protein B)—predicted incident CVD in all the models tested. In a fully adjusted model that controlled for lipids and other risk factors, the hazard ratio was 2.17 per SD increase of SFTPB (95% confidence interval, 1.12–4.21, P = 0.022). In addition, plasma fractionation demonstrated that SFTPB is nearly entirely bound to HDL. Although previous studies have shown that high plasma levels of SFTPB associate with prevalent atherosclerosis only in smokers, we found that SFTPB predicted incident CVD in T1DM independently of smoking status and a wide range of confounding factors, including HDL-C, LDL-C, and triglyceride levels. Because SFTPB is almost entirely bound to plasma HDL, our observations support the proposal that SFTPB carried by HDL is a marker—and perhaps mediator—of CVD risk in patients with T1DM.     

Management of Hypothyroidism and Hypothyroxinemia During Pregnancy

ObjectiveTo review the diagnosis and management of hypothyroidism during pregnancy, in the preconception period, and in the postpartum period.MethodsA literature review of English-language papers published between 1982 and 2022, focusing on the most recent literature.ResultsDuring pregnancy, thyroid function laboratory tests need to be interpreted with regard to gestational age. Overt hypothyroidism, regardless of the thyroid-stimulating hormone (TSH) level, should always be promptly treated when it is diagnosed before conception or during pregnancy or lactation. Most women with pre-existing treated hypothyroidism require an increase in levothyroxine (LT4) dosing to maintain euthyroidism during gestation. LT4-treated pregnant patients need close monitoring of their serum TSH levels to avoid overtreatment or undertreatment. There is no consensus about whether to initiate LT4 in women with mild forms of gestational thyroid hypofunction. However, in light of current evidence, it is reasonable to treat women with subclinical hypothyroidism with LT4, particularly if the TSH level is >10 mIU/L or thyroperoxidase antibodies are present. Women who are not treated need to be followed up to ensure that treatment is initiated promptly if thyroid failure progresses. Additional studies are needed to better understand the effects of the initiation of LT4 in early gestation in women with subclinical hypothyroidism and hypothyroxinemia and determine optimal strategies for thyroid function screening in the preconception period and during pregnancy.ConclusionThe diagnosis and management of hypothyroidism in the peripregnancy period present specific challenges. While making management decisions, it is essential to weigh the risks and benefits of treatments for not just the mother but also the fetus.     

Elevated n-3/n-6 PUFA ratio in early life diet reverses adverse intrauterine kidney programming in female rats

Intrauterine growth restriction (IUGR) predisposes to chronic kidney disease via activation of proinflammatory pathways, and omega-3 PUFAs (n-3 PUFAs) have anti-inflammatory properties. In female rats, we investigated 1) how an elevated dietary n-3/n-6 PUFA ratio (1:1) during postnatal kidney development modifies kidney phospholipid (PL) and arachidonic acid (AA) metabolite content and 2) whether the diet counteracts adverse molecular protein signatures expected in IUGR kidneys. IUGR was induced by bilateral uterine vessel ligation or intrauterine stress through sham operation 3.5 days before term. Control (C) offspring were born after uncompromised pregnancy. On postnatal (P) days P2–P39, rats were fed control (n-3/n-6 PUFA ratio 1:20) or n-3 PUFA intervention diet (N3PUFA; ratio 1:1). Plasma parameters (P33), kidney cortex lipidomics and proteomics, as well as histology (P39) were studied. We found that the intervention diet tripled PL-DHA content (PC 40:6; P < 0.01) and lowered both PL-AA content (PC 38:4 and lyso-phosphatidylcholine 20:4; P < 0.05) and AA metabolites (HETEs, dihydroxyeicosatrienoic acids, and epoxyeicosatrienoic acids) to 25% in all offspring groups. After ligation, our network analysis of differentially expressed proteins identified an adverse molecular signature indicating inflammation and hypercoagulability. N3PUFA diet reversed 61 protein alterations (P < 0.05), thus mitigating adverse IUGR signatures. In conclusion, an elevated n-3/n-6 PUFA ratio in early diet strongly reduces proinflammatory PLs and mediators while increasing DHA-containing PLs regardless of prior intrauterine conditions. Counteracting a proinflammatory hypercoagulable protein signature in young adult IUGR individuals through early diet intervention may be a feasible strategy to prevent developmentally programmed kidney damage in later life.     

Differences in Primary Hyperparathyroidism Between Pre- and Postmenopausal Women in India

ObjectivePrimary hyperparathyroidism (PHPT) is a common endocrine disorder in women which becomes more prevalent after menopause. In this study, we compared the demographic, clinical, and biochemical variables between premenopausal (pre-M) and postmenopausal (post-M) women with PHPT.MethodsA retrospective analysis (from 2005 to 2019) of enrolled women PHPT patients from an online Indian PHPT registry.ResultsOf the women with PHPT, 232 and 122 were pre-M and post-M, respectively. The number of post-M PHPT cases registered had a 3.3-fold increase in 2015-2019 from 2005-2009 compared with only a 2.5-fold increase in pre-M cases in the same duration. The majority were symptomatic (90%), although pre-M had a higher proportion of symptomatic than post-M (92% vs 85%; P = .04). Pre-M women showed more prevalence of osteitis fibrosa cystica than post-M women (28% vs 13%; P = .03), although hypertension and gallstone disease were seen more frequently in post-M PHPT women. Pre-M women had a significantly higher median PTH (403 vs 246 pg/mL; P = .02) and median alkaline phosphatase (202 vs 145 pg/mL; P = .02) than post-M women, and vitamin D deficiency was more common in pre-M women (58% vs 45%; P = .03). Gland localization, tumor weight, and disease cure rates did not differ according to menopausal status.ConclusionPHPT was more prevalent in pre-M women, although the number of post-M cases had significantly increased in the last 10 years. Pre-M women had generally more severe clinical and biochemical variables than post-M PHPT women.