Association between plasma leptin and cesarean section after induction of labor: a case control study

Background Obesity in pregnancy is common, with more than 50% of pregnant women being overweight or obese. Obesity has been identified as an independent predictor of dysfunctional labor and is associated with increased risk of failed induction of labor resulting in cesarean section. Leptin, an adipokine, is secreted from adipose tissue under the control of the obesity gene. Concentrations of leptin increase with increasing percent body fat due to elevated leptin production from the adipose tissue of obese individuals. Interestingly, the placenta is also a major source of leptin production during pregnancy. Leptin has regulatory effects on neuronal tissue, vascular smooth muscle, and nonvascular smooth muscle systems. It has also been demonstrated that leptin has an inhibitory effect on myometrial contractility with both intensity and frequency of contractions decreased. These findings suggest that leptin may play an important role in dysfunctional labor and be associated with the outcome of induction of labor at term. Our aim is to determine whether maternal plasma leptin concentration is indicative of the outcome of induction of labor at term. We hypothesize that elevated maternal plasma leptin levels are associated with a failed term induction of labor resulting in a cesarean delivery. Methods In this case-control study, leptin was measured in 3rd trimester plasma samples. To analyze labor outcomes, 174 women were selected based on having undergone an induction of labor (IOL), (115 women with successful IOL and 59 women with a failed IOL). Plasma samples and clinical information were obtained from the UI Maternal Fetal Tissue Bank (IRB# 200910784). Maternal plasma leptin and total protein concentrations were measured using commercially available assays. Bivariate analyses and logistic regression models were constructed using regression identified clinically significant confounding variables. All variables were tested at significance level of 0.05. Results Women with failed IOL had higher maternal plasma leptin values (0.5 vs 0.3 pg, P = 0.01). These women were more likely to have obesity (mean BMI 32 vs 27 kg/m2, P = 0.0002) as well as require multiple induction methods (93% vs 73%, p = 0.008). Logistic regression showed Bishop score (OR 1.5, p < 0.001), BMI (OR 0.92, P < 0.001), preeclampsia (OR 0.12, P = 0.010), use of multiple methods of induction (OR 0.22, P = 0.008) and leptin (OR 0.42, P = 0.017) were significantly associated with IOL outcome. Specifically, after controlling for BMI, Bishop Score, and preeclampsia, leptin was still predictive of a failed IOL with an odds ratio of 0.47 (P = 0.046). Finally, using leptin as a predictor for fetal outcomes, leptin was also associated with of fetal intolerance of labor, with an odds ratio of 2.3 (P = 0.027). This association remained but failed to meet statistical significance when controlling for successful (IOL) (OR 1.5, P = 0.50). Conclusions Maternal plasma leptin may be a useful tool for determining which women are likely to have a failed induction of labor and for counseling women about undertaking an induction of labor versus proceeding with cesarean delivery.

Roles of plasma leptin and resistin in novel subgroups of type 2 diabetes driven by cluster analysis

Background A novel classification has been introduced to promote precision medicine in diabetes. The current study aimed to investigate the relationship between leptin and resistin levels with novel refined subgroups in patients with type 2 diabetes mellitus (T2DM). Methods The k-means analysis was conducted to cluster 541 T2DM patients into the following four subgroups: mild obesity-related diabetes (MOD), severe insulin-deficient diabetes (SIDD), severe insulin-resistant diabetes (SIRD) and mild age-related diabetes (MARD). Individuals meeting the exclusion criteria were eliminated, the data for 285 patients were analyzed. Characteristics were determined using various clinical parameters. Both the leptin and resistin levels were determined using enzyme-linked immunosorbent assay. Results The highest levels of plasma leptin were in the MOD group with relatively lower levels in the SIDD and SIRD groups (P < 0.001). The SIRD group had a higher resistin concentration than the MARD group (P = 0.024) while no statistical significance in resistin levels was found between the SIDD and MOD groups. Logistic regression demonstrated that plasma resistin was associated with a higher risk of diabetic nephropathy (odds ratios (OR) = 2.255, P = 0.001). According to receiver operating characteristic (ROC) curves, the area under the curve (AUC) of resistin (0.748, 95% CI 0.610–0.887) was significantly greater than that of HOMA2-IR (0.447, 95% CI 0.280–0.614) (P < 0.05) for diabetic nephropathy in the SIRD group. Conclusions Leptin levels were different in four subgroups of T2DM and were highest in the MOD group. Resistin was elevated in the SIRD group and was closely related to diabetic nephropathy.

Plasma Leptin Is Increased in Intensive Care Patients with COVID-19—An Investigation Performed in the PronMed-Cohort

COVID-19 has shaken the world and intensive care units (ICU) have been challenged by numerous patients suffering from a previously unknown disease. Leptin is a polypeptide pleiotropic hormone, mainly expressed by adipocytes. It acts as a proinflammatory cytokine and is associated with several conditions, known to increase the risk of severe COVID-19. Very little is known about leptin in severe viral disorders. Plasma leptin was analyzed in 222 out of 229 patients with severe COVID-19 on admission to an ICU at Uppsala University Hospital, a tertiary care hospital in Sweden, and compared to plasma leptin in 25 healthy blood donors. COVID-19 was confirmed by positive PCR. Leptin levels were significantly higher in patients with COVID-19 (18.3 ng × mL−1; IQR = 30.4), than in healthy controls (7.8 ng × mL−1; IQR = 6.4). Women had significantly higher leptin values (22.9 ng × mL−1; IQR = 29.8) than men (17.5 ng × mL−1; IQR = 29.9). Mortality at 30 days was 23% but was not associated with increased leptin levels. Neither median duration of COVID-19 before admission to ICU (10 days; IQR = 4) or median length of ICU stay (8 days; IQR = 11) correlated with the plasma leptin levels. Leptin levels in COVID-19 were higher in females than in males. Both treatment (e.g., use of corticosteroids) and prophylaxis (vaccines) have been improved since the start of the COVID-19 pandemic, which may contribute to some difficulties in deciphering relations between COVID-19 and leptin.

Butyrate Protects against Diet-Induced NASH and Liver Fibrosis and Suppresses Specific Non-Canonical TGF-β Signaling Pathways in Human Hepatic Stellate Cells

In obesity-associated non-alcoholic steatohepatitis (NASH), persistent hepatocellular damage and inflammation are key drivers of fibrosis, which is the main determinant of NASH-associated mortality. The short-chain fatty acid butyrate can exert metabolic improvements and anti-inflammatory activities in NASH. However, its effects on NASH-associated liver fibrosis remain unclear. Putative antifibrotic effects of butyrate were studied in Ldlr-/-.Leiden mice fed an obesogenic diet (HFD) containing 2.5% (w/w) butyrate for 38 weeks and compared with a HFD-control group. Antifibrotic mechanisms of butyrate were further investigated in TGF-β-stimulated primary human hepatic stellate cells (HSC). HFD-fed mice developed obesity, insulin resistance, increased plasma leptin levels, adipose tissue inflammation, gut permeability, dysbiosis, and NASH-associated fibrosis. Butyrate corrected hyperinsulinemia, lowered plasma leptin levels, and attenuated adipose tissue inflammation, without affecting gut permeability or microbiota composition. Butyrate lowered plasma ALT and CK-18M30 levels and attenuated hepatic steatosis and inflammation. Butyrate inhibited fibrosis development as demonstrated by decreased hepatic collagen content and Sirius-red-positive area. In TGF-β-stimulated HSC, butyrate dose-dependently reduced collagen deposition and decreased procollagen1α1 and PAI1 protein expression. Transcriptomic analysis and subsequent pathway and upstream regulator analysis revealed deactivation of specific non-canonical TGF-β signaling pathways Rho-like GTPases and PI3K/AKT and other important pro-fibrotic regulators (e.g., YAP/TAZ, MYC) by butyrate, providing a potential rationale for its antifibrotic effects. In conclusion, butyrate protects against obesity development, insulin resistance-associated NASH, and liver fibrosis. These antifibrotic effects are at least partly attributable to a direct effect of butyrate on collagen production in hepatic stellate cells, involving inhibition of non-canonical TGF-β signaling pathways.

The Impact of Re-Mating Interval and Genotype on Physiological Response of Rabbits after First Kindling

This is an experiment aimed to study the effect of re-mating interval on rabbit does after first kindling on hormonal (insulin, leptin, and T3) and metabolites (triglycerides, urea, and glucose) levels. DNA damage in ovary cells of rabbit does during the 2nd parity was also studied. Two varieties were used: APRI (synthetic line) and Baladi Black (BB, Egyptian breed). A total number of 120 mature rabbit does (60 does for each breed) were 6 months of age and were used at the beginning of the breeding season. Does of each breed were divided into three equal groups according to reproductive rhythm. The 1st group was postpartum (PP). The 2nd group was 11 days after parturition (P11). The 3rd group was post-weaning (PW). There were significant (P&ge;0.05) differences in plasma leptin concentration during 1st parity. The highest value of plasma leptin concentration was recorded by the PW group at mating. Also, there were significant differences in plasma insulin and T3 hormones concentrations of doe rabbits. The highest value of plasma insulin concentration was recorded by the PW group at mating in 1st parity and the highest value of plasma T3 hormone concentration was recorded for the PS group at mating. While there were insignificant differences during 2nd parity in T3 hormone concentration in rabbits, the differences of plasma glucose and triglyceride concentrations of doe rabbits during 1st parity and 2nd parity were significant. However, the highest significant value of plasma glucose concentration was recorded by the PW group at mating. On the other hand, there were insignificant differences in plasma urea concentration of doe rabbits during 1st parity and 2nd parity. Finally, no significant effects were observed on comet length, head diameter, tail length, or DNA % tail.

Protection against APOE4-associated aging phenotypes with a longevity-promoting intervention

Two of the primary risk factors for late onset Alzheimer’s Disease (AD) are aging and APOE genotype. While the causal relationship between aging and AD is not well defined, there are strong leads from shared phenotypes such as decreased metabolic function and increased inflammation. APOE genotype may be linked to AD phenotypes through the regulation of aging processes. The NIA Interventions Testing Program (ITP) recently found that 17α-estradiol (17αE2) treatment increases rodent lifespan. Since 17αE2 acts upon systemic and neural pathways associated with AD pathology, we propose that 17αE2 may be a pleiotropic intervention strategy. Further, because APOE4 is associated with a senescent phenotype, 17αE2 may have APOE genotype-specific effects. Using 10-month-old APOE3 or APOE4 targeted replacement male mice maintained on normal chow with and without 14.4 ppm 17aE2 for 20 weeks, our initial results indicate genotype differences in the efficacy of 17αE2 across multiple outcomes. APOE4 mice exhibited an aged phenotype compared to APOE3, with APOE4 mice having a higher frailty index; however, 17αE2 treatment reduced the frailty index most strongly in APOE4 mice. APOE4 mice were impaired across multiple metabolic measures including body weight, plasma leptin, and hepatic steatosis. 17αE2 significantly attenuated the APOE4 metabolic phenotype. These data confirm and extend prior findings that APOE4 is linked to progeroid effects both peripheral and neural outcomes associated with AD risk. Importantly, 17αE2 significantly improved a range of measures, but showed the strongest effects in the APOE4 genotype. This research was funded by the Cure Alzheimer's Fund.

1391. Body Mass Index and Leptin Levels at Different Stages of the Tuberculosis Spectrum

Background Leptin is an adipose tissue-derived cytokine that plays a role in energy regulation and immune functions. High leptin levels and obesity have been associated with decreased risk of developing active TB. We aimed to characterize the association between body mass index (BMI) and leptin levels in patients at different stages of tuberculosis (TB). Methods Data from a cross-sectional cardiovascular risk study of 40 to 70 years old individuals enrolled in Lima, Peru, and Cincinnati, US, were analyzed. Four categories based on TB and treatment status were defined: no TB infection (QuantiFERON-TB test negative; n= 31), latent TB infection (LTBI; QuantiFERON-TB test positive; n= 43), active TB on treatment (in the continuation TB treatment phase; n= 30), and post-TB (within one year of TB treatment completion; n=16). BMI and plasma leptin levels were compared among the four groups using the Kruskal-Wallis test, followed by Dunn’s multiple comparison test if differences were found in the Kruskal-Wallis test. Multivariate ordered logistic regression models were used to assess factors associated with leptin levels, adjusted for potential confounders. Results The median age was 53 years, and 51% were female. BMI was different between study groups (p&lt; 0.01), with LTBI individuals having the highest BMI compared to other groups; see Figure 1A. Leptin levels were marginally low in the group with active TB on treatment, but no significant differences were found between groups (p=0.44; see Figure 1B). In multivariate analysis, leptin was associated with female sex (OR 23, 95%CI, 9-58), BMI (OR, 1.5, 95%CI, 1.2-1.7), and coronary plaque ≥25% stenosis (OR, 0.29, 95%CI, 0.08-0.99). Body mass index (BMI) and plasma leptin levels in participants with negative QuantiFERON-TB test (QFN-), latent tuberculosis infection (LTBI), active tuberculosis on treatment (ATBT), and post-TB treatment (TB-treated). Significance was determined using the Kruskal-Wallis test, followed by Dunn’s multiple comparison test if the Kruskal- Wallis test p-value was &lt;0.05. Conclusion LTBI individuals had a higher BMI compared to persons with active TB on treatment and post-TB. Higher leptin levels were associated with higher BMI, but we found no association between leptin and TB status in our cohort. Disclosures All Authors: No reported disclosures

GP.2 Changes in Leptin, CCL16 and sTNF-RII as a distinctive plasma immune profile in patients with fast progressing ALS

Background: Amyotrophic lateral sclerosis (ALS) is highly heterogeneous with survival rate ranging from months to decades. Approximately 10-20% of patients develop a rapidly progressive disease and may die within the first year. Therefore, there is an increasing need for an early detection of unique molecular signatures associated with more aggressive forms of disease as it may help identify therapeutic targets. Methods: To identify a unique molecular signature in fast progressing patients, we recruited 45 sporadic ALS (sALS) patients and 35 age-matched healthy controls and measured 62 immune markers in plasma using cytokines array. Results: We found that leptin was significantly downregulated in plasma of sALS patients and more importantly in fast progressing disease. Immune markers CCL16 and sTNF-RII were significantly increased in rapidly progressing disease. We also found that leptin was significantly downregulated in plasma of SOD1G93A mice across disease stage. This was caused by an increased in levels of phospho-AMPK in mice adipocytes and in adipocytes exposed to fast sALS patients’ plasma. Conclusions: We propose that the combination of decreased plasma leptin levels and up-regulation in CCL16/sTNF-RII may be used as a prognostic biomarker to identify fast progressing ALS patients. This unique immune/metabolic profile may cause dysfunction in metabolic homeostasis.

Hindbrain Administration of Oxytocin Reduces Food Intake, Weight Gain and Activates Catecholamine Neurons in the Hindbrain Nucleus of the Solitary Tract in Rats

Existing studies show that CNS oxytocin (OT) signaling is important in the control of energy balance, but it is unclear which neurons may contribute to these effects. Our goals were to examine (1) the dose-response effects of acute OT administration into the third (3V; forebrain) and fourth (4V; hindbrain) ventricles to assess sensitivity to OT in forebrain and hindbrain sites, (2) the extent to which chronic 4V administration of OT reduces weight gain associated with the progression of diet-induced obesity, and (3) whether nucleus tractus solitarius (NTS) catecholamine neurons are downstream targets of 4V OT. Initially, we examined the dose-response effects of 3V and 4V OT (0.04, 0.2, 1, or 5 μg). 3V and 4V OT (5 μg) suppressed 0.5-h food intake by 71.7 ± 6.0% and 60 ± 12.9%, respectively. 4V OT (0.04, 0.2, 1 μg) reduced food intake by 30.9 ± 12.9, 42.1 ± 9.4, and 56.4 ± 9.0%, respectively, whereas 3V administration of OT (1 μg) was only effective at reducing 0.5-h food intake by 38.3 ± 10.9%. We subsequently found that chronic 4V OT infusion, as with chronic 3V infusion, reduced body weight gain (specific to fat mass) and tended to reduce plasma leptin in high-fat diet (HFD)-fed rats, in part, through a reduction in energy intake. Lastly, we determined that 4V OT increased the number of hindbrain caudal NTS Fos (+) neurons (156 ± 25) relative to vehicle (12 ± 3). The 4V OT also induced Fos in tyrosine hydroxylase (TH; marker of catecholamine neurons) (+) neurons (25 ± 7%) relative to vehicle (0.8 ± 0.3%). Collectively, these findings support the hypothesis that OT within the hindbrain is effective at reducing food intake, weight gain, and adiposity and that NTS catecholamine neurons in addition to non-catecholaminergic neurons are downstream targets of CNS OT.