A longitudinal study of free leptin index in pre-eclamptic pregnancies

The ratio between circulating levels of leptin and soluble leptin receptor (sOB-R), the free leptin index (FLI), is used as a marker of leptin resistance. Therefore, the aim of our study was to investigate the FLI in mild pre-eclamptic pregnancies in a nested case-control study within a prospective observational study. Circulating levels of leptin and sOB-R levels rise significantly during pregnancy in healthy (p < 0.05) (n = 46) and pre-eclamptic pregnancies (p < 0.05) (n = 20). Serum levels of leptin were significantly higher in pre-eclamptic compared to healthy pregnancies at second and third trimesters of pregnancy (p < 0.05). Additionally, serum levels of sOB-R were significantly lower in pre-eclamptic pregnancies during the second and third trimesters of pregnancy compared to healthy pregnancies (p < 0.05). Moreover, we found that FLI did not vary significantly during pregnancy in healthy women (p > 0.05), while it increases in pre-eclamptic pregnancies (p < 0.05). Indeed, FLI was significantly higher at second and third trimesters of pregnancy in pre-eclamptic compared to healthy pregnancies (p < 0.05). In addition, FLI was significantly higher in the luteal phase compared with the follicular phase of the menstrual cycle in eumenorrheic women (p < 0.05). Receiver operating characteristic (ROC) curve analysis revealed the ability of leptin (AUC = 0.72) and FLI (AUC = 0.67) as a reliable predictor for mild pre-eclampsia during the second trimester of pregnancy. In conclusion, our findings show that FLI were significantly increased in mild pre-eclamptic pregnancies and allowed us to hypothesize that this rise might alter leptin bioavailability and bioactivity which might lead to the sympathetic hyperactivity and the hypertensive disorders during pregnancy.

SAT-028 Leptin, Leptin Soluble Receptor and FLI in Healthy and Preeclamptic Pregnancies

Context

Leptin is an adipokine involved in many pleiotropic and key physiological actions and circulates free and active, or inactive bound to the leptin binding protein and sOB-r. Thus, the ratio Leptin/sOB-r or free leptin index (FLI) is commonly used as a marker of leptin sensitivity in different pathologies.

Objective

Evaluate serum concentrations of leptin and sOB-r and determine FLI in healthy pregnant and mild pre – eclamptic women in the three trimesters of gestation.

Design

A nested case-control study within a prospective cohort study of pregnant women, enrolled in the Department of Obstetrics and Gynecology of the School of Medicine at Universidad Nacional.

Main Outcome Measure and Methods

From the initial cohort, 46 healthy pregnant women and 19 mild pre – eclamptic pregnant women were randomly selected. Anthropometric, biochemical and clinical parameters were determined during three stages of pregnancy [1^st (11.3±2.3 weeks), 2^nd (24.4±3.10 weeks) and 3^rd (34.84±4.41 weeks) periods of gestation]. Data were presented as mean ± SD. A p value <0.05 was considered to be statistically significant.

Results

Serum leptin levels and sOB-r levels rose significantly throughout pregnancy in both healthy women [Leptin (1^st 23.28±9.87 ng/mL; 2^nd 34.58±18.45 ng/mL; 3^rd 38.27±19.64 ng/mL trimester) (p=0.0001); sOB-r (1^st 32.12±7.29 ng/mL; 2^nd 43.26±9.25 ng/mL; 3^rd 45.16±10.70 ng/mL trimester) (p<0.0000)] and preeclamptic women [Leptin (1^st 29.91±9.91 ng/mL; 2^nd 47.10±25.70 ng/mL; 3^rd 63.00±3012 ng/mL trimester) (p<0.0000); sOB-r (1^st 32.09±6.97 ng/mL; 2^nd 37.54±6.33 ng/mL; 3^rd 36.96±7.66 ng/mL trimester) (p=0.0380)].

Serum leptin levels were significantly higher in preeclamptic pregnant women compared to healthy pregnant women at 2^nd (p=0.029) and 3^rd trimesters of pregnancy (p<0.000). Additionally, serum sOB-r levels were also significantly lower in pre - eclamptic pregnant women during the 2^nd (p=0.017) and 3^rd trimester (p=0.0036) of pregnancy compared to healthy pregnant women. As a result, the FLI index did not vary significantly during any of the three periods of pregnancy studied in healthy pregnant women [(1^st 7.99±4.85; 2^nd 8.72±6.5; 3^rd 9.15±5.84 trimester) (p >0.05)], whereas, in contrast, this index markedly increased throughout pregnancy in pre - eclamptic women [(1^st 8.69±4.96; 2^nd 13.54±8.78; 3^rd 18.06±10.35 trimester) (p=0.0044)]. Indeed, the FLI index was significantly higher at 2^nd (p=0.0186) and 3^rd (p<0.000) trimesters of pregnancy in pre - eclamptic women compared to healthy pregnant.

Conclusions

The present results demonstrate for the first time in a longitudinal study that FLI increases significantly in pre - eclamptic pregnant women towards the end of pregnancy. Hence, high FLI index values should be further explored as a potentially valuable indicator for the clinical manifestations of this pathology.

SAT-228 A Longitudinal Prospective Cohort Study of Fasting Glucose to Insulin Ratio and Fasting Insulin Resistance Index in Normal and Preeclamptic Pregnancies

Gestation is a diabetogenic state due to insulin resistance. Pregnant women with higher insulin resistance are at risk of developing preeclampsia and vascular dysfunction. Fasting glucose to insulin ratio (G₀/I₀) and Fasting Insulin Resistance Index (FIRI = (G₀&nbsp;x I₀)/25) are surrogate indices of insulin sensitivity of the euglycemic-hyperinsulinemic clamp. The aim of this study was to determine G₀/I_0&nbsp;and FIRI in normal (n = 142) and preeclamptic pregnancies (n = 18), during the three periods of gestation, and three months postpartum. Also, 52 healthy non-pregnant women were studied. The study was approved by the Ethics Committee of the Faculty of Medicine and the participants provided written informed consent. A serum biochemical analysis of fasting insulin, blood glucose, total cholesterol, triglyceride and HDL cholesterol was done. G₀/I₀&nbsp;and FIRI were calculated. Statistical analyzes were performed with R software. In healthy pregnancy, G₀/I₀&nbsp;decreased significantly in the second (8.5 ± 4.3) and third periods (6.7 ± 3.0), compared to the first one (11.1 ± 5.7), non-pregnant women (11.3 ± 7.0) and postpartum (13.1 ± 7.9) (p<0.01). In preeclamptic patients, G₀/I₀&nbsp;decreased significantly from the first period (7.1 ± 1.6) to the end of pregnancy (6.2 ± 4.2) (p<0.05). In these women, G₀/I₀&nbsp;rose in the postpartum period (7.6 ± 4.4) without reaching the values of non-pregnant women (11.3 ± 7.0). The difference in the G₀/I₀, between healthy pregnant and preeclamptic women was due to the increase in basal insulin. A significant correlation was found between G₀/I₀&nbsp;and QUICKI, HOMA-IR and FIRI indices, during the three gestation periods and postpartum in healthy and preeclamptic, and in non-pregnant women. In healthy pregnancy, FIRI decreased significantly (p <0.05) in the first period (27.4 ± 13.7), and increased in the third period (38.4 ± 16.1 compared with non-pregnant women 33.3 ± 16.0), and decreased significantly (p <0.05) in the postpartum (27.7 ± 17.3 (p<0.01)). In preeclamptic women, the FIRI increased significantly from the second period (47.3 ± 13.7) to the end of pregnancy (45.7 ± 21.5) (p <0.05) and in postpartum (48.5 ± 28.1), compared with non-pregnant women (33.3 ± 16.0). The FIRI was not different in the third period of gestation between healthy pregnant and preeclamptic women. The FIRI was correlated with QUICKI, HOMA-IR and G₀/I₀&nbsp;indices during the different periods of pregnancy and postpartum, in healthy pregnant and preeclamptic women, and with the TyG and TG/HDL-c indices only in postpartum in preeclamptic women. In conclusion, these different indices of surrogate insulin resistance (G₀/I₀, FIRI, QUICKI, HOMA-IR, TyG and TG/HDL-c) can be used to predict insulin resistance during pregnancy. Preeclamptic women had more insulin resistance from early pregnancy and this state persists longer than in healthy pregnant women.

Serum 25-hydroxyvitamin D levels throughout pregnancy: a longitudinal study in healthy and preeclamptic pregnant women

BACKGROUND

Worldwide there is a high prevalence of 25-hydroxyvitamin D (25OHD) deficiency and has been associated with adverse outcomes during pregnancy.

OBJECTIVE

This is a nested, case-control study in a longitudinal cohort to compare the serum 25OHD levels and other biomarkers throughout pregnancy in a group of 20 preeclamptic women and 61 healthy pregnant women. An additional group of 29 healthy non-pregnant women were also studied during the two phases of the menstrual cycle.

RESULTS

Mean 25OHD levels in non-pregnant women were 31.9 ng/mL and 34.9 ng/mL during follicular and luteal phase, respectively (P < 0.01). Mean serum 25OHD levels in healthy pregnant women were 26.5, 30.1 and 31.9 ng/mL, at first, second and third trimester, respectively (P < 0.001). The first trimester levels of 25OHD were lower than those of healthy non-pregnant women (P < 0.001), showing a significant recovery at third trimester. In the group of healthy pregnant women, the 25OHD levels were 25.7 ng/mL and 27.2 ng/mL at 3 and 6 months postpartum, respectively; both values were lower than those observed in the non-pregnant women (P < 0.001). In preeclamptic women, 25OHD serum levels were similar to those of healthy pregnant women; nevertheless, they remained almost unchanged throughout pregnancy.

CONCLUSION

There were no significant differences between healthy and preeclamptic pregnant women in terms of 25OHD levels throughout the pregnancy. Serum 25OHD levels in non-pregnant women were higher during luteal phase compared with follicular phase. The 25OHD levels of non-pregnant women tended to be higher than those of pregnant women.