Gender differences in serum leptin concentrations from umbilical cord blood of newborn infants born to nondiabetic , gestational diabetic and type-2 diabetic mothers

Int J Diab Dev Ctries | October-December 2009 | Volume 29 | Issue 4 To investigate gender differences, if any, in leptin concentrations from umbilical cord blood of new born infants of mothers with type 2 diabetes mellitus (DM), gestational diabetes mellitus (GDM), and Non diabetic (ND) at delivery. Serum leptin concentrations were measured in 105 newborns (53 males and 52 females in the three groups). Blood was taken from the umbilical cord of the babies at delivery. Maternal anthropometric measurements were recorded within 48 hours after delivery. Pearson correlation coeffi cient was used to explore the relationship between serum leptin concentrations and anthropometric measures of the fetus and their mother . Both Serum leptin level and serum C-peptide was measured by chemiluminescence based ELISA. The median range of leptin concentration in cord blood was ND group: Male [13.91 (3.22 – 47.63)], Female [16.88 (2 – 43.65)]; GDM group: Male [32 (7 – 76.00)], Female [36.73 (4.80 – 81.20)]; DM group: Male [20.90 (2 –76.00)], Female [32 {2.58 – 80.67)]. Cord serum leptin levels correlated with birth weight(r=0.587, p=0.0001), ponderal index (PI) (r=.319, p=0.024)of the babies and body mass index (BMI) (r=-0.299, p=0.035) of their mothers but did not correlate with gestational age, cord serum C-peptide concentration or placental weight at delivery. Leptin concentrations were higher in the female fetus in comparison to the male fetus. Birth weight of the female fetuses were also higher than that of male fetus. We found that there are very strong associations between cord leptin

To investigate gender differences, if any, in leptin concentrations from umbilical cord blood of new born infants of mothers with type 2 diabetes mellitus (DM), gestational diabetes mellitus (GDM), and Non diabetic (ND) at delivery.Serum leptin concentrations were measured in 105 newborns (53 males and 52 females in the three groups).Blood was taken from the umbilical cord of the babies at delivery.Maternal anthropometric measurements were recorded within 48 hours after delivery.Pearson correlation coeffi cient was used to explore the relationship between serum leptin concentrations and anthropometric measures of the fetus and their mother .Both Serum leptin level and serum C-peptide was measured by chemiluminescence based ELISA.The median range of leptin concentration in cord blood was ND group: Male [13.91 (3.22 -47.63) .0001),ponderal index (PI) (r=.319, p=0.024)of the babies and body mass index (BMI) (r=-0.299,p=0.035) of their mothers but did not correlate with gestational age, cord serum C-peptide concentration or placental weight at delivery.Leptin concentrations were higher in the female fetus in comparison to the male fetus.Birth weight of the female fetuses were also higher than that of male fetus.We found that there are very strong associations between cord leptin

Introduction
] In a cross-sectional study of a large population of children of both sexes, it was observed that, at any age and at any pubertal stage studied, the girls always had higher leptin concentration than the boys. [8]This Þ nding was evident even in the youngest age group studied, 5 years, which is a period of child development without any sex-related hormonal changes.These diff erences concentrations at delivery and birth weight, ponderal index of the baby, body mass index of the mothers with Type 2 DM.We also found that high leptin levels could represent an important feedback modulator of substrate supply and subsequently for adipose tissue status during late gestation or adipose tissue is the major determinant of circulating leptin levels.in serum leptin concentrations between boys and girls could not be explained by diff erences in weight, height, age or adiposity.It has been reported that leptin concentration is higher in cord blood of DM and GDM babies.Therefore, it is worthy to examine if gender diff erence exists in diff erent leptinemic conditions.
In the present study, we measured leptin concentrations in umbilical cord serum of a large group of infants of both sexes born to mothers having type-2 DM, GDM, ND at the time of delivery.

Materials and Methods
The study population consisted of 30 babies, 15 male and 15 female babies, from nondiabetic mothers (NDbabies.30 babies, 17 male and 13 female babies, born to gestational diabetes mellitus mothers (GDM-babies), 45 babies from type-2 DM mothers (DM babies), of them 21 were male babies and 24 were female babies.
All of the newborns were healthy and their mothers had no remarkable illnesses during their pregnancy and none was taking any medication, except vitamins and iron supplements.
Gestational age at the time of delivery was calculated according to the LMP and conÞ rmed by USG during Þ rst trimester.
Birth weights of the babies were measured using standard weighing balance.Placentas were delivered within 10 min aft er delivery of the infants.Placental weight was measured by a weighing balance.
A sample of venous cord blood was collected from each newborn just aft er delivery from placental side of umbilical cord.
The serum was immediately separated and frozen at -70 C until analysis.
All of the parents of the newborns gave their writt en informed consent prior to enrollment.
Neonates born to mothers who experienced medical complications other than GDM and type-2 DM during, or before pregnancy were excluded.

Statistical analysis
Diff erences between groups were evaluated by Student's unpaired t-test.SigniÞ cance was considered to be P <0.05.Data are presented as the median (range).

Results
Birth weights of female babies of ND, GDM and type-2 DM groups were higher compared to the male babies of the respective groups [weight in kg, median (range) Table 1].
Serum leptin concentrations of female babies of ND, GDM and type-2 DM groups were also higher compared to the male babies of the same groups.[Leptin concentrations in (ng /ml), median (range)]

Discussion
[14] Various mechanisms have been postulated to explain this difference.[17] Others have proposed a heightened hypothalamic feedback loop in leptin adiposity regulation in the female. [18]The gender dimorphism in leptin production which is observed in the very early life may also indicate the genetic diff erence in leptin production. [19]gher leptin in the off spring of diabetic mother has been largely att ributed to the increase in the adiposity of the off spring of diabetic mother.Others have proposed a regulatory role of insulin in the production of leptin.Placental production of leptin might be responsible for hyperinsulinemia in the off spring of DM mother. [20]e mechanism of production and regulation of leptin concentration in the fetus is not fully understood.The cause for diff erences in leptin concentration between the genders is also controversial.
The present study examined whether sex diff erences also exist in leptinaemic condition which may provide further clues to the mechanism of sex diff erence in leptin concentration.Our study reveals significant diff erence of leptin concentration between male and female fetuses of diabetic mother despite the fact that both male and female babies of DM mother have much higher concentration of leptin than the off spring of non-diabetic mother.In a study, Kostolova et al had shown no gender diff erence in leptin concentration of the off spring of DM mother.Our present study has also shown gender diff erences of leptin concentration in the off spring of DM mothers.The diff erences of Þ ndings in the gender diff erence of diabetic off spring of Kostolova and in the DM mother of the present study could be due to diff erences in body weight between male and female.This study emphasizes that adiposity of the fetus is one of the most determinant factors of leptin concentration.
Although the adiposity cannot be solely responsible for leptin production in the fetus as there is marked diff erence of leptin concentration between off spring of diabetic and nondiabetic mothers which cannot be fully att ributed due to weight diff erences of the off spring between the groups.
ur study is consistent with other studies; our observations may imply that placental leptin might be one of the responsible factors for higher concentration of leptin in the off spring of diabetic mother.
The diabetic male fetus had higher mean value of leptin than that of female which implies that if the female off spring of diabetic mother had similar leptin concentration like that of the male off spring, it could adequately inhibit the hypothalamic control loop.
This negates the higher hypothalamic threshold in leptin adiposity control loop as a possible cause for gender diff erence.So it seems to be more rational to att ribute the diff erences in leptin production to genetic factors.

Conclusion
Our study provides information about diff erences in leptin concentration between two genders in a diff erent leptinaemic situation.This will help to explore the issue further in explaining gender diff erences in leptin production.