Irisin level and neonatal birthweight: A systematic review and meta-analysis

The Complex Interplay of Irisin Levels, Low Birth Weight, and Blood Pressure in Prepubescent Children

BACKGROUND

Irisin regulates various metabolic, inflammatory, and oxidative stress processes. It has been considered a promising target in the context of the development and maintenance of cardiovascular diseases. We conducted a study to evaluate the levels of plasma irisin in prepubertal children, examining its relationship with birth weight, anthropometric parameters, biochemical profile, and blood pressure levels.

METHODS

A cross-sectional study was conducted involving 136 prepubertal children aged 6 to 11 years, with 27.9% born at a low weight. Anthropometric parameters, blood pressure, and biochemical profiles were assessed.

RESULTS

Children with low birth weight had significantly lower irisin levels compared to those with normal birth weight (p < 0.001). Birth weight was negatively correlated with blood pressure levels (systolic: r = -0.213, p = 0.013; diastolic: r = -0.223, p = 0.009) and positively correlated with irisin levels (p < 0.001). Irisin levels were positively associated with systolic blood pressure, even after adjusting for birth weight, BMI, and physical activity (p < 0.001). The linear regression analysis indicated that low birth weight and high plasma levels of irisin were recognized as predictive factors of elevated blood pressure levels.

CONCLUSION

The positive correlation observed between circulating irisin and systolic blood pressure levels in children with low birth weight, despite their lower irisin levels, suggests a complex interplay between birth weight, irisin, cardiovascular regulation, and metabolic function. Understanding this relationship may require considering that irisin may play dual roles in different tissues, compensatory mechanisms, and the broader context of cardiometabolic programming in children with low birth weight.

Evaluation of Selected Pro- and Anti-Inflammatory Adipokines in Colostrum from Mothers with Gestational Diabetes Mellitus

Adipokines related to gestational diabetes mellitus (GDM) are an emerging area of interest. The aim of this study was to evaluate the associations between GDM and adipokine levels in human milk. This was an observational cohort study targeting mothers with gestational diabetes, which evaluated the association of maternal hyperglycemia severity, classified as GDM-G1 (diet treatment) and GDM-G2 (insulin treatment), with colostral adipokines involved in pro- and anti-inflammatory processes. Colostrum was collected from hyperglycemic (N = 34) and normoglycemic (N = 26) mothers, and adipokine levels were determined by immunoenzymatic assay. Among anti-inflammatory adipokines, only for irisin and vaspin, but not for obestatin and adropin, were significantly different levels noted between the GDM-G1, GDM-G2 and non-GDM cohorts. Colostrum of the GDM-G2 subgroup contained more vaspin (4.77 ng/mL) than that of normoglycemic mothers (3.12 ng/mL) and more irisin (26.95 μg/mL) than in the GDM-G1 subgroup (17.59 μg/mL). The levels of pro-inflammatory adipokines, namely, dermcidin, chemerin and visfatin, were at similar levels irrespective of maternal glycemia. Moreover, irisin showed a negative correlation with dermcidin in GDM-G2 and non-GDM cohorts. Associations were observed between colostral irisin and maternal preconception BMI, dermcidin and gestational age, and vaspin and maternal age. This study provides evidence that the way of restoring glucose homeostasis in pregnant women has an impact on the anti-inflammatory adipokines irisin and vaspin, but not on obestatin and adropin. GDM, regardless of severity, did not influence the colostral pro-inflammatory adipokines visfatin, chemerin and dermcidin.

Irisin in Reproduction: Its Roles and Therapeutic Potential in Male and Female Fertility Disorders

The current study focused on identifying the potential of irisin in mammalian reproduction. The established role of irisin, a proteolytic product of FNDC5, in adipose tissue browning, energy metabolism, and thermogenesis suggests its role in reproductive health, often disturbed by metabolic imbalances. Various studies on mice demonstrated irisin's role in improving spermatogenesis, sperm count, and testosterone levels by influencing the hypothalamus-pituitary-gonadal axis. Moreover, in females, there is a fluctuation in levels of irisin during critical reproductive stages, including menstrual cycles, puberty, and pregnancy. Conditions like pregnancy complications, precocious puberty, and polycystic ovary syndrome (PCOS) are found to have an association with abnormal irisin levels. The potential role of irisin in endometrial receptivity and preventing endometritis is also discussed in this review. Overall, the influence of irisin on female and male reproduction is evident from various studies. However, further research is needed to elucidate irisin mechanism in reproduction and its potential as a therapeutic or diagnostic tool for reproductive dysfunctions and infertility.

Associations between total, free and bioavailable 25-hydroxyvitamin D forms with adiponectin and irisin in maternal-neonatal pairs at birth from Greece

Background

Apart from the well-established skeletal effects, vitamin D has been explored as a secretagogue influencing various adipokines, including adiponectin and irisin. Recent evidence suggests that specific forms of 25-Hydroxyvitamin D (25(OHD), such as free and bioavailable 25(OH)D, may provide more accurate measurements of vitamin D status. The relationship between vitamin D status and serum irisin and adiponectin concentrations remains largely unexplored, particularly during pregnancy.

Methods

We analyzed data from 67 healthy maternal-neonatal pairs from Northern Greece at birth. Biochemical and hormonal tests were conducted on each maternal-neonatal pair. The vitamin D forms were estimated using validated mathematical models. Subsequently, regression analyses were conducted to determine the association between the vitamin D forms and adipokine levels.

Results

Bioavailable maternal 25(OH)D was inversely associated with neonatal irisin concentrations [β=-73.46 (-140.573 to -6.341), p=0.034]. No other associations were observed between maternal vitamin D status and neonatal adipokine concentrations.

Conclusion

In conclusion, maternal bioavailable vitamin D concentrations are inversely associated with neonatal serum irisin concentrations, warranting further studies to evaluate the underlying mechanisms for this finding.

Prenatal exercise in fetal development: a placental perspective

Maternal obesity (MO) and gestational diabetes mellitus (GDM) are common in Western societies, which impair fetal development and predispose offspring to metabolic dysfunction. Placenta is the organ linking the mother to her fetus, and MO suppresses the development of vascular system and expression of nutrient transporters in placenta, thereby affecting fetal development. For maintaining its proper physiological function, placenta is energy demanding, which is met through extensive oxidative phosphorylation. However, the oxidative capacity of placenta is suppressed due to MO and GDM. Recently, several studies showed that physical activity during pregnancy enhances oxidative metabolism and improves placental function, which might be partially mediated by exerkines, referring to cytokines elicited by exercise. In addition, as an endocrine organ, placenta secretes cytokines, termed placentokines, including apelin, superoxide dismutase 3, irisin, and adiponectin, which mediate fetal development and maternal metabolism. Possible molecular mechanisms linking maternal exercise and placentokines to placental and fetal development are further discussed. As an emerging field, up to now, available studies are limited, mostly conducted in rodents. Given the epidemics of obesity and metabolic disorders, as well as the prevalence of maternal sedentary lifestyle, the effects of exercise of pregnant women on placental function and placentokine secretion, as well as their impacts on fetal development, need to be further examined.