Salivary and serum insulin-like growth factor (IGF-1) assays in anorexic patients

The influence of anorexia nervosa on oral health and related parameters potentially relevant to orthodontic treatment: a systematic review and meta-analysis

OBJECTIVES

Information on the oral health of patients with anorexia nervosa remains not satisfactory. The aim of this systematic review is to evaluate oral health parameters in anorexic patients compared to healthy individuals. Furthermore, potential clinical implications for orthodontic treatment are discussed from an orthodontic perspective.

MATERIALS AND METHODS

Electronic databases were searched for case-control and controlled clinical trial studies on dentofacial manifestations in anorexic patients up to 2/2024. Study selection, data extraction and risk of bias assessment was done independently by two authors. Random-effects meta-analyses of mean differences (MDs) or relative risks (RRs) with their 95% confidence intervals (CIs) were conducted, followed by sensitivity analyses.

RESULTS

Eleven out of 573 initially identified studies were included. They involved oral health analyses of general anorexic patients ≥ 12 years (mean age 18.4). The meta-analysis showed that anorexia nervosa was associated with a significantly increased caries experience (DMFT), plaque accumulation and gingival inflammation (BOP). PH and salivary flow rate were significantly altered in patients with anorexia nervosa, although no significant relationship between α-amylase levels and anorexia nervosa was demonstrated.

CONCLUSIONS

These data enabled us to formulate modalities for anorexia-specific orthodontic treatments. Based on the results, patients with anorexia nervosa exhibit an increased risk of caries and gingival inflammatory signs.

CLINICAL RELEVANCE

The systematic information on dentofacial manifestations obtained in this study should be considered to better manage the oral health of anorexia patients.

Challenges of insulin-like growth factor-1 testing

Insulin-like growth factor 1 (IGF-1), primarily synthesized in the liver, was initially discovered due to its capacity to replicate the metabolic effects of insulin. Subsequently, it emerged as a key regulator of the actions of growth hormone (GH), managing critical processes like cell proliferation, differentiation, and apoptosis. Notably, IGF-1 displays a longer half-life compared to GH, making it less susceptible to factors that may affect GH concentrations. Consequently, the measurement of IGF-1 proves to be more specific and sensitive when diagnosing conditions such as acromegaly or GH deficiency. The recognition of the existence of IGFBPs and their potential to interfere with IGF-1 immunoassays urged the implementation of various techniques to moderate this issue and provide accurate IGF-1 results. Additionally, in response to the limitations associated with IGF-1 immunoassays and the occurrence of discordant IGF-1 results, modern mass spectrometric methods were developed to facilitate the quantification of IGF-1 levels. Taking advantage of their ability to minimize the interference caused by IGF-1 variants, mass spectrometric methods offer the capacity to deliver robust, reliable, and accurate IGF-1 results, relying on the precision of mass measurements. This also enables the potential detection of pathogenic mutations through protein sequence analysis. However, despite the analytical challenges, the discordance in IGF-1 reference intervals can be attributed to a multitude of factors, potentially leading to distinct interpretations of results. The establishment of reference intervals for each assay is a demanding task, and it requires nationwide multicenter collaboration among laboratorians, clinicians, and assay manufacturers to achieve this common goal in a cost-effective and resource-efficient manner. In this comprehensive review, we examine the challenges associated with the standardization of IGF-1 measurement methods, the minimization of pre-analytical factors, and the harmonization of reference intervals. Particular emphasis will be placed on the development of IGF-1 measurement techniques using "top-down" or "bottom-up" mass spectrometric methods.

Insulin, but not adiponectin, is detectable in equine saliva using an automated, commercial assay

BACKGROUND

The hormones insulin and adiponectin are commonly measured in equids because of their involvement in endocrinopathic laminitis. These are currently measured in serum/plasma, although jugular venipuncture can cause stress in some animals and may be impossible in needle-shy individuals. However, both hormones can be measured in saliva in other species.

OBJECTIVES

To determine whether [insulin] and [total adiponectin] are detectable in equine saliva using automated assays and whether saliva collection is associated with changes in stress indicators. Additionally, the correlation between serum and salivary [insulin] was investigated.

STUDY DESIGN

In vivo experiment.

METHODS

Paired blood and saliva samples were collected from eight adult ponies at multiple time-points (n = 45 paired samples). [Insulin] and [total adiponectin] were measured using automated assays validated for equine serum/plasma. Blink rates and heart rates were determined, using video recordings and a wearable heart rate monitor respectively, to assess the effects of sample collection on stress indicators compared with a control situation without a stressful stimulus.

RESULTS

[Total adiponectin] was undetectable in saliva. However, salivary [insulin] was measurable with acceptable inter-assay (1.3 ± 0.9%) and intra-assay (1.1 ± 0.6%) variability. Blink and heart rates during saliva collection did not differ significantly from those in the control setting. Serum and salivary [insulin] were not significantly correlated.

MAIN LIMITATIONS

Small sample size comprising native UK ponies; potential sampling bias as animals were recruited to the study partly based on their behaviour during blood sampling; saliva collected from unfasted animals.

CONCLUSIONS

Insulin is measurable in equine saliva using an automated assay currently available in the UK, but further validation and the determination of specific diagnostic thresholds are required. Saliva collection was not associated with changes in stress indicators. Further research is therefore needed to determine the potential of equine saliva as a non-invasive alternative to blood for insulin determination.

Metabolic actions of the growth hormone-insulin growth factor-1 axis and its interaction with the central nervous system

The growth hormone/insulin growth factor-1 axis is a key endocrine system that exerts profound effects on metabolism by its actions on different peripheral tissues but also in the brain. Growth hormone together with insulin growth factor-1 perform metabolic adjustments, including regulation of food intake, energy expenditure, and glycemia. The dysregulation of this hepatic axis leads to different metabolic disorders including obesity, type 2 diabetes or liver disease. In this review, we discuss how the growth hormone/insulin growth factor-1 axis regulates metabolism and its interactions with the central nervous system. Finally, we state our vision for possible therapeutic uses of compounds based in the components of this hepatic axis.

Growth factors in anorexia nervosa: a systematic review and meta-analysis of cross-sectional and longitudinal data

OBJECTIVES

Growth factors are signalling molecules that play roles in the survival, proliferation, migration, and differentiation of cells. Studies have found alterations in specific growth factors in anorexia nervosa (AN).

METHODS

This systematic review and meta-analysis examined articles from three databases, measuring growth factors in AN cross-sectionally and longitudinally, and in recovered AN (rec-AN) cross-sectionally. Random-effects meta-analyses were conducted for brain-derived neurotrophic factor (BDNF) and insulin growth factor-I (IGF-1) for cross-sectional and longitudinal studies.

RESULTS

A total of 82 studies were included: 56 cross-sectional (BDNF: n = 15; IGF-1: n = 41) and 24 longitudinal (BDNF: n = 5; IGF-1: n = 19) were meta-analysed and 20 studies were narratively synthesised. In cross-sectional analyses, BDNF and IGF-1 were lower in AN compared to controls, and BDNF was marginally greater in rec-AN compared to controls. In longitudinal meta-analyses, BDNF and IGF-1 increased from baseline to follow-up. Cross-sectional subgroup analyses revealed no differences in BDNF between controls and AN binge-eating/purging subtypes.

CONCLUSIONS

It is likely that the low BDNF and IGF-1 levels found in AN are consequences of starvation, which are reversible with weight restoration. The increase in BDNF and IGF-1 during therapeutic weight restoration might improve neuroplasticity, which is the basis of learning, and thus psychotherapeutic success.

Characterization of comprehensive dynamic epigenetic changes during human primary Sjögren's syndrome progression

Background

Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by reduced exocrine gland (principally the salivary and lacrimal glands) activity caused by chronic lymphocytic infiltration. Although pSS has been closely associated with an increased risk of mucosa-associated lymphoid tissue (MALT) lymphoma, the dynamic epigenetic changes in the gland cells that accompany the pathogenesis are not entirely understood.

Methods

In this study, we harvested tissue samples from the labial gland with (LG_pSS) or without pSS (LG_NC) before MALT development, as well as the parotid gland with tumor tissues (PG_MALT) and paracancerous tissues (PG_NC) of two pSS patients with MALT lymphoma, and conducted RNA-seq and ChIP-seq for tri-methylated histone 3 lysine 4, 9, 27, 36, and 79 (H3K4/9/27/36/79me3).

Results

Transcriptome landscapes indicated two outcomes of pSS progression with or without MALT lymphoma represented by distinct populations of differentially expressed genes and their functions. Furthermore, the epigenetic atlas of genome-wide H3K4/9/27/36/79me3 was in different stages for various samples, indicating that the variance of H3K4me3 was the earliest event, followed by selective alterations of H3K9/27/36/79me3. These four epigenetic modifications determine the final outcome of pSS progression.

Conclusions

Our results not only advance the understanding of the dynamics of pSS progression and highlight the importance of epigenetic alterations in regulating transcription during this pathological process, but also identify potential therapeutic targets for pSS treatment and lymphoma intervention.

Regulation of GH and GH Signaling by Nutrients

Growth hormone (GH) and insulin-like growth factor-1 (IGF-I) are pleiotropic hormones with important roles in lifespan. They promote growth, anabolic actions, and body maintenance, and in conditions of energy deprivation, favor catabolic feedback mechanisms switching from carbohydrate oxidation to lipolysis, with the aim to preserve protein storages and survival. IGF-I/insulin signaling was also the first one identified in the regulation of lifespan in relation to the nutrient-sensing. Indeed, nutrients are crucial modifiers of the GH/IGF-I axis, and these hormones also regulate the complex orchestration of utilization of nutrients in cell and tissues. The aim of this review is to summarize current knowledge on the reciprocal feedback among the GH/IGF-I axis, macro and micronutrients, and dietary regimens, including caloric restriction. Expanding the depth of information on this topic could open perspectives in nutrition management, prevention, and treatment of GH/IGF-I deficiency or excess during life.

Study of salivary and serum vaspin and total antioxidants in anorexia nervosa

OBJECTIVES

Patients with anorexia nervosa (AN) are primarily at high risk of multiple somatic complications, including oral diseases. In recent years, a number of new molecules that may play a potentially important role in AN progress and prognosis have been identified in saliva, but their exact roles are still poorly understood. Two such group of substances are antioxidants and vaspin. The purpose of this observational, cross-sectional study was to measure both the salivary and serum total antioxidant status (TAS), and vaspin (VASP) concentrations of patients with AN in comparison to an average population.

MATERIAL AND METHODS

Ninety subjects participated (30 patients with AN, 60 matched healthy control subjects). A clinical examination was made, and blood and salivary samples were taken during the acute stage of AN (BMI < 15 kg/m²) in the first week of hospitalization. Enzyme immunoassay (ELISA) suitable for measuring VASP and colorimetric assay for TAS were used.

RESULTS

Anorexic patients had significant reductions in salivary flow, TAS, and an elevation in VASP levels in their saliva and serum. Significant correlations between TAS, VASP, salivary flow, and nutritional status were detected.

CONCLUSION

Determination of TAS and VASP in combined biological material confirmed that saliva might be a reliable non-invasive source of information for potent nutritional biomarkers.

CLINICAL RELEVANCE

Our findings suggest that VASP cannot be excluded, as its increased concentration in saliva is an adaptive mechanism in reduced TAS, one resulting from diminished salivary secretion. It is therefore worth conducting further research aimed at recognizing the role of TAS and VASP in the saliva of underweight patients.

Salivary alpha-amylase, secretory IgA and free cortisol as neurobiological components of the stress response in the acute phase of anorexia nervosa

Objectives One novel hypothesis of the pathogenesis of anorexia nervosa (AN) is the possible role of mental stress in hyperactivity of the autonomic nervous system (ANS) and of the hypothalamic-pituitary-adrenal (HPA) axis. Two components of stress response - salivary alpha-amylase (sAA) and free cortisol - have been proposed. They can be determined in saliva, which closely reflects their concentrations in plasma. The purpose of this study was to measure salivary free cortisol, sAA and their correlation to secretory IgA (sIgA) of patients with AN in comparison to the average population. Methods A controlled clinical trial was designed for a matched group of 47 AN patients and 54 healthy individuals. After clinical examination, unstimulated salivary samples were taken during the acute stage of AN (BMI < 15 kg/m(2)) in the first week of hospitalisation. An enzyme-linked immunosorbent assay (ELISA) suitable for measuring sAA, sIgA and free cortisol were used. Results Anorexic patients exhibited disturbances in sAA secretion, and significantly increased cortisol and sIgA levels with a distinct correlation between these two parameters. Conclusions The behaviour of cortisol, sAA and sIgA levels can be assessed as an effect of stress reaction among AN patients with hyperactivity of the HPA axis and ANS dysregulation. The effect of stress response can be assessed reliably in saliva.