Salivary pH as a marker of plasma adiponectin concentrations in Women

Taste Changes and Salivary Flow Rate Disparities in Premenopausal and Postmenopausal Women: Exploring the Zinc Connection

INTRODUCTION

Menopause triggers hormonal changes that can manifest in oral symptoms like dysgeusia, xerostomia, and burning sensations, substantially impacting daily life, including chewing, swallowing, and taste perception. Menopausal women are particularly susceptible to nutritional fluctuations, including variations in zinc levels, which are believed to be linked to taste perception. Taste alterations can render food unappetizing, leading to malnutrition and diminished quality of life. The study aims to assess taste alterations, salivary flow rate, and zinc levels in premenopausal and postmenopausal women, investigating the correlation between these factors.

MATERIALS AND METHODS

This research involved 30 premenopausal and 30 postmenopausal women randomly selected from outpatients at the Department of Oral Medicine and Radiology, Panineeya Institute of Dental Sciences and Research Centre, Hyderabad, India. Saliva samples were collected, unstimulated salivary flow rates were measured, taste perception was evaluated using a whole mouth threshold taste test, and serum zinc levels were assessed.

RESULTS

The study revealed that a significantly higher percentage of postmenopausal women could not identify sucrose taste at concentrations 1 (76.7%, p = 0.017) and concentrations 2 (56.7%, p = 0.007) compared to premenopausal women (43.3%, 20%, respectively). A statistically significant number of postmenopausal women also couldn't identify the bitter taste at concentration 1 (43.3%, p=0.047) compared to premenopausal women. No significant difference in taste perception of salt and sour was observed between both groups at all tested concentrations. In both groups, mean taste perception rankings were similar, with salt being most perceived, followed by sour bitter, and at least with sucrose. Salivary flow rates and zinc levels did not significantly differ between premenopausal and postmenopausal women. The correlation between zinc levels and taste perception was weak and non-significant, indicating that zinc levels were not significant predictors of taste perception in either group.

CONCLUSION

Postmenopausal women exhibited reduced perceptions of sucrose and quinine hydrochloride, potentially impacting eating habits, while taste perception of sodium chloride and citric acid remained relatively consistent. Salivary flow rates and zinc levels were within the normal range for postmenopausal women up to 60 years of age included in the study. The study demonstrated that zinc levels did not significantly influence perception among postmenopausal women, suggesting that taste impairment is a multifactorial phenomenon.

High Glucose Reduces the Paracellular Permeability of the Submandibular Gland Epithelium via the MiR-22-3p/Sp1/Claudin Pathway

Tight junctions (TJs) play an important role in water, ion, and solute transport through the paracellular pathway of epithelial cells; however, their role in diabetes-induced salivary gland dysfunction remains unknown. Here, we found that the TJ proteins claudin-1 and claudin-3 were significantly increased in the submandibular glands (SMGs) of db/db mice and high glucose (HG)-treated human SMGs. HG decreased paracellular permeability and increased claudin-1 and claudin-3 expression in SMG-C6 cells. Knockdown of claudin-1 or claudin-3 reversed the HG-induced decrease in paracellular permeability. MiR-22-3p was significantly downregulated in diabetic SMGs and HG-treated SMG-C6 cells. A miR-22-3p mimic suppressed claudin-1 and claudin-3 expression and abolished the HG-induced increases in claudin-1 and claudin-3 levels in SMG-C6 cells, whereas a miR-22-3p inhibitor produced the opposite effects. Specificity protein-1 (Sp1) was enhanced in diabetic SMGs and HG-treated SMG-C6 cells, which promoted claudin-1 and claudin-3 transcription through binding to the corresponding promoters. A luciferase reporter assay confirmed that miR-22-3p repressed Sp1 by directly targeting the Sp1 mRNA 3′-untranslated region (3′-UTR). Consistently, the miR-22-3p mimic suppressed, whereas the miR-22-3p inhibitor enhanced, the effects of HG on Sp1 expression. Taken together, our results demonstrate a new regulatory pathway through which HG decreases the paracellular permeability of SMG cells by inhibiting miR-22-3p/Sp1-mediated claudin-1 and claudin-3 expression.

A Review of Salivary Diagnostics and Its Potential Implication in Detection of Covid-19

Saliva is an exocrine secretion produced from the salivary glands and has numerous functions, such as cleansing and protection of the oral cavity, antimicrobial effects and aids in digestion. Due to the speedy development in the field of salivaomics, saliva is now well accepted as a pool of biological markers that vary from changes in biochemicals, nucleic acids and proteins to the microflora. Saliva has an immense potential as a diagnostic fluid and offers an edge over other biological fluids as its collection method does not require invasive procedure, economical and is useful for monitoring systemic health. Development of sensitive and precise salivary diagnostic tools and the formulation of defined guidelines following meticulous testing will allow salivary diagnostics to be utilised as chair side tests for various oral and systemic diseases in the near future. The coronavirus disease (Covid-19) pandemic is the biggest challenge and global health crisis for the world since World War Two. Rapid and accurate diagnosis of Covid-19 is crucial in controlling the outbreak in the community and in hospitals. Nasopharyngeal and oropharyngeal swabs are the recommended specimen types for Covid-19 diagnostic testing. The collection of these specimen types requires close contact between healthcare workers and patients and poses a risk of transmission of the virus, causes discomfort and may cause bleeding, especially in patients with condition such as thrombocytopenia. Hence, nasopharyngeal or oropharyngeal swabs are not desirable for sequential monitoring of viral load. Saliva specimens can be obtained easily as the patient is asked to spit into a sterile bottle. The collection of saliva is non-invasive and greatly minimizes the exposure of healthcare workers to Covid-19. Saliva has a high consistency rate of greater than 90% with nasopharyngeal specimens in the detection of respiratory viruses, including coronaviruses. Saliva has also been used in screening respiratory viruses among hospitalized patients without pyrexia or respiratory symptoms. SARS-CoV can be detected in saliva at high titers. Salivary diagnostics is a dynamic field that is being incorporated as part of disease diagnosis, clinical monitoring of systemic health and to make significant clinical decisions for patient care. More research is required to analyze the potential diagnostic of Covid-19 in saliva to develop rapid chair side tests for the detection of Covid-19 and it is also pivotal to improve and develop successful strategies for prevention, especially for dentists and healthcare professionals who are involved in performing aerosol-generating procedures.

Saliva as a diagnostic tool for oral and systemic diseases

Early disease detection is not only vital to reduce disease severity and prevent complications, but also critical to increase success rate of therapy. Saliva has been studied extensively as a potential diagnostic tool over the last decade due to its ease and non-invasive accessibility along with its abundance of biomarkers, such as genetic material and proteins. This review will update the clinician on recent advances in salivary biomarkers to diagnose autoimmune diseases (Sjogren's syndrome, cystic fibrosis), cardiovascular diseases, diabetes, HIV, oral cancer, caries and periodontal diseases. Considering their accuracy, efficacy, ease of use and cost effectiveness, salivary diagnostic tests will be available in dental offices. It is expected that the advent of sensitive and specific salivary diagnostic tools and the establishment of defined guidelines and results following rigorous testing will allow salivary diagnostics to be used as chair-side tests for several oral and systemic diseases in the near future.

Evaluation of salivary adiponectin profile in obese patients

Obesity is a chronic inflammatory disease significantly risen worldwide, especially among children. Adipokines, secreted from adipose tissue, are hormones involved in various cellular processes such as energy metabolism and inflammation. Among the others, adiponectin is gaining increasing interest for its insulin-sentitizing, anti-atherogenic and anti-inflammatory properties. This adipokine undergoes different post-translational modifications, after which it circulates as oligomers of high, medium and low molecular weight (HMW, MMW, LMW); HMW are the most biologically active oligomers. Serum adiponectin levels as well as the amount of its oligomers are inversely correlated to BMI and closely associated with obesity and related diseases. In this study, we analyzed total adiponectin expression and its oligomeric profile in saliva samples from 27 obese compared to 27 age- and sex-matched controls. Moreover, we compared adiponectin oligomerization between serum and saliva samples. The analysis of the different adiponectin oligomers reveals a slightly higher expression of total, HMW and LMW salivary adiponectin in obese patients compared to controls. Finally, FPLC analysis evidenced that HMW oligomers in saliva have a higher molecular weight than in serum confirming the presence of more complex oligomers in saliva, previously identified as super HMW (S-HMW). Saliva is considered a potential source of novel biomarkers for the diagnosis of metabolic disorders. The assessment of total adiponectin and its oligomeric profiles in saliva samples may represent a promising biological marker for the analysis of metabolic diseases.

Comparative Evaluation of the Effect of Menstruation, Pregnancy and Menopause on Salivary Flow Rate, pH and Gustatory Function

OBJECTIVE

There are five situations in a women's life during which hormone fluctuations make them more susceptible to oral health problems - during puberty, at certain points in the monthly menstrual cycle, when using birth control pills, during pregnancy, and at menopause. The present study aimed at evaluating the effect of menstruation, pregnancy and menopause on salivary flow rate, pH and gustatory function.

MATERIALS AND METHODS

The study was carried out on 120 patients including 30 controls (with normal menstrual cycle of 28 to 30 d) and 90 cases (30 patients within three days of menstruation, 30 pregnant and 30 postmenopausal). Paraffin-stimulated saliva samples were obtained by expectoration to calculate salivary flow rate, pH was measured electrometically and patients were prospectively evaluated for gustatory function. Then, whole mouth taste test was performed in which the quality identification and intensity ratings of taste solutions were measured.

RESULTS

No statistically significant difference was found between the groups with respect to salivary flow rate but pH values were significantly lower in post menopausal women (p<0.05). Regarding correct quality identification the results were non-significant. Intensity for taste perception for sucrose was significantly lower in postmenopausal women than intensity of taste perception for other tastes (p<0.05). Also, postmenopausal women reported change in their dietary habits as all of them expressed liking for sweeter food.

CONCLUSION

Reduced salivary flow rate and pH in postmen-opausal women may make them more prone to the occurrence of oral health problems. Also, pregnant and postmenopausal women appeared to have a reduced perception of sucrose, which can alter eating habits, such as intake of more sweet foods whereas no significant difference is observed in taste perception of NaCl, citric acid and quinine hydrochloride between the subjects.

Adiponectin: a manifold therapeutic target for metabolic syndrome, diabetes, and coronary disease?

Adiponectin is the most abundant peptide secreted by adipocytes, being a key component in the interrelationship between adiposity, insulin resistance and inflammation. Central obesity accompanied by insulin resistance is a key factor in the development of metabolic syndrome (MS) and future macrovascular complications. Moreover, the remarkable correlation between coronary artery disease (CAD) and alterations in glucose metabolism has raised the likelihood that atherosclerosis and type 2 diabetes mellitus (T2DM) may share a common biological background. We summarize here the current knowledge about the influence of adiponectin on insulin sensitivity and endothelial function, discussing its forthcoming prospects and potential role as a therapeutic target for MS, T2DM, and cardiovascular disease. Adiponectin is present in the circulation as a dimer, trimer or protein complex of high molecular weight hexamers, >400 kDa. AdipoR1 and AdipoR2 are its major receptors in vivo mediating the metabolic actions. Adiponectin stimulates phosphorylation and AMP (adenosin mono phosphate) kinase activation, exerting direct effects on vascular endothelium, diminishing the inflammatory response to mechanical injury and enhancing endothelium protection in cases of apolipoprotein E deficiency. Hypoadiponectinemia is consistently associated with obesity, MS, atherosclerosis, CAD, T2DM. Lifestyle correction helps to favorably modify plasma adiponectin levels. Low adiponectinemia in obese patients is raised via continued weight loss programs in both diabetic and nondiabetic individuals and is also accompanied by reductions in pro-inflammatory factors. Diet modifications, like intake of fish, omega-3 supplementation, adherence to a Mediterranean dietary pattern and coffee consumption also increase adiponectin levels. Antidiabetic and cardiovascular pharmacological agents, like glitazones, glimepiride, angiotensin converting enzyme inhibitors and angiotensin receptor blockers are also able to improve adiponectin concentration. Fibric acid derivatives, like bezafibrate and fenofibrate, have been reported to enhance adiponectin levels as well. T-cadherin, a membrane-associated adiponectin-binding protein lacking intracellular domain seems to be a main mediator of the antiatherogenic adiponectin actions. The finding of novel pharmacologic agents proficient to improve adiponectin plasma levels should be target of exhaustive research. Interesting future approaches could be the development of adiponectin-targeted drugs chemically designed to induce the activaton of its receptors and/or postreceptor signaling pathways, or the development of specific adiponectin agonists.

Salivary uric acid as a noninvasive biomarker of metabolic syndrome

BACKGROUND

Elevated serum uric acid is associated with obesity, hypertension and metabolic syndrome. Because a linear relationship exists between serum and salivary uric acid (SUA) concentration, saliva testing may be a useful noninvasive approach for monitoring cardiometabolic risk. The goal of this pilot study was to determine if SUA is increased in patients with metabolic syndrome and to investigate correlations between SUA and individual cardiometabolic risk factors.

FINDINGS

Volunteers between the ages of 18 and 65 without conditions known to affect serum uric acid levels were recruited. Height, weight, blood pressure and waist circumference were measured and a full lipid panel along with fasting blood glucose was obtained. Saliva samples were collected and uric acid levels were determined. 78 volunteers, 35% of whom had metabolic syndrome, completed the study. SUA was significantly elevated in patients with metabolic syndrome (p=.002). The incidence of metabolic syndrome in the 4th quartile for SUA was 67% compared to 25% in quartiles1-3 combined. Significant correlations were seen between SUA and systolic blood pressure (r=.440, p=.000), diastolic blood pressure ( r=.304, p=.007), waist circumference (r=.332, p=.003), BMI ( r=.269, p=.018), fasting blood glucose ( r=.341, p=.002), triglycerides (r=.410, p=.000), HDL ( r=.237, p=.036) and the number of cardiometabolic risk factors present (r=0.257, p=.023).

CONCLUSIONS

These results suggest that SUA may be a useful biomarker for noninvasive monitoring of cardiometabolic risk. Larger studies are needed to validate this approach.