The Effect of Exercise on the Skin Content of the Reduced Form of NAD and Its Response to Transient Ischemia and Reperfusion in Highly Trained Athletes

Wearable solid-phase microextraction sampling for enhanced detection of volatile analytes in human ears

BACKGROUND

Investigating ear at molecule level is challenging task, since there is a lack of molecular detection by traditional diagnosis techniques such as otologic endoscopy, ear swab culture, and imaging diagnostic technique. Therefore, new development of noninvasive, highly sensitive, and convenient analytical method for investigating human ears is highly needed.

RESULTS

We developed a wearable sampling device for extracting trace analytes in ear by fixing solid-phase microextraction fibers into modified earmuffs (SPME-in-earmuffs). After sampling, SPME fiber was coupled with gas chromatography-mass spectrometry (GC-MS) for identification and quantification of extracted analytes. Enhanced detection of various analytes such as volatile metabolites, exposures, and therapeutic drugs of ears were demonstrated in this work. Particularly, sport-induced metabolic changes such as fatty acids, aldehyde compounds and oxidative produces were found from human ears using this method. Acceptable analytical performances were obtained by using this newly developed method for detecting ear medicines, e.g., low limit of detection (LOD, 0.005-0.021 ng/mL) and limit of quantification (LOQ, 0.018-0.071 ng/mL), excellent linear dynamic responses (R2 > 0.99, ranging from 0.050-8.00 ng/mL), good relative standard deviations (RSDs, 13.19 % ∼ 21.40 %, n = 6) and accuracy (84.43-150.18 %, n = 6) at different concentrations.

SIGNIFICANCE

For the first time, this work provides a simple, convenient, and wearable microextraction method for enhanced detection of trace volatiles in human ears. The enclosed space between ear and earmuff allows headspace SPME sampling of volatile analytes, and thus provides a new wearable method for monitoring ear metabolites and human exposures, showing potential applications in human health, disease diagnosis, and sport science.

Influence of cosmetic foundation cream on skin condition during treadmill exercise

BACKGROUND

There is a growing trend of individuals wearing cosmetics while participating in physical activities. Nonetheless, there remains a need for further understanding regarding the effects of makeup on the facial epidermis during exercise, given the existing knowledge gaps.

PURPOSE

This study aimed to evaluate the effects of a cosmetic foundation cream on skin conditions during physical activity.

METHODS

Forty-three healthy college students, 20 males (26.3 ± 1.5 years) and 23 females (23.1 ± 1.0 years), were enrolled in this study. Foundation cream was applied to participants on half of the face in two different areas (MT: makeup T zone and MU: makeup U zone). The other half of the face served as internal control (T: non-makeup T zone and U: non-makeup U zones). Skin levels of moisture, elasticity, pore, sebum, and oil were measured using a skin analysis device (Aramhuvis, Gyeonggi, Republic of Korea) before and after a 20-min treadmill exercise. Paired t-test and independent t-test were performed for skin condition measurements at pre- and postexercise.

RESULTS

The skin moisture levels in both the T and MT significantly increased after exercise (p < 0.05) (pre-T: 24.5 ± 1.3, post-T: 38.5 ± 3.5 and pre-MT: 18.7 ± 0.7, post-MT: 40.4 ± 4.8). Elasticity also significantly improved in both the T and MT (p < 0.05) (pre-T: 25.6 ± 1.3, post-T: 41.5 ± 3.5 and pre-MT: 20.0 ± 0.9, post-MT: 41.7 ± 3.7). The size of the pores in the T zone observed a significant increase after exercise (p < 0.05) (pre-T: 41.7 ± 2.1, post-T: 47.8 ± 2.4). The sebum levels in the T zone exhibited a reduction following physical activity, whereas there was a notable increase in sebum levels in the makeup zones (p < 0.05) (pre-MT: 2.4 ± 0.7, post-MT:4.2 ± 0.8 and pre MU 1.8 ± 0.34, post MU 4.9 ± 0.9). The oil level was increased in the non-makeup zones (pre-T: 6.1 ± 1.4, post-T: 11.8 ± 2.0 and pre-U: 7.3 ± 1.5, post-U: 11.9 ± 1.9; p < 0.05) and decreased in the makeup zones (pre-MT: 13.3 ± 1.9, post-MT: 7.4 ± 2.3 and pre-MU: 22.1 ± 2.4, post-MU: 3.2 ± 1.0; p < 0.05).

CONCLUSIONS

The findings suggest that using foundation cream during aerobic exercise can reduce skin oil, causing dryness. Additionally, makeup can clog pores and increase sebum production. Therefore, wearing makeup may not be recommended for people with dry skin conditions based on the results of the current study. This research offers important insights to the public, encouraging them to consider the possible consequences of using makeup while exercising.

Effects of Acute Beetroot Juice and Sodium Nitrate on Selected Blood Metabolites and Response to Transient Ischemia: A Crossover Randomized Clinical Trial

BACKGROUND

Modification of the nitrate (NO3)-nitrite (NO2)-nitric oxide (NO) pathway can be induced by oral intake of inorganic NO3 (NIT) or NO3-rich products, such as beetroot juice (BRJ).

OBJECTIVES

The primary aim of this study was to evaluate the plasma changes in betaine, choline, trimethylamine (TMA), trimethylamine N-oxide (TMAO), and NO3/NO2 (NOx) concentrations over 4 h after single oral ingestion of NIT or BRJ. The flow-mediated skin fluorescence (FMSF) method was applied to measure the changes in nicotinamide adenine dinucleotide reduced form (NADH) in response to transient ischemia and reperfusion. We hypothesized that various sources of NO3 may differently affect endothelial and mitochondrial functions in healthy human subjects.

METHODS

In a randomized crossover trial, 8 healthy young adults ingested 800 mg NO3 from either NIT or BRJ on 2 separate days with ≥3 d apart. Venous blood samples were collected every hour, and FMSF determination was applied bihourly.

RESULTS

Plasma betaine and choline concentrations peaked at 1 h after BRJ ingestion, and remained significantly higher than baseline values at all time points (P < 0.001 and P < 0.001, compared to preingestion values). Over time, BRJ was more effective in increasing NOx compared with NIT (fixed-trial effect P < 0.001). Baseline fluorescence decreased after both NIT and BRJ consumption (fixed-time effect P = 0.005). Transient ischemia and reperfusion response increased because of NO3 consumption (fixed-time effect P = 0.003), with no differences between trials (P = 0.451; P = 0.912; P = 0.819 at 0, 2, and 4 h, respectively).

CONCLUSIONS

Acute ingestion of BRJ elevated plasma betaine and choline, but not TMA and TMAO. Moreover, plasma NOx levels were higher in the BRJ trial than in the NIT trial. Various sources of NO3 positively affected endothelial and mitochondrial functions. This trial was registered at clinicaltrials.gov as NCT05004935.

Tissue-specific effects of exercise as NAD+ -boosting strategy: Current knowledge and future perspectives

Nicotinamide adenine dinucleotide (NAD⁺ ) is an evolutionarily highly conserved coenzyme with multi-faceted cell functions, including energy metabolism, molecular signaling processes, epigenetic regulation, and DNA repair. Since the discovery that lower NAD⁺ levels are a shared characteristic of various diseases and aging per se, several NAD⁺ -boosting strategies have emerged. Other than pharmacological and nutritional approaches, exercise is thought to restore NAD⁺ homeostasis through metabolic adaption to chronically recurring states of increased energy demand. In this review we discuss the impact of acute exercise and exercise training on tissue-specific NAD⁺ metabolism of rodents and humans to highlight the potential value as NAD⁺ -boosting strategy. By interconnecting results from different investigations, we aim to draw attention to tissue-specific alterations in NAD⁺ metabolism and the associated implications for whole-body NAD⁺ homeostasis. Acute exercise led to profound alterations of intracellular NAD⁺ metabolism in various investigations, with the magnitude and direction of changes being strongly dependent on the applied exercise modality, cell type, and investigated animal model or human population. Exercise training elevated NAD⁺ levels and NAD⁺ metabolism enzymes in various tissues. Based on these results, we discuss molecular mechanisms that might connect acute exercise-induced disruptions of NAD⁺ /NADH homeostasis to chronic exercise adaptions in NAD⁺ metabolism. Taking this hypothesis-driven approach, we hope to inspire future research on the molecular mechanisms of exercise as NAD⁺ -modifying lifestyle intervention, thereby elucidating the potential therapeutic value in NAD⁺ -related pathologies.

Investigating the Ischaemic Phase of Skin NADH Fluorescence Dynamics in Recently Diagnosed Primary Hypertension: A Time Series Analysis

The reduced form of nicotinamide adenine dinucleotide (NADH) is crucial in cellular metabolism. During hypoxia, NADH accumulation results from anaerobic cytoplasmic glycolysis and impaired mitochondrial function. This study aimed to compare the dynamic changes in the 460-nm forearm skin fluorescence, which reflects cellular NADH content, during transient ischaemia between healthy individuals and patients with newly diagnosed, untreated essential hypertension (HA). Sixteen healthy volunteers and sixty-five patients with HA underwent non-invasive measurement of forearm skin NADH content using the Flow Mediated Skin Fluorescence (FMSF) method at rest and during a 100-s transient ischaemia induced by inflation of the brachial cuff. The fluorescent signal was sampled at 25 Hz. All samples were normalised to the end of the ischaemic phase, which is the most stable phase of the whole recording. Slope values of 1 s linear regressions were determined for every 25-sample neighbouring set. The 1-s slopes in the early phase of skin ischaemia, indicating quicker hypoxia-induced NADH accumulation in skin, were significantly higher in patients with HA than in healthy individuals. These findings suggest that some protecting mechanisms postponing the early consequences of early cellular hypoxia and premature NADH accumulation during skin ischaemia are impaired in patients with untreated HA. Further studies are needed to investigate this phenomenon.

Chronic Fatigue Associated with Post-COVID Syndrome versus Transient Fatigue Caused by High-Intensity Exercise: Are They Comparable in Terms of Vascular Effects?

Purpose

The pathophysiology of chronic fatigue associated with post-COVID syndrome is not well recognized. It is assumed that this condition is partly due to vascular dysfunction developed during an acute phase of infection. There is great demand for a diagnostic tool that is able to clinically assess post-COVID syndrome and monitor the rehabilitation process.

Patients and Methods

The Flow Mediated Skin Fluorescence (FMSF) technique appears uniquely suitable for the analysis of basal microcirculatory oscillations and reactive hyperemia induced by transient ischemia. The FMSF was used to measure vascular circulation in 45 patients with post-COVID syndrome. The results were compared with those for a group of 26 amateur runners before and after high-intensity exercise as well as for a control group of 32 healthy age-matched individuals.

Results

Based on the observed changes in the NOI (Normoxia Oscillatory Index) and RHR (Reactive Hyperemia Response) parameters measured with the FMSF technique, it was found that chronic fatigue associated with post-COVID syndrome is comparable with transient fatigue caused by high-intensity exercise in terms of vascular effects, which are associated with vascular stress in the macrocirculation and microcirculation. Acute and chronic fatigue symptomatology shared similarly altered changes in the NOI and RHR parameters and both can be linked to calcium homeostasis modification.

Conclusion

The NOI and RHR parameters measured with the FMSF technique can be used for non-invasive clinical assessment of post-COVID syndrome as well as for monitoring the rehabilitation process.

Assessment of microvascular function using a novel technique Flow Mediated Skin Fluorescence (FMSF) in patients with diabetic kidney disease: A preliminary study

BACKGROUND

Diabetic kidney disease (DKD) plays an important role in morbidity and mortality in patients with diabetes mellitus. The pathogenesis of this microangiopathy is mainly due to impaired vascular endothelial function. The Flow Mediated Skin Fluorescence (FMSF) method is an innovative, non-invasive tool for assessing the microcirculation function (especially microcirculatory response to hypoxia), also in patients with complications of diabetes mellitus (DM).

MATERIAL AND METHODS

The study was conducted at the Medical University of Lodz, Poland. Total of 84 volunteers including 30 patients with DKD, 33 patients with DM without complications, and 21 healthy subjects underwent microvascular function assessments using FMSF. This technique measures changes in the intensity of nicotinamide adenine dinucleotide (NADH) fluorescence from the skin on the forearm as a function of time, in response to blocking and releasing blood flow in the forearm. In this study we asses two key parameters: Reactive Hyperemia Response (RHR) and Hypoxia Sensitivity [log(HS)] to characterize vascular circulation in patients with DKD and their response to transient ischemia.

RESULTS

The patients with low reactive hyperemic response (the RHR parameter) had a significantly higher sCr than patients with moderate and high RHR value (p < 0.001, p < 0.05, respectively) and a significantly lower eGFR than the patients with moderate and high RHR parameter (p < 0.001, p < 0.01, respectively). The patients with very low and low log(HS) values had a significantly higher sCr than the patients with high log(HS) (p < 0.001, p < 0.01, respectively), and a significantly lower eGFR than the patients with high log(HS) parameter (p < 0.001, p < 0.01, respectively). The patients with very low log(HS) had a significantly higher sCr and a significantly lower eGFR than the patients with moderate (p < 0.05, p < 0.01, respectively). The mean value of the RHR parameter was significantly lower in DKD patients (18.31 ± 5.06 %) compared to both healthy subjects (34.37 ± 8.18 %, p < 0.001) and DM without complications subgroup (28.75 ± 7.12 %, p < 0.001). Similar trends were noted with the mean value of log(HS) parameter in DKD subgroup (1.03 ± 0.5) vs. healthy subjects (1.59 ± 0.53, p < 0.001), and vs. DM without complications subgroup (1.73 ± 0.52, p < 0.001). We observed a significant inverse correlation between the RHR parameter and serum creatinine (sCr) and a significant positive correlations with eGFR (R =  -0.3; p < 0.05, R = 0.61; p < 0.001, respectively). We found also a significant negative correlations of the log(HS) measure with sCr and a significant positive correlations with eGFR (R = -0.33; p < 0.01, R = 0.55; p < 0.001, respectively). We observed also a significant inverse correlation between the RHR and log(HS) parameters and advanced glycation end products (AGEs) (R = -0.6; p < 0.001, R = -0.32; p < 0.01, respectively). The AGEs parameter was also a significantly higher in patients with low RHR parameter than in patients with moderate (p < 0.01) and high (p < 0.001).

CONCLUSIONS

The FMSF technique makes it possible to identify impairments of the microvascular function in patients with DKD. This study confirms that the simple two-parametric approach diagnostic tool perfectly characterizes the state of the microvascular system in diabetic patients with impaired renal function. These preliminary results require further validation in a larger patients cohort.

The Effect of Antihypertensive Drugs on NADH in Newly Diagnosed Primary Hypertension

Background

Some antihypertensive medications alter cellular energy production, presumably by modification of the mitochondrial function. In vivo studies of such effects are challenging in humans. We applied a noninvasive forearm skin measurement of the 460-nm fluorescence specific for the reduced form of nicotinamide adenine dinucleotide (NADH) to study the 6-week effects of four different antihypertensive medications on mitochondrial function using the Flow-Mediated Skin Fluorescence (FMSF).

Methods

In a prospective open-label study, we compared the long-term effects of a 6-week treatment with either amlodipine (5 mg), perindopril (5 mg), nebivolol (5 mg), or metoprolol (50 mg) on the dynamic flow-mediated changes in the skin NADH content in 76 patients (29 women) with untreated primary arterial hypertension (HA). Patients underwent 24-hour ambulatory blood pressure monitoring. To study mitochondrial function, the FMSF was measured at rest, during 100-second ischemia and postischemic reperfusion. The control group consisted of 18 healthy people (7 women).

Results

There were no significant differences in the FMSF parameters between the control and the study group before medication. After the 6-week treatment, all drugs similarly reduced blood pressure. Neither amlodipine, perindopril, nor nebivolol changed the flow-mediated 460-nm skin fluorescence significantly. However, metoprolol raised this fluorescence at rest, during ischemia and reperfusion (P at most <0.05), indicating an increase in the total NADH skin content.

Conclusion

Amlodipine, perindopril, and nebivolol appear neutral for the skin NADH content during the 6-week antihypertensive treatment. Similar treatment with metoprolol increased skin NADH at rest, during ischemia and reperfusion, probably due to an effect on microcirculation and altered mitochondrial function. Explanation of the potential mechanisms behind metoprolol influence on the skin NADH metabolism requires further investigation.

Exercise as a multi-modal disease-modifying medicine in systemic sclerosis: An introduction by The Global Fellowship on Rehabilitation and Exercise in Systemic Sclerosis (G-FoRSS)

Systemic sclerosis (SSc) is a heterogeneous multisystem autoimmune disease whereby its main pathological drivers of disability and damage are vascular injury, inflammatory cell infiltration, and fibrosis. These mechanisms result in diffuse and diverse impairments arising from ischemic circulatory dysfunction leading to painful skin ulceration and calcinosis, neurovascular aberrations hindering gastrointestinal (GI) motility, progressive painful, incapacitating or immobilizing effects of inflammatory and fibrotic effects on the lungs, skin, articular and periarticular structures, and muscle. SSc-related impairments impede routine activities of daily living (ADLs) and disrupt three critical life areas: work, family, social/leisure, and also impact on psychological well-being. Physical activity and exercise are globally recommended; however, for connective tissue diseases, this guidance carries greater impact on inflammatory disease manifestations, recovery, and cardiovascular health. Exercise, through myogenic and vascular phenomena, naturally targets key pathogenic drivers by downregulating multiple inflammatory and fibrotic pathways in serum and tissue, while increasing circulation and vascular repair. G-FoRSS, The Global Fellowship on Rehabilitation and Exercise in Systemic Sclerosis recognizes the scientific basis of and advocates for education and research of exercise as a systemic and targeted SSc disease-modifying treatment. An overview of biophysiological mechanisms of physical activity and exercise are herein imparted for patients, clinicians, and researchers, and applied to SSc disease mechanisms, manifestations, and impairment. A preliminary guidance on exercise in SSc, a research agenda, and the current state of research and outcome measures are set forth.

Non-invasive in vivo human model of post-ischaemic skin preconditioning by measurement of flow-mediated 460-nm autofluorescence

AIMS

Transient ischaemia and reperfusion (TIAR) induce early ischaemic preconditioning (IPC) in different tissues and organs, including the skin. IPC protects tissues by modifying the mitochondrial function and decreasing the amount of the reduced form of nicotinamide adenine dinucleotide (NADH). Skin 460-nm autofluorescence is proportional to the NADH content and can be non-invasively measured during TIAR. We propose a non-invasive in vivo human model of skin IPC for studying the effects of repeated TIARs on the NADH content.

METHODS

Fifty-one apparently healthy volunteers (36 women) underwent three 100-second forearm ischaemia episodes induced by inflation of brachial pressure cuff to the pressure of 60 mmHg above systolic blood pressure, followed by 500-second long reperfusion episodes. Changes in skin NADH content were measured using 460-nm fluorescence before and during each of the three TIARs.

RESULTS

The first two TIARs caused a significant reduction in the skin NADH content before (P = .0065) and during the third ischaemia (P = .0011) and reperfusion (P = .0003) up to 3.0%. During the third TIAR, the increase in skin NADH was 20% lower than during the first ischaemia (P = .0474).

CONCLUSIONS

The measurement of the 460-nm fluorescence during repeated TIARs allows for a non-invasive in vivo investigation of human skin IPC. Although IPC reduces the overall NADH skin content, the most noticeable NADH reduction appears during ischaemia after earlier TIARs. Studying the skin model of IPC may provide new avenues for in vivo physiological, clinical and pharmacological research on mitochondrial metabolism.

Healthy Lifestyle Recommendations: Do the Beneficial Effects Originate from NAD+ Amount at the Cellular Level?

In this review, we describe the role of oxidized forms of nicotinamide adenine dinucleotide (NAD⁺) as a molecule central to health benefits as the result from observing selected healthy lifestyle recommendations. Namely, NAD⁺ level can be regulated by lifestyle and nutrition approaches such as fasting, caloric restriction, sports activity, low glucose availability, and heat shocks. NAD⁺ is reduced with age at a cellular, tissue, and organismal level due to inflammation, defect in NAMPT-mediated NAD⁺ biosynthesis, and the PARP-mediated NAD⁺ depletion. This leads to a decrease in cellular energy production and DNA repair and modifies genomic signalling leading to an increased incidence of chronic diseases and ageing. By implementing healthy lifestyle approaches, endogenous intracellular NAD⁺ levels can be increased, which explains the molecular mechanisms underlying health benefits at the organismal level. Namely, adherence to here presented healthy lifestyle approaches is correlated with an extended life expectancy free of major chronic diseases.

The Skin Interactome: A Holistic "Genome-Microbiome-Exposome" Approach to Understand and Modulate Skin Health and Aging

Higher demands on skin care cosmetic products for strong performance drive intense research to understand the mechanisms of skin aging and design strategies to improve overall skin health. Today we know that our needs and influencers of skin health and skin aging change throughout our life journey due to both extrinsic factors, such as environmental factors and lifestyle factors, as well as our intrinsic factors. Furthermore, we need to consider our microflora, a collection of micro-organisms such as bacteria, viruses, and fungi, which is a living ecosystem in our gut and on our skin, that can have a major impact on our health. Here, we are viewing a holistic approach to understand the collective effect of the key influencers of skin health and skin aging both reviewing how each of them impact the skin, but more importantly to identify molecular conjunction pathways of these different factors in order to get a better understanding of the integrated “genome-microbiome-exposome” effect. For this purpose and in order to translate molecularly the impact of the key influencers of skin health and skin aging, we built a digital model based on system biology using different bioinformatics tools. This model is considering both the positive and negative impact of our genome (genes, age/gender), exposome: external (sun, pollution, climate) and lifestyle factors (sleep, stress, exercise, nutrition, skin care routine), as well as the role of our skin microbiome, and allowed us in a first application to evaluate the effect of the genome in the synthesis of collagen in the skin and the determination of a suitable target for boosting pro-collagen synthesis. In conclusion, we have, through our digital holistic approach, defined the skin interactome concept, as an advanced tool to better understand the molecular genesis of skin aging and further develop a strategy to balance the influence of the exposome and microbiome to protect, prevent, and delay the appearance of skin aging signs and preserve good skin health condition. In addition, this model will aid in identifying and optimizing skin treatment options based on external triggers, as well as helping to design optimal treatments modulating the intrinsic pathways.

The Effect of a 7-Week Training Period on Changes in Skin NADH Fluorescence in Highly Trained Athletes

The study aimed to evaluate the changes of nicotinamide adenine dinucleotide (NADH) fluorescence in the reduced form in the superficial skin layer, resulting from a 7-week training period in highly trained competitive athletes (n = 41). The newly, non-invasive flow mediated skin fluorescence (FMSF) method was implemented to indirectly evaluate the mitochondrial activity by NADH fluorescence. The FMSF measurements were taken before and after an exercise treadmill test until exhaustion. We found that athletes showed higher post-training values in basal NADH fluorescence (pre-exercise: 41% increase; post-exercise: 49% increase). Maximum NADH fluorescence was also higher after training both pre- (42% increase) and post-exercise (47% increase). Similar changes have been revealed before and after exercise for minimal NADH fluorescence (before exercise: 39% increase; after exercise: 47% increase). In conclusion, physical training results in an increase in the skin NADH fluorescence levels at rest and after exercise in athletes.

Flowmotion Monitored by Flow Mediated Skin Fluorescence (FMSF): A Tool for Characterization of Microcirculatory Status

Oscillations in the microcirculation, known as flowmotion, are a well-recognized characteristic of cutaneous blood flow. Since flowmotion reflects the microcirculatory status of the vascular system, which is very often impaired in many diseases and disorders, a quantitative assessment of skin flowmotion could potentially be used to screen for early symptoms of such conditions. In this study, skin flowmotion was monitored using the Flow Mediated Skin Fluorescence (FMSF) technique. The flowmotion parameter was used for quantitative assessment of basal flowmotion both at rest (FM) and during reperfusion [FM(R)] following the post-occlusive reactive hyperemia (PORH). The study population was composed of healthy volunteers between the ages of 30 and 72 (n = 75). The FM parameter showed an inverse dependence relative to age, while the FM(R) parameter was inversely correlated to blood pressure. The FM(R) parameter reflects the strong effect of hypoxia on flowmotion, which is mainly due to increased myogenic activity in the vessels. The FMSF technique appears to be uniquely suited for the analysis of basal flowmotion and the hypoxia response, and may be used for the characterization of microcirculatory status.