Healthy Young Adult Population Research Articles

The effect of transcranial electrical stimulation on the relief of mental fatigue.

The presence of mental fatigue seriously affects daily life and working conditions. Non-invasive transcranial electrical stimulation has become an increasingly popular tool for relieving mental fatigue. We investigated whether transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS) could be used to alleviate the state of mental fatigue in a population of healthy young adults and compared their effects. We recruited 10 participants for a blank control, repeated measures study. Each participant received 15 min of anodal tDCS, α-tACS, and blank stimulation. Participants were required to fill in the scale, perform the test task and collect ECG signals in the baseline, fatigue and post-stimulus states. We then assessed participants' subjective fatigue scale scores, test task accuracy and HRV characteristics of ECG signals separately. We found that both anodal tDCS and α-tACS significantly (P < 0.05) reduced subjective fatigue and improved accuracy on the test task compared to the blank group, and the extent of change was greater with tACS. For the HRV features extracted from ECG signals. After tACS intervention, SDNN (t = -3.241, P = 0.002), LF (t = -3.511, P = 0.001), LFn (t = -3.122, P = 0.002), LFn/HFn (-2.928, P = 0.005), TP (t = -2.706, P = 0.008), VLF (t = -3.002, P = 0.004), SD2 (t = -3.594, P = 0.001) and VLI (t = -3.564, P = 0.001) showed a significant increasing trend, and HFn (t = 3.122, P = 0.002), SD1/SD2 (t = 3.158, P = 0.002) and CCM_1 (t = 3.106, P = 0.003) showed a significant decreasing trend. After tDCS intervention, only one feature, TINN, showed a significant upward trend (P < 0.05). The other features showed non-significant changes but roughly the same trend as the tACS group. Both tDCS and α-tACS can be effective in relieving mental fatigue, and α-tACS is more effective than tDCS. This study provides theoretical support for tDCS with α-tACS having a alleviating effect on mental fatigue and the use of ECG as a valid objective assessment tool.

Agreement and differences between the equations for estimating muscle and bone mass using the anthropometric method in recreational strength trainees.

The interest in estimating muscle mass (MM) and bone mass (BM) has grown in the sporting arena, and more specifically in recreational strength trainees, leading to the creation of different strategies to assess them. The aims were: 1) to investigate the agreement between different MM and BM formulas, and the muscle-bone index (MBI), and to establish the differences between them, in a healthy young adult population; and 2) to analyze if there are differences between males and females in the comparison of MM, BM and MBI formulas. This study followed a descriptive cross-sectional design. A total of 130 adult active recreational strength trainees were evaluated according to the procedures described by the International Society for the Advancement in Kinanthropometry (ISAK). Estimations were made in kilograms of MM and BM by following the equations by different authors. The results showed significant differences between the values obtained by all the MM and BM formulas in the general sample (p < 0.001), and by the majority of formulas for male and female samples. In the general sample, Lin's coefficient indicated a strong agreement between Kerr, Lee, and Poortmans' MM estimation equations (concordance correlation coefficient (CCC) = 0.96-0.97). However, when stratifying by sex, this agreement persisted only in males (CCC = 0.90-0.94), in contrast with a lack of agreement observed in females (CCC < 0.90). Discrepancies in bone mass agreement were noted both in the general sample (CCC < 0.15) and when stratified by sex (CCC < 0.12). In general, differences were found between the values reported by the MM and BM formulas in recreational strength trainees, without an agreement between them. Sex was shown to significantly influence the differences found. The practical implications are that when comparing an individual with reference tables, other studies, or if analyzing an individual's evolution, the same estimation equation should be used, as they are not interchangeable.

Can hubs of the human connectome be identified consistently with diffusion MRI?

Recent years have seen a surge in the use of diffusion MRI to map connectomes in humans, paralleled by a similar increase in processing and analysis choices. Yet these different steps and their effects are rarely compared systematically. Here, in a healthy young adult population (n = 294), we characterized the impact of a range of analysis pipelines on one widely studied property of the human connectome: its degree distribution. We evaluated the effects of 40 pipelines (comparing common choices of parcellation, streamline seeding, tractography algorithm, and streamline propagation constraint) and 44 group-representative connectome reconstruction schemes on highly connected hub regions. We found that hub location is highly variable between pipelines. The choice of parcellation has a major influence on hub architecture, and hub connectivity is highly correlated with regional surface area in most of the assessed pipelines (ρ > 0.70 in 69% of the pipelines), particularly when using weighted networks. Overall, our results demonstrate the need for prudent decision-making when processing diffusion MRI data, and for carefully considering how different processing choices can influence connectome organization.

Testing the concurrent validity and reliability of a lipowise digital skinfold caliper to assess muscle mass in healthy young adults

The aim of this study was to assess the validity and reliability of a novel tool to assess skinfolds and to compare the muscle mass measured through dual-x-ray-absorptiometry (DXA) and estimated using the Lee equation from the values of the skinfolds and girths in a healthy young adult population. Methods: The present study followed a cross-sectional design, including 38 participants, with 27 males (22.04 ± 5.20 years) and 11 females (21.55 ± 2.39 years). The measurement protocol included a DXA evaluation, basic measurements of body mass and stature, eight skinfolds with two skinfold calipers of different brands (Harpenden and Lipowise), and three girths. The order in which the skinfold calipers were used was randomized. The muscle mass was then calculated using the formula established by Lee et al. Results: No significant differences were found between the two skinfold calipers considering all the outcomes (p > 0.05). The correlation coefficients were between 0.724 and 0.991, which suggest very-large to nearly perfect correlations. The correlations performed revealed that muscle mass estimated from DXA is nearly perfectly correlated with both muscle mass estimated from the data obtained with the Harpenden skinfold caliper (r = 0.955) and muscle mass estimated from the data obtained with the Lipowise skinfold caliper (r = 0.954). From the results, we conclude that Lipowise caliper is an accurate skinfold caliper and it can be an alternative tool for the technician that need to assess body fat or muscle mass in precise, valid and time efficient evaluation. It should be noted that the caution to use skinfold calipers interchangeable with each other when evaluating skinfolds remains a necessity and is advisable to perform the measurements with the same brand and model of skinfold caliper when the purpose is to perform follow-up assessments.

Dual-task changes in gait and brain activity measured in a healthy young adult population

BackgroundDual Task (DT) walking in everyday life is the norm rather than the exception. Complex cognitive-motor strategies are employed during DT and it is necessary to coordinate and regulate neural resources to ensure adequate performance. However, the underlying neurophysiology involved is not fully understood. Therefore, the aim of this study was to examine the neurophysiology and gait kinematics during DT gait. Research questionOur main research question was whether gait kinematics changed during DT walking for healthy young adults and whether this is reflected in brain activity. MethodsTen healthy young adults walked on a treadmill, performed a Flanker test while standing and performed the Flanker test while walking on a treadmill. Electroencephalography (EEG), spatial temporal, and kinematic data was recorded and analyzed. ResultsAverage alpha and beta activities were modulated during DT walking compared to single task (ST) walking while ERPs during the Flanker test showed larger P300 amplitudes and longer latencies for DT compared to standing. Cadence reduced and cadence variability increased during DT compared to ST whilst kinematic results showed that hip and knee flexions decreased, and the center of mass moved slightly back in the sagittal plane. SignificanceIt was found that healthy young adults employed a cognitive-motor strategy that included directing more neural resources to the cognitive task while adopting a more upright posture during DT walking.

Association Between Serum Bicarbonate Levels and Prediabetes and Subclinical Inflammation in Young Healthy Adults: A Cross-sectional Study.

Low bicarbonate, a hallmark of metabolic acidosis is associated with various diseases. This study investigated associations between bicarbonate levels with prediabetes and subclinical inflammation among healthy young adults in Qatar. A cross-sectional study was carried out with 825 participants aged 18-40 years, devoid of any known comorbidities, using data from the Qatar Biobank. For each participant, blood samples were taken for measurements of bicarbonate, prediabetes, and subclinical inflammation biomarkers. Prediabetes was defined using HbA1c between 5.7 and 6.4% and subclinical inflammation was defined using monocyte to high density lipoprotein (HDL) cholesterol ratio (MHR). Associations between bicarbonate levels and the outcomes were analyzed using multivariable linear and logistic regression and then stratified by gender. A total of 825 participants with mean age 29.2 years (5.9) of which 365 (44.2%) were males. After multivariable logistic regression, each unit increase in serum bicarbonate was associated with a 17% decreased risk of prediabetes (OR: 0.83, 95%CI: 0.70-0.99, p=0.034), in males but no association was observed for females. Similarly, after multivariable linear regression, a unit increase in serum bicarbonate was associated with a 0.18 unit decrease in MHR (beta -0.18, 95%CI: -0.29, -0.07, p=0.002), again with no association observed in females. In a healthy young adult population, higher serum bicarbonate levels were inversely associated with both prediabetes and subclinical inflammation in males, but not in females.

Normal values of electrocardiogram among healthy young adult African population

Abstract Background: The study aimed at establishing the normal value of electrocardiographic parameters in healthy young African population, in sub-Saharan Africa, using digital electrocardiogram (ECG) recordings and comparing between males and females. Methods: The study population included 656 healthy young adults from the ages of 15–40 years, undergraduate students, made up of 357 females and 299 males. The study took place in the Department of Human Physiology Laboratory of our University. The 12-lead ECGs were recorded and read using a validated computer program. Various parameters were recorded and the 2nd and 98th percentiles were taken as the normal range of the study population. Results: Findings from our study show some differences from studies made in the same region using manual methods of ECG readings and compared to studies done in other races. The 2nd percentile, median, and 98th percentile of the studied parameters were as follows: PR interval was 102 ms, 140 ms, and 196 ms, respectively, in females and 104 ms, 144 ms, and 202 ms, respectively, in males. P-wave duration was 76 ms, 100 ms, and 126 ms in females and 62 ms, 98 ms, and 130 ms in males, respectively. We found the QTc (Bazett) to be 371 ms, 420 ms, and 467 ms in females and 344 ms, 389 ms, and 442 ms in males, respectively. Frontal QRS axis was − 6°, 53°, and 113° in females and − 11°, 57°, and 108° in males; frontal T axis was − 8°, 36°, and 141° in females and − 127°, 48°, and 75° in males; and QRS-T angle was 8°, 43°, and 115° in females and 25°, 84°, and 153° in males, respectively. Conclusion: This study provided reference values for healthy young Sub-Saharan African population using digital 12-lead ECG. It will serve as a reference for what is normal in our race and also prognosticate and monitor those that are predisposed to developing some cardiovascular diseases in the future.

The influence of refractive state and heterophorias on visual acuity and stereoacuity in healthy young adults

To evaluate associations of refractive error and heterophoria with best-corrected visual acuity and stereoacuity in a population of healthy young adults. Data extracted from the Israeli Defense Forces Air Force candidates database was analyzed retrospectively. Myopia and hyperopia were defined as spherical equivalent of ≤ -0.50 D and ≥ +0.50 D. Cylinder of ≥0.75 D was considered astigmatism. Oblique astigmatism was defined as axis between 30°-60° and 120°-150°. Heterophoria of ≥8Δ for near was considered exo- or esophoria. The study population included 5,491 subjects (75.8% male), with a mean age of 17.6 ± 0.9 years: 2,355 (42.9%) had myopia, 640 (11.6%) had hyperopia, and the rest were emmetropic. Astigmatism was present in 2,006 participants (36.5%), and of those, 619 (30.9%) had oblique astigmatism. Emmetropia was correlated with better best-corrected visual acuity; astigmatism and high hyperopia, with poorer best-corrected visual acuity. A total of 331 subjects (6%) had heterophoria of ≥8Δ; of those, 300 (90.6%) had exophoria and 31 (9.4%) had esophoria. The prevalence of exophoria was higher in the myopic group, and exophoria was not associated with stereoacuity. Esophoria and anisometropia were associated with worse stereoacuity. The best stereopsis was achieved by emmetropic subjects with no astigmatism. Emmetropia is associated with better best-corrected visual acuity and stereoacuity. Astigmatism and high hyperopia are correlated with poorer best-corrected visual acuity. Exophoria does not interfere with stereopsis, but both esophoria and anisometropia do.

Cartilage thickness and bone shape variations as a function of sex, height, body mass, and age in young adult knees

The functional relationship between bone and cartilage is modulated by mechanical factors. Scarce data exist on the relationship between bone shape and the spatial distribution of cartilage thickness. The aim of the study was to characterise the coupled variation in knee bone morphology and cartilage thickness distributions in knees with healthy cartilage and investigate this relationship as a function of sex, height, body mass, and age. MR images of 51 knees from young adults (28.4 ± 4.1 years) were obtained from a previous study and used to train a statistical shape model of the femur, tibia, and patella and their cartilages. Five multiple linear regression models were fitted to characterise morphology as a function of sex, height, body mass, and age. A logistic regression classifier was fitted to characterise morphological differences between males and females, and tenfold cross-validation was performed to evaluate the models’ performance. Our results showed that cartilage thickness and its distribution were coupled to bone morphology. The first five shape modes captured over 90% of the variance and described coupled changes to the bone and spatial distribution of cartilage thickness. Mode 1 (size) was correlated to sex (p < 0.001) and height (p < 0.0001). Mode 2 (aspect ratio) was also correlated to sex (p = 0.006) and height (p = 0.017). Mode 4 (condylar depth) was correlated to sex only (p = 0.024). A logistic regression model trained on modes 1, 2, and 4 could classify sex with an accuracy of 92.2% (95% CI [81.1%, 97.8%]). No other modes were influenced by sex, height, body mass, or age. This study demonstrated the coupled relationship between bone and cartilage, showing that cartilage is thicker with increased bone size, diaphysis size, and decreased femoral skew. Our results show that sex and height influence bone shape and the spatial distribution of cartilage thickness in a healthy young adult population, but body mass and age do not.

Differences between Four Skinfold Calipers in the Assessment of Adipose Tissue in Young Adult Healthy Population.

Background: The aim of this study was to analyze the validity of four different skinfold calipers, as well as to establish the differences between them in a healthy young adult population. Methods: The present study followed a cross-sectional design, including 138 participants, with 69 males (21.46 ± 2.52 years) and 69 females (22.19 ± 2.85 years). The measurement protocol included basic measurements of body mass and stretch stature and eight skinfolds with a Harpenden, Holtain, Slim Guide, and Lipowise. The ∑6 and ∑8 skinfolds and fat mass were calculated. The order in which the skinfold calipers were used was randomized. Results: No significant differences were found in either the Σ6 and Σ8 skinfolds or masses and fat percentages calculated with the skinfolds obtained with the different calipers (p > 0.05), and the inclusion of the covariates of sex, BMI, and hydration status of the participants showed no effect on the differences. The Bland–Altman test showed significant differences between the calipers (p < 0.001). Conclusion: It has been observed that the analyzed calipers have shown validity for the assessment of adiposity-related variables in a male and female sample of non-overweight, young healthy adults, but they are not interchangeable with each other when the assessment is meant to be compared over time or with other samples.

On the Relationship between Corneal Biomechanics, Macrostructure, and Optical Properties.

Optical properties of the cornea are responsible for correct vision; the ultrastructure allows optical transparency, and the biomechanical properties govern the shape, elasticity, or stiffness of the cornea, affecting ocular integrity and intraocular pressure. Therefore, the optical aberrations, corneal transparency, structure, and biomechanics play a fundamental role in the optical quality of human vision, ocular health, and refractive surgery outcomes. However, the inter-relationships of those properties are not yet reported at a macroscopic scale within the hierarchical structure of the cornea. This work explores the relationships between the biomechanics, structure, and optical properties (corneal aberrations and optical density) at a macro-structural level of the cornea through dual Placido–Scheimpflug imaging and air-puff tonometry systems in a healthy young adult population. Results showed correlation between optical transparency, corneal macrostructure, and biomechanics, whereas corneal aberrations and in particular spherical terms remained independent. A compensation mechanism for the spherical aberration is proposed through corneal shape and biomechanics.

Anthropometric, biochemical, and haematological indicators associated with hyperhomocysteinemia and their relation to global DNA methylation in a young adult population

ABSTRACT Increased homocysteine (Hcy) levels have been associated with a higher risk of cardiovascular and neurodegenerative diseases. Passive DNA demethylation has been suggested as one of the mechanisms implicated in the development of these conditions, and most studies have investigated this relationship in older adult populations. Therefore, this study aimed to evaluate the relationship between corporal composition and biochemical and haematological indicators with plasma homocysteine levels and genome-wide methylation (Alu, LINE-1, and SAT2) in a population of healthy young adults (median age, 18 years). We showed that the prevalence of hyperhomocysteinemia was significantly higher in men (18.5%) than in women (6.6%) (P = 0.034). Increased Hcy level was substantially associated with higher levels of body mass index and visceral fat in females, whereas in males, it was significantly associated with reduced red cell distribution width and high-density lipoprotein (HDL) cholesterol (HDL-C) levels and increased low-density lipoprotein/HDL ratio. Hypomethylation of Alu was significantly associated with reduced levels of HDL-C (<40.0 mg dL–1), whereas hypomethylation of LINE-1 and SAT2 was significantly associated with higher levels of skeletal muscle (<39.3%) in males. These results highlight the participation of hormonal factors in regulating Hcy metabolism, primarily in the female population, whereas changes in DNA methylation observed in males might be associated with the consumption of a protein diet with high levels of methionine, independent of increased Hcy levels.

Utility of Smartphone-based real-time report (Ecological Momentary Assessment) in the assessment and monitoring of awake bruxism: A multiple-week interval study in a Portuguese population of university students.

The Ecological Momentary Assessment (EMA) concept was the basis for developing a smartphone application for the on-time report of awake bruxism (AB) activities. This study aims to monitor AB report over time in a population of healthy young adults. A population of young adults recruited among dental students in good general health was recruited. All answered to a questionnaire, including the Oral Behavior Checklist (OBC-1). They were then monitored with a smartphone application for AB report during seven consecutive days and completed three further observation periods (EMA-1, 2 and 3) at one-month intervals. After the third period (EMA-3), participants answered again the OBC questionnaire (OBC-2). Changes over time were described, and Pearson Correlation test was performed to assess the correlation between EMA and OBC items reports. A significance level of p=.01 was set. Thirty-one University students completed the study protocol. Answers to the OBC showed an increase in the prevalence of self-reported bracing and teeth clenching from the first to second report (38.7%-54.8% and 77.4%-90.3%, respectively). A slight increase in the 'relaxed' condition (62.5%-69.0%) was observed with EMA-based smartphone application over time. No correlation between OBC items and EMA was detected between OBC-1 and EMA-1. A moderate positive correlation in bracing report (+0.509, p=.01) and weak positive correlation in teeth contact report (+0.380, p=.05) were found between OBC-2 and EMA-3. Using a smartphone-based approach to AB report may be helpful to monitor AB over time and increase an individual's awareness to recognise actions such as bracing and teeth contact concerning the single-time report.

Memory decay distinguishes subtypes of gist

Memories are thought to become more gist-like over time. Multiple related memories might form generalized memory representations, losing specific details but enhancing or retaining gist. The time course within which gist memory emerges, however, is the subject of less consensus. To address this question, we focused our design on four kinds of gist: inferential gist (relations extracted across non-contiguous events), statistical learning (regularities extracted from a series), summary gist (a theme abstracted from a temporally contiguous series of items), and category gist (characterization of a stimulus at a higher level in the semantic hierarchy). Seventy participants completed memory encoding tasks addressing these types of gist and corresponding retrieval tasks the same evening, the morning after, and one week later, as well as an MRI at a later time point. We found little evidence that gist slowly emerges over time or that gist traces are more resistant to forgetting than detail traces. Instead, we found that initial gist memory shortly after encoding was either retained over time or decayed. Inferential gist and statistical learning were retained over a week, whereas memory for category and summary gist decayed. We discuss several interpretations for differences between these two subtypes of gist. Individual differences in REM or slow-wave sleep and hippocampal volumes did not predict changes in memory for these four kinds of gist in a healthy young adult population.

An examination into the effect of genetic taste status and intensity of carbonation on swallowing and palatability in healthy young adults.

Dysphagia is a highly prevalent condition and affects a wide range of cohorts. A common compensatory strategy to manage dysphagia is diet modification. However, this technique is often associated with poor patient quality of life and adverse long-term effects. Carbonated liquids have shown promise as an alternative compensatory strategy for the management of dysphagia. To examine the effect of genetic taste status and intensity of carbonation on swallowing and palatability in a healthy young adult population. To examine the palatability of carbonated liquids over time. A total of 35 healthy young adults were recruited for this prospective, quantitative cohort study. They each drank 150 ml of still water (SW), lightly carbonated water (LCW) and highly carbonated water (HCW). Swallow function, palatability and genetic taste status were assessed using the timed water swallow test, the hedonic general labelled magnitude scale and participant ratings of the bitterness of propylthiouracil strips, respectively. Participants were divided into groups of supertasters, moderate tasters and non-tasters. A significant difference was found between SW and HCW on three tests of swallow function. Average time per swallow increased (p = 0.03), average swallow velocity decreased (p = 0.001) and average volume per swallow decreased (p = 0.017) on HCW compared with SW. HCW had a greater impact on swallow function than LCW. A significant mean difference in palatability ratings was found across intensity levels of carbonated fluids (p = 0.002), specifically between SW and HCW (p = 0.001). HCW was less palatable than SW. The palatability of carbonated liquids, investigated within a subgroup of five participants, did not decrease after a 24-h period during which participants only drank carbonated liquids (p = 0.102). A significant difference was found between supertasters' (n = 9) (mean = 13.33) and non-tasters' (n = 20) (mean = -24.5) palatability ratings of HCW (p = 0.03). Despite differences in swallow function between SW and HCW, no differences were detected between supertasters' and non-tasters' swallow function on SW, LCW or HCW. Carbonated liquids have the ability to alter swallow function in a healthy young adult population; however, liquids must be highly carbonated in order to have an effect. Additionally, highly carbonated liquids are less palatable than SW, but the palatability of carbonated liquids does not decrease over time. Furthermore, supertasters find HCW more palatable than non-tasters. These findings suggest that carbonated liquids alter swallowing in a healthy population. Further research in a clinical population is needed to better understand the potential role of sensory stimulation as a dysphagia intervention. What is already known on the subject Several studies have found that carbonated liquids have the ability to alter swallow function in both healthy and clinical populations. However, there is a lack of evidence around the optimum intensity of CO2 in carbonated liquids and the palatability of carbonated liquids as well as the palatability of carbonated fluids over time. What this paper adds to existing knowledge The findings from this study suggest that carbonated liquids can alter swallow function in a healthy young adult population, but liquids must be highly carbonated in order to have an effect. HCW is less palatable than SW, but the palatability of carbonated liquids does not decrease over time. Additionally, supertasters find HCW more palatable than non-supertasters (non-tasters). What are the potential or actual clinical implications of this work? The findings from this study suggest that carbonated liquids may be suitable for use as a sensory stimulation technique for people with dysphagia, as their palatability does not decrease over time; however, further research in a clinical population is needed in order to determine this. Additionally, intensity of stimulus is an important factor to consider during dysphagia evaluation to identify what intensity is required to optimize swallowing.

Serum MMP-3 and its association with central arterial stiffness among young adults is moderated by smoking and BMI.

Central arterial stiffness is an independent predictor of cardiovascular disease. It is characterized by a marked reduction in the elastin‐collagen ratio of the arterial wall extracellular matrix (ECM), and is largely the result of degradation of various ECM components. Matrix metalloproteinase‐3 (MMP‐3) may contribute to central arterial stiffness via its involvement in ECM homeostasis and remodeling. This study examined the association between serum MMP‐3 concentrations and central arterial stiffness and potential interactions of MMP‐3 and traditional cardiovascular risk factors in a population of healthy young adults. A total of 206 participants (n = 109 females) aged 19–25 years were included in the current study. Central arterial stiffness was measured non‐invasively as carotid‐femoral pulse wave velocity (cfPWV) (m/s). MMP‐3 concentrations (ng/ml) were measured using ELISA techniques. Regression analyses were used to examine the association between cfPWV and MMP‐3, adjusting for age, sex, smoking status, body mass index (BMI), instantaneous mean arterial pressure (MAP) and heart rate, and serum C‐reactive protein. Interactions between MMP‐3 with smoking, BMI, sex, and MAP were analyzed in subsequent regression models. MMP‐3 was an independent predictor of cfPWV (β = 0.187, p = 0.007), and significant interactions between MMP‐3 and regular smoking (β = 0.291, p = 0.022), and MMP‐3 and BMI (β = 0.210, p = 0.013) were observed. Higher serum MMP‐3 concentrations were associated with a faster cfPWV and thus, greater central arterial stiffness. Interactions between MMP‐3 and smoking, and MMP‐3 and BMI may, in part, drive the association between MMP‐3 and central arterial stiffness.

Cosinor-rhythmometry for 24-h urinary sodium, potassium, creatinine excretion in the Chinese adult population.

Background:The low accuracy of equations predicting 24-h urinary sodium excretion using a single spot urine sample contributed to the misclassification of individual sodium intake levels. The application of single spot urine sample is limited by a lack of representativity of urinary sodium excretion, possibly due to the circadian rhythm in urinary excretion. This study aimed to explore the circadian rhythm, characteristics, and parameters in a healthy young adult Chinese population as a theoretical foundation for developing new approaches.Methods:Eighty-five participants (mean age 32.4 years) completed the 24-h urine collection by successively collecting each of the single-voided specimens within 24 h. The concentrations of the urinary sodium, potassium, and creatinine for each voided specimen were measured. Cosinor analysis was applied to explore the circadian rhythm of the urinary sodium, potassium, and creatinine excretion. The excretion per hour was computed for analyzing the change over time with repeated-measures analysis of variance and a cubic spline model.Results:The metabolism of urinary sodium, potassium, and creatinine showed different patterns of circadian rhythm, although the urinary sodium excretion showed non-significant parameters in the cosinor model. A significant circadian rhythm of urinary creatinine excretion was observed, while the circadian rhythm of sodium was less significant than that of potassium. The circadian rhythm of urinary sodium and creatinine excretion showed synchronization to some extent, which had a nocturnal peak and fell to the lowest around noon to afternoon. In contrast, the peak of potassium was observed in the morning and dropped to the lowest point in the evening. The hourly urinary excretion followed a similar circadian rhythm.Conclusion:It is necessary to consider the circadian rhythm of urinary sodium, potassium, and creatinine excretion in adults while exploring the estimation model for 24-h urinary sodium excretion using spot urine.

How Much Superior Rectus Underaction is Considered Normal?

Purpose:It is considered normal to have a small amount of superior rectus weakness in laevo and dextro elevation; however, there is no documented definition for these normal parameters within a healthy young adult population using ocular movement testing and the synoptophore. The aim of this study was to collect normative data on the degree of superior rectus underaction in healthy young adults.Method:Twenty-nine healthy adults (3 males and 26 females, mean age 20.30 ± 1.70 years) were recruited. Superior recti underactions and inferior oblique overactions were recorded during routine ocular movement testing and mean and median values calculated. Subjective horizontal, vertical and torsional measurements were taken in degrees on the synoptophore in primary position, laevo elevation and dextro elevation.Results:Most participants (79.31%) had some degree of observable superior rectus underaction in either eye or in both eyes on ocular movement testing (mean superior rectus underaction of –0.69 units in laevo elevation and –0.71 units in dextro elevation, range = –1.5 to –0.5 units; median –1 units, interquartile range (IQR) = –1 to –1 units). Most participants (62.07%) had some degree of superior rectus underaction in either eye or in both eyes on the synoptophore (mean left and right superior recti underactions of –0.48 degrees, range = –3 to –1 degrees; median 0 degrees, IQR = –1 to –1 degrees).Conclusion:The majority of young healthy adults in this study showed some degree of superior rectus underaction. On ocular movement testing, –0.70 units of underaction, and on the synoptophore, –0.48 degrees of underaction are the mean levels of weakness to be expected. Superior rectus underactions greater than –1 units for ocular movement testing and –1 degrees on the synoptophore in healthy young adults should be carefully evaluated, together with other important clinical signs.

Incidence of radiographic findings of femoroacetabular impingement in a healthy Egyptian population: a cross-sectional study

Background: Femoroacetabular impingement (FAI) is a unique pathological problem affecting young adults. It can be defined as the impingement between the proximal femur and the acetabular rim. Although clinical presentation usually is hip pain, it can be asymptomatic. Radiographic FAI findings are quite common in a population of healthy young adults and must be correlated to the clinical presentation. The aim of our study was to evaluate the incidence of radiographic findings of FAI among a cohort of healthy Egyptian participants. Methods: From March 2017 to April 2019, a cross-sectional study was conducted among a cohort of 160 Egyptians (100 men and 60 women) from 20 to 40 yr old. Anteroposterior and frog-leg lateral views were obtained for 320 hips. By using computer software (ICONICO Screen Protractor, ICONICO, Inc., New York, NY), we measured central edge crossover sign alpha angle and the acetabular index. Results: Pincer type FAI was found in 86 hips on the right side (53.27%) and in 104 hips on the left side (65%). Cam type of FAI was found in 54 hips on the right side (34.2%) and in 54 hips on the left side (34.2%). Mixed type was found in 26 hips on the right side (16.25%) and in 32 hips on the left side (20%). Conclusions: Radiographic FAI findings are quite common in Egyptian healthy young adults who have no hip symptoms. Clinical diagnosis is necessary for FAI and must be correlated with the radiographic data. Level of Evidence: Level II.

Validity and Reliability of the Turkish Version of the Munich Chronotype Questionnaire.

The Morningness-Eveningness Questionnaire (MEQ) has been widely used to determine chronotype. The Munich Chronotype Questionnaire (MCTQ) was developed as an alternative measurement tool to the MEQ, focusing on different sleep behaviors on work and free days. The aim of this study was to adapt the MCTQ to the Turkish language and to validate the questionnaire on young and healthy adult members of the Turkish population. This study was conducted with total of 214 (161 Female, 53 Male) healthy young adult volunteers between the ages of 18-30 (M=20.72, SD=2.33) from Hacettepe University. After adaptation to the Turkish language to form the MCTQ-TR, the psychometric properties were compared with the MEQ-TR. The test retest reliability of the MCTQ-TR was investigated on 25 participants (19 Female, 6 Male), 4 months after the first application. The test-retest reliability coefficient of the MCTQ-TR was calculated as r=0.643 (p<0.05). The validity and reliability results indicated a negative and statistically significant correlation between the MEQ-TR and MCTQ-TR scores (r=-0.627; p<0.001). The MCTQ-TR is a valid and reliable measurement tool that can be used to determine chronotype in healthy Turkish young adult population.