Effects of Chin-Down Maneuver on Pharyngeal Pressure Generation According to Dysphagia and Viscosity.

OBJECTIVE: To demonstrate the effects of chin-down maneuver on swallowing by using high-resolution manometry (HRM). METHODS: HRM data of 20 healthy subjects and 64 dysphagic patients were analyzed. Participants swallowed 5 mL of thin and honey-like liquids in neutral and chin-down positions. HRM was used to evaluate maximal velopharyngeal pressure/area, maximal tongue base pressure/area, maximal pharyngeal constrictor pressure, pre-/post-swallow upper esophageal sphincter (UES) peak pressure, minimal UES pressure, UES activity time, and nadir duration. RESULTS: Compared to the neutral position, the chin-down maneuver significantly increased tongue base pressure in both normal and dysphagic groups as well as for both honey-like and thin viscosities, although the honey-like liquid did not reach statistical significance in the dysphagic group. Regarding pharyngeal constrictors and pre-swallow peak UES pressure, the healthy group showed a significant decrease in thin liquid swallowing and decreasing tendency in honeylike liquid swallowing. UES nadir duration was significantly decreased for honey-like liquid swallowing in the dysphagic group and for both thin and honey-like liquids in the healthy group. UES nadir duration of honey-like and thin flow swallowing in the dysphagia group was 0.26 seconds after the chin-down maneuver, which was severely limited. CONCLUSION: This study showed a different kinetic effect of the chin-down maneuver between the healthy and dysphagic groups, as well as between thin and honey-like viscosities. The chin-down maneuver increased tongue base pressure and decreased UES nadir duration, which the latter was severely limited in dysphagic patients. Therefore, appropriate application of the chin-down maneuver in clinical practice is required.

Application of Automatic Kinematic Analysis Program for the Evaluation of Dysphagia in ALS patients.

Dysphagia in amyotrophic lateral sclerosis (ALS) increases the risk of malnutrition, dehydration, and aspiration pneumonia. Kinematic analysis of videofluoroscopic swallowing study (VFSS) can provide detailed movement of the hyoid bone, revealing abnormalities of swallowing in ALS patients. We developed an automated kinematic analysis program (AKAP) that analyzes the trajectory of the hyoid bone via a visual tracking method. The aim of this study was to investigate the hyoid movement in ALS patients using AKAP and compare it with non-dysphagic subjects. Thirty ALS patients who underwent VFSS in Seoul National University Bundang Hospital between 2015 and 2017 were recruited. For comparison, 30 age-matched control subjects were also enrolled; the same swallowing study was conducted using thin fluid and yogurt. The hyoid bone movement was analyzed by evaluating the vertical and horizontal distances with four peak points (A, B, C, D), and the time of each point were also calculated. With respect to distance parameters, only vertical peak distance (distance between B, D points) during thin fluid swallowing was significantly decreased in ALS patients. (p = 0.038) With respect to temporal parameters, Time ABC, Time ABCD, and Duration C were significantly increased in ALS patients when swallowing both thin fluid and yogurt. (Time ABC p = 0.019, p = 0.002; Time ABCD p = 0.001, p = 0.004; Duration C p = 0.004, p = 0.025 respectively). This result revealed that dysphagia in ALS patient is caused by decreased velocity of hyoid bone movement due to the development of weakness in swallowing-related muscles. The parameters of kinematic analysis could be used to quantitatively evaluate dysphagia in motor neuron disease.

Handgrip Strength in the Korean Population: Normative Data and Cutoff Values.

BACKGROUND: We aimed to report the age- and sex-specific normative data of Korean handgrip strength (HGS) and to establish the cutoffs values of low HGS in Korean populations. METHODS: We analyzed the HGS data of 23,716 Koreans (10,793 men and 12,923 women) from the Korea National Health and Nutrition Examination Survey from 2014 to 2017. The means with standard deviations (SDs) of HGS were calculated for each 5-year interval starting from 10 years of age. To determine the relationship between HGS and body mass index (BMI), correlation analysis was also performed. The sex-specific cutoff values for low HGS were presented by deriving the -2 SD values of healthy young adults. RESULTS: The mean HGS was 39.5±9.3 kg in men and 24.4±5.3 kg in women. The mean HGS increased from 10 to 39 years and peaked at 35-39 years in both men (46.0±7.2 kg) and women (27.2±4.6 kg). Men showed a higher correlation between HGS and BMI (r=0.378) than did women (r=0.134). The cutoff values for low HGS were 29.6 kg for men and 16.8 kg for women for -2 SD below the reference for healthy young adults. CONCLUSION: In Koreans, the mean HGS peaked at 35-39 years in both men and women, and the aging curve of HGS was steeper in men than in women. The cutoff values for low HGS were 29.6 kg and 16.8 kg for men and women, respectively.

The Association between Self-reported Sleep Duration and Body Mass Index among Korean Adolescents.

Previous research has shown that lack of sleep is related to Body Mass Index (BMI) in adolescence. This study was designed to investigate the association between sleep duration and BMI among Korean adolescents. We conducted a school-based cross-sectional study of 3,785 adolescents (males: 58.2%, females: 41.8%) in middle and high school between the ages of 11 and 18 years (mean age 15.26 ± 1.45). Using a self-reported questionnaire, we obtained information regarding weekday sleep duration, weekend sleep duration, height, weight, time spent at private tutoring institutes, socioeconomic status and scores on the Beck Depression Inventory (BDI). We investigated the association between self-reported sleep duration and BMI. After adjusting for confounding factors including age, gender, time spent at private tutoring institutes, academic performance, economic status and BDI scores, longer sleep duration on both weekdays and weekends was associated with decreased BMI (P = 0.002 and P < 0.001, respectively) for both genders. Increased weekend catch-up sleep duration was associated with decreased BMI in females (P = 0.038), but not in males (P = 0.343). The results of the present study indicated that longer sleep duration on weekdays and weekends in adolescents was associated with lower BMI. Longer weekend catch-up sleep may compensate effects of insufficient sleep on BMI for female adolescents.