Development and validation of equations for predicting appendicular skeletal muscle mass in male patients with head and neck cancer and normal hydration status.

OBJECTIVE: Muscle mass is typically assessed by abdominal computed tomography, magnetic resonance imaging, and dual-energy x-ray absorptiometry. However, these tests are not routinely performed in patients with head and neck cancer (HNC), making sarcopenia assessment difficult. The aim of this study was to develop and validate equations for predicting appendicular skeletal muscle mass (ASM) from data obtained in daily medical practice, with bioelectrical impedance analysis (BIA)-measured appendicular skeletal muscle mass (BIA-ASM) as a reference. METHODS: This cross-sectional study included 103 men with HNC who were randomly placed into development and validation groups. The prediction equations for BIA-ASM were developed by multiple regression analysis and validated by Bland-Altman analyses. The estimated skeletal muscle mass index (eSMI) was also statistically evaluated to discriminate the cutoff value for BIA-measured SMI according to the Asian Working Groups for Sarcopenia. RESULTS: Two practical equations, which included 24-h urinary creatinine excretion volume (24hUCrV), handgrip strength (HGS), body weight (BW), and body height (BHt), were developed: ASM (kg) = -39.46 + (3.557 × 24hUCrV [g]) + (0.08872 × HGS [kg]) + (0.1263 × BW [kg]) + (0.2661 × BHt [cm]) if available for 24hUCrV (adjusted R2 = 0.8905), and ASM (kg) = -42.60 + (0.1643 × HGS [kg]) + (0.1589 × BW [kg]) + (0.2807 × BHt [cm]) if not (adjusted R2 = 0.8589). ASM estimated by these two equations showed a significantly strong correlation with BIA-ASM (R > 0.900). Bland-Altman analyses showed a good agreement, and eSMI accuracy was high (>80%) in both equations. CONCLUSIONS: These two equations are a valid option for estimating ASM and diagnosing sarcopenia in patients with HNC in all facilities without special equipment.

The effects of continuous administration of diazepam on the recovery of lesion-induced nystagmus in unilaterally labyrinthectomised rats.

BACKGROUND: Diazepam, a gamma-aminobutyric acid type A receptor agonist, is classified as a vestibular suppressant and is effective in treating acute vertigo. However, its effects on vestibular compensation (VC) remain unclear. OBJECTIVES: We examined the effects of continuous administration of diazepam on the frequency of spontaneous nystagmus (SN) after unilateral labyrinthectomy (UL) as an index of the initial process of VC in rats. MATERIALS AND METHODS: Diazepam was continuously administered at doses of 3.5 and 7.0 mg/kg/day, intraperitoneally, via an osmotic minipump. The frequency of SN beating against the lesion side after UL was measured. Potassium chloride (KCl) solution (1 M) was injected intratympanically to induce SN beating to the injection side. RESULTS: Continuous administration of diazepam significantly and dose-dependently decreased the frequency of SN after UL, and also reduced the x intercept of the nonlinear regression curve of the decline in UL-induced SN with time in rats. However, the continuous administration of diazepam did not affect the frequency of intratympanic KCl-induced SN in the rats. CONCLUSION: These findings suggested that continuous administration of diazepam accelerates the initial process of VC; however, it does not suppress the nystagmus-driving mechanisms in rats.

Muscle mass, quality, and strength; physical function and activity; and metabolic status in cachectic patients with head and neck cancer.

BACKGROUND & AIMS: Cancer cachexia is commonly associated with poor prognosis in patients with head and neck cancer (HNC). However, its pathophysiology and treatment are not well established. The current study aimed to assess the muscle mass/quality/strength, physical function and activity, resting energy expenditure (REE), and respiratory quotient (RQ) in cachectic patients with HNC. METHODS: This prospective cross-sectional study analyzed 64 patients with HNC. Body composition was measured via direct segmental multifrequency bioelectrical impedance analysis, and muscle quality was assessed using echo intensity on ultrasonography images. Muscle strength was investigated utilizing handgrip strength and isometric knee extension force (IKEF). Physical function was evaluated using the 10-m walking speed test and the five times sit-to-stand (5-STS) test. Physical activity was examined using a wearable triaxial accelerometer. REE and RQ were measured via indirect calorimetry. These parameters were compared between the cachectic and noncachectic groups. RESULTS: In total, 23 (36%) patients were diagnosed with cachexia. The cachectic group had a significantly lower muscle mass than the noncachectic group. Nevertheless, there was no significant difference in terms of fat between the two groups. The cachectic group had a higher quadriceps echo intensity and a lower handgrip strength and IKEF than the noncachectic group. Moreover, they had a significantly slower normal and maximum walking speed and 5-STS speed. The number of steps, total activity time, and time of activity (<3 Mets) did not significantly differ between the two groups. The cachectic group had a shorter time of activity (≥3 Mets) than the noncachectic group. Furthermore, the cachectic group had a significantly higher REE/body weight and REE/fat free mass and a significantly lower RQ than the noncachectic group. CONCLUSIONS: The cachectic group had a lower muscle mass/quality/strength and physical function and activity and a higher REE than the noncachectic group. Thus, REE and physical activity should be evaluated to determine energy requirements. The RQ was lower in the cachectic group than that in the noncachectic group, indicating changes in energy substrate. Further studies must be conducted to examine effective nutritional and exercise interventions for patients with cancer cachexia.

Effects of Betahistine on the Development of Vestibular Compensation after Unilateral Labyrinthectomy in Rats.

BACKGROUND: Vestibular compensation (VC) after unilateral labyrinthectomy (UL) consists of the initial and late processes. These processes can be evaluated based on the decline in the frequency of spontaneous nystagmus (SN) and the number of MK801-induced Fos-positive neurons in the contralateral medial vestibular nucleus (contra-MVe) in rats. Histamine H3 receptors (H3R) are reported to be involved in the development of VC. OBJECTIVE: We examined the effects of betahistine, an H3R antagonist, on the initial and late processes of VC in UL rats. METHODS: Betahistine dihydrochloride was continuously administered to the UL rats at doses of 100 and 200 mg/kg/day using an osmotic minipump. MK801 (1.0 mg/kg) was intraperitoneally administered on days 7, 10, 12, and 14 after UL, while Fos-positive neurons were immunohistochemically stained in the contra-MVe. RESULTS: The SN disappeared after 42 h, and continuous infusion of betahistine did not change the decline in the frequency of SN. The number of MK801-induced Fos-positive neurons in contra-MVe significantly decreased on days 7, 10, and 12 after UL in a dose-dependent manner in the betahistine-treated rats, more so than in the saline-treated rats. CONCLUSION: These findings suggest that betahistine facilitated the late, but not the initial, process of VC in UL rats.

Comparative study of anti-vertiginous and anti-anxious drugs for the treatment of chronic vestibular patients with secondary anxiety.

Background: Regarding the relationship between psychiatric disorders and dizziness, anxiety is the most frequently seen psychiatric disorder in dizzy patients. Objective: We compared the effects of anti-anxious benzodiazepines (loflazepate) and anti-vertiginous cholinergic antagonist (diphenidol) on the subjective symptoms in chronic vestibular patients with secondary anxiety. Methods: Forty-three patients who had chronic dizziness lasting more than three months due to organic vestibular diseases with secondary anxiety. Anxiety was evaluated by the State-Trait Anxiety Inventory (STAI). Subjective handicaps due to dizziness were assessed by the validated questionnaire consisted of 14 questions that were categorized into two physical and three emotional factors. During the initial six months of the study, 21 patients were treated by anti-anxious benzodiazepines (loflazepate, 2 mg/day) for four weeks, whereas anti-vertiginous cholinergic antagonist (diphenidol, 75 mg/day) was used for four weeks for other 22 patients during the later six months-period. Subjective handicaps and STAI were compared between pre- and post-treatment. Results: Loflazepate improved not only three emotional factors and state anxiety but also one of the physical factors. Diphenidol improved two physical factors but no emotional factors nor state and trait anxiety. Conclusions: Targeting for comorbid anxiety was beneficial for subjective symptoms of chronic dizziness with secondary anxiety.