Mode-specific effects of concentric and eccentric isokinetic training of the hamstring muscle at slow angular velocity on the functional hamstrings-to-quadriceps ratio-a randomized trial.

Background: Previous studies have examined the mode specificity of eccentric and concentric isokinetic training, but have reported conflicting results. Few studies have reported that eccentric and concentric isokinetic training are mode-specific, i.e., they will increase only the eccentric or concentric strength, respectively. Other studies have reported that mode specificity does not exist. Therefore, this study aimed to assess the mode-specific effects of eccentric and concentric isokinetic training of the hamstring muscle at slow angular velocity on eccentric peak torque of the hamstring (PTecc), concentric peak torque of the quadriceps (PTcon), acceleration time of the hamstring (AThams) and quadriceps (ATquad), deceleration time of the hamstring (DThams) and quadriceps (DTquad), time to peak torque of the hamstring (TPThams) and quadriceps (TPTquad), and functional Hamstring-to-Quadriceps ratio (PTecc/PTcon). Subjects: A total of 30 participants were randomly divided into eccentric and concentric groups. Methods: Two groups pre-test-post-test experimental design was used. In the eccentric and concentric groups, eccentric and concentric isokinetic training of hamstring muscle was performed respectively, at an angular velocity of 60°/s for 6 weeks duration. PTecc, PTcon, AThams, ATquad, DThams, DTquad, TPThams, TPTquad, and PTecc/PTcon were measured before and after the completion of training. Results: In the eccentric group, a significant difference (p < 0.05) was observed in PTecc (increased by 21.55%), AThams (decreased by 42.33%), ATquad (decreased by 28.74%), and PTecc/PTcon (increased by 17.59%). No significant difference (p > 0.05) was observed in PTcon, TPThams, TPTquad, DThams, and DTquad. In the concentric group, a significant difference (p < 0.05) was observed in PTecc (increased by 12.95%), AThams (decreased by 27.38%) ATquad (decreased by 22.08%), DTquad (decreased by 26.86%), and PTecc/PTcon (increased by 8.35%). No significant difference (p > 0.05) was observed in PTquad, TPThams, TPTquad, and DThams. Between-group analysis revealed a significant difference (p < 0.05) only in TPTquad; otherwise, in the rest of the parameters, no significant difference (p > 0.05) was observed. Conclusions: Both eccentric and concentric isokinetic training of the hamstring for 6 weeks increased PTecc, PTecc/PTcon, and decreased AThams and ATquad. The effects of eccentric and concentric isokinetic training of the hamstring on PTecc, PTecc/PTcon, AThams, and ATquad were not mode specific.

Obstructive sleep apnea screening in young people: Psychometric validation of a shortened version of the STOP-BANG questionnaire using categorical data methods.

BACKGROUND: The STOP-BANG is an easily administrable questionnaire for the screening of obstructive sleep apnea in adults, which may be adapted for use by young people. Here, we assessed the psychometric properties of the STOP-BN, a shortened version of the STOP-BANG questionnaire, using categorical data methods. METHODS: Four hundred and three young people (age 20.71 ± 1.93 years) were selected by random sampling to participate in this cross-sectional study. Participants completed the STOP-BN, a tool for recording social and demographic characteristics, and the Epworth Sleepiness Scale (ESS), a measure of daytime sleepiness. The obtained data were analyzed using categorical data methods. RESULTS: A two-factor model was identified for the STOP-BN, using the Kaiser's criteria (eigenvalue >1) and the screen test. However, the parallel analysis based on minimum rank, and the cumulative variance criteria (>40%) identified an one-factor model. Factor loadings ranged from 0.364 to 0.745. The identified two-factor model showed acceptable fit as the reported goodness of fit index and weighted root mean square residual were in the ideal range, and the comparative fit index was close to the ideal range. Greatest lower bound to reliability for two factors of the STOP-BN was 0.67 and 0.67, indicating an acceptable internal consistency. A weak to a nonsignificant correlation between the ESS and the STOP-BN score was demonstrated, favoring STOP-BN's divergent validity. CONCLUSION: Categorical methods support the psychometric validity of the STOP-BN in the study population.

Migraine screen questionnaire: further psychometric evidence from categorical data methods.

BACKGROUND: Psychometric investigations of tools used in the screening of migraine including the migraine screen questionnaire (MS-Q), using an adequate statistical approach is needed. We assessed the psychometric properties of the migraine screen questionnaire (MS-Q) using categorical data methods. MATERIAL AND METHODS: A total of 343 students at Mizan-Tepi University, Ethiopia, age range = 18-35 years were selected by a simple random sampling method to participate in a cross-sectional study. The respondents completed the MS-Q, a semi-structured socio-demographic questionnaire, and a visual analog scale for attention (VAS-A). RESULTS: The cumulative variance rule (> 40%), the Kaiser's criteria (Eigenvalue> 1), the Scree test and, the parallel analysis (minimum rank) identified a 1-factor model for the MS-Q with the factor loadings in the range of 0.78 to 0.84. Fit indices favored a 1-factor model of the MS-Q as indicated by comparative fit index (0.993), weighted root mean square residual (0.048), root mean square error of approximation (0.067), the goodness of fit index (1.00), and non-normed fit index (0.987). The values of the Factor Determinacy Index (0.953), marginal reliability (0.909), H-latent (0.909), H-observed (0.727), explained common variance (0.906) and the mean item residual absolute loadings (0.225) further complimented finding of the 1-Factor model. McDonald's Omega (0.903) suggested adequate internal consistency. Discriminative validity was supported by significantly higher scores for the total and all the MS-Q items except one among those with complaints of attention. CONCLUSION: The categorical methods support the psychometric validity of the MS-Q in the study population.

Dimensionality of the Pittsburgh Sleep Quality Index: a systematic review.

BACKGROUND: The Pittsburgh Sleep Quality Index (PSQI) dimensionality is much debated, with the greatest number of reported factor structures. Therefore, this review appraised the methodologies of studies investigating the factor structure of the PSQI. MATERIAL AND METHODS: MEDLINE, PsycInfo, AJOL, BASE, Cochrane Library, Directory of Open Access Journals (Lund University), CINAHL, and Embase were searched systematically to include articles published till 23rd March, 2018. The articles with the objective of factor analysis of the PSQI (20 articles) or with a major section on the same subject (25 articles) were included. There was no limitation about participant characteristics. Descriptive analysis of articles for measures of the suitability of the data for factor analysis, details of the exploratory factor analysis (EFA) and details of the confirmatory factor analysis (CFA) was performed. RESULTS: The analysis used by the majority did not employ the simplest scheme for interpreting the observed data: the parsimony principle. Other shortcomings included under- or non-reporting of sample adequacy measures (11 out of 45 articles), non-use of EFA (20 out of 45 articles), use of EFA without relevant details, non-use of CFA (11 out of 45 articles), and use of CFA without relevant details. Overall, 31 out of 45 articles did not use either EFA or CFA. CONCLUSION: We conclude that the various PSQI factor structures for standard sleep assessment in research and clinical settings may need further validation. TRIAL REGISTRATION: Not applicable because this was a review of existing literature.

Association between sleep quality and inflammatory complement components in collegiate males.

BACKGROUND: An accumulating amount of evidence has linked humoral mediators of inflammation with sleep measures. Nevertheless, important details of this association, in particular the role of the complement components in the context of chronic sleep attributes, have remained largely uncharacterized. MATERIALS AND METHODS: Fifty university students (age, 23.3 ± 3.8 years; BMI, 23.7 ± 2.9 kg/m(2)) completed the study. Four dichotomized sleep measures assessed by the Pittsburgh Sleep Quality Index (PSQI) were used in association analysis using binary logistic regression with complement component 3, 4, and complement factor I (CFI). The sleep measures were defined as sleep quality (good sleep/poor sleep; PSQI ≤5/PSQI >5), bedtime (early/late; before 00:00 h/after 0:00 h), sleep duration (short/normal ≤6 h/>6 h), and sleep onset latency (normal/disturbed; 0-1 score/2-3 score on the PSQI component of sleep latency). RESULTS: The complement component 4 was associated with sleep quality (unadjusted, OR = 1.025, p < 0.05; adjusted for age, OR = 1.025, p < 0.05; adjusted for BMI, OR = 1.027, p < 0.05) and sleep duration (unadjusted, OR = 1.041, p < 0.01; adjusted for age, OR = 1.041, p < 0.01; adjusted for BMI, OR = 1.046, p < 0.01). CFI was associated with bedtime (unadjusted, OR = 0.737, p < 0.01; adjusted for age, OR = 0.717, p < 0.01; adjusted for BMI, OR = 0.677, p < 0.01) and with sleep duration (unadjusted, OR = 0.796, p < 0.05; adjusted for age, OR = 0.796, p < 0.05). CONCLUSION: The findings indicate the importance of the role of complement components in the dynamics of sleep. Therefore, sleep should be assessed in conditions where complement components are affected.

Resistance Training Leads to Clinically Meaningful Improvements in Control of Glycemia and Muscular Strength in Untrained Middle-aged Patients with type 2 Diabetes Mellitus.

BACKGROUND: Previous studies in diverse ethnic groups have reported that progressive resistance training is effective for glycemic control. However, it is unknown whether this form of exercise therapy leads to clinically meaningful changes in metabolic, cardiovascular and anthropometric parameters in Asian Indians. AIM: The study was designed to investigate the efficacy of progressive resistance training on glycemic, musculoskeletal, anthropometric and cardiovascular variables in untrained middle-aged type 2 diabetic patients living in North India. MATERIALS AND METHODS: Forty-eight untrained patients, 35 men and 13 women (mean ± SD age, 44.7 ± 4.2 years), with a diagnosis of type 2 diabetes were randomly divided into 2 groups: A group receiving progressive resistance training and a control group who provided participative involvement. The primary outcomes were glycemic control and muscle strength. Additionally, anthropometric and cardiovascular risk parameters were evaluated at baseline and after intervention or control program at 8 weeks. RESULTS: Mixed ANOVA revealed a significant group-by-time interaction for the main outcomes of the study. Change in glycosylated hemoglobin was mean ± SD, 0.6 ± 0.5 in progressive resistance training group compared to no change in control group (P < .001). Progressive resistance training group showed a greater improvement in upper and lower body muscle strength (P < .001), waist circumference (P = .008), and high density lipoprotein cholesterol (P = .004). However, no significant group-by-time interaction was detected on body weight, total cholesterol, triglycerides, low density lipoprotein cholesterol, and systolic and diastolic blood pressure. CONCLUSIONS: A short-term progressive resistance training program leads to clinically meaningful improvements in glycemic control and muscle strength in untrained middle-aged type 2 diabetic patients of Asian Indian ethnicity.

Total sleep deprivation study in delayed sleep-phase syndrome.

Delayed sleep-phase syndrome (DSPS) is characterized by delayed sleep onset against the desired clock time. It often presents with symptoms of sleep-onset insomnia or difficulty in awakening at the desired time. We report the finding of sleep studies after 24 h total sleep deprivation (TSD) in a 28-year-old DSPS male patient. He had characteristics of mild chronic DSPS, which may have been precipitated by his frequent night shift assignments. The TSD improved the patients sleep latency and efficiency but all other sleep variables showed marked differences.