The effects of adiposity, muscular strength, cardiorespiratory fitness, and fatigue on gait biomechanics in overweight and obese children.

BACKGROUND: Obesity rates continue to increase in the child population. Muscular strength, cardiorespiratory fitness, and fatigue can potentially affect joint stresses in obese children. The purposes are to examine: (1) the relationship between cardiorespiratory fitness and the change in joint stress pre- to post-fatigue; (2) the predictive value of fitness, adiposity, and muscular strength on joint stresses in fatigued and non-fatigued states; and, (3) the relationships between % body fat from skinfold and air displacement plethysmography. METHODS: Twenty-seven children, with body mass index above the 85th percentile for their age participated in this study. Lower limb joint moments were recorded before and after a fatiguing Progressive Aerobic Cardiovascular Endurance Run protocol. Linear regression was used to assess the relationship between (1) fitness and change in joint stress pre- to post-fatigue, and (2) measures of %body fat using skinfold and plethysmography. Furthermore, Bland-Altman analysis quantified the agreement between measured adiposity using the two methods. FINDINGS: The strongest relationship was observed between fitness and the change in the knee extensor moment pre- to post-fatigue (R2 = 0.24). Regardless of fatigue state, adiposity and strength were identified as the strongest predictors of joint moments. Skinfold estimates were moderately predictive (R2 = 0.56) of %body fat from air displacement plethysmography, and these two measures demonstrated instrument agreement with no proportional bias. INTERPRETATION: Fitness level is not related to changes in biomechanics pre- to post-fatigue in overweight and obese children. Adiposity and lower extremity strength most strongly influenced joint moments in the frontal and sagittal planes.

Observational study of skin and soft-tissue Staphylococcus aureus infection in patients infected with HIV-1 and epidemics of Panton-Valentine leucocidin-positive community-acquired MRSA infection in Osaka, Japan.

BACKGROUND: In patients infected with human immunodeficiency virus (HIV)-1 at our hospital, we observed increases in skin and soft-tissue infections (SSTIs) by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Therefore, we analyzed factors related to CA-MRSA infection and performed a molecular epidemiological investigation. METHODS: HIV-1-infected patients were diagnosed with SSTIs related to S. aureus between 2007 and 2017, and MRSA was classified into community and hospital-acquired types according to published criteria. Information was collected retrospectively from clinical records, and multivariate analysis by logistic regression was performed concerning factors related to CA-MRSA infection. We evaluated the staphylococcal cassette chromosome mec (SCCmec) type, multilocus sequence type, and the presence of genes encoding Panton-Valentine leucocidin (PVL) in 27 MRSA samples isolated during and after 2015. RESULTS: We found 218 episodes of SSTIs in 169 patients, and among initial episodes of SSTIs, the MRSA ratio was higher from 2015 to 2017 relative to that from 2007 to 2014 (88% vs. 44%; p < 0.0001). Multivariate analysis showed that in men having sex with men [MSM; odds ratio (OR): 13] and exhibiting onset during and after 2015 (OR: 5.4), CD4+ cell count ≥200 cells/µL (OR: 5.6) and the presence of lesions in the lower abdomen or buttocks (OR: 9.5) were independent factors related to CA-MRSA infection. Additionally, PVL+/ST8/SCCmec type IV MRSA was the predominant pathogen (22 cases; 81%). CONCLUSIONS: These data describe an increased prevalence of SSTIs due to PVL-positive ST8-MRSA-IV, not previously considered epidemic in Japan, in MSM infected with HIV-1 in Osaka, Japan.