Increased oxidative stress in patients with severe disability: Association with nutrition

Plasma superoxide dismutase activity in relation to disability in activities of daily living and objective physical functioning among Chinese older adults

BACKGROUND

This study aimed to examine the associations of plasma superoxide dismutase (SOD) activity, an indicator of oxidative stress, with disability in activities of daily living (ADL) and objective physical functioning among Chinese older adults.

METHODS

We used cross-sectional data of 2223 older adults (≥65 years, including 1505 adults≥80 years) from the 2011/2012 main survey of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and the 2012 biomarker sub-study. Plasma SOD activity was assessed by the T-SOD assay kit based on the hydroxylamine method. Outcomes included ADL disability and disability in three objective physical tasks (standing up from a chair, picking up a book from the floor, and turning around 360°). Logistic regression models were used to examine the associations of plasma SOD activity with outcomes.

RESULTS

After controlling for age and sex, compared with participants in the lowest quartile group of SOD activity, those in the highest quartile group had 31% lower odds of ADL disability (odds ratio [OR]: 0.69; 95%CI: 0.48, 0.98); 60% lower odds of disability in standing up from a chair (OR: 0.40; 95%CI: 0.25, 0.63); and 57% lower odds of disability in picking up a book from a floor (OR: 0.43; 95%CI: 0.28, 0.65). The results did not change substantially after controlling for additional covariates. We did not observe statistically significant age and sex differences.

CONCLUSIONS

Overall, plasma SOD activity was associated with subjectively and objectively measured disability in Chinese older adults, highlighting the potential of SOD activity to serve as a biomarker of physical functioning.

Associations between Disability and Infertility among U.S. Reproductive-Aged Women

We aim to evaluate the association between self-reported disabilities and infertility and whether disabilities are associated with decreased likelihood of seeking infertility-related care. This US nationally representative cross-sectional analysis includes 3789 non-pregnant women aged 18–49 years without history of hysterectomy or oophorectomy (NHANES, 2013–2018). Disabilities and infertility were both self-reported in personal interviews with trained interviewers. Logistic regression models estimated the adjusted odds ratio (aOR) and 95% confidence intervals for the association between disabilities and infertility and related care seeking. Models adjusted for potential confounders and complex probability sampling. Compared to women without disabilities, women with disabilities (WWD) had higher odds of infertility (aOR: 1.78 (1.31–2.40)). Similar findings were observed for sensory (2.32 (1.52–3.52)) and cognitive disabilities (1.77 (1.28–2.44)). Among women with infertility, WWD were less likely to seek infertility-related care (0.68 (0.32–1.44)) but these estimates were not statistically significant. WWD have increased odds of reporting infertility, and if affected, are less likely to visit a health care provider for this condition. While more research is needed to understand reproductive health issues and needs among WWD, it is important to push for more equitable policies and practices to address the health needs of this underserved population.

Emission-related Heavy Metal Associated with Oxidative Stress in Children: Effect of Antioxidant Intake

Heavy metals, the common pollutants emitted from industrial activities, are believed to cause harmful effects, partially through the mechanism of elevated oxidative stress, and antioxidant intake has been hypothesized to provide a potential protective effect against oxidative stress. This study aims to investigate the heavy metal exposure and the associated oxidative damage of young children living near a petrochemical complex and to assess the protective effect of antioxidant intake. There were 168 children recruited from the kindergartens near a huge petrochemical complex, with 87 as the high exposure group and 81 as the low exposure group. Urinary concentrations of eleven metals were detected by inductively coupled plasma mass spectrometry, and four biomarkers of oxidative stress were measured in urine by liquid chromatography-tandem mass spectrometry. The food frequency questionnaire was collected to assess participants’ intake of antioxidants. Multiple linear regression was performed to determine the predictors of metals for oxidative stress and to measure the beneficial effect of antioxidants. Weighted quantile sum regression was performed to determine the contributors among metals to the oxidative stress. Results showed that high exposure group had significantly higher concentrations of chromium, manganese, nickel, arsenic, strontium, cadmium, and lead when compared to those in low exposure group. There was no obviously difference on the total antioxidant intake and dietary profile between two groups. The elevated levels of two oxidative stress markers were significantly associated with most of the urinary metal concentrations in all study subjects after adjusting confounders, while no significant association was found between oxidative stress and antioxidant intake. Among the metals, mercury and strontium showed the dominated contributions for elevated levels of oxidative stress. It concluded that higher metal exposure was associated with elevated oxidative stress but with no protective effect by antioxidant intake among the young children residents near a petrochemical industry.

Should the Gross Motor Function Classification System be used for children who do not have cerebral palsy?

This literature review addressed four questions. (1) In which populations other than cerebral palsy (CP) has the Gross Motor Function Classification System (GMFCS) been applied? (2) In what types of study, and why was it used? (3) How was it modified to facilitate these applications? (4) What justifications and evidence of psychometric adequacy were used to support its application? A search of PubMed, MEDLINE, and Embase databases (January 1997 to April 2017) using the terms: 'GMFCS' OR 'Gross Motor Function Classification System' yielded 2499 articles. 118 met inclusion criteria and reported children/adults with 133 health conditions/clinical descriptions other than CP. Three broad GMFCS applications were observed: as a categorization tool, independent variable, or outcome measure. While the GMFCS is widely used for children with health conditions/clinical description other than CP, researchers rarely provided adequate justification for these uses. We offer recommendations for development/validation of other condition-specific classification systems and discuss the potential need for a generic gross motor function classification system.

WHAT THIS PAPER ADDS

The Gross Motor Function Classification System should not be used outside cerebral palsy or as an outcome measure. The authors provide recommendations for development and validation of condition-specific or generic classification systems.