Selenium and impaired physical function in US and Spanish older adults

Background

Selenium (Se) is a trace element with a narrow safety margin.

Objectives

To evaluate the cross-sectional and longitudinal dose-response association between Se exposure and measures of impaired physical function and disability in older adults.

Design

NHANES 2011–2014 cross-sectional (US, n = 1733, age ≥60 years) and Seniors-ENRICA-2 2017–2019 cross-sectional and longitudinal (Spain, n = 2548 and 1741, respectively, age ≥65 years) data were analyzed. Whole blood and serum Se levels were measured using inductively coupled plasma-mass spectrometry. Lower-extremity performance was assessed with the Short Physical Performance Battery, and muscle weakness with a dynamometer. Incident mobility and agility limitations, and disability in instrumental activities of daily living (IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders, including physical activity. Results across studies were pooled using random-effects meta-analysis.

Results

Meta-analyzed odds ratios (95% confidence interval) per log2 increase in whole blood Se were 0.54 (0.32; 0.76) for weakness, 0.59 (0.34; 0.83) for impaired lower-extremity performance, 0.48 (0.31; 0.68) for mobility limitations, 0.71 (0.45; 0.97) for agility limitations, and 0.34 (0.12; 0.56) for disability in at least one IADL. Analyses for serum Se in NHANES showed similar results. Findings suggest the inverse association with grip strength is progressive below 140 μg/L (p-value for non-linear trend in the Seniors-ENRICA-2 study = 0.13), and above 140 μg/L (p-value for non-linear trend in NHANES = 0.11). In the Seniors-ENRICA-2 cohort, with a 2.2 year follow-up period, a doubling in baseline Se levels were associated with a lower incidence of weakness [odds ratio (95% confidence interval): 0.45 (0.22; 0.91)], impaired lower-extremity performance [0.63 (0.32; 1.23)], mobility [0.43 (0.21; 0.91)] and agility [0.38 (0.18; 0.78)] limitations.

Discussion

In US and Spanish older adults, Se concentrations were inversely associated with physical function limitations. Further studies are needed to elucidate underlying mechanisms.

Trends in mortality from cutaneous malignant melanoma in Spain (1982-2016): sex-specific age-cohort-period effects

BACKGROUND

Mortality from malignant cutaneous melanoma increased alarmingly during the second half of the 20th century in Spain and other European countries.

OBJECTIVE

The aim was to analyse sex- and age-specific trends in melanoma mortality in Spain in the period 1982-2016.

METHODS

European age-standardized melanoma mortality rates during the period 1982-2016 were calculated from mortality figures provided by the National Statistics Institute. Joinpoint regressions were used to identify significant points of change in trends and to compute average annual per cent change (AAPC). Age-cohort-period models were fitted to explore the effect of these variables on mortality.

RESULTS

During the period 1982-2016, age-standardized melanoma mortality rates increased in Spain from 0.90 to 1.80 deaths per 100 000 people in men and from 0.64 to 1.11 per 100 000 in women, rising noticeably from 1982 to 1995 in both sexes and in all age groups. From the mid-90s different trends were observed depending on sex and age: there was a decrease in mortality in the population younger than 45 years (AAPC -2 in both sexes) and aged 45-64 years (AAPC -1 among men and -0.2 among women), but in the group over 64 years rates continued to increase (AAPC 1.7 and 0.2, respectively, for men and women). The mortality sex ratio decreased in the younger population but increased in older individuals. A cohort effect was observed with lower mortality in the cohorts born after 1943 in men and 1956 in women. There was also a period effect with decreased mortality rates at the beginning of the 1990s.

CONCLUSIONS

Melanoma mortality rates in Spain increased during the last decades of the 20th century; however, later they stabilized in women and began to decrease in younger cohorts and middle-aged men. Promotion of primary and secondary prevention measures should continue, with particular emphasis on males over 65 years.

Physical activity and self-reported health status among adolescents: a cross-sectional population-based study

OBJECTIVES

Little is known about the dose-response relationship between physical activity and health benefits among young people. Our objective was to analyse the association between the frequency of undertaking moderate-to-vigorous physical activity (MVPA) and the self-reported health status of the adolescent population.

DESIGN

Cross-sectional study.

SETTING

All regions of Spain.

PARTICIPANTS

Students aged 11-18 years participating in the Spanish Health Behaviour in School-aged Children survey 2006. A total of 375 schools and 21 188 students were selected.

MAIN OUTCOMES

The frequency of undertaking MVPA was measured by a questionnaire, with the following four health indicators: self-rated health, health complaints, satisfaction with life and health-related quality of life. Linear and logistic regression models were used to analyse the association, adjusting for potential confounding variables and the modelling of the dose-response relationship.

RESULTS

As the frequency of MVPA increased, the association with health benefits was stronger. A linear trend (p<0.05) was found for self-rated health and health complaints in males and females and for satisfaction with life among females; for health-related quality of life this relationship was quadratic for both sexes (p<0.05). For self-reported health and health complaints, the effect was found to be of greater magnitude in males than in females and, in all scales, the benefits were observed from the lowest frequencies of MVPA, especially in males.

CONCLUSIONS

A protective effect of MVPA was found in both sexes for the four health indicators studied, and this activity had a gradient effect. Among males, health benefits were detected from very low levels of physical activity and the magnitude of the relationship was greater than that for females.