Functional capacity, renal function and vitamin D in community-dwelling oldest old

Prevalence of vitamin D deficiency in South America: a systematic review and meta-analysis

CONTEXT

Vitamin D deficiency is considered a global public health issue, even in low-latitude countries where there is abundant sunlight radiation. Nevertheless, the prevalence of vitamin D insufficiency and deficiency in the South American continent has not been well characterized.

OBJECTIVE

The aim of this review was to estimate the prevalence of vitamin D deficiency (25-hydroxy-calciferol < 20 ng/mL) in South American populations.

DATA SOURCES

Seven electronic databases (MEDLINE, Web of Science, Embase, Biblioteca Virtual de Saúde, SciELO, Scopus, and Google Scholar) were searched systematically for observational studies published before July 1, 2021, and reporting vitamin D status of healthy adults in South America.

DATA EXTRACTION

Data were extracted using a standardized form. Risk of bias was assessed by the Joanna Briggs Institute Critical Appraisal Instrument for Studies Reporting Prevalence. All steps were conducted independently by two authors. Data were pooled using a random-effects model. Stratified meta-analysis and meta-regression were conducted (R software).

DATA ANALYSIS

Of 9460 articles identified, 96 studies with a total of 227 758 participants were included. The overall prevalence of vitamin D deficiency was 34.76% (79 studies; 95%CI, 29.68-40.21; I2 = 99%). There were significant differences in prevalence rates related to age, sex, country, latitude, season, and year of publication.

CONCLUSION

The prevalence of vitamin D deficiency is unexpectedly elevated in South American populations. Public health strategies should include efforts to prevent, detect, and treat vitamin D deficiency.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020169439.

Vitamin D status and cognitive performance in community-dwelling adults: A dose-response meta-analysis of observational studies

Low vitamin D status is linked with poorer cognition in adults while findings in relation to high levels are mixed.We performed a systematic review and meta-analyses to examine dose-response associations between 25-hydroxyvitamin D (25OHD) levelsand cognitive performance in community-dwelling adults. Thirty-eight observational studies were included in dose-response meta-analyses. Positive, nonlinear associations were identified between baseline25OHD levels and global cognition incross-sectional and longitudinal analyses, and for performance in memory and executive function in longitudinal analyses. When restricted to studies involving older adults, thepattern emerged forspecific domains in cross-sectional analyses. Poorer performance was associated with low 25OHD levels, while a sharp improvement was associated withlevels up to 60-70 nM/L. Further improvement was observed only for longitudinal global cognition. Our findings support the association between low vitamin D and poorer cognition and suggest levels of at least 60 nM/L are associated with better cognition during ageing.

Serum 25 hydroxyvitamin D concentrations in individuals over 80 years old and their correlations with musculoskeletal and health parameters

PURPOSE

The present study aims to evaluate the serum concentrations of 25 hydroxyvitamin D[25(OH)D] in individuals aged ≥80 years, independent, free-living in Sao Paulo, Brazil (Lat 23.5 ^oS), and to investigate their associations with musculoskeletal system, physical performance and health markers.

METHOD

This cross-sectional study included 212 community dwellers aged ≥80 years and evaluated serum 25(OH)D, PTH, calcium, albumin, phosphorus, creatinine, bone markers, and bone mineral density. Physical performance was evaluated with stationary march, Flamingo, and functional reach tests, questionnaires to assess falls and fractures in the previous year, energy expenditure (MET), and Charlson index. Physical activity was evaluated with the International Physical Activity Questionnaire.

RESULTS

Vitamin D deficiency (<20 ng/mL) was observed in 56% and severe vitamin D deficiency (<10 ng/mL) in 13% of those individuals. Serum concentrations of 25(OH)D were significantly and positively associated with BMD total hip (p = 0.001), femoral neck (p = 0.011) and 33% radius (p = 0.046) BMDs, MET (p = 0.03) and functional reach test (p = 0.037) and negatively with age (p = 0.021), PTH (p = 0.004) and osteoporosis diagnosis (p = 0.012). Long-lived individuals with 25(OH)D ≥ 20 ng/mL had higher total hip and femoral neck BMDs (p = 0.012 and p = 0.014, respectively) and lower PTH (p = 0.030). In multiple linear regression analysis, age and osteoporosis diagnosis remained negatively associated with 25(OH)D levels (p = 0.021 and p = 0.001, respectively), while corrected calcium and cholecalciferol use remained positively associated (p = 0.001 and p = 0.024, respectively).

CONCLUSION

We observed high vitamin D inadequacy prevalence in those Brazilian community dwellers' oldest old. Serum concentrations of 25(OH)D were positively associated with bone mass and dynamic balance, and negatively with PTH and osteoporosis diagnosis. Additionally, 25(OH)D ≥ 20 ng/mL was associated with better bone mass and lower PTH levels.

Grip strength is a strong predictor of survival in nonagenarians and centenarians

Objectives: To understand the importance of hand grip strength (HGS) as a survival predictor in nonagenarians and centenarians. Methods: Longitudinal, observational and analytical study, using HGS measurements obtained during a first evaluation performed in 2016. Participants were nonagenarians and centenarians, randomly selected in various neighborhoods of Porto Alegre (RS) and evaluated in their homes. The time elapsed between the first evaluation and the date of death or last contact (for survivors) was used to calculate the hazard ratio (HR) using survival analysis on simple and adjusted Cox regression models. Results: The sample comprised 212 participants (155 women), of whom 83 (39%) died during follow-up (until August 30, 2019). Using the lowest quartile (25%) for HGS, participants with < 10 kgf for women and 17 kgf for men were considered to have poor HGS performance. In the simple regression model, participants with lower HGS presented a HR of 2.75 (1.76–4.30, p < 0.001) for death. Also in the simple model, participants aged between 90 and 94 years old presented an HR of 0.37 (0.16–0.85, p = 0.019) compared to those aged 100 or older. In the adjusted model, age lost its significance in the presence of HGS. The following were significant predictors in both simple and adjusted models: cognitive performance, calf circumference, ability to participate in social activities, shop, and prepare meals alone, performance in the Timed Up and Go test, and ease to perform activities requiring upper limb strength. Conclusions: HGS was an important independent and modifiable predictor of survival among nonagenarians and centenarians.

Association between baseline Mini-Mental State Examination score and dementia incidence in a cohort of oldest old

BACKGROUND

The Brazilian population has aged rapidly. The oldest old, defined as persons aged 80 years or older, is the fastest growing segment of the Brazilian population. Several instruments have been used to assess the cognitive performance of the older people and predict dementia. One of the most commonly used is the Mini-Mental State Examination (MMSE).

OBJECTIVE

The aim of this study was to investigate the relationship between baseline MMSE score and the incidence of dementia in a Brazilian cohort of independent oldest old.

METHODS

Sociodemographic data and serial cognitive assessment of 248 older adults were analyzed.

RESULTS

Mean follow-up time of subjects was 4.0(±1.9) years, 71.4% were women, and mean MMSE score at entry was 25(±3.5). Mean MMSE scores at baseline were significantly higher (p=0.001) in the cognitively intact group than in those who developed dementia. The logistic regression showed that for a one point increase in MMSE score at baseline there was a 10% reduction in the probability of dementia.

CONCLUSIONS

In the Brazilian scenario of a rapidly growing population of oldest old, the extensive use of the MMSE gives rise to the need not only to determine its effectiveness for screening dementia, but also to interpret its score in terms of future conversion to dementia.