Association Between Plasma 25-hydroxyvitamin D Concentrations and Incident Activities of Daily Living Disability: A Longitudinal Community-Based Cohort Study

Surveillance and Evaluation of Vitamin D Nutrition and Its Health Impact in Chinese Older Adults

Vitamin D is an essential fat-soluble vitamin for humans and vitamin D deficiency (VDD) affects all age groups, with older adults being at high risk of VDD. A deficiency in vitamin D has been associated with a range of health concerns in older adults, including osteomalacia and osteoporosis. Additionally, there is limited evidence suggesting that VDD may be associated with increased risk of developing cognitive impairment, muscle-wasting disorders, cardiovascular disease, type 2 diabetes mellitus, and mortality. This review synthesizes the latest research advances in China and abroad to provide detailed information on the current status of vitamin D nutritional monitoring, causes of deficiency, health risks, and proposed intake for reducing risk of diet-related noncommunicable diseases in the Chinese older adults.

Serum 25-Hydroxyvitamin D and Risk of Disability in Activities of Daily Living among the Oldest-Old: An Observational and Mendelian Randomization Study

BACKGROUND

Vitamin D deficiency and disability are both prevalent among older adults. However, the association between them has rarely been investigated in the oldest-old subjects (aged ≥80 y), and the causality remains unclear.

OBJECTIVE

This study aimed to elucidate the causal effect of vitamin D on the incident risk of disability in activities of daily living (ADL) among Chinese oldest-old based on the 2012-2018 Chinese Healthy Ageing and Biomarkers Cohort Study.

METHODS

Serum 25-hydroxyvitamin D [25(OH)D] concentrations and ADL status at baseline and follow-up interviews were documented. Cox regression models were applied among 1427 oldest-old (mean age, 91.2 y) with normal baseline ADL status. One sample Mendelian randomization (MR) analyses were performed on a subset of 941 participants with qualified genetic data, using a 25(OH)D-associated genetic risk score as the genetic instrument.

RESULTS

During a median follow-up of 3.4 y, 231 participants developed disability in ADL. Serum 25(OH)D concentration was inversely associated with the risk of disability in ADL [per 10 nmol/L increase hazard ratio (HR) 0.85; 95% CI: 0.75, 0.96]. Consistent results from MR analyses showed that a 10 nmol/L increment in genetically predicted 25(OH)D concentration corresponded to a 20% reduced risk of ADL disability (HR 0.80; 95% CI: 0.68, 0.94). Nonlinear MR demonstrated a monotonic declining curve, with the HRs exhibiting a more pronounced reduction among individuals with 25(OH)D concentrations below 50 nmol/L. Subgroup analyses showed that the associations were more distinct among females and those with poorer health conditions.

CONCLUSIONS

Our study supports an inverse causal relationship between serum 25(OH)D concentration and the risk of disability in ADL among Chinese oldest-old. This protective effect was more distinct, especially for participants with vitamin D deficiency. Appropriate measures for improving vitamin D might help reduce the incidence of physical disability in this specific age group.

Long-term exposure to air pollution and incident non-alcoholic fatty liver disease and cirrhosis: A cohort study

BACKGROUND AND AIMS

Epidemiological evidence regarding the association of air pollution with the risk of non-alcoholic fatty liver disease (NAFLD) is limited. This study was to examine the associations of long-term exposure to various air pollutants and overall air pollution with risk of incident NAFLD as well as cirrhosis, a major liver-related morbidity for NAFLD.

METHODS

Included were 456 687 UK residents. Air pollution data included PM_2.5 , PM_2.5-10 , PM₁₀ , NO₂ and NO_x . A weighted air pollution score was also generated from PM₁₀ and NO_x . Cox proportional hazard models were employed to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

We identified 4978 cases of NAFLD and 1575 cases of incident cirrhosis, over a median follow-up of 11.9 years. PM_2.5 , PM₁₀ , NO₂ and NO_x exposures contributed to the excess risk of NAFLD associated with air pollution score; and the corresponding adjusted HRs (95% CI) were 1.10 (1.05, 1.14), 1.14 (1.09, 1.20), 1.19 (1.13, 1.24) and 1.11 (1.07, 1.15), respectively, for each interquartile range increase in the above specific air pollutants. Similar patterns were also indicated for cirrhosis risk. Alcohol consumption was an effect modifier for the association between air pollution score and NAFLD risk, whereas body mass index modified the association for cirrhosis risk.

CONCLUSION

Long-term exposure to air pollution was associated with risks of NAFLD and cirrhosis among the UK population.

Sarcopenia: an unsolved problem after hip fracture

INTRODUCTION

Sarcopenia, loss of muscle mass and strength, leads to functional dependence and disability. To date, no study reported the postoperative change of sarcopenia prevalence after hip fractures. Thus, we assessed postoperative changes in the prevalence of osteoporosis and sarcopenia in hip fracture patients.

MATERIALS AND METHODS

Among 1159 patients, who underwent surgery for low-energy hip fractures between May 2012 and December 2019, 224 patients (38 men and 186 women with a mean age of 76.8 ± 8.7 years) were studied with preoperative and follow-up dual-energy X-ray absorptiometry (DXA). Bone mineral density (BMD) and skeletal muscle mass were measured on DXA scans. The postoperative changes in the prevalence of osteoporosis and that of the sarcopenia were evaluated as well as Koval grade of the hip fracture patients.

RESULTS

While there was no significant change in BMD, SMI significantly decreased postoperatively. Mean decrease of the SMI was 0.53 kg/m2 in men and 0.38 kg/m2 in women. Prevalence of sarcopenia increased from 63 to 89% (p = 0.014) in men and from 45 to 57% (p = 0.006) in women. Lower BMI (Odds ratio (OR) 0.85 (95% confidence interval (CI) 0.76-0.96), p = 0.008) and prior sarcopenia (OR 14.47 (95% CI 5.29-35.39), p < 0.001) were the risk factors for the decrease of SMI after hip fracture.

CONCLUSIONS

After hip fracture, osteoporosis seemed to be well managed and the prevalence of osteoporosis did not increase. However, SMI decreased and the prevalence of sarcopenia increased. More active measures are warranted to prevent sarcopenia in elderly hip fracture patients.

Sex Differences in Vitamin D Status as a Risk Factor for Incidence of Disability in Instrumental Activities of Daily Living: Evidence from the ELSA Cohort Study

Vitamin D deficiency compromises elements underlying the disability process; however, there is no evidence demonstrating the association between vitamin D deficiency and the incidence of disability in instrumental activities of daily living (IADL). We investigated the association between vitamin D deficiency and the risk of incidence of IADL disability separately in men and women. A total of 4768 individuals aged ≥50 years from the English Longitudinal Study of Aging (ELSA) and without IADL disability according to the Lawton scale were available. Vitamin D was evaluated at baseline by serum 25(OH)D concentrations and classified as sufficient (>50 nmol/L), insufficient (>30 to ≤50 nmol/L) or deficient serum (≤30 nmol/L). IADL were reassessed after 4 years. Poisson models stratified by sex and controlled by covariates demonstrated that deficient serum 25(OH)D was a risk factor for the incidence of IADL disability in men (IRR: 1.43; 95% CI 1.02, 2.00), but not in women (IRR: 1.23; 95% CI 0.94, 1.62). Men appear to be more susceptible to the effect of vitamin D deficiency on the incidence of IADL disability, demonstrating the importance of early clinical investigation of serum 25(OH)D concentrations to prevent the onset of disability.

Characterization of the gut microbiota in hemodialysis patients with sarcopenia

PURPOSE

Maintenance hemodialysis (MHD) patients are at high risk of sarcopenia. Gut microbiota affects host metabolic and may act in the occurrence of sarcopenia importantly. This study aimed to study the characterization of the gut microbiota in MHD patients with sarcopenia, and to further reveal the complex pathophysiology of sarcopenia in MHD patients.

METHODS

Fecal samples and clinical data were collected from 30 MHD patients with sarcopenia, and 30 age-and-sex-matched MHD patients without sarcopenia in 1 general hospital of Jiangsu Province from December 2020 to March 2021. 16S rRNA sequencing technology was used to analyze the genetic sequence of the gut microbiota for evaluation of the diversity, species composition, and differential microbiota of the two groups.

RESULTS

Compared to MHD patients without sarcopenia, the ACE index of patients with sarcopenia was lower (P = 0.014), and there was a structural difference in the β-diversity between the two groups (P = 0.001). At the genus level, the relative abundance of Tyzzerella_4 in the sarcopenia group was significantly higher than in the non-sarcopenia group (P = 0.039), and the relative abundance of Megamonas (P = 0.004), Coprococcus_2 (P = 0.038), and uncultured_bacterium_f_Muribaculaceae (P = 0.040) decreased significantly.

CONCLUSION

The diversity and structure of the gut microbiota of MHD patients with sarcopenia were altered. The occurrence of sarcopenia in MHD patients may be influenced by gut microbiota.

Alterations of body composition patterns in pre-dialysis chronic kidney disease patients

PURPOSE

Body mass index (BMI) might be an inaccurate estimate of detailed body composition because it does not differentiate muscle from fat mass. We sought to understand the effect of kidney function decline on alterations of body composition patterns among pre-dialysis CKD patients.

METHODS

Body composition was measured by multi-frequency bioelectrical impedance analysis (BIA). Low muscle mass was defined as appendicular muscle mass (kg) adjusted to the square of height in meters < 7.0 and 5.7 kg/m² in men and women, respectively. The designation of obesity by percent body fat was ≥ 25% in men and ≥ 30% in women. Alternative definition of obesity by BMI was ≥ 25 kg/m². Visceral fat area cut point was > 100 cm² as indication of abdominal obesity.

RESULTS

Mean age of participants was 61.3 ± 13.8 years (n = 103). The average glomerular filtration rate (GFR) was 34.0 ± 24.2 mL/min/1.73 m². By BIA, the prevalence of low muscle mass was 16.5% and was comparable between both sexes. Obesity by percent body fat was identified in 71.8% of patients and 38.2% had abdominal obesity. Using BMI criteria, the prevalence of obesity was less common (55.3%) and associated with under-identification of obesity by 27.0%. Low muscle mass and obesity by percent body fat were more prevalent in the more advanced stages of CKD. By multivariable regression analysis, a 10 mL/min/1.73 m² decline in GFR was associated with a 0.59 kg reduction of total body muscle mass (p = 0.01), but not fat mass or BMI, after adjusting for confounders.

CONCLUSION

Low muscle mass was prevalent among pre-dialysis CKD patients. BMI commonly classified obese CKD individuals by percent body fat criteria as non-obese. The reduction of muscle mass was associated with GFR decline.