Vitamin d and physical activity status: associations with five-year changes in body composition and muscle function in community-dwelling older adults

Association between breakfast skipping and psychosomatic symptoms among Canadian adolescents

This cross-sectional study aimed to examine the mediating roles of gender and substance use in the influence of breakfast skipping on psychosomatic symptoms. The study used data among a nationally-representative sample of 2855 Canadian adolescents who participated in the 2018 Health Behavior in School-aged Children (HBSC) survey. Sequential logistic regressions were used to estimate the associations between breakfast skipping and psychosomatic symptoms. Path analysis using a non-parametric bootstrapping technique tested the hypothesized mediating roles. Results showed that adolescents who skipped breakfast were 2.55 times more likely to report higher psychosomatic symptoms compared to non-breakfast skippers (AOR = 2.55; 95% CI = 1.75-3.82). The bootstrapping mediation models showed that breakfast skipping indirectly influenced psychosomatic symptoms through substance use and gender, accounting for 18.47% ( β = 0.0052, Boots 95% CI = 0.0025, 0.00730) and 10.70% ( β = 0.0091, Boots 95% CI = 0.0052, 0.0125), respectively, of the total effect. Our findings have important implications for targeted public and mental health interventions to address both breakfast skipping and psychosomatic symptoms among adolescents.  Conclusion: The study compellingly underscores the significance of incorporating gender-specific factors and substance use in understanding the correlation between breakfast skipping and psychosomatic symptoms. These insights hold importance for tailoring public health interventions to alleviate the prevalence of psychosomatic symptoms among adolescents by actively addressing breakfast skipping. What is Known: • Breakfast is considered the most important meal of the day due to its role in providing the brain with the energy necessary to enhance cognitive functions. • Adolescents commonly exhibit a prevalent lifestyle behaviour of skipping breakfast. What is New: • This study provides robust evidence supporting the association between breakfast skipping and elevated psychosomatic symptoms in adolescents. • Gender and substance use mediate this association, offering novel insights into the complex interplay that contributes to psychosomatic symptoms among this demographic group. • Longitudinal research is needed to unravel causal relationships and illuminate the underlying mechanisms of this intricate connection.

Problematic social media use and overweight/obesity: explanatory pathway analysis of 124 667 in-school adolescents in 39 high-income countries

BACKGROUND

The relationship between adolescent problematic social media use (PSMU) and overweight/obesity and the potential explanatory pathways for this association are unclear. This study (1) examined the relationship between PSMU and overweight/obesity and (2) evaluated potential explanatory pathways for this association.

METHODS

The data used in this study came from the 2018 Health Behaviour in School-aged Children (HBSC) survey. A sample of 124 667 in-school adolescents from 39 high-income countries was analysed. Sequential logistic regressions were used to estimate the association between PSMU and overweight/obesity. Pathway analysis using a non-parametric bootstrapping technique tested the hypothesized mediating roles.

RESULTS

The multivariable logistic regressions indicated that higher problematic social media users were 1.11 times more likely to be overweight/obese compared with those who reported low PSMU (AOR = 1.11; 95% CI = 1.05-1.18). Our bootstrapping mediation analyses showed that PSMU indirectly influenced overweight/obesity through breakfast skipping, life satisfaction, family communication, self-rated health, and physical activity, accounting for 19.8% (β = 0.0068, Boots 95% CI = 0.0056-0.0074), 15.1% (β = 0.0050, Boots 95% CI = 0.0046-0.0056), 9.2% (β = 0.0031, Boots 95% CI = 0.0024-0.0038), 7.8% (β = 0.0024, Boots 95% CI = 0.001-0.004), and 5.2% (β = 0.0017, Boots 95% CI = 0.0014-0.0023), respectively, of the total effect.

CONCLUSION

To the best of our knowledge, this is the first study that used nationally representative data from multiple countries in high-income countries to examine the association between PSMU and overweight/obesity and potential explanatory pathways among school-going adolescents. This finding has important implications for public health interventions to reduce overweight/obesity rates among young people.

Longitudinal associations of objectively measured physical activity and sedentary time with leg muscle strength, balance and falls in middle-aged women

We examined the longitudinal associations of accelerometer-measured physical activity and sedentary time with leg muscle strength (LMS), balance, and falls in middle-aged women. This was a 5-year cohort study among 308 women aged 36-56 years. We used linear mixed-effects models to examine associations of baseline and change in accelerometer-measured sedentary time, light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) with baseline and 5-year change in LMS and balance (timed up and go test [TUG], functional reach test [FRT], lateral reach test [LRT], and step test [ST]), and negative binomial/Poisson and log-binomial regression as appropriate to assess associations with falls after 5-year follow-up. Greater baseline MVPA was associated with better baseline LMS (β = 4.65 kg/SD, 95% CI: 1.37, 7.93) and TUG (β = -0.09 s/SD, 95% CI: -0.18, -0.01) but not with change in them over 5 years. Baseline MVPA was not associated with FRT at baseline but associated with a greater decrease in FRT (β = -0.87 cm/SD, 95% CI: -1.57, -0.17). Increased MVPA over 5 years was associated with less deterioration in FRT (β = 0.88 cm/SD, 95% CI: 0.14, 1.61). Increased sedentary time over 5 years was associated with a larger decrease in FRT (β = -0.82 cm/SD, 95% CI: -1.58, -0.07). Higher baseline LPA was associated with higher falls risk (IRR = 1.27, 95% CI: 1.02, 1.57). Higher baseline MVPA may benefit LMS and balance, while increasing MVPA in the medium term has little effect on change in these outcomes in mid-life. Detrimental association of LPA with falls may be due to greater exposures to environmental hazards.HighlightsOur study for the first time examined the longitudinal associations of objectively measured physical activity and sedentary time with leg muscle strength, balance and falls in middle-aged women.Higher baseline moderate-to-vigorous physical activity (MVPA) may be beneficial for muscle strength and balance at baseline but increasing MVPA in the medium term has little effect on change in LMS or balance outcomes in middle-aged women.Higher baseline light physical activity (LPA) was associated with an increased risk of falls.The detrimental association of LPA with falls may be due to a greater exposure to environmental hazards in midlife, which needs to be clarified in future research.

Effects of Whey Protein, Leucine, and Vitamin D Supplementation in Patients with Sarcopenia: A Systematic Review and Meta-Analysis

(1) Background: In this study, a meta-analysis was performed to investigate the effects of whey protein, leucine, and vitamin D in sarcopenia; (2) Methods: We searched PubMed, Cochrane Library, Embase, and Scopus databases and retrieved studies published until 5 December 2022. Randomized controlled trials were included to evaluate muscle mass, strength, and function, after using whey protein, leucine, and vitamin D supplementation in patients with sarcopenia; (3) Results: A total of three studies including 637 patients reported the effectiveness of using whey protein, leucine, and vitamin D supplementation in patients with sarcopenia. Without considering whether or not a physical exercise program was combined with nutritional supplementation, no significant differences in grip strength or short physical performance battery (SPPB) scores between the experimental and control groups were noted. However, appendicular muscle mass significantly improved in the experimental group compared to the control group. The results were analyzed according to the presence or absence of a concomitant physical exercise program. With the use of a concomitant physical exercise program, handgrip strength and SPPB scores in the experimental group significantly improved when compared to the control group. In contrast, when physical exercise was not combined, there was no significant improvement in the handgrip strength and SPPB scores of patients with sarcopenia. In addition, the appendicular muscle mass significantly increased regardless of the presence of a concomitant physical exercise program; (4) Conclusions: Whey protein, leucine, and vitamin D supplementation can increase appendicular muscle mass in patients with sarcopenia. In addition, combining a physical exercise program with whey protein, leucine, and vitamin D supplementation can improve muscle strength and function.

Serum vitamin D status and circulating irisin levels in older adults with sarcopenia

Background

Emerging evidence suggests sarcopenia, which is involved in the serum vitamin D deficiency and development of abnormal muscle metabolism, is predominately centered in the general older population. In the present study, we aimed to explore the relationship between the level of serum vitamin D and irisin concentrations in the older adults with sarcopenia.

Methods

A cross-sectional study was conducted which included 422 sarcopenia participants (146 males and 276 females). Sarcopenia was assessed according to the recommended diagnostic criteria of the Asia Working Group for Sarcopenia (AWGS). The levels of serum 25-hydroxyvitamin D (25(OH)D), 25-hydroxyvitamin D₂ (25(OH)D₂) and 25-hydroxyvitamin D₃ (25(OH)D₃) were determined by LC-MS/MS. Irisin levels were measured by enzyme-linked immunosorbent assay (ELISA). The relationship between serum concentration of vitamin D and irisin were determined using multiple linear regression analysis.

Results

After adjustment for potential confounding factors, a significant and positive relationship between changes in irisin across 25(OH)D, and 25(OH)D₃ was observed (standard regression coefficients of 0.150 and 0.151, respectively, P < 0.05). However, no significant relationship was observed between serum vitamin D concentrations and irisin levels in males.

Conclusions

This study demonstrated that a higher level of serum vitamin D is independently related to the increment of irisin in sarcopenia females, not in males. These investigations need to be verified in other large-scale prospective studies.

The Vitamin D/Vitamin D receptor (VDR) axis in muscle atrophy and sarcopenia

Muscle atrophy and sarcopenia (the term given to the age-related decline in muscle mass and function), influence an individuals risk of falls, frailty, functional decline, and, ultimately, impaired quality of life. Vitamin D deficiency (low serum levels of 25-hydroxyvitamin D (25(OH)D₃)) has been reported to impair muscle strength and increase risk of sarcopenia. The mechanisms that underpin the link between low 25(OH)D₃ and sarcopenia are yet to be fully understood but several lines of evidence have highlighted the importance of both genomic and non-genomic effects of active vitamin D (1,25-dihydroxyvitamin D (1,25(OH)₂D₃)) and its nuclear vitamin D receptor (VDR), in skeletal muscle functioning. Studies in vitro have demonstrated a key role for the vitamin D/VDR axis in regulating biological processes central to sarcopenic muscle atrophy, such as proteolysis, mitochondrial function, cellular senescence, and adiposity. The aim of this review is to provide a mechanistic overview of the proposed mechanisms for the vitamin D/VDR axis in sarcopenic muscle atrophy.

Vitamin D and Muscle Health: A Systematic Review and Meta-analysis of Randomized Placebo-Controlled Trials

The objective of this study was to investigate the effects of vitamin D supplementation versus placebo on muscle health. For this systematic review and trial-level meta-analysis of placebo-controlled trials, a systematic search of randomized controlled trials published until October 2020 was performed in Medline, Embase, and Google Scholar. We included studies in humans (except athletes) on supplementation with vitamin D2 or D3 versus placebo, regardless of administration form (daily, bolus, and duration) with or without calcium co-supplementation. The predefined endpoints were physical performance reported as timed up and go test (TUG; seconds), chair rising test (seconds), 6-minute walking distance (m), and Short Physical Performance Battery (SPPB; points). Furthermore, endpoints were maximum muscle strength (Newton) measured at handgrip, elbow flexion, elbow extension, knee flexion, and knee extension, as well as muscle (lean tissue) mass (kg). Falls were not included in the analysis. Cochrane Review Manager (version 5.4.1.) calculating mean difference (MD) using a random effect model was used. In total, 54 randomized controlled trials involving 8747 individuals were included. Vitamin D versus placebo was associated with a significantly longer time spent performing the TUG (MD 0.15 [95% confidence interval (CI) 0.03 to 0.26] seconds, N = 19 studies, I²  = 0%, n = 5223 participants) and a significant lower maximum knee flexion strength (MD -3.3 [-6.63 to -0.03] Newton, N = 12 studies, I²  = 0%, n = 765 participants). Total score in the SPPB showed a tendency toward worsening in response to vitamin D compared with placebo (MD -0.18 [-0.37 to 0.01] points, N = 8 studies, I²  = 0%, n = 856 participants). Other measures of muscle health did not show between-group differences. In subgroup analyses, including studies with low vitamin D levels, effects of vitamin D supplementation did not differ from placebo. Available evidence does not support a beneficial effect of vitamin D supplementation on muscle health. Vitamin D may have adverse effects on muscle health, which needs to be considered when recommending vitamin D supplementation. © 2021 American Society for Bone and Mineral Research (ASBMR).

Correlation between physical activity and cardiovascular risk factors in postmenopausal women from Colombia Caribbean

Postmenopausal period disturbances are more frequently observed in women with unhealthy lifestyles, insufficient physical activity is related to increased cardiovascular risk (CVR). There is a lack of evidence-based information on physical activity in postmenopausal women and its relationship with CVR factors, including D vitamin serum levels.

Objective

To determine the physical activity level in postmenopausal women from the Colombia Caribbean and establish relationships between the physical activity and biochemical and anthropometric CVR factors.

Methods

A correlational descriptive study in which 183 postmenopausal women were linked for convenience sampling. Level of physical activity (International Physical Activity Questionnaire) and their relationships with anthropometric variables, blood pressure, lipid profile, glycemic and serum vitamin D were evaluated.

Results

According to the physical activity, 82.5% of women were classified as inactive, 9.3% as insufficiently active and only 8.2% as physically active. Physical inactivity was significantly related to higher glucose, triglycerides, and total cholesterol serum levels (P < .05). The prevalence of the women with vitamin D levels less than 30 ng/mL were of 69.9%. The women physically active and with eutrophic nutritional condition had more high levels of vitamin D.

Conclusions

82.5% of the postmenopausal women evaluated were physically inactive and this condition was associated with higher serum levels of glycemic, total cholesterol and triglycerides. Serum vitamin D concentrations were higher in traffic and physically active women.

Walking in the Light: How History of Physical Activity, Sunlight, and Vitamin D Account for Body Fat-A UK Biobank Study

OBJECTIVE

The high prevalence of vitamin D deficiency and obesity drives the need for successful strategies that elevate vitamin D levels, prevent adipogenesis, and stimulate lipolysis. This study provides a theoretical model to evaluate how physical activity (PA) and sunlight exposure influence serum vitamin D levels and regional adiposity. This study hypothesized a posteriori that sunlight is associated with undifferentiated visceral adiposity by increasing the ratio of brown to white adipose tissue.

METHODS

Using 10-year longitudinal data, accelerometry, a sun-exposure questionnaire, and regional adiposity quantified by dual-energy x-ray absorptiometry imaging, a structural-equation mediation model of growth curves was constructed with a data-driven methodology.

RESULTS

Sunlight and PA conjointly increased serum vitamin D. Changes in vitamin D levels partially mediated how sunlight and PA impacted adiposity in visceral and subcutaneous regions within a subjective PA model. In an objective PA model, vitamin D was a mediator for subcutaneous regions only. Interestingly, sunlight was associated with less adiposity in subcutaneous regions but greater adiposity in visceral regions.

CONCLUSIONS

Sunlight and PA may increase vitamin D levels. For the first time, this study characterizes a positive association between sunlight and visceral adiposity. Further investigation and experimentation are necessary to clarify the physiological role of sunlight exposure on adipose tissue.

Hypovitaminosis D, Low Bone Mineral Density, and Diabetes Mellitus as Probable Risk Factors for Benign Paroxysmal Positional Vertigo in the Elderly

Introduction  Studies have found that elderly patients with benign paroxysmal positional vertigo (BPPV) may present low levels of vitamin D (25 (OH) D), changes in bone mineral density, and diabetes mellitus (DM).

Objective : To investigate the possible association between BPPV, bone mineral density, hypovitaminosis D, 25 (OH) D and DM.

Methods  The sample consisted of 109 elderly subjects. The BPPV was verified by a standardized questionnaire and the Dix-Hallpike maneuver. Blood samples were collected for the investigation of 25 (OH) D serum levels. The bone mineral density was evaluated by means of a densitometer. Diabetes mellitus verification was performed using a self-reported questionnaire.

Results  Of the 109 participants, 17 had BPPV. There was a statistically significant difference between BPPV and gender ( p  = 0.027, phi = 0.222), with female representing 88.2% of those with BPPV. In the group with BPPV, there was a statistically significant difference for the amount of vitamin D found ( p  = 0.001) and for age ( p  = 0.001). In the elderly group with DM and BPPV, a difference was found for the standard deviation of the femur ( p  = 0.022) with posthoc Dunn, identifying the difference between diabetics with and without BPPV ( p  = 0.047).

Conclusion  Although no association was found (25 (OH) D levels) with BPPV in the general population of this study, it was observed that there was an association with bone mineral density in the elderly group with DM and BPPV, and, in the group with BPPV, there was an association between the amount of vitamin D and age.

Low Maternal Vitamin D and Calcium Food Intake during Pregnancy Associated with Place of Residence: A Cross-Sectional Study in West Sumatran Women, Indonesia

BACKGROUND

There is a high prevalence of vitamin D deficiency in pregnancy worldwide, and variable availability of vitamin D-rich foods may affect the adequacy of vitamin D food intake in different regions.

AIM

We analysed the relationship between place of residence and maternal food intake of vitamin D and calcium in West Sumatra, Indonesia.

METHODS

This cross-sectional study was conducted in 203 pregnant women. Data collection was carried out in four districts in West Sumatra - two in coastal locations and two in mountainous locations - with subjects divided into groups based on their place of residence. The dietary intakes of pregnant women were assessed through a semi-quantitative food-frequency questionnaire (SQ-FFQ).

RESULTS

The means of maternal vitamin D and calcium food intake were 7.92 ± 5.26 µg/day and 784.88 ± 409.77 mg/day, respectively. There were no reports of vitamin D supplement intake during pregnancy. A total of 86.7% and 89.7% of the study subjects had low vitamin D and calcium food intake status, respectively. There was a significant association between maternal vitamin D intake and place of residence (p = 0.02) and significant different mean levels of vitamin D food intake with the place of residence (9.04 vs 6.55 µg/day; p = 0.01). Mothers who had higher education levels had adequate calcium food intake (p = 0.015; OR: 0.295; 0.116-0.751).

CONCLUSION

Low maternal vitamin D and calcium food intake were found to be common in West Sumatra, Indonesia and their differed between those residents in mountainous and in coastal areas.

Adapted Moderate Training Exercise Decreases the Expression of Ngal in the Rat Kidney: An Immunohistochemical Study

Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of several injuries and is upregulated in inflammatory conditions. Vitamin D was shown to have anti-inflammatory effects and to increase after physical activity. This work aimed to assess, through immunohistochemistry, the effects of an adapted moderate training exercise (AMTE) on the expression of NGAL and vitamin D receptor (VDR) in the kidney and heart of rats. Sixteen rats were distributed into two groups: the sedentary control group and the experimental group, subjected to AMTE on the treadmill for 12 weeks. The results showed the basal expression of NGAL and VDR in both the heart and the kidney in sedentary rats; no differences in the expression of both NGAL and VDR in the heart; and a decreased NGAL and an increased VDR expression in the kidney of rats subjected to AMTE. These results suggest a possible protective role of AMTE on NGAL-associated injuries in the kidney, probably through the vitamin D signaling pathway. Our results represent an interesting preliminary data that may open new horizons in the management of NGAL-associated kidney injuries. However, further studies are needed to confirm these results and to comprehend the specific interaction between NGAL and VDR pathways in the kidney.

Associations of Serum 25-Hydroxyvitamin D with Physical Performance and Bone Health in Overweight and Obese Older Adults

Low vitamin D status commonly accompanies obesity, and both vitamin D deficiency and obesity have been associated with falls and fracture risk in older adults. We aimed to determine the associations of serum 25-hydroxyvitamin D (25(OH)D) concentrations with physical performance and bone health in community-dwelling, overweight and obese older men and women. Serum 25(OH)D concentrations were measured in 84 participants with body mass index ≥25 kg/m² (mean ± SD age 62.4 ± 7.9 years; 55% women). Physical function was determined by short physical performance battery, hand grip and quadriceps strength, and stair climb power tests. Body composition and bone structure were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography, respectively. Mean ± SD 25(OH)D was 49.6 ± 17.7 nmol/L, and 50% of participants had low 25(OH)D (<50 nmol/L) levels. 25(OH)D concentrations were positively associated with quadricep strength and stair climb power in women (B = 0.15; 95% CI 0.02–0.27 kg and B = 1.07; 95% CI 0.12–2.03 W, respectively) but not in men. There were no associations between 25(OH)D and bone parameters in either sex after multivariable adjustment (all p > 0.05). Lower 25(OH)D concentrations are associated with poorer quadricep strength and muscle power in overweight and obese older women but not men.

The Effect of Nordic Walking Training Combined with Vitamin D Supplementation on Postural Control and Muscle Strength in Elderly People-A Randomized Controlled Trial

Nordic Walking (NW) and Vitamin D concentration (Vit D) alone have been shown to contribute to the health and performance of elderly people. However, the interaction between these two factors has yet to be explored. In this study 42 women over 60 years of age (69.02 ± 5.56 years) were recruited and divided in two NW groups: a high-intensity interval training group (HI-NW) and a moderate-intensity continuous training group (MI-NW). Individuals from each group completed a 12-week NW training program (3 times a week/2 hours) combined with randomized Vitamin D supplementation (HD = high dose: 4000 IU/day or LD = low dose: 800 IU/day). Body composition, postural control, muscle strength and Vitamin D serum concentration were measured twice; before and after the intervention. To investigate the interaction between supplementation and training a mixed-design analysis of variance (ANOVA) was performed. The HI-NW group, regardless of supplementation dose, increased their Vit D and elbow torque performance. On the other hand, in the MI-NW group the same Vit D outcome was seen only with HD supplementation and was also associated with increased leg muscle mass. In conclusion, beneficial effects of both HI-NW and MI-NW training regimes were seen. The impact of the dose supplementation on Vit D and body composition was related to the type of NW training.

Pattern of physical activity can influence its efficacy on muscle and bone health in middle-aged men and women

Purpose

This study aimed at investigating whether association between physical activity, and bone density and muscle strength depends on daily activity pattern.

Methods

Loading dose of moderate-to-vigorous physical activity (MVPA) was measured using accelerometer on 54 men (M _age = 54.1 years) and 59 women (M _age = 52.1 years). Pattern of MVPA was quantified as number and length of MVPA bouts, and the length of break bouts between MVPA bouts. Knee extension torque (KET) and broadband ultrasound attenuation (BUA) of the calcaneus were also measured. Regression analysis was employed to examine the moderation effect of MVPA pattern.

Results

Loading dose had a larger effect on BUA (b = .002, p = .035) and KET (b = .004, p = .01) with the increase of median length of MVPA bout, but had a smaller effect on KET with the increase of maximal length of break bout (b = - .015, p = .024).

Conclusions

This study suggests that pattern of physical activity can influence its efficacy on muscle and bone health.

Effects of oral paricalcitol therapy on arterial stiffness and osteopontin in hypertensive patients with chronic kidney disease and secondary hyperparathyroidism

BACKGROUND

Arterial stiffness is linked to the progression of atherosclerosis, while activation of vitamin D receptor exerts favorable cardiovascular effects in patients with renal insufficiency. In this study, we investigated the effects of oral treatment with paricalcitol, a potent vitamin D receptor activator, on arterial stiffness and osteopontin, a marker of atherosclerosis, in hypertensive patients with chronic kidney disease (CKD) and secondary hyperparathyroidism.

METHODS

We followed up 29 treated hypertensive patients (mean age: 74.1 years, 19 men, office blood pressure = 132/85 mmHg) with CKD stages 3-5 (mean glomerular filtration rate [GFR] = 19.4 ml/min/1.73 m²) who were on therapy with oral paricalcitol for 1 year. The control group consisted of 10 age-, sex-, and GFR-matched hypertensive patients with secondary hyperparathyroidism.

RESULTS

After 1 year of treatment with paricalcitol compared to baseline, there was no statistical difference in levels of GFR, office blood pressure, and osteopontin (p = NS for all), while carotid-femoral PWV was reduced from 11.8 ± 2.6 m/s to 11.2 ± 2.4 m/s (p < 0.05). The control group exhibited no significant changes in carotid-femoral PWV (p = NS).

CONCLUSIONS

Treatment with oral paricalcitol in hypertensive subjects suffering from CKD stages 3-5 and secondary hyperparathyroidism is accompanied by amelioration of arterial stiffness as reflected by the reduction of carotid-femoral PWV.

Association between physical activity and vitamin D: A narrative literature review

Summary This narrative review of the medical literature assessed whether outdoor and indoor physical activity would increase the plasma levels of vitamin D. Synthesis of this liposoluble vitamin is mainly mediated by sunlight on the skin, where it is activated to perform its main action, which is to control the serum levels of calcium as soon as the element is absorbed in the intestines, assisting in the regulation of bone metabolism. Physical activity is any body movement that results in energy expenditure, while outdoor physical activity refers to physical activity carried out at public parks or other open spaces, as is the case of the popular practice of taking walks. Exercising outdoors would have both the benefits of physical activity and of sun exposure, namely the synthesis of vitamin D. However, according to the studies analyzed, increased plasma concentration of vitamin D occurs with physical activity both indoors and outdoors.

Biomarkers associated with sedentary behaviour in older adults: A systematic review

OBJECTIVE

Pathomechanisms of sedentary behaviour (SB) are unclear. We conducted a systematic review to investigate the associations between SB and various biomarkers in older adults.

METHODS

Electronic databases were searched (MEDLINE, EMBASE, CINAHL, AMED) up to July 2015 to identify studies with objective or subjective measures of SB, sample size ≥50, mean age ≥60years and accelerometer wear time ≥3days. Methodological quality was appraised with the CASP tool. The protocol was pre-specified (PROSPERO CRD42015023731).

RESULTS

12701 abstracts were retrieved, 275 full text articles further explored, from which 249 were excluded. In the final sample (26 articles) a total of 63 biomarkers were detected. Most investigated markers were: body mass index (BMI, n=15), waist circumference (WC, n=15), blood pressure (n=11), triglycerides (n=12) and high density lipoprotein (HDL, n=15). Some inflammation markers were identified such as interleukin-6, C-reactive protein or tumor necrosis factor alpha. There was a lack of renal, muscle or bone biomarkers. Randomized controlled trials found a positive correlation for SB with BMI, neck circumference, fat mass, HbA1C, cholesterol and insulin levels, cohort studies additionally for WC, leptin, C-peptide, ApoA1 and Low density lipoprotein and a negative correlation for HDL.

CONCLUSION

Most studied biomarkers associated with SB were of cardiovascular or metabolic origin. There is a suggestion of a negative impact of SB on biomarkers but still a paucity of high quality investigations exist. Longitudinal studies with objectively measured SB are needed to further elucidate the pathophysiological pathways and possible associations of unexplored biomarkers.

Sarcopenia: a potential cause and consequence of type 2 diabetes in Australia's ageing population?

The incidence of type 2 diabetes is increasing in Australia's older adult population. Sarcopenia, the age-related decline in skeletal muscle mass, quality and function, may make a significant but under-appreciated contribution to increasing the risk of type 2 diabetes. As skeletal muscle is the largest insulin-sensitive tissue in the body, low muscle mass in sarcopenia likely results in reduced capacity for glucose disposal. Age-related declines in muscle quality, including increased mitochondrial dysfunction and fat infiltration, are also implicated in skeletal muscle inflammation and subsequent insulin resistance. Prospective studies have shown that low muscle mass and strength are associated with increased risk of incident type 2 diabetes. Prevalent type 2 diabetes also appears to exacerbate progression of sarcopenia in older adults. Recently developed operational definitions and the inclusion of sarcopenia in the International classification of diseases, 10th revision, clinical modification, provide impetus for clinicians to diagnose and treat sarcopenia in older patients. Simple assessments to diagnose sarcopenia can potentially play a role in primary and secondary prevention of type 2 diabetes in older patients. Lifestyle modification programs for older adults with type 2 diabetes, particularly for those with sarcopenia, should incorporate progressive resistance training, along with adequate intakes of protein and vitamin D, which may improve both functional and metabolic health and prevent undesirable decreases in muscle mass associated with weight loss interventions. As some older adults with type 2 diabetes have a poor response to exercise, clinicians must ensure that lifestyle modification programs are appropriately prescribed, regularly monitored and modified if necessary.

Moderate-to-Vigorous Physical Activity But Not Sedentary Time Is Associated With Musculoskeletal Health Outcomes in a Cohort of Australian Middle-Aged Women

Associations between physical activity and time spent sedentary and musculoskeletal outcomes remain unclear in middle-aged adults. This study aimed to describe associations between objectively-measured physical activity and sedentary time and musculoskeletal health outcomes in middle-aged women. This cross-sectional study from a population-based sample of 309 women (age 36 to 57 years) examined associations of total physical activity (accelerometer counts/min of wear time), and time spent sedentary, in light physical activities and moderate-to-vigorous physical activities (MVPA) (by Actigraph GT1M accelerometer) with lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD) (by dual-energy X-ray absorptiometry), lower limb muscle strength (LMS), and functional mobility and balance tests (timed up and go test [TUG], functional reach test [FRT], lateral reach test [LRT], and step test [ST]) using linear regression. Total physical activity was beneficially associated with FN BMD (values are β; 95% CI) (0.011 g/cm² ; 95% CI, 0.003 to 0.019 g/cm² ), LMS (2.13 kg; 95% CI, 0.21 to 4.06 kg), and TUG (-0.080 s; 95% CI, -0.129 to -0.030 s), after adjustment for confounders. MVPA was also beneficially associated with FN BMD (0.0050 g/cm² ; 95% CI, 0.0007 to 0.0094 g/cm² ), LMS (1.48 kg; 95% CI, 0.45 to 2.52 kg), ST (0.12 steps; 95% CI, 0.02 to 0.23 steps), and TUG (-0.043 s; 95% CI, -0.070 to -0.016 s). Associations between MVPA and LMS, TUG and ST persisted after further adjustment for sedentary time. Only TUG was associated with sedentary time, with a detrimental effect (0.075 s; 95% CI, 0.013 to 0.137 s) and this did not persist after further adjustment for MVPA. Light physical activity was not associated with any outcome. MVPA appears more important than light physical activity or sedentary time for many musculoskeletal outcomes in middle-aged women. This needs to be considered when developing interventions to improve habitual physical activity that aim to improve musculoskeletal health. © 2016 American Society for Bone and Mineral Research.

Association of Serum 25-hydroxy-vitamin D Concentration and Arterial Stiffness among Korean Adults in Single Center

Background

There are growing concerns about the role of vitamin D deficiency in cardiovascular diseases. Therefore, we investigated the correlation between serum 25-hydroxy-vitamin D (25[OH]D) and arterial stiffness among Korean adults.

Methods

We retrospectively reviewed the medical charts of 302 people (115 women and 187 men) who visited a tertiary hospital from January 2015 to December 2016. Serum 25(OH)D was measured using the radioimmunoassay technique, and brachial-ankle pulse wave velocity (baPWV) was measured using an automatic wave analyzer. We obtained the doctor's report on the medical history of the participants, their alcohol consumption and smoking habits, and their exercise status. Metabolic syndrome was diagnosed based on guidelines from the National Cholesterol Education Program (NCEP)-Adult Treatment Panel (ATP III) and the International Diabetes Federation (IDF). Results of basic blood tests and physical assessment were also collected.

Results

In the Pearson correlation analysis, serum 25(OH)D and baPWV showed a statistically significant inverse relationship (r=-0.279, P<0.001). Using multiple regression analysis, and after adjusting for possible confounders, serum 25(OH)D concentration was found to be significantly associated with baPWV (β=-0.121, P=0.011).

Conclusions

We observed an association between serum 25(OH)D concentration and arterial stiffness. Further studies involving larger sample sizes will be needed to confirm this associations.

Associations of Vitamin D with Inter- and Intra-Muscular Adipose Tissue and Insulin Resistance in Women with and without Polycystic Ovary Syndrome

Low vitamin D and insulin resistance are common in polycystic ovary syndrome (PCOS) and associated with higher inter- and intra-muscular adipose tissue (IMAT). We investigated associations between vitamin D, IMAT and insulin resistance in a cross-sectional study of 40 women with PCOS and 30 women without PCOS, and pre- and post-exercise in a 12-week intervention in 16 overweight participants (10 with PCOS and six without PCOS). A non-classical body mass index (BMI) threshold was used to differentiate lean and overweight women (BMI ≥ 27 kg/m²). Measurements included plasma 25-hydroxyvitamin D (25OHD), insulin resistance (glucose infusion rate (GIR; mg/m²/min), fasting glucose and insulin, and glycated haemoglobin), visceral fat, mid-thigh IMAT (computed tomography) and total body fat (dual-energy X-ray absorptiometry). Women with both PCOS and low 25OHD levels had the lowest GIR (all p < 0.05). Higher IMAT was associated with lower 25OHD (B = −3.95; 95% CI −6.86, −1.05) and GIR (B = −21.3; 95% CI −37.16, −5.44) in women with PCOS. Overweight women with pre-exercise 25OHD ≥30 nmol/L had significant increases in GIR, and decreases in total and visceral fat (all p < 0.044), but no associations were observed when stratified by PCOS status. Women with PCOS and low 25OHD levels have increased insulin resistance which may be partly explained by higher IMAT. Higher pre-training 25OHD levels may enhance exercise-induced changes in body composition and insulin resistance in overweight women.

Accelerometer-determined physical activity, muscle mass, and leg strength in community-dwelling older adults

INTRODUCTION

The aim of this study was to describe the relationship between accelerometer-determined physical activity (PA), muscle mass, and lower-limb strength in community-dwelling older adults.

METHODS

Six hundred thirty-six community-dwelling older adults (66 ± 7 years) were studied. Muscle mass was measured using dual-energy x-ray absorptiometry, whilst lower limb strength was measured via dynamometry. We measured minutes/day spent in sedentary, light, moderate, and vigorous intensity activity using Actigraph GT1M accelerometers.

RESULTS

Participants spent a median of 583(Interquartile ratio (IQR) 522-646), 225(176-271), 27(12-45) and 0(0-0) min in sedentary, light, moderate, and vigorous activity, respectively. PA intensity was positively associated with both lean mass percentage and lower limb strength in a dose-response fashion. Sedentary activity was negatively associated with lean mass percentage, but not lower-limb strength. There was a positive association between PA and appendicular lean mass in men only. There was an interaction between age and activity; as age increased, the magnitude of the association of PA with lean mass percentage decreased. Those who adhered to the Australian Department of Health PA guidelines (moderate/vigorous PA >/=150 min/week) had greater lean mass percentage, appendicular lean mass, and lower limb strength.

CONCLUSIONS

Using accelerometer technology, both the amount and intensity of accelerometer-determined PA had an independent, dose-response relationship with lean mass percentage and lower limb strength, with the largest effect for vigorous activity. Time spent in sedentary activity was negatively associated with lean mass percentage, but was not associated with lower limb strength. The magnitude of the association between PA and lean mass percentage decreased with age, suggesting that PA programmes may need to be modified with increasing age.

Effect of vitamin D supplementation on measures of arterial stiffness: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Low vitamin D has been associated with poor arterial compliance in observational studies. Arterial stiffness has prognostic value for cardiovascular disease risk. The aim of this systematic review was to clarify the literature surrounding the use of vitamin D to ameliorate arterial stiffness.

METHODS

We conducted a systematic review of the MEDLINE, Scopus and EMBASE databases for randomized controlled clinical trials investigating the effect of vitamin D supplementation on pulse wave velocity (PWV) and/or augmentation index (AI) as indicators of arterial stiffness. We meta-analysed data and calculated standardized mean difference (SMD) and 95% confidence intervals (CI) using inverse-variance models on RevMan v5.3 software. Study quality was assessed using a modified Jadad scale.

RESULTS

A total of 607 unique records were identified, of which 18 satisfied our inclusion and exclusion criteria. Study quality was high, ranging from 9 to 12 (of 13). Study design in terms of vitamin D dosing protocol (range: 1000-5700 IU/day), follow-up times (range: 1-12 months), sample size (range: n = 29-183) and recruitment strategies varied markedly. Thirteen studies had data for meta-analysis. Vitamin D was associated with nonsignificant reductions in PWV [SMD = -0·10; 95% CI: -0·24, 0·04; P = 0·17; n = 806 from ten studies] and AI [-0·15; -0·32, 0·02; 0·08; n = 551 from eight studies].

DISCUSSION

There is inconsistent evidence to suggest that vitamin D supplementation improves indicators of arterial stiffness. This may be attributable to the heterogeneity in study design. Therefore, large and well-designed randomized studies are required to determine the casual relationships between vitamin D and arterial stiffness and cardiovascular risk.

A Cross-sectional Examination of Vitamin D, Obesity, and Measures of Pain and Function in Middle-aged and Older Adults With Knee Osteoarthritis

OBJECTIVES

The prevalence of knee osteoarthritis (OA) is increasing with the aging population and is exacerbated by the growing numbers of obese older adults. Low levels of vitamin D, measured by serum 25-hydroxyvitamin D (25(OH)D), in older adults and obese individuals are correlated with several negative health conditions, including chronic pain. This cross-sectional study sought to examine the interactive influence of 25(OH)D levels and obesity on knee OA pain and functional performance measures.

METHODS

The sample consisted of 256 (63% female) racially diverse (55% black/African Americans) middle-aged and older adults (mean age 56.8 y). Blood was collected for analysis of 25(OH)D by high-performance liquid chromatography. Participants provided self-report regarding knee OA pain and underwent a lower extremity functional performance test.

RESULTS

Results demonstrated that obesity was associated with lower levels of 25(OH)D. Participants with adequate 25(OH)D levels reported significantly less knee OA pain compared with participants with deficient or insufficient levels, regardless of obesity status. Furthermore, there was a significant interaction between obesity and 25(OH)D levels for lower extremity functional performance, such that obese individuals with adequate 25(OH)D levels demonstrated better performance than those obese participants with deficient or insufficient 25(OH)D levels.

DISCUSSION

The mechanisms by which adequate 25(OH)D levels are associated with pain severity and improved function have not been completely elucidated. It may be that the pleiotropic role of biologically active 25(OH)D influences pain and pain processing through peripheral and central mechanisms. Alternatively, higher levels of pain may lead to reduced outdoor activity, which may contribute to both obesity and decreased vitamin D. Thus, investigating vitamin D status in obese and nonobese individuals with knee OA warrants further study.

Vitamin D status, body composition and glycemic control in an ambulatory population with diabetes and chronic kidney disease

BACKGROUND/OBJECTIVES

To determine the interrelationships between body composition, glycemic control and vitamin D status in an ambulatory population with diabetes (DM) and chronic kidney disease (CKD).

SUBJECTS/METHODS

Adult (18-80 years) patients (n=60) with DM and stage 1-4 CKD were recruited from the Northern Alberta Renal Program. Outcome variables included body composition (absolute/regional fat (FM)/lean soft tissue/total mass, percent fat/lean/fat-free (FFM) mass), glycemic control (glycated hemoglobin (HbA1c)), vitamin D intake (dietary/supplemental) and vitamin D status (25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D)) measured by validated methodologies. Sarcopenia was determined as an appendicular skeletal mass/height(2) less than 7.26 kg/m(2) (males) and 5.45 kg/m(2) (females).

RESULTS

Suboptimal HbA1c (>7%), 25(OH)D (<50 nmol/l) and 1,25(OH)2D (<43 pmol/l) concentrations were present in 57, 8 and 11% of participants. Ten percent of subjects had sarcopenia. Gender/age/DM type, not CKD, significantly influenced regional/whole body composition. Females, older participants and those with type 2 DM had higher %FM. No significant interrelationships between vitamin D status and glycemic control were observed (P>0.05). Serum 25(OH)D concentrations were inversely associated with arm lean soft tissue/FFM/total mass, weight, appendicular skeletal mass, lean soft tissue/height(2), FFM/height(2), appendicular skeletal mass/height(2) and body mass index (P<0.05). Sarcopenia occurred more frequently in patients with 25(OH)D concentrations ⩾100 nmol/l. Regional/whole body %FM was inversely related to 1,25(OH)2D, not 25(OH)D.

CONCLUSIONS

Body composition, not glycemic control, is associated with vitamin D status in an ambulatory population of adults with DM and CKD.

Fall and Fracture Risk in Sarcopenia and Dynapenia With and Without Obesity: the Role of Lifestyle Interventions

Due to their differing etiologies and consequences, it has been proposed that the term "sarcopenia" should revert to its original definition of age-related muscle mass declines, with a separate term, "dynapenia", describing muscle strength and function declines. There is increasing interest in the interactions of sarcopenia and dynapenia with obesity. Despite an apparent protective effect of obesity on fracture, increased adiposity may compromise bone health, and the presence of sarcopenia and/or dynapenia ("sarcopenic obesity" and "dynapenic obesity") may exacerbate the risk of falls and fracture in obese older adults. Weight loss interventions are likely to be beneficial for older adults with sarcopenic and dynapenic obesity but may result in further reductions in muscle and bone health. The addition of exercise including progressive resistance training and nutritional strategies, including protein and vitamin D supplementation, may optimise body composition and muscle function outcomes thereby reducing falls and fracture risk in this population.