Correlation between vitamin D and cardiovascular disease predictors in overweight and obese Koreans

Predicting vitamin D deficiency using optimized random forest classifier

BACKGROUND

Vitamin D can be acquired from various dietary sources, but exposure to sunlight's ultraviolet rays can convert a natural compound called ergosterol present in the skin into vitamin D.

AIM

The current study aimed to investigate vital parameters and use an optimized random forest (OptRF) classifier to understand better and predict the effect of environmental and nutritional factors of Vitamin D deficiency.

METHODS

A predictive, cross-sectional, and correlational design was utilized in a study involving 350 male and female Tabuk citizens in Saudi Arabia. The Weka machine-learning tool was employed for comprehensive data analysis, with the OptRF algorithm being tailored through advanced feature selection methods and meticulous hyperparameter tuning.

RESULTS

In addition to the OptRF classifier, a number of traditional machine learning techniques have been tested and compared on the dataset of vitamin D to analyze and build the predictive model for classifying vitamin D deficiency. In general, the OptRF-based predictive model can statistically describe data for determining significant features related to Vitamin D deficiency. OptRF demonstrated its ability to classify vitamin D deficiency cases with high accuracy 91.42 %.

CONCLUSION

This study showed that Tabuk citizens are at high risk of vitamin D deficiency especially among females (gender predictor) with little regard to age, income, smoking, and sun exposure. In addition, exercise, less Vitamin D intake, and less intake of Calcium are also predictors of Vitamin D deficiency. Due to the link between Vitamin D Deficiency and major chronic illnesses, it is important to emphasize the importance of identifying risk factors and screening for Vitamin D Deficiency. It may be appropriate for nutritionists, nurses, and physicians to promote community awareness about strategies to improve dietary Vitamin D intake or consider recommending supplements.

The association between vitamin D deficiency and metabolic syndrome in Ukrainian adolescents with overweight and obesity

PURPOSE

This work aims to determine the association between vitamin D deficiency and metabolic syndrome in overweight and obese adolescents from Ukraine.

METHODS

Anthropometric measurements were taken and general and biochemical examinations were performed on 136 obese and overweight adolescents and 60 adolescents with normal body weight. The vitamin D status was determined using 25-hydroxyvitamin D (25(OH)D) (calcidiol) levels in blood serum. To establish the factors influencing vitamin D status, the subjects were asked to answer a questionnaire and 2007 International Diabetes Federation diagnostic criteria were used to determine the incidence of metabolic syndrome. All research results were processed statistically.

RESULTS

A calcidiol sufficiency level was found in 3.9% of obese adolescents and 6.7% of overweight adolescents. Metabolic syndrome was found in 64.4% of obese adolescents with vitamin D deficiency, and in 26.2% of overweight adolescents. Factors associated with an increased risk of developing vitamin D deficiency in adolescents with metabolic syndrome included male sex (p=0.042), low income per family member (p=0.040), daily milk consumption of up to 1 cup per day (p=0.001), physical activity (p=0.001), duration of outdoor stays (p=0.001), and passive rest in front of a computer or television (p=0.001). Adolescents with metabolic syndrome were found predominance of body mass index (p<0.001), waist circumference (p<0.001), fasting blood glucose level (Р<0.001), and decreased calcidiol level (p=0.022). Among metabolic syndrome components, vitamin D deficiency was strongly associated with waist circumference and increased fasting blood glucose (p<0.05).

CONCLUSION

Vitamin D deficiency is prevalent in overweight and obese adolescents from Ukraine. Vitamin D deficiency is associated with metabolic syndrome criteria in overweight and obese adolescents.

The supplementary effects of omega-3 fatty acid alone and in a combination with vitamin D3 on serum leptin levels: A randomized clinical trial on men and women with vitamin D deficiency

Purpose: This randomized clinical trial (RCT) was designed to assess the effect of VD3, n-3FA, and their combination on serum leptin levels in people with vitamin D deficiency (VDD).

Subjects and methods: One hundred and forty six participants, were randomly assigned into four groups supplemented with the dose of 50,000 IU VD3 taken weekly (D), 300 mg n-3FA taken daily (Om), and their combination (D+Om) or control (C) for eight weeks. Fasting baseline and follow-up (10 weeks; 8 weeks supplementation plus washout period of 2 weeks) of serum 25 hydroxyvitamin D (25OHD), leptin, glucose, triglycerides (TG), parathyroid hormone (PTH), calcium, and phosphorus were assayed. A paired T-test was used to assess the changes in serum leptin levels over of the follow-up period.

Results: Significant increase in follow-up serum leptin (10.62 ± 7.18 to 14.42 ± 8.29 ng/mL, P = 0.002) and TG (154 ± 84.4 to 200.1 ± 79, P = 0.015) levels were observed in n-3-FA supplemented group. Combination therapy (VD3 plus n-3 FA) significantly increased serum 25OHD (13.49 ± 4.64 to 37.09 ± 11.13 ng/mL, P &lt; 0.001), TG levels (114.3 ± 57.3 to 139.1 ± 60.7 mg/mL, P = 0.007) and insignificantly serum leptin (6.74 ± 4.87 to 8.01 ± 6.77 ng/mL, P = 0.269).

Conclusion: Our study referred that notable elevation in leptin and TG levels might be linked to leptin resistance. However, further RCTs are required to clarify possible consequences resulted from the extensive administration of n-3FA supplements and their combinations with high doses of VD3 supplements on humans’ health.

Effect of Improving Dietary Structure on Serum 25(OH)VitD₃ Level in Hypertensive Patients in a Chinese Rural Area

Background

In this study, we explored the effect of an improved dietary pattern on 25-hydroxyvitamin D₃ [25(OH)VitD₃] level in hypertensive patients in a rural setting and investigated the possible mechanism for lowering blood pressure.

Material/Methods

Thirty-three participants with overweight or obesity were randomly divided into 2 groups. A 24-h dietary review method was used for dietary assessment. Participants in both groups were provided the same balanced diet except for the breakfast staple food for 4 weeks. General characteristics, body composition analysis, blood pressure, serum lipid profile, inflammatory indices, and serum 25(OH)VitD₃ level were assessed at baseline and at the completion of the 4-week dietary intervention. Nutrient intake was analyzed by dietary analysis software, and SPSS software was used for correlation and regression analyses.

Results

Thirty-one participants completed the study. The prevalence of vitamin D deficiency was 100% at baseline. After the dietary intervention, the prevalence of vitamin D deficiency decreased to 45%. Levels of dietary intake of vitamin D, cholesterol, protein, fat, and calcium showed a significantly positive correlation with the serum 25(OH)VitD₃ level. Body fat, visceral fat, waist-to-hip ratio, serum triglyceride, and Toll-2 expression were negatively correlated with the serum 25(OH)VitD₃ level. Blood pressure had a significant negative correlation with 25(OH)VitD₃ level. Participants in both groups experienced a significant decrease in blood pressure.

Conclusion

Intake of a balanced diet rich in vitamin D, with appropriate amounts of cholesterol, protein, calcium, and fat, helped improve body composition, ameliorated lipid metabolism disorder, reduced inflammation, and improved serum 25(OH)VitD₃ level, thus lowering blood pressure.

Serum vitamin D status and metabolic syndrome: a systematic review and dose-response meta-analysis

BACKGROUD/OBJECTIVES

Evidence has suggested an association between serum vitamin D and metabolic syndrome (MetS), but prospective studies are very limited. The objective was to assess the dose-response association between serum vitamin D concentration and MetS risk using a systematic review and meta-analysis of updated observational studies.

MATERIALS/METHODS

Using MEDLINE, PubMed, and Embase, a systematic literature search was conducted through February 2020 and the references of relevant articles were reviewed. A random-effects model was used to estimate the summary odds ratio/relative risk and 95% confidence interval (CI). Heterogeneity among studies was evaluated with I² statistic. In total, 23 observational studies (19 cross-sectional studies, and four cohort studies) were included in the meta-analysis.

RESULTS

The pooled estimates (95% CI) for MetS per 25-nmol/L increment in serum vitamin D concentration were 0.80 (95% CI, 0.76–0.84; I² = 53.5) in cross-sectional studies, and 0.85 (95% CI, 0.72–0.98; I² = 85.8) in cohort studies. Similar results were observed, irrespectively of age of study population, study location, MetS criteria, and adjustment factors. There was no publication bias for the dose-response meta-analysis of serum vitamin D concentrations and MetS.

CONCLUSIONS

Dose-response meta-analysis demonstrated that a 25-nmol/L increment in the serum vitamin D concentration was associated with 20% and 15% lower risks of MetS in cross-sectional studies and cohort studies, respectively.

Vitamin D Supplementation in Laboratory-Bred Mice: An In Vivo Assay on Gut Microbiome and Body Weight

Saudi Arabia is in a tropical geographical region with a population that has access to adequate diet. There is, however, a high level of vitamin D deficiency in the Kingdom, comorbid with other disease. There is the postulation of a correlation between a healthy gut microbiota and balanced levels of serum vitamin D. This investigation looks into the effect of vitamin D supplementation on the gut flora of laboratory-bred mice as well as any possible association on body weight. BALB/C mice weighing between 34 and 35.8 g were divided into 4 groups and placed on daily doses of vitamin D of 3.75 µg (low dose), 7.5 µg (normal dose), and 15 µg (high dose). The fourth group was the control group that did not receive any supplementation with vitamin D. Body weights were monitored on weekly basis, while faecal samples from the rectum were obtained for microbial culturing and the monitoring of bacterial colony count using the Vitek 2 Compact automated system (BioMerieux, Marcy-l’Etoile, France) according to manufacturer’s guidelines. The data presented as mean ± SD, while significant differences were determined with 2-way analysis of variance in comparing differences within and between treatment groups. The different doses of vitamin D showed varying effects on the body weight and gut microbial colonies of the mice. There was a highly significant difference between the control, 15 µg (high), and 7.5 µg (normal) dose groups. This is suggestive that supplementation with vitamin D could a role in the gut microbial flora in the gut which could reflect in changes in body weight.

Associations of C-reactive Protein with 25-hydroxyvitamin D in 24 Specific Diseases: A Cross-sectional Study from NHANES

Most diseases might be associated with acute or chronic inflammation, and the role of vitamin D in diseases has been extensively explored in recent years. Thus, we examined the associations of one of the best markers for inflammation ― C-reactive protein (CRP) with 25-hydroxyvitamin D [25(OH)D] in 24 specific diseases. We performed cross-sectional analyses among 9,809 subjects aged ≥18 years who participated in the U.S. National Health and Nutrition Examination Survey (NHANES) in 2007~2010. The generalized additive model (GAM) was used to explore the associations of CRP with 25(OH)D in different diseases, adjusted for the age, gender, examination period and race. Distributions of CRP were significantly different (P < 0.05) in gender, examination period and race, and distributions of 25(OH)D were different (P < 0.05) in the examination period and race. Generally, CRP was negatively associated with 25(OH)D for majority diseases. 25(OH)D was negatively associated with CRP generally, and the associations were disease-specific and disease category-specific. In respiratory, gastrointestinal and mental diseases, the associations tended to be approximately linear. While in metabolic diseases, the associations were nonlinear, and the slope of the nonlinear curve decreased with 25(OH)D, especially when 25(OH)D < 30 μg/L.

Prevalence and Determinants of Vitamin D Deficiency Among the Overweight and Obese Singaporeans Seeking Weight Management Including Bariatric Surgery: a Relationship with Bone Health

PURPOSE

Low vitamin D status is prevalent worldwide and has been linked to a variety of pathologies including obesity in adults. The severity of vitamin D deficiency amongst the overweight and obese Singaporeans is not well documented. The purpose of this prospective observational study was to assess the prevalence and determinants of vitamin D deficiency in a multi-ethnic Asian population referred for weight management, including those seeking bariatric surgery.

MATERIALS AND METHODS

This was a cross-sectional study conducted among 111 consecutive subjects referred to a single institution weight management service in Singapore. The data collected included their anthropometric data, body mass index (BMI), body fat percentage, waist circumference, 25-hydroxyvitamin D [25(OH)D] and other bone turnover markers.

RESULTS

The average BMI among the 111 subjects was 40.1 ± 8.2 kg/m² and mean age of 40 ± 10 years. Vitamin D deficiency was found in 75.7% of the population. There was a significant negative association of vitamin D with adiposity markers including BMI (r = - 0.31), body fat percentage (r = - 0.34) and waist circumference (r = - 0.26). Predictors of vitamin D deficiency included age > 50 years, female gender, waist circumference and body fat percentage.

CONCLUSION

Vitamin D deficiency is prevalent among this target population in Singapore regardless of ethnicity. In particular, the elderly, females, those with larger waist circumference and body fat percentage were significantly associated with lower serum 25(OH)D level. Hence, routine screening for the overweight and obese subjects in multi-ethnic Singapore seeking weight management is indicated.

Prevalence of vitamin D deficiency and associated comorbidities among Abu Dhabi Emirates population

OBJECTIVE

The study explored the prevalence of vitamin D deficiency, its seasonal variation and associated comorbidities among the Abu Dhabi Emirati population living in urban and suburban settings.

RESULT

Of the 12,346 participants 36.9% were male and 63.1% female. The majority (72%) were either vitamin D deficient (< 50 nmol/L), or (10%) vitamin D insufficient (50-74 nmol/L). Vitamin D deficiency was similar in both sexes (male 83.1% vs female 83.8%) as insufficiency (male 12.7% vs female 11.2%). Low vitamin D levels were associated with high blood pressure, high body mass index, central obesity, high cholesterol, impaired blood glucose levels and a high Framingham risk score. The mean vitamin D level was highest in January (winter) and lowest in July (summer).

Vitamin D supplementation and muscle strength in pre-sarcopenic elderly Lebanese people: a randomized controlled trial

Previous studies have shown that improving vitamin D status among the elderly may lead to an improvement in muscle mass and muscle strength. In our study, vitamin D supplementation showed significant improvements in vitamin D concentrations as well as appendicular muscle mass in pre-sarcopenic older Lebanese people. However, we found no significant effect on muscle strength.

INTRODUCTION

Improving vitamin D status might improve muscle function and muscle mass that lead to sarcopenia in older subjects. The aim of this randomized, controlled, double-blind study was to examine the effect of vitamin D supplementation on handgrip strength and appendicular skeletal muscle mass in pre-sarcopenic older Lebanese subjects. We also examined whether this effect differs in normal vs. obese subjects.

METHODS

Participants (n = 128; 62 men and 66 women) deficient in vitamin D (25(OH)D = 12.92 ± 4.3 ng/ml) were recruited from Saint Charles Hospital, Beirut, Lebanon. The participants were given a supplement of 10,000 IU of cholecalciferol (vitamin D group; n = 64) to be taken three times a week or a placebo tablet (placebo group; n = 64) for 6 months. One hundred fifteen subjects completed the study: 59 had normal weight, while 56 were obese. Strength and functional assessment and biochemical analysis were performed at the start and after 6 months.

RESULTS

Compared to placebo, the vitamin D supplemented group showed significant improvements in appendicular skeletal muscle mass (ASMM) (P < 0.001) but not in handgrip strength (P = 0.2901). ANCOVA for ASMM adjusting for obesity and including the interaction between obesity and vitamin D showed a significant interaction. The increase in ASMM with vitamin D in normal-weight subjects was higher than that of obese subjects (B = 35.09 vs. B = 2.19).

CONCLUSION

Treatment with vitamin D showed beneficial effects on appendicular muscle mass in pre-sarcopenic older Lebanese men and women. However, it had no effect on muscle strength relative to placebo. This trial was registered at isrctn.org as ISRCTN16665940.

Relationship of serum Vitamin D concentrations with Adipokines and Cardiometabolic risk among non-Hispanic black type 2 diabetic and non-diabetic subjects: a cross-sectional study

BACKGROUND

To report the association of serum 25-hydroxyvitamin D [25(OH)D] and its association with adipokines and cardiometabolic risk factors in Haitian Americans (HA) and African Americans (AA) by ethnicity and type 2 diabetes (T2D) status.

METHODS

A cross-sectional study in 197 HA (92 with T2D and 102 without T2D) and 200 AA (97 with T2D and 103 without T2D) recruited in South Florida. Serum 25(OH)D concentrations and adipokines were analyzed by ELISA and cardiometabolic risk factors were indexed by obesity, glycemic control, insulin sensitivity, lipid profile, and blood pressure.

RESULTS

Controlling for age, BMI, energy intake, smoking status and HOMA2-IR in multivariate linear regression analyses, serum 25(OH)D concentrations were significantly associated with WC (R² = 0.760, B = - 0.092, P = 0.027), HbA1C (R² = 0.142, B = - 0.012, P = 0.010), and TG (R² = 0.159, B = - 1.192, P = 0.003) in only HA without T2D. While serum 25(OH)D concentrations were significantly associated with TC (R² = 0.168, B = - 0.329, P = 0.040), log leptin (R² = 0.544, B = - 0.007, P = 0.021), and adiponectin (R² = 0.144, B = 0.111, P = 0.033), but slightly associated with LDL-c (R² = 0.133, B = - 0.278, P = 0.064) in only AA without T2D. Among individuals with T2D, serum 25(OH)D concentrations were marginally associated with IL-6 (R² = 0.109, B = 0.076, P = 0.085) in HA with T2D, and there was a trend toward significance with log leptin (R² = 0.393, B = - 0.006, P = 0.075) in AA with T2D in regression analysis.

CONCLUSIONS

The findings that the associations of serum 25(OH)D concentrations with adipokines and cardiometabolic factors differ between HA and AA has clinical and public implications to guide design of T2D preventive strategies that are culturally specific even within the same ethnicity.

Effect of Vitamin D Supplementation on Weight Loss, Glycemic Indices, and Lipid Profile in Obese and Overweight Women: A Clinical Trial Study

Introduction

Vitamin D (vit D) deficiency has defined as a health problem worldwide. World Health Organization (WHO) has declared that obesity is an epidemic of the 21^st century. Previous studies have shown that obesity may increase the risk of Vit D deficiency. Furthermore, other studies have demonstrated that vit D insufficiency was accompanied with higher risk of type 2 diabetes, cardiovascular diseases, hypertension, and obesity. The aim of this study was to survey the effect of vit D supplementation on weight loss among overweight and obese women aged 20-40 years in Isfahan.

Methods

This double-blind clinical trial was done on 50 overweight and obese women who were divided into two groups, in which one group received vit D supplements and the other group received placebo. Intervention group received vit D with dozes 50,000 IU/w for 6 weeks. The levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), fasting blood sugar (FBS), insulin (ins), homeostasis model assessment of ins resistance (IR), C-reactive protein (CRP), height, weight (WT), waist circumference (WC), hip circumference (HC), and blood pressure (BP) were measured before and after intervention.

Results

After using vit D supplementation for 6 weeks, WT, WC, and body mass index (BMI) were decreased significantly and serum vit D increased significantly compared to control group (P < 0.001). Other factors including TC, TG, LDL-c, HDL-c, FBS, CRP, ins, IR, and waist to hip ratio (WHR) did not change significantly (P > 0.05).

Conclusions

After 6 weeks of intervention, the means of WT, BMI, WC, and HC decreased significantly. Previous studies have shown that vit D deficiency was more prevalence in obese people and there was an inverse association among vit D with BMI and WC. The relationship between vit D and lipid profiles such as glycemic indexes, anthropometric indexes, CRP, and BP is not clear and needs more study in the future.

Review on Potential Vitamin D Mechanism with Type 2 Diabetes Mellitus Pathophysiology in Malaysia

Evidences on vitamin D deficiency suggest there is increasing risk of diabetes. To date, some cohort, observation, cross-sectional studies on populations and randomized controlled trials in vitamin D supplements highlighting the potential of vitamin D are essentially in modifying Type 2 Diabetes Mellitus (T2DM) pathophysiology. Relevant literature sought in a various databases focus on the discovery of vitamin D studies in Malaysia, particularly in dietary, health status and disease study. However, recent data in Malaysia, the scope of the literature focuses on the deficient vitamin D mediated insulin impairment. The development of literary findings encompasses on the etiology of diabetes which highly correlates with decreased mechanism of action of vitamin D. It is important to understand diabetes etiology before explaining more about insulin resistance mechanisms which is strongly correlated with the involvement of c-Jun N-terminal kinase (JNK) pathways in insulin signalling. Furthermore, the vitamin D works synergistically with calcium homeostasis which is believed to have interaction with insulin. The purpose of this article is to illustrate the potential of vitamin D in modulating T2DM pathophysiology. Existing evidence showing the biochemical function of vitamin D is strongly involved in the pathogenesis of T2DM which requires considerable attention.

Is There Any Relationship between Plasma 25-Hydroxyvitamin D₃, Adipokine Profiles and Excessive Body Weight in Type 2 Diabetic Patients?

A growing interest in the role of vitamin D in metabolic diseases led us to study the relationships between 25-hydroxyvitamin D₃ (25(OH)D₃) and the profiles of selected adipokines in type 2 diabetic (T2DM) patients. The study comprised 92 type 2 diabetics divided into quartiles regarding 25(OH)D₃ concentration. Each group was divided into male and female subgroups. All the studied patients had their anthropometric and biochemical parameters determined. Plasma 25-hydroxyvitamin D₃ concentration was determined by HPLC, while the selected adipokines (leptin, adiponectin, resistin and visfatin) by ELISA methods. The ratio of leptin to adiponectin (L/A) was calculated for all the patients. In 85.3% of diabetics a full (<20 ng/mL) or moderate (20-30 ng/mL) vitamin D deficit was found. Irrespective of sex, plasma leptin concentration decreased across increasing quartiles of 25(OH)D₃ level. In women, 25(OH)D₃ was negatively correlated with BMI, leptin level as well as L/A ratio, and positively with adiponectin concentration. In men, 25(OH)D₃ was positively correlated with HDL and negatively with systolic blood pressure (SBP), leptin level and L/A ratio. Considering all the patients, there ocurred a significant negative correlation between 25(OH)D₃ and SBP, BMI, WHR, TG, leptin and L/A ratio and positive ones between 25(OH)D₃ and both adiponectin and HDL. The results of the study support the existence of the relationship among vitamin D, obesity and leptin in type 2 diabetic patients.

The effects of vitamin D supplementation on proatherogenic inflammatory markers and carotid intima media thickness in subjects with metabolic syndrome: a randomized double-blind placebo-controlled clinical trial

PURPOSE

Metabolic syndrome may predispose to cardiovascular diseases. Since, in recent studies, vitamin D is advocated for cardioprotective roles, this study was designed to investigate the effects of vitamin D supplementation on proatherogenic inflammatory markers and common carotid intima media thickness in subjects with metabolic syndrome.

METHODS

This randomized double blind clinical trial was conducted in Tabriz, Iran. Eligible subjects (n = 80) with metabolic syndrome were recruited thorough advertisement and randomized to receive either vitamin D (50,000 IU/week) or matching placebo for 16 weeks. Interlukin-6, high sensitivity C-reactive protein, vascular cell adhesion molecule-1, E-selectin, and common carotid intima media thickness were measured at the beginning and end of the study. The study was registered at http://www.irct.ir (code: IRCT201409033140N14).

RESULTS

Sixteen weeks supplementation with vitamin D increased median of serum 25-hydroxy vitamin D [25(OH)D] and mean calcium levels (p < 0.001) in the intervention group. There was also a significant difference in parathyroid hormone level at the end of the study (p < 0.001). Vitamin D treatment reduced IL-6 level after 16 weeks (p = 0.027). Compared to baseline, vascular cell adhesion molecule-1 and E-selectin levels decreased significantly in vitamin D treated subjects; however, there were no significant differences between two groups. No effect of vitamin D supplementation was observed in either common carotid intima media thickness or high sensitivity C-reactive protein concentrations at the end of the study (p > 0.05).

CONCLUSIONS

Vitamin D supplementation improved some proatherogenic inflammatory markers in subjects with metabolic syndrome. No changes of high sensitivity C-reactive protein and carotid intima media thickness were shown after 16 weeks.

Vitamin D and inflammation: evaluation with neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio

INTRODUCTION

Association of vitamin D, inflammation and endothelial dysfunction, beside the classic bone metabolism disorders, may explain the pathogenesis of numerous diseases associated with vitamin D deficiency. While large numbers of reports support the relationship of vitamin D with inflammation, several reports fail to confirm this relationship. Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are novel and inexpensive markers of inflammation that can be studied in all centers. The goal of this study was to investigate the association between 25-hydroxy vitamin D (25(OH)D) and inflammation with the novel inflammatory markers NLR and PLR.

MATERIAL AND METHODS

This study was performed retrospectively. Results of the simultaneously performed 25(OH)D, parathyroid hormone, albumin, calcium, phosphorus, alkaline phosphatase and creatinine level measurements and complete blood count were recorded. The data of 4120 patients were included in the study.

RESULTS

Between vitamin D deficient and non-deficient groups there were significant differences in PLR (p < 0.001) and NLR (p = 0.001). Vitamin D had a significant negative correlation with PLR (p < 0.001) and NLR (p < 0.001). Multiple regression analysis indicated that 25(OH)D was independently and negatively correlated with PLR (OR = 0.994, 95% CI 0.991-0.998, p = 0.02).

CONCLUSIONS

Platelet-to-lymphocyte ratio and NLR were significantly associated with 25(OH)D levels, and PLR was found to be an independent predictor of 25(OH)D levels. Our study revealed an inverse association of vitamin D levels and inflammation with these inexpensive and universally available markers.

Counter-regulatory paracrine actions of FGF-23 and 1,25(OH)2 D in macrophages

Mechanisms underlying the association between fibroblastic growth factor 23 (FGF-23) and inflammation are uncertain. We found that FGF-23 was markedly up-regulated in LPS/INF-γ-induced proinflammatory M1 macrophages and Hyp mouse-derived peritoneal macrophages, but not in IL-4-induced M2 anti-inflammatory macrophages. NF-КB and JAK/STAT1 pathways mediated the increased transcription of FGF-23 in response to M1 polarization. FGF-23 stimulated TNF-α, but not IL-6, expression in M0 macrophages and suppressed Arginase-1 expression in M2 macrophages through FGFR-mediated mechanisms. 1,25(OH)2 D stimulated Arginase-1 expression and inhibited FGF-23 stimulation of TNF-α. FGF-23 has proinflammatory paracrine functions and counter-regulatory actions to 1,25(OH)2 D on innate immune responses.

Association between 25-hydroxyvitamin D and inflammatory biomarker levels in a cross-sectional population-based study, São Paulo, Brazil

Besides the classic vitamin D function on bone homeostasis, there are bodies of evidence showing that adequate status of vitamin D can modulate inflammation. We hypothesized that higher plasma levels of 25-hydroxyvitamin D (25[OH]D) would correlate with lower plasma levels of proinflammatory cytokines, acute-phase proteins, and soluble adhesion molecules and higher plasma levels of anti-inflammatory cytokines. We included all adults (age, 20-59 years) of the population-based, cross-sectional study, Health Survey-São Paulo, conducted in São Paulo (Brazil) in the study (n = 281). Anthropometric parameters, blood pressure measurements, and a fasting blood sample were collected by trained fieldworkers. Serum 25(OH)D concentration, plasma inflammatory biomarker levels (C-reactive protein, interleukin [IL]-1β, IL-6, IL-8, IL-10, tumor necrosis factor [TNF] α, IL-12p70, adiponectin, monocyte chemoattractant protein-1, soluble intercellular adhesion molecule-1, and soluble vascular cell adhesion molecule-1), and plasma blood lipid parameters were evaluated. The prevalence of vitamin D inadequacy (<50 nmol/L) was 65.5%. Inadequate participants were younger, with lower body mass index (BMI), systolic and diastolic blood pressures, triglyceride, and total cholesterol levels as well as low-density lipoprotein cholesterol, compared with individuals adequate for vitamin D status. After adjustment, plasma concentration of soluble intercellular adhesion molecule-1 was statistically higher among adequate participants. Stratifying for BMI categories, a negative association was observed between plasma IL-6 and TNF-α levels and serum 25(OH)D concentration in normal-weight participants, whereas a negative association was detected between plasma adiponectin level and serum 25(OH)D concentration in overweight participants. The present findings suggest that BMI interacts with serum 25(OH)D levels, modulating inflammatory response and affecting plasma IL-6, TNF-α, and adiponectin levels. These data indicate that BMI plays a determinant role in the vitamin D-inflammation axis.

Effect of vitamin D supplementation on selected inflammatory biomarkers in older adults: a secondary analysis of data from a randomised, placebo-controlled trial

Observational studies have suggested that 25-hydroxyvitamin D (25(OH)D) levels are associated with inflammatory markers. Most trials reporting significant associations between vitamin D intake and inflammatory markers used specific patient groups. Thus, we aimed to determine the effect of supplementary vitamin D using secondary data from a population-based, randomised, placebo-controlled, double-blind trial (Pilot D-Health trial 2010/0423). Participants were 60- to 84-year-old residents of one of the four eastern states of Australia. They were randomly selected from the electoral roll and were randomised to one of three trial arms: placebo (n 214), 750 μg (n 215) or 1500 μg (n 215) vitamin D3, each taken once per month for 12 months. Post-intervention blood samples for the analysis of C-reactive protein (CRP), IL-6, IL-10, leptin and adiponectin levels were available for 613 participants. Associations between intervention group and biomarker levels were evaluated using quantile regression. There were no statistically significant differences in distributions of CRP, leptin, adiponectin, leptin:adiponectin ratio or IL-10 levels between the placebo group and either supplemented group. The 75th percentile IL-6 level was 2·8 pg/ml higher (95 % CI 0·4, 5·8 pg/ml) in the 1500 μg group than in the placebo group (75th percentiles:11·0 v. 8·2 pg/ml), with a somewhat smaller, non-significant difference in 75th percentiles between the 750 μg and placebo groups. Despite large differences in serum 25(OH)D levels between the three groups after 12 months of supplementation, we found little evidence of an effect of vitamin D supplementation on cytokine or adipokine levels, with the possible exception of IL-6.

Serum 25-hydroxyvitamin D levels and metabolic health status in extremely obese individuals

OBJECTIVE

Vitamin D deficiency is prevalent in obese individuals. 25-hydroxyvitamin D [25(OH)D] levels in metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) adult individuals were examined and the relationship between 25(OH)D levels and other clinical parameters was evaluated.

METHODS

This is a retrospective chart review of outpatient medical records from the Nutrition and Weight Management Center at Boston Medical Center. Subjects were divided into two groups, MHO and MUO, using the homeostasis model assessment of insulin resistance criteria.

RESULTS

A total of 191 obese subjects were included in this analysis. The average body mass index (BMI) was 43.0 ± 9.2 kg/m(2) . Sixty-three subjects (33%) met criteria for MHO. MHO subjects had lower BMI and waist circumferences compared to MUO subjects. 25(OH)D levels were not significantly different between the two groups (P = 0.242). Overall, there were high prevalences of vitamin D deficiency (48.7%) and vitamin D insufficiency (33.0%). 25(OH)D levels were inversely correlated with BMI, body weight, waist circumferences, and HbA1c levels but not with blood pressure, total cholesterol, HDL, triglycerides, or LDL.

CONCLUSIONS

In extremely obese individuals, 25(OH)D levels were not related to metabolic health status or insulin resistance but correlated with the degree of adiposity.

Association between Vitamin D and Adiponectin and Its Relationship with Body Mass Index: The META-Health Study

Background: Low vitamin D and adiponectin levels are both associated with obesity and cardiovascular disease. Previous studies have indicated that vitamin D levels are directly associated with adiponectin, and that this association varies across body mass index (BMI) categories; stronger with increasing BMI. Few studies examined this association in African-Americans (AA), known to have lower levels of vitamin D and adiponectin, and in whites.

Methods: We assessed whether serum vitamin D is associated with serum adiponectin in a biracial population-based sample. Cross-sectional analyses were performed on 426 non-diabetic participants (218 whites and 208 AA) from the META-Health Study, a random sample from the metro Atlanta. Age-adjusted correlations and multivariable linear regression were used for analyses. We investigated the effect modification of the BMI categories of lean, overweight, and obese as defined by standard cut-points (25 and 30 kg/m²).

Results: The mean (SD) age of our study sample was 50.5 (9) years. The mean (SD) levels of vitamin D were 27.4 (9.8) ng/mL in white women, 25.5 (9.3) ng/mL in white men, 16.9 (7.3) ng/mL in AA women, and 18.8 (7.3) ng/mL in AA men. The mean (SD) levels of adiponectin were 17.0 (17.1) μg/mL in white women, 9.9 (11.3) μg/mL in white men, 6.6 (4.8) μg/mL in AA women, and 9.4 (11.6) μg/mL in AA men. Among lean white women (n = 63), there was a significant direct association between vitamin D and adiponectin (β = 0.02, p = 0.04) after adjustment for age, systolic blood pressure, HDL-cholesterol, triglycerides, income, and season of blood drawing. On the contrary, in lean AA women (n = 23), there was a significant inverse association (β = −0.06, p = 0.01).

Conclusion: The association of vitamin D and adiponectin is dependent on race, gender, and BMI category. Among lean white women, there was a significant direct association, whereas in lean AA women the association was inverse. No association was present among obese individuals.

Association between serum vitamin D concentrations and inflammatory markers in the general adult population

OBJECTIVE

In recent years links among vitamin D deficiency, inflammation and cardio-metabolic disease were proposed. As information regarding the associations between vitamin D and inflammatory markers in the general population is sparse, we investigated the associations of 25-hydroxy vitamin D [25(OH)D] with high-sensitivity C-reactive protein (hs-CRP), fibrinogen and white blood cell count (WBC).

MATERIALS/METHODS

The study population comprised 2723 men and women aged 25-88 years from the first follow-up of the Study of Health in Pomerania. Analyses of variance, linear and logistic regressions were performed to assess the associations between 25(OH)D and the three inflammatory markers. The models were adjusted for age, sex, waist circumference, diabetes mellitus, dyslipidemia, anti-inflammatory medication and month of blood sampling. The association between 25(OH)D and WBC was assessed separately in smokers (n = 718) and non-smokers (n = 2005) as effect modification was observed.

RESULTS

We detected a U-shaped association between 25(OH)D and hs-CRP with a nadir of 21-25 ng/ml in fully-adjusted linear regression models with restricted cubic splines (p < 0.01; p' < 0.01). We further detected an inverse association between 25(OH)D and fibrinogen (p < 0.01). In addition, there was an inverse association between 25(OH)D and WBC in smokers (p = 0.02) but no association in non-smokers (p = 0.73).

CONCLUSION

Our study confirms a potential role of 25(OH)D in chronic inflammation. Yet, different inflammatory biomarkers are differently associated with 25(OH)D. Beneficial effects of increasing 25(OH)D were observed for fibrinogen and WBC (in smokers only). In contrast, the U-shaped association between 25(OH)D and hs-CRP indicates that ever-increasing 25(OH)D concentrations may also be related to proinflammatory states.

Vitamin D and Dysfunctional Adipose Tissue in Obesity

Vitamin D deficiency and dysfunctional adipose tissue are involved in the development of cardiometabolic disturbances (eg, hypertension, insulin resistance, type 2 diabetes mellitus, obesity, and dyslipidemia). We evaluated the relation between vitamin D and adipocytokines derived from adipose tissue. We studied 50 obese individuals who were classified into different subgroups according to medians of observed anthropometric parameters (body mass index, body fat percentage, waist circumference, and trunk fat mass). There was a negative correlation between vitamin D level and leptin and resistin (r = -.61, P < .01), while a positive association with adiponectin concentrations was found (r = .7, P < .001). Trend estimation showed that increase in vitamin D level is accompanied by intensive increase in adiponectin concentrations (growth coefficient: 12.13). In conclusion, a positive trend was established between vitamin D and the protective adipocytokine adiponectin. The clinical relevance of this relationship needs to be investigated in larger studies.

National report on the association of serum vitamin D with cardiometabolic risk factors in the pediatric population of the Middle East and North Africa (MENA): the CASPIAN-III Study

OBJECTIVES

As the first, to our knowledge, nationwide study in the Middle East and North Africa (MENA), this study aimed to investigate the association of serum 25 hydroxy vitamin D [25(OH)D] levels with cardiometabolic risk factors in a nationally representative sample of the pediatric population in Iran. The second objective was to provide the prevalence of hypovitaminosis D and the percentiles of serum 25(OH)D in the study population.

METHODS

This national population-based study was conducted among 1100 Iranian students living in 27 provinces in Iran. The association of 25(OH)D with each cardiometabolic risk factor was determined after adjustment for age, gender, body mass index, and waist circumference.

RESULTS

Participants consisted of 1095 students (52% boys) with a mean age of 14.74 ± 2.61 y. The median 25(OH)D level corresponded to a vitamin D insufficiency level: 12.70 ng/mL in boys and 13.20 ng/mL in girls. Overall, 40% of participants were vitamin D deficient, and 39% had vitamin D insufficiency. There were no significant differences in these findings between boys and girls. Adjusted regression analysis revealed a significant weak inverse association of 25(OH)D with systolic blood pressure, diastolic blood pressure, total cholesterol, and low-density lipoprotein cholesterol. This association was significantly positive with high-density lipoprotein cholesterol, but not with fasting plasma glucose and metabolic syndrome.

CONCLUSION

We found a considerably high prevalence of hypovitaminosis D in the pediatric population of a sunny region. Our findings also revealed an association of hypovitaminosis D with many cardiometabolic risk factors from childhood; these associations were independent of obesity indexes. It is of special concern that the highly prevalent disorders of low 25(OH)D and low high-density lipoprotein cholesterol in children and adolescents of the MENA region had significant association. The clinical importance of our findings needs to be confirmed in longitudinal studies.

The anabolic effect of teriparatide is undermined by low levels of high-density lipoprotein cholesterol

Intermittent parathyroid hormone (PTH) administration has a potent ability to increase bone mass, regardless of underlying conditions or species. A recent study using LDLR(-/-) mice showed that the anabolic effect of PTH was blunted by hyperlipidemia, whereas PTH anabolism was rescued by enhancement of high-density lipoprotein cholesterol (HDL-C) function. We conducted a retrospective longitudinal study to determine whether lipid profiles also affect the anabolic effect of intermittent PTH treatment in humans. Fifty-two patients (8 males and 44 females, ages 38-85 years) with severe osteoporosis who had been treated with teriparatide (TPTD, recombinant human PTH(1-34) for 12 months were studied at Severance Hospital, Yonsei University. C-telopeptide (CTX) and osteocalcin (OCN) were measured at 0, 3, and 12 months; and total cholesterol, triglycerides, and HDL-C were measured at baseline. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry at 0 and 12 months. Lumbar spine BMD increased significantly after 12 months of treatment with TPTD (10.0 ± 9.3%, p < 0.001). Initial 3-month changes in CTX and OCN levels revealed positive correlations with the increase in lumbar BMD (r = 0.546, p = 0.001 and r = 0.500, p = 0.006, respectively). Moreover, percentage change in lumbar BMD at 12 months showed a negative correlation with baseline total cholesterol (r = -0.438, p = 0.009) and a positive correlation with HDL-C (r = 0.498, p = 0.016). A smaller 3-month increase in OCN and a lower HDL-C level at baseline were associated with a smaller lumbar BMD increase after TPTD treatment, even after adjustment for age, sex, and other confounding factors (β = 0.462, p = 0.031 for ΔOCN and β = 0.670, p = 0.004 for HDL-C). Plasma levels of lipids, especially HDL-C, seem to be associated with the extent of osteoanabolic effects of TPTD in humans.

Ability of vitamin D to reduce inflammation in adults without acute illness

In vitro studies and some clinical studies suggest that vitamin D plays an important role in reducing inflammation. The objective of this review was to examine recent evidence that vitamin D status influences the level of inflammation in adults without acute illness or injury. Five large cross-sectional studies and two randomized controlled trials are the focus of this review. Associations between 25-hydroxyvitamin D (25OHD) and inflammation markers are significant and inverse in study populations with low 25OHD levels (<21 ng/mL). They are also inverse in adults with relatively high inflammation levels. These associations in the few available randomized controlled vitamin D intervention trials have been null; this may be because they were not examined in populations with sufficiently low levels of 25OHD or high levels of inflammation.