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

Major risk factors underlying the development of metabolic syndrome in vitamin D-deficient rats

Background

Vitamin D is essential for calcium-phosphorus homeostasis, skeletal mineralization, and cardiovascular health. Its deficiency is associated with increased risk of metabolic syndrome and cardiovascular diseases. In this study, we aimed to investigate the relationship between vitamin D deficiency and cardiovascular metabolic syndrome while identifying underlying mechanisms.

Methodology

Forty-eight Wistar albino rats were divided into four groups: control, vitamin D deficient (VD-), metabolic syndrome (MetS), and combined vitamin D deficient with metabolic syndrome (VD- + MetS). VD- and VD- + MetS rats were fed a vitamin D-deficient diet with increased calcium and phosphate to prevent secondary hyperparathyroidism and to determine the direct effects of vitamin D. Metabolic syndrome was induced via 10% fructose in drinking water for 8 weeks. Evaluations included metabolic syndrome markers (hypertension, diabetes, dyslipidemia, and obesity), myocardial injury indicators (lactate dehydrogenase [LDH] and creatine kinase-MB [CK-MB]), and oxidative stress/inflammation markers (malondialdehyde [MDA] and nitric oxide [NO]). Vascular reactivity in thoracic aorta tissues, heart weight, and histopathological changes were also assessed.

Result

The results revealed that vitamin D deficiency was strongly related to each component of metabolic syndrome. Combined vitamin D deficiency and metabolic syndrome induced a highly significant increase in CK-MB, LDH, NO, and MDA levels (p < 0.05). However, there was no significant difference in CK-MB and NO levels for the (VD-) group compared to the control (p > 0.05). Heart weight was significantly increased, and a histological examination of the heart showed increased left ventricular and aortic wall thickness in the combined group (p < 0.05). Vascular response to phenylephrine was significantly increased, whereas the vascular response to acetylcholine was significantly decreased in all experimental groups (VD-, MetS, and VD- + MetS) compared to control (p < 0.05).

Conclusion

The present study demonstrates that vitamin D deficiency is considered one of the major risky and predisposing factors for cardiovascular metabolic syndrome, which could affect the outcome of the disease, partly by affecting endothelial function, vascular oxidative stress, and inflammation.

The Optimal Protective 25-Hydroxyvitamin D Level for Different Health Outcomes in Adults: A Brief Summary of Dose-Response Meta-Analyses

Vitamin D is very important for bone metabolism as well as for the prevention of various diseases, such as type 2 diabetes, cardiovascular disease and different types of cancer. Although vitamin D deficiency is widespread and an important public health problem, there exists controversy in the scientific community, with no established standard definition of adequate and deficient vitamin D status. To add new information on this topic, the aim of this brief opinion paper is to identify and discuss the optimal 25(OH)D concentration (range) for a reduction in the risk of various disease outcomes by summarizing dose-response reporting meta-analyses.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Bariatric surgery and calcifediol treatment, Gordian knot of severe-obesity-related comorbidities treatment

Background

Obesity (OB) is a chronic metabolic disease with important associated comorbidities and mortality. Vitamin D supplementation is frequently administered after bariatric surgery (BS), so as to reduce OB-related complications, maybe including chronic inflammation.

Aim

This study aimed to explore relations between vitamin D metabolites and components of the inflammasome machinery in OB before and after BS and their relations with the improvement of metabolic comorbidities.

Patients and methods

Epidemiological/clinical/anthropometric/biochemical evaluation was performed in patients with OB at baseline and 6 months after BS. Evaluation of i) vitamin-D metabolites in plasma and ii) components of the inflammasome machinery and inflammatory-associated factors [NOD-like-receptors (NLRs), inflammasome-activation-components, cytokines and inflammation/apoptosis-related components, and cell-cycle and DNA-damage regulators] in peripheral blood mononuclear cells (PBMCs) was performed at baseline and 6 months after BS. Clinical and molecular correlations/associations were analyzed.

Results

Significant correlations between vitamin D metabolites and inflammasome-machinery components were observed at baseline, and these correlations were significantly reduced 6 months after BS in parallel to a decrease in inflammation markers, fat mass, and body weight. Treatment with calcifediol remarkably increased 25OHD levels, despite 24,25(OH)2D3 remained stable after BS. Several inflammasome-machinery components were associated with improvement in metabolic comorbidities, especially hypertension and dyslipidemia.

Conclusion

The beneficial effects of vitamin D on OB-related comorbidities after BS patients are associated with significant changes in the molecular expression of key inflammasome-machinery components. The expression profile of these inflammasome components can be dynamically modulated in PBMCs after BS and vitamin D supplementation, suggesting that this profile could likely serve as a sensor and early predictor of the reversal of OB-related complications after BS.

The Mutual Interplay between Bone, Glucose and Lipid Metabolism: The Role of Vitamin D and PTH

BACKGROUND

We sought to investigate the mutual interplay between bone, glucose and lipid metabolism in a wide cohort of community-based subjects.

METHODS

We studied 1240 blood donors (F/M ratio 1/3.2, mean age 41.9 ± 11.7 SD). Serum ionized (Ca⁺⁺), magnesium (Mg⁺⁺), 25-hydroxy-vitamin D [25(OH)D], PTH-1-84, 1,25-dihydroxyvitamin D [1,25(OH)₂D], total cholesterol (C), HDL-C, triglycerides and glucose were measured and LDL-C levels were calculated in all subjects.

RESULTS

25(OH)D negatively correlated with BMI (R = -0.11), PTH (R = -0.16) (p < 0.0001), total C (R = -0.06, p < 0.05) and triglycerides (R = -0.13, p < 0.0001) and positively with 1,25(OH)₂D (R = 0.12) and creatinine (R = 0.17) (p < 0.0001). Serum PTH positively correlated with total C (R = 0.08, p < 0.01), LDL-C (R = 0.1, p < 0.001), triglycerides (R = 0.09, p < 0.01) and glucose (R = 0.15, p < 0.0001) and negatively with HDL-C (R = -0.09, p < 0.01). The odds of showing abnormal serum triglycerides and HDL-C increased as 25(OH)D decreased (p < 0.0001 and p < 0.03) and PTH increased (p < 0.03 and p = 0.05), while the odds of showing abnormal LDL-C levels increased in association with elevated PTH (p < 0.01).

CONCLUSION

Vitamin D, PTH, glucose and lipid metabolism are mutually influenced. Hypovitaminosis D predisposes toward worsening lipid profiles through the actions of PTH, while serum PTH levels per se associate with higher glucose and LDL-C levels.

Vitamin D3 supplementation had no benefits in patients with metabolic syndrome and vitamin D deficiency: A pilot study

BACKGROUND

Vitamin D deficiency has been observed in individuals with metabolic syndrome (MetS). This study evaluated the effects of vitamin D supplementation in patients with MetS and vitamin D deficiency.

METHODS

Vitamin D₃ supplementation was performed in patients with MetS and 25(OH)D levels ≤20 ng/mL arranged in two phases. The first phase corresponded to 50,000 IU/week for eight weeks, and the second phase was 7000 IU/week for twelve weeks.

RESULTS

The 20-week intervention resulted in an increment of 14.3 ng/mL of 25(OH)D. HbA1c showed a reduction of 0.69% (95% CI [-1.16, -0.21], p = 0.005); however, the triglycerides, HDL-cholesterol, fasting blood glucose, blood pressure, and waist circumference were not responsive to supplementation.

CONCLUSION

Vitamin D₃ supplementation did not favor the MetS components.

Effect of vitamin D deficiency on metabolic syndrome among Korean shift workers

OBJECTIVE

This study aimed to investigate the effect of vitamin D deficiency on metabolic syndrome among shift workers.

METHODS

This study included 207 756 workers who underwent a comprehensive health examination at a large South Korean university hospital between 2012 and 2018. We performed multivariate-adjusted logistic regression analysis and analyzed mediation and exposure-mediator interaction.

RESULTS

Overall, 5.5% of the participants had metabolic syndrome. Compared to day work, the odds ratios (OR) of metabolic syndrome and vitamin D deficiency (<12 ng/mL) for shift work were 1.14 [95% confidence interval (CI) 1.06-1.22] and 1.63 (95% CI 1.57-1.70), respectively. Among shift workers, the OR of metabolic syndrome for vitamin D levels of 12-20 and <12 ng/mL, compared with a level of ≥20 ng/mL, were 1.36 (95% CI 1.15-1.61) and 1.51 (95% CI 1.26-1.81), respectively. Shift work and vitamin D deficiency showed an additive interaction; the relative excess risks due to interaction, attributable proportion, and synergy index were 0.26 (95% CI 0.08-0.44), 0.17 (95% CI 0.07-0.28), and 2.09 (95% CI 1.23-3.55), respectively. When vitamin D deficiency was treated as a mediator, the direct and total effects of shift work on metabolic syndrome were 1.12 (95% CI 1.04-1.22) and 1.15 (95% CI 1.07-1.25), respectively. The indirect effect was 1.03 (95% CI 1.02-1.04) and accounted for 18% of the total effect.

CONCLUSION

Vitamin D is a potential mediator of the impact of shift work on metabolic risk factors.

Association between Serum Vitamin D and Metabolic Syndrome in a Sample of Adults in Lebanon

The evidence on the association between vitamin D and metabolic syndrome (MetS) is inconclusive. This was a cross-sectional study to explore the relationship between vitamin D serum levels and MetS in a sample of Lebanese adults (n = 230), free of diseases that affect vitamin D metabolism, recruited from an urban large university and neighboring community. MetS was diagnosed according to the International Diabetes Federation criteria. A logistic regression analysis was performed taking MetS as the dependent variable, and vitamin D was forced into the model as an independent variable. The covariates included sociodemographic, dietary, and lifestyle variables. The mean (SD) serum vitamin D was 17.53 (12.40) ng/mL, and the prevalence of MetS was 44.3%. Serum vitamin D was not associated with MetS (OR = 0.99 (95% CI: 0.96, 1.02), p < 0.757), whereas the male sex, compared with the female sex and older age, was associated with higher odds of having MetS (OR = 5.92 (95% CI: 2.44, 14.33), p < 0.001 and OR = 1.08 (95% CI: 1.04, 1.11), p < 0.001, respectively). This result adds to the controversy in this field. Future interventional studies are warranted to better understand the relationship between vitamin D and MetS and metabolic abnormalities.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Vitamin D, Gut Microbiota, and Cardiometabolic Diseases-A Possible Three-Way Axis

Metabolic syndrome (MetSyn) is a precursor for several cardiometabolic diseases such as obesity, type-2 diabetes mellitus (T2DM), and cardiovascular diseases. Emerging evidence suggests that vitamin D deficiency links to cardiometabolic diseases through microbiota. A combination of poor vitamin D status and dysbiosis may contribute to the progression of cardiometabolic diseases. Therefore, in this review, we present the relationship among vitamin D, microbiota, and cardiometabolic diseases with a focus on MetSyn. We searched major databases for reports on vitamin D, microbiota, and MetSyn until June 2022. We reviewed 13 reports on the relation between vitamin D and MetSyn (6 randomized controlled and 7 cross-sectional studies) and 6 reports on the effect of vitamin D on the gut microbiome. Adequate vitamin D status has a beneficial effect on gut microbiota, therefore preventing the progression of MetSyn. Further, well-controlled studies are needed for a better understanding of the mechanisms of action involving vitamin D and microbiota in the pathogenesis of cardiometabolic diseases.

Association between vitamin D and cardiovascular health: Myth or Fact? A narrative review of the evidence

Vitamin D deficiency is prevalent worldwide. Since the discovery of the expression of vitamin D receptor in ventricular cardiomyocytes, fibroblasts, and blood vessels, there has been a growing body of literature assessing the link between vitamin D status and cardiovascular health from one side, and the effect of vitamin D supplementation on prevention of cardiovascular diseases from the other side. In this review, we summarized studies highlighting the role of vitamin D on cardiovascular health, namely atherosclerosis, hypertension, heart failure, and metabolic syndrome, a recognized significant risk factor for cardiovascular diseases. Studies showed discrepancies between findings from cross-sectional and longitudinal cohorts and those from interventional trials, but also between one outcome and another. Cross-sectional studies found a strong association between low 25 hydroxyvitamin D (25(OH)D3) and acute coronary syndrome, and heart failure. These findings encouraged the promotion for vitamin D supplementation as a preventive measure for cardiovascular diseases in the elderly, namely in women. This fact, however, turned out into a myth with the results of large interventional trials that did not show any benefit from vitamin D supplementation in reducing ischemic events, heart failure or its outcomes, or hypertension. Although some clinical studies showed beneficial effect of vitamin D supplementation on insulin sensitivity and metabolic syndrome, this effect was not consistent across all studies.

Changes in Vitamin D Status in Korean Adults during the COVID-19 Pandemic

The aim of this study was to investigate changes in 25(OH)D (25-hydroxyvitamin D) levels and in the vitamin D status of Korean adults before and during the coronavirus disease (COVID-19) pandemic. This study compared serum 25(OH)D levels before and after the pandemic in 1483 adults aged 19 years and older who were screened at a university hospital. Subjects were selected only from participants tested in the same season before and after the pandemic. The pre-COVID-19 testing period was from 1 March 2018 to 31 November 2019; the testing period in the COVID-19 era was from 1 June 2020 to 31 November 2021. The mean 25(OH)D level for all participants was 21.4 ± 10.2 ng/mL prior to the outbreak of COVID-19, which increased to 23.6 ± 11.8 ng/mL during the COVID-19 lockdown period (p < 0.001). The increase was particularly dramatic in elderly females (28.8 ± 12.3 ng/mL to 37.7 ± 18.6 ng/mL, p = 0.008). The prevalence of vitamin D deficiency decreased in both males (48.4% to 44.5%, p = 0.005) and females (57.0% to 46.0%, p < 0.001). In conclusion, 25(OH)D levels in Korean adults increased during the COVID-19 era, and the prevalence of vitamin D deficiency decreased accordingly.

Vitamin D and family history of hypertension in relation to hypertension status among college students

Hypertension and vitamin D concentrations have heritable components, although these factors remain uninvestigated in young adults. The objective of this study was to investigate hypertension risk among young adults with respect to family history of hypertension, adjusting for vitamin D status. Resting blood pressure (BP) was measured in 398 individuals aged 18-35 and classified according to the 2017 American Heart Association criteria. Plasma vitamin D metabolite (25(OH)D3; 24,25(OH)2D3; 1,25(OH)2D3) concentrations were determined using liquid chromatography tandem mass spectrometry (LC-MS/MS). Stepwise logistic regression was used to select covariates. Participants' mean age was 21, 30.3% had hypertension, and nearly all unaware of their hypertensive status (90.7%). Compared with no parental history, the adjusted odds ratio (AOR) for hypertension was elevated among participants with two parents having hypertension (AOR = 4.5, 95% CI: 1.70-11.76), adjusting for sex, body mass index, physical activity, and plasma 25(OH)D3. Results for systolic hypertension (SH) were similar but more extreme (two parents AOR = 7.1, 95% CI: 2.82, 17.66), although dihydroxy metabolites (1,25(OH)2D3 and 24,25(OH)2D3) were significant. There was a strong, independent association with dual parental history and hypertension status, regardless of vitamin D status. Hypertension was prevalent in nearly one-third of the sample and underscores the need for targeted prevention for young adults.

Prevalence and Correlates of Metabolic Syndrome and Its Components in Chinese Children and Adolescents Aged 7–17: The China National Nutrition and Health Survey of Children and Lactating Mothers from 2016–2017

This descriptive study aimed to determine the prevalence of metabolic syndrome (MetS) and its components among Chinese children and adolescents aged 7–17 from 2016–2017 according to the Cook’s criteria modified for age on the basis of the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) and to evaluate the associations between the factors of interest (especially vitamin A, vitamin D and hyperuricemia) of MetS and its components, using data from the China National Nutrition and Health Survey of Children and Lactating Mothers from 2016–2017. A total of 54,269 school-aged children and adolescents were ultimately included in this study. Anthropometric measurements and laboratory examinations of the subjects and their relevant information were also collected. A multivariate logistic regression analysis model was applied to analyze the relationships between relevant factors associated with MetS and its components. In the present study, the prevalence of MetS in children and adolescents was 5.98%. Among the five components of MetS, elevated blood pressure (BP) and abdominal obesity were the most prevalent (39.52% and 17.30%), and 58.36% of the subjects had at least one of these components. In the multivariate logistic regression, an overweight condition, obesity and hyperuricemia were positively correlated with the incidence of MetS and all five components. There was also a positive association observed between vitamin A and the risk of MetS and some components of MetS (abdominal obesity and high triglycerides (TG)) and vitamin A was negatively associated with the risk of low high-density lipoprotein cholesterol (HDL-C). Subjects with vitamin D inadequacy had a higher risk of MetS (OR = 1.364, 95%CI: 1.240–1.500) and four of its components, excepting elevated FBG (fast blood glucose). Vitamin D deficiency was positively associated with MetS (OR = 1.646, 95%CI: 1.468–1.845) and all five of its components. Well-designed, large-scale prospective studies are also needed in the future.

Factors Showing the Growing Relation Between Vitamin D, Metabolic Syndrome, and Obesity in the Adult Population: A Systematic Review

Several theories suggest an inverse association between increasing adiposity, particularly abdominal fat, and low vitamin D levels. As a result, several routes are likely to impact how vitamin D, obesity, and metabolic syndrome (MetS) interact. This systematic study followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. A comprehensive PubMed, PubMed Central, Google Scholar, and ScienceDirect database search was conducted for published papers over the previous five years. Studies were identified using the following criteria 1) participants, interventions, and outcomes (PIO) components, 2) free full text, 3) studies published in English, and 4) human studies, including systematic and narrative reviews and cross-sectional, observational studies, were among the inclusion and exclusion criteria. In total, 151 articles were returned, and 16 duplicates were rejected. After verifying the titles and abstracts of these records using the review's PIO components and eligibility criteria, 17 received a 70% or above score. On review of the literature, the release of adiponectin from fatty tissues was inversely correlated with body weight and BMI suggesting a link between vitamin D deficiency and insulin resistance.

Association of Serum 25(OH)D with Metabolic Syndrome in Chinese Women of Childbearing Age

Objective: To analyze the associations between serum 25(OH)D levels and the risk of metabolic syndrome (MetS) and its components, and the related genetic and non-genetic factors in non-diabetic women of childbearing age in China. Methods: Subjects were randomly selected from the 2015 Chinese Adult Chronic Disease and Nutrition Surveillance. The data of sociodemographic characteristics and lifestyle factors were obtained through questionnaire survey. Anthropometry was measured by trained interviewers, and fasting blood was collected to test 25-hydroxyvitamin D [25(OH)D], total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), and other related parameters. Generalized linear mode and multivariate logistic analysis were performed to analyze the associations between serum 25(OH)D and MetS and its components, adjusting for the possible confounders. Results: Body mass index (BMI), serum alanine aminotransferase (ALT), hypersensitive C-reactive protein (hs-CRP), 25(OH)D, phosphorus (P), and parathyroid hormone (PTH) levels were associated with the number of MetS’s components. G allele carriers of GC rs2282679 had higher diastolic blood pressure (DBP) and FBG levels compared with the TT genotypes, while higher genetic risk score (GRS) seemed to be associated with reduced HDL-C level. The odds ratio (OR) for MetS in lowest group of 25(OH)D was 1.533 (0.980−2.399) after adjusting for season, district, area type, latitude, age, BMI, PTH, P, ALT, CRE, interleukin-6 (IL-6), and hs-CRP, compared with the median group, but the association was not significant. An insufficient 25(OH)D concentration (<14.22 ng/mL) was significantly related to the risk of elevated waist circumference (WC) (OR = 1.612 (1.014−2.561)) and TG (OR = 2.210 (1.318−3.706)), and reduced HDL-C (OR = 1.639 (1.206−2.229)) after adjusting for the confounders among these women. Moreover, these relationships were not affected by vitamin D metabolism-related gene polymorphisms. Conclusion: After comprehensively considering various influencing factors, significant associations between insufficient serum 25(OH)D and MetS‘s components, including elevated WC, TG, and reduced HDL-C, were observed. However, MetS, hypertension, and hyperglycemia were not found independently associated with 25(OH)D levels.

Contribution of vitamin D status as a determinant of cardiometabolic risk factors: a structural equation model, National Food and Nutrition Surveillance

Background

Structural equation modeling (SEM) is a method used to evaluate linear causal relationships among variables. This study aimed to investigate the direct and indirect effects of serum 25(OH) D on certain cardiovascular risk factors using SEM.

Methods

An analytical cross-sectional study was conducted in six provinces of Iran. Subjects (n = 922), aged 19–65 years, were selected from National Food and Nutrition Surveillance. The assessments were sun-exposure behavior, anthropometric and biochemical measurements. A series of SEM models were tested and the model with the best fit indices was considered for use in the structural part of the model. Based on the literature review of previous theoretical models and supporting bivariate analyses, an overall SEM examined direct or indirect associations among observed and latent variables. We put the demographic, duration of sun exposure, anthropometric and metabolic variables in our model.

Results

The paths between serum 25(OH) D and BMI were inverse and statistically significant, whereas age showed a positive association with BMI (B = 0.06, p < 0.001), both direct (st. effect = 0.11, p = 0.01) and indirect via vitamin D (st. effect = − 0.02, p = 0.01). The results confirmed that serum 25(OH) D concentration is a predictor for latent variable of lipid profile (B = − 0.13, p = 0.01) both through direct (p = 0.02) and indirect effects via BMI (p = 0.01).

Conclusion

Serum 25(OH) D concentration is a predictor of BMI and also a latent variable of lipid profile via direct and indirect effects. It can also attenuate the harmful effect of age on BMI and lipid profile particularly in women.

Metabolic Profile and Bone Status in Post-Menopausal Women with Rheumatoid Arthritis: A Monocentric Retrospective Survey

Background: Rheumatoid arthritis (RA) and metabolic syndrome (MetS) are chronic conditions that share common inflammatory mechanisms. Both diseases can lead to an impairment of the bone microarchitecture. The aims of our study were to evaluate clinical, metabolic, and bone parameters in RA patients with or without MetS (MetS+, MetS-) and potential correlations between the glico-lipidic profile, RA disease activity, and bone status. Methods: A total of thirty-nine RA female post-menopausal patients were recruited (median age 66.6 ± 10.4, disease duration 3 ± 2.7). Anthropometric data, medical history, and current treatment were recorded along with basal blood tests, bone, and lipid metabolism biomarkers. RA disease activity and insulin resistance were evaluated through standard scores. Quantitative assessment of the bone (bone mineral density-BMD) was performed by dual-energy-X ray absorption (DXA), whereas bone quality was quantified with the trabecular bone score (TBS). Results: No statistically significant differences concerning both BMD and TBS were detected between the MetS+ and MetS- RA patients. However, the MetS+ RA patients exhibited significantly higher disease activity and lower serum 25-hydroxyvitamin D [25(OH)D] concentrations (respectively, p = 0.04 and p = 0.01). In all RA patients, a significant negative correlation emerged between the BMD of the femoral trochanter with plasmatic triglycerides (TG) concentrations (r = -0.38, p = 0.01), whereas the lumbar BMD was positively correlated with the abdominal waist (AW) and fasting glucose (FG) concentrations. On the other hand, the TBS was negatively correlated with insulin concentrations, FG, and RA disease activity (respectively, r = -0.45, p = 0.01, r = -0.40, p = 0.03, r = -0.37, p = 0.04), the last one was further negatively correlated with 25-OHD serum concentrations (r = -0.6, p = 0.0006) and insulin-resistance (r = 0.3, p = 0.04). Conclusions: Bone quantity (BMD) and quality (TBS) do not seem significantly changed among MetS+ and MetS- RA patients; however, among MetS+ patients, both significantly higher disease activity and lower vitamin D serum concentrations were observed. In addition, the significant negative correlations between the alterations of metabolic parameters limited to the TBS in all RA patients might suggest that qualitative bone microarchitecture impairments (TBS) might manifest despite unchanged BMD values.