Vitamin D deficiency in relation to general and abdominal obesity among high educated adults

Vitamin D Deficiency in Patients Hospitalized for Heart Failure Living in the Tropics

Background and Objectives

Vitamin D, as a steroid hormone, has multiple effects on human body and its deficiency has been associated with an increased risk of heart failure (HF) and unfavorable outcomes. The present study investigated the prevalence of vitamin D deficiency (VDD) and its relationship with cardiometabolic parameters in patients hospitalized for HF living in the city of Recife (latitude 8° South).

Methods

Analytical cross-sectional study, with men and women aged 40-64 years. The HF group was recruited during hospitalization due to decompensation. A matched control group was recruited from the general endocrine clinics. Vitamin D status was assessed by measuring serum 25-hydroxyvitamin D (25OHD), considering deficiency when 25OHD <20 ng/mL (<50 nmol/L).

Results

A total of 243 patients were evaluated (HF group: 161, control group: 82). Lower serum 25OHD levels were observed in the HF group (25.2±9.4 vs. 30.0±7.7ng/mL; p<0.001), as well as a higher prevalence of VDD (27.3% vs. 9.8%; prevalence ratio, 2.80; 95% confidence interval, 1.38-5.67; p=0.002). In patients with HF, VDD was associated with diabetes mellitus (65.9% vs. 41.0%; p=0.005) and female sex (65.9% vs. 44.4%; p=0.015). In the subgroup with VDD, higher values of hemoglobin A1c (7.9% [6.0-8.9] vs. 6.2% [5.7-7.9]; p=0.006) and dyslipidemia were also observed.

Conclusions

We found higher rates of VDD in patients hospitalized for HF and this was associated with deleterious laboratory metabolic parameters.

Association of combined healthy lifestyle with general and abdominal obesity

Background

Data linking joint healthy lifestyle factors to general and abdominal obesity are scarce, in particular in the Middle East. The aim of this study was to examine the association of combined healthy lifestyle factors with general and abdominal obesity in a large population of Iranian adults.

Methods

This cross-sectional study was done on 3,172 Iranian adults aged ≥18 years. We constructed healthy lifestyle score using information on dietary intakes, physical activity, smoking status, and psychological distress. To evaluate components of healthy lifestyle, we applied a validated 106-item semi-quantitative Food Frequency Questionnaire (FFQ), General Practice Physical Activity Questionnaire (GPPAQ), General Health Questionnaire (GHQ), and other pre-tested questionnaires. General obesity was defined as having a body mass index (BMI) ≥30 kg/m2 and abdominal obesity as a waist circumference (WC) of ≥102 cm in men and ≥88 cm in women.

Results

Mean age of participants was 36.54 ± 7.97 years. General and abdominal obesity were prevalent among 8.7% and 21.5% of study participants, respectively. Linear analysis showed a significant positive relationship between healthy lifestyle score and BMI among men (β: 0.30, 95% CI: 0.05, 0.54). However, no significant association was found between healthy lifestyle and abdominal obesity in men. Among women, one score increase in healthy lifestyle score was associated with a reduction of 0.65 cm in WC. In terms of individual components of healthy lifestyle, we found that low-distressed women had lower odds of abdominal obesity compared with high-distressed women.

Conclusion

We found a significant inverse association between healthy lifestyle and WC among women. However, healthy lifestyle was positively associated with BMI among men.

Are There Any Correlations between Vitamin D, Calcium, and Magnesium Intake and Coronary and Obesity Indices?

OBJECTIVE

The association between nutrient intake and obesity and coronary problems has received great attention. So, this study aimed to examine the association between vitamin D, calcium, and magnesium intake and obesity and coronary indices.

METHODS

A total of 491 male and female university employees (18-64 years) were randomly included in a cross-sectional study. Blood samples were drawn, and the lipid profile was analyzed. Different anthropometrics were measured. Obesity and coronary indices were calculated based on standard formulas. A 24-h recall was used to measure the average dietary intake of vitamin D, calcium, and magnesium.

RESULTS

For the total sample, vitamin D had a significantly weak correlation with the abdominal volume index (AVI) and weight-adjusted waist index (WWI). However, calcium intake had a significant moderate correlation with the AVI and a weak correlation with the conicity index (CI), body roundness index (BRI), body adiposity index (BAI), WWI, lipid accumulation product (LAP), and atherogenic index of plasma (AIP). In males, there was a significant weak correlation between calcium and magnesium intake and the CI, BAI, AVI, WWI, and BRI. Additionally, magnesium intake had a weak correlation with the LAP. In female participants, calcium and magnesium intake had a weak correlation with CI, BAI, AIP, and WWI. Additionally, calcium intake showed a moderate correlation with the AVI and BRI and a weak correlation with the LAP.

CONCLUSION

Magnesium intake had the greatest impact on coronary indices. Calcium intake had the greatest impact on obesity indices. Vitamin D intake had minimal effects on obesity and coronary indices.

Vitamin D status and its relationship with obesity indicators in Moroccan adult women

Background: Although vitamin D deficiency has been studied in various populations, there are few data on its prevalence and associated factors among Moroccan women. Aim: To determine the prevalence of vitamin D deficiency and investigate its association with body mass index (BMI), waist circumference, and serum concentrations of parathyroid hormone, calcium, and phosphorus in a sample of Moroccan adult women. Methods: This is a cross-sectional study conducted at Mohammed V Military Hospital of Instruction, Rabat. Anthropometric measurements and biochemical analyses were performed using standard procedures Results: A total of 714 women aged 18-65 years participated in this study. The overall prevalence of vitamin D deficiency was 74.4%. Approximately 24% and 51% of women had severe and moderate vitamin D deficiency, respectively. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were inversely correlated with BMI in vitamin D-deficient subjects (P = 0.036) and with parathyroid hormone 1-84 (PTH1-84) levels in the study sample (P = 0.010). PTH1-84 concentrations were greater among overweight/obese individuals compared to their non-overweight peers (P = 0.001) and tended to be higher among vitamin D-deficient women than vitamin D-sufficient women (P = 0.053). Conclusion: This study showed a very high prevalence of vitamin D deficiency in this sample of Moroccan women. Lower serum 25(OH)D levels were associated with increased BMI in vitamin D-deficient women and with elevated PTH1-84 levels among the study sample. Although these findings come from a convenience sample of women that attended a nutrition clinic, they underscore the urgent need to develop public health interventions to improve women's vitamin D status.

Genetic scores associated with favourable and unfavourable adiposity have consistent effect on metabolic profile and disease risk across diverse ethnic groups

AIM

This study aims to investigate the associations between genetic risk scores (GRS) for favourable and unfavourable adiposity and a wide range of adiposity-related outcomes across diverse populations.

METHODS

We utilised previously identified variants associated with favourable (36 variants) and unfavourable (38 variants) adiposity to create GRS for each adiposity phenotype. We used summary statistics from 39 outcomes generated by the Pan-UKB genome-wide association studies Version 0.3, incorporating covariates such as age, sex and principal components in six populations: European (n = 420,531), African (6636), American (980), Central/South Asian (8876), East Asian (2709) and Middle Eastern (1599).

RESULTS

The favourable adiposity GRS was associated with a healthy metabolic profile, including lower risk of type 2 diabetes, lower liver enzyme levels, lower blood pressure, higher HDL-cholesterol, lower triglycerides, higher apolipoprotein A, lower apolipoprotein B, higher testosterone, lower calcium and lower insulin-like growth factor 1 generally consistently across all the populations. In contrast, the unfavourable adiposity GRS was associated with an adverse metabolic profile, including higher risk of type 2 diabetes, higher random glucose levels, higher HbA1c, lower HDL-cholesterol, higher triglycerides, higher liver enzyme levels, lower testosterone, and higher C-reactive protein generally consistently across all the populations.

CONCLUSION

The study provides evidence that the genetic scores associated with favourable and unfavourable adiposity have consistent effects on metabolic profiles and disease risk across diverse ethnic groups. These findings deepen our understanding of distinct adiposity subtypes and their impact on metabolic health.

Vitamin D and Visceral Obesity in Humans: What Should Clinicians Know?

The extraskeletal effect of vitamin D on adipose tissue biology and modulation in human obesity is of great interest and has been extensively investigated. Current evidence from preclinical and clinical studies in human adipose tissue suggests that the anti-inflammatory effects of vitamin D are evident and consistent, whereas the effects of vitamin D on adipocyte differentiation, adipogenesis, and energy metabolism and the effects of vitamin D supplementation on adipokine levels are inconclusive. Interventional studies related to medical and surgical weight loss in humans have shown small or no improvement in vitamin D status. Additionally, the benefit of vitamin D supplementation for the reduction in visceral adipose tissue has only been demonstrated in a few studies. Overall, the findings on the relationship between vitamin D and visceral adipose tissue in humans are still inconclusive. Further studies are required to confirm the beneficial effects of vitamin D on ameliorating adipose tissue dysfunction.

Predictive Ability of Machine-Learning Methods for Vitamin D Deficiency Prediction by Anthropometric Parameters

Background: Vitamin D deficiency affects the general population and is very common among elderly Europeans. This study compared different supervised learning algorithms in a cohort of Spanish individuals aged 35–75 years to predict which anthropometric parameter was most strongly associated with vitamin D deficiency. Methods: A total of 501 participants were recruited by simple random sampling with replacement (reference population: 43,946). The analyzed anthropometric parameters were waist circumference (WC), body mass index (BMI), waist-to-height ratio (WHtR), body roundness index (BRI), visceral adiposity index (VAI), and the Clinical University of Navarra body adiposity estimator (CUN-BAE) for body fat percentage. Results: All the anthropometric indices were associated, in males, with vitamin D deficiency (p < 0.01 for the entire sample) after controlling for possible confounding factors, except for CUN-BAE, which was the only parameter that showed a correlation in females. Conclusions: The capacity of anthropometric parameters to predict vitamin D deficiency differed according to sex; thus, WC, BMI, WHtR, VAI, and BRI were most useful for prediction in males, while CUN-BAE was more useful in females. The naïve Bayes approach for machine learning showed the best area under the curve with WC, BMI, WHtR, and BRI, while the logistic regression model did so in VAI and CUN-BAE.

Association of serum 25-hydroxyvitamin D concentration with anthropometric measures in children and adolescents: the CASPIAN-V study

BACKGROUND

Serum 25-hydroxyvitamin D (25(OH)D) concentrations reflect vitamin D status, with deficiency implicated as an underlying factor for many adverse health effects. This study aims to analyze the association between vitamin D status and different anthropometric measures in a large pediatric population.

METHODS

This nationwide cross-sectional study was conducted in 2019 in blood samples obtained from school students of 30 provinces in Iran. Participants were 2596 children and adolescents aged 7-18 years. Weight, height, waist circumference (WC), hip circumference (HC), neck circumference (NC), and wrist circumference (WrC) were measured. Body mass index (BMI) and waist-to-height ratio (W/HtR) were calculated. Serum 25(OH)D concentrations were measured using chemiluminescent immunoassay.

RESULTS

Participants consisted of 55% boys, 71.3% urban inhabitants, with a mean (SD) age of 12.1 (3.0) years. Overall, vitamin D deficiency was documented in 10.6% of participants, insufficiency in 60.4%, and sufficiency in 29% of the population studied. The mean of BMI and WC was higher in the vitamin D deficient than in the vitamin D sufficient group (19.31 kg/m² and 69.24 cm vs. 18.34 kg/m² and 65.73 cm, respectively, P < 0.01). Multivariate linear regression models revealed a significant association of vitamin D insufficiency with WC and W/HtR (P < 0.05). Likewise, in the multivariate regression models, vitamin D deficiency was associated with BMI, WC, and W/HtR (P < 0.05).

CONCLUSION

Our findings on the inverse association between vitamin D status and some anthropometric measures underscore the importance of providing vitamin D by fortification and supplementation programs of vitamin D for the pediatric population.

LEVEL OF EVIDENCE

V.

Fruit and vegetable consumption in relation to primary headaches: the MEPHASOUS study

BACKGROUND

Fruit and vegetable consumption may beneficially affect the odds of primary headaches due to their antioxidant contents. However, no study has examined the association between fruit and vegetable consumption and primary headaches among university students.

AIM

To assess the relation between fruit and vegetable intakes and primary headaches among Iranian university students.

METHODS

Overall, 83,214 university students with an age range of ≥ 18 years participated in the present study. Dietary intakes and also data on confounding variables were collected using validated questionnaires. Data on dietary intakes were collected using a validated dietary habits questionnaire. We used the International Classification of Headache Disorders-3 (ICHD-3) criteria to define primary headaches.

RESULTS

Fruit consumption was negatively associated with primary headaches; such that after controlling for potential confounders, greater intake of fruits was associated with 30% lower odds of primary headaches (OR: 0.70, 95% CI 0.58-0.84). Such an inverse association was also found for vegetable consumption. In the fully adjusted model, students in the top category of vegetable consumption were 16% less likely to have primary headaches compared with those in the bottom category (OR: 0.84, 95% CI 0.74-0.95). Subgroup analysis revealed that fruit consumption was inversely associated with primary headaches in females, unlike males, and vegetable consumption was inversely associated with these headaches in males, as opposed to females. Moreover, fruit and vegetable consumption was related to lower odds of primary headaches in normal-weight students.

CONCLUSION

Fruit and vegetable intakes were associated with reduced odds of primary headaches.

LEVEL OF EVIDENCE

Level III, cross-sectional analytic studies.

Association of serum 25-hydroxy vitamin D with obesity-related indices in Chinese adults: A cross-sectional study

Obesity has been a well-known risk factor of low-level serum vitamin D. Compared with the traditional obesity-related indicator (body mass index, BMI), associations for two novel anthropometric indices, a body shape index (ABSI) and body roundness index (BRI) with vitamin D deficiency or insufficiency, still remain unclear. This study aimed to assess the associations of serum 25-hydroxy vitamin D (25(OH)D) status with these three obesity-related indices among Chinese adults. A total of 1666 individuals were included. Anthropometric measurements were performed to calculate the indices, and fasting blood was collected to determine serum 25(OH)D deficiency (<12 ng/ml) and insufficiency (12-20 ng/ml). Deficiency or insufficiency of 25(OH)D was found in 37.5% and 43.1% of the participants, respectively. After adjustment for potential confounders, a significantly increased prevalence of 25(OH)D deficiency was observed for higher ABSI (OR Q4 vs Q1 2.334, 95% CI 1.458-3.734; p trend = 0.002) and BRI (OR Q4 vs Q1 2. 215, 95%CI 1.365-3.594; p trend = 0.010), and for higher BMI in men. Regarding 25(OH)D insufficiency, a significant association was also found for ABSI (OR Q4 vs Q1 2.372, 95%CI 1.558-3.612; p trend = 0.001). The area under the ROC of ABSI (0.731, 95%CI 0.687-0.774) for predicting a low level of 25(OH)D was significantly larger than that of BMI (0.695, 95%CI 0.649-0.741) in men, but not in women. A positive association between obesity and lower 25(OH)D serum concentration was found among Chinese adults. Besides BMI, novel obesity-related indicator, ABSI and BRI were associated with lower serum 25(OH)D to some extent, and further studies are needed to clarify their potential to be used as screening tools in clinical practice.

The association of serum levels of zinc and vitamin D with wasting among Iranian pre-school children

PURPOSE

Wasting is a main indicator of Child's undernutrition that is associated with several non-communicable diseases and child mortality. This is the first population-based study which evaluated the association of serum zinc and vitamin D levels with wasting in a Middle East region. We also reported the prevalence of vitamin D and zinc deficiencies among Iranian pre-school children aged 6 years.

METHODS

This was a multicenter cross-sectional study that included 425 children aged between 5 and 7 years (on average 6 years) with BMI-for-age Z-scores of < - 1 SD resident in urban and rural areas of Iran in the spring of 2012 as part of the National Integrated Micronutrient Survey 2 (NIMS-2). Anthropometric measurements and blood sampling were obtained. The prevalence of vitamin D and zinc deficiencies together with the correlations of these variables with the increase of BMI-for-age Z-scores were evaluated.

RESULTS

The prevalence of vitamin D and zinc deficiencies was 18.8% and 12.7%, respectively. In addition, 31.1% of children were wasted. Children in the second tertile of 25(OH)D levels were less likely to have wasting compared with those in the first tertile in both crude and adjusted models (OR 0.47, 95% CI 0.27-0.83). A significant inverse association was found between serum levels of zinc and wasting (OR 0.57, 95% CI 0.34-0.96); such that after adjusting for confounders, children in the highest tertile of serum zinc had 47% less odds of wasting compared with those in the first tertile (OR 0.53, 95% CI 0.31-0.91).

CONCLUSION

The prevalence of vitamin D and zinc deficiencies among Iranian pre-school children aged 6 years was 18.8 and 12.7%, respectively. Serum levels of vitamin D and zinc were inversely associated with wasting either before or after controlling for confounders.

LEVEL OF EVIDENCE

Level III, case-control analytic studies.

Serum vitamin D levels in relation to abdominal obesity: A systematic review and dose-response meta-analysis of epidemiologic studies

Although several observational studies have investigated the relationship between vitamin D deficiency and risk of central obesity, the results were inconsistent. We performed a dose-response meta-analysis on epidemiologic studies that evaluated the association of vitamin D status and abdominal obesity in adults. A systematic search was carried out of all published articles, up to May 2020, in five electronic databases, including MEDLINE (Pubmed), EMBASE, Institute for Scientific Information (ISI) (Web of science), Scopus and Google scholar. Forty-one observational studies reported odds ratios (ORs) or relative risks (RRs) with 95% confidence intervals (CIs) for abdominal obesity in relation to serum vitamin D levels in adults were included in the analysis. Using a random effects model, the overall effect size was calculated. Combining 44 effect sizes from 36 cross-sectional studies with 257,699 participants revealed that the highest versus the lowest serum vitamin D level was significantly associated with a 23% decreased odds of abdominal obesity (OR: 0.77; 95% CI [0.71, 0.83]). This inverse association was significant in almost all subgroups based on different covariates. Dose-response analysis showed that each 25 nmol/L increase in serum vitamin D was related to 8% reduced risk of abdominal obesity (OR: 0.92; 95% CI [0.85, 0.99]). When we confined the analysis to 23 effect sizes from 17 studies with representative population (242,135 participants), the same results were obtained (OR: 0.79; 95% CI [0.71, 0.87]). Dose-response analysis indicated that each 25 nmol/L increase in blood vitamin D levels was linked to 10% decreased central adiposity risk in representative populations (OR: 0.90; 95% CI [0.82, 0.99]). This meta-analysis of epidemiologic studies revealed that serum vitamin D level was inversely associated with risk of abdominal obesity in adults, in a dose-response manner. The same findings were obtained in representative populations. Further prospective studies are required to examine the causal association between serum vitamin D levels and abdominal obesity.

Breakfast consumption is inversely associated with primary headaches in university students: The MEPHASOUS study

OBJECTIVE

This study was conducted to examine the association between breakfast consumption pattern and primary headaches in a large population of university students.

METHODS

This cross-sectional study was done on the MEPHASOUS dataset that contained the information of 83,677 university students, aged ≥18 years, from 28 provinces of Iran. Dietary intakes and breakfast consumption pattern were assessed using a validated self-administered dietary habits questionnaire. Primary headaches were determined according to the International Classification of Headache Disorders-3 (ICHD-3) criteria. Binary logistic regression in different adjusted models was used to assess the association between breakfast consumption and primary headaches.

RESULTS

The mean age of participants was 21.50 ± 4.01. Primary headaches were prevalent among 9% of university students. A significant inverse association was seen between breakfast consumption and odds of primary headaches [odds ratio (OR): 0.57, 95 % confidence interval (CI): 0.51-0.62]. This association remained significant even after taking potential confounders into account; such that students who consumed breakfast frequently had 26 % lower odds of primary headaches compared with those who consumed it <1 day/week (OR: 0.74, 95 % CI: 0.65-0.85). Moreover, such a significant inverse association was observed in female students (OR: 0.54, 95 % CI: 0.49-0.61) as well as those with BMI < 25 kg/m² (OR: 0.68, 95 % CI: 0.58-0.79). However, it became non-significant in male students and those with overweight or obesity.

CONCLUSION

We found that frequent breakfast consumption is associated with a decreased odds of primary headaches in female students and those with BMI < 25 kg/m². Further prospective studies are needed to confirm our findings.

Lack of a relationship between vitamin D status and resting metabolic rate in Iranian adults

OBJECTIVES

Studies suggest a positive relationship between 25-hydroxy vitamin D (25(OH)D)) and resting metabolic rate (RMR). We aimed to determine whether this relationship was also true of populations with very low vitamin D status.

METHODS

Fat mass (FM) and fat free mass (FFM) were determined from multifrequency bioimpedance analysis (InBody 720, Korea). RMR was based on indirect calorimetry (Cortex Metalyser 3B, Germany). Fasting blood measurements of 25(OH)D concentration, glucose and triglycerides were measured. Data were analyzed separately on men and women by tertile of vitamin D status and multiple linear regression analysis.

RESULTS

Two hundred and sixty-three subjects (115 males; 148 females) with a mean age of 37 years and mean %body fat of 30.5% were studied. In women but not men, age, body weight, waist circumference, FM, and FFM increased significantly across tertiles of 25(OH)D. However, there was no difference in unadjusted or adjusted RMR across tertiles of 25OHD in both women and men. Stepwise forward regression analysis showed that age and FFM in men, age and FM in women but not by 25(OH)D, were determinants of RMR. In addition, RMR adjusted for age, sex, FM, FFM and triglyceride-glucose index did not relate to 25(OH)D when linear (r = 0, P = .98), quadratic (r = 0.008, P = .34), or cubic (r = 0.010, P = .43) relationships were tested.

CONCLUSIONS

Residual variation in RMR did not relate to vitamin D status in a group of Iranian adults with very low vitamin D status. Future studies could examine whether such a relationship holds true, after the normalization of vitamin D status.

Associations of vitamin D with novel and traditional anthropometric indices according to age and sex: a cross-sectional study in central southern China

PURPOSE

Vitamin D insufficiency and obesity are recognized as worldwide concerns and have been linked with each other. New anthropometric indices reflect visceral obesity better than traditional anthropometric indices. Our aim was to identify the specific correlations of novel and traditional anthropometric indices with 25-hydroxyvitamin D (25(OH)D) concentrations by sex and age.

METHODS

Cross-sectional data on sociodemographic characteristics, lifestyle factors, clinical characteristics and biochemical measurements were collected for 12,617 Chinese adults. Four traditional anthropometric indices, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR), and two novel anthropometric indices, body roundness index (BRI) and body shape index (ABSI), were calculated.

RESULTS

In both sexes, the mean values of BMI, WC, WHtR and BRI tended to increase with 25(OH)D insufficiency, regardless of adjustment (all P < 0.05). Males with insufficient 25(OH)D had increased odds of obesity (assessed by BMI, WC, WHtR, BRI and ABSI) compared to the odds of males with sufficient 25(OH)D. Females with insufficient 25(OH)D had a higher chance of general obesity (assessed by BMI). Low 25(OH)D status was associated with indicators of obesity only in participants aged 45-64 years in both sexes.

CONCLUSION

A inverse association between obesity and lower vitamin D levels was found. Moreover, in addition to BMI, novel indicators of visceral adiposity, such as BRI and ABSI, were associated with lower 25(OH)D serum concentrations in males. The effects of optimizing vitamin D levels in obese Chinese adults need further examination, particularly in middle-aged males.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

The Relationship between Vitamin D Status and Visceral Fat Accumulation in Males with Type 2 Diabetes

Vitamin D deficiency may play an important role in obesity. The aim of the study was to explore the relationship between vitamin D status and visceral fat accumulation in males with type 2 diabetes. A cross-sectional study was conducted on 128 adult males with type 2 diabetes in Qinhuangdao. The nutritional status of vitamin D was assessed by circulating levels of 25(OH)D, vitamin D deficiency <30 nmol/L, vitamin D insufficiency 30-50 nmol/L and vitamin D sufficiency >50 nmol/L. Accumulation of visceral fat was defined as visceral fat area ≥100 cm². The prevalence of visceral fat accumulation was 35.9%. The prevalence of visceral fat accumulation was 14.6%, 45.1% and 50.0% in type 2 diabetes with vitamin D sufficiency, vitamin D insufficiency and vitamin D deficiency, respectively. In multiple logistic regression analysis, subjects with vitamin D insufficiency [OR=4.255, p=0.012] and vitamin D deficiency [OR=6.122, p=0.022] were more likely to have visceral fat accumulation compared with subjects with vitamin D sufficiency. Visceral fat accumulation linked to the cluster of cardiometabolic risk factor in males with type 2 diabetes. There was a significant correlation between vitamin D status and visceral fat accumulation in males with type 2 diabetes.

The relationship between lifestyle and anthropometric factors with the sleep characteristics among university students in Iran: the MEPHASOUS study

Background

Healthy sleep habits have an important role in normal cognitive function, emotional performance, and well-being. The aims of this study were to describe the characteristics of sleep among university students in Iran. In addition, we assessed the relationship between lifestyle and anthropometric factors with the sleep characteristics.

Methods

This population-based cross-sectional study was conducted using the data of "Mental and Physical Health Assessment of University Students in Iran" survey 2012-2013. This survey was conducted on newly admitted students in 74 public universities in 28 provinces. The participants were younger adults. Univariate and multivariate logistic regression models were utilized to recognize associated factors with sleep pattern and range.

Result

Of total 78,848 students who completed the survey, 54.64% (n = 43,079) were females. The average age of the students was 21.53 ± 4.08 and 21.54 ± 3.99 among males and females, respectively. More than 90% (n = 70,923), were non-smokers. Out of the total respondents, 40.56% (n = 31,756) had irregular sleep pattern. Male students were less likely to have irregular sleep pattern than female students.

Conclusion

Our findings indicated that irregular sleep pattern is associated with overweight and obesity. So, these results underscore the need to educate students on importance of healthy sleep pattern and duration on health conditions.

Effects of Vitamin D Supplementation on General and Central Obesity: Results from 20 Randomized Controlled Trials Involving Apparently Healthy Populations

Background: The obesity pandemic has been paralleled by a high prevalence of vitamin D deficiency (VDD). There is growing epidemiological evidence linking low vitamin D status with obesity events. In addition, observational studies also show that obesity may increase the risk of VDD. However, there is insufficient knowledge to understand whether there is a causality between the two. Moreover, the impact of vitamin D supplementation on obesity indices has shown inconsistent outcomes. Objective: This meta-analysis aimed to assess whether vitamin D supplementation modified general and central obesity indices in apparently healthy populations. Methods: A systematic retrieval of relevant randomized controlled trials (RCTs) was undertaken using Pubmed, Embase, Web of Knowledge and Chinese National Knowledge Infrastructure databases. The pooled weighted mean difference (WMD) and 95% confidence intervals (CI) were used to assess the changes in body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and 25-hydroxyvitamin D (25[OH]D) from baseline. Results: Twenty RCTs involving 3,153 participants reporting either BMI, WC, WHR or 25(OH)D met the inclusion criteria. When compared with placebo, vitamin D supplementation had no significant decreases in BMI (WMD = –0.09 kg/m2, 95% CI –0.19 to 0.01, p = 0.08), WC (WMD = –0.71 cm, 95% CI –1.58 to 0.16, p = 0.112) or WHR (WMD = 0.00, 95% CI –0.01 to 0.01, p = 0.749). However, in the subgroups of females, Asia region studies and intervention duration ≥6 months, a beneficial and significant reduction in BMI and WC was noted (all p < 0.026). On the other hand, pooled results showed that there was a significant increase in serum 25(OH)D levels (WMD = 13.20 ng/mL, 95% CI 9.83–16.58, p < 0.001) after vitamin D intervention. No publication bias was found in our study. Conclusions: Overall, supplementation with vitamin D produced no significant effect on the BMI, WC or WHR of healthy adults.

Dairy Consumption in Relation to Hypertension Among a Large Population of University Students: The MEPHASOUS Study

BACKGROUND

Hypertension is a chronic condition that its prevalence is increasing at an alarming rate. Findings on the association between dairy consumption and hypertension are conflicting and few data are available in the Middle East.

AIM

To assess the association between dairy consumption and hypertension among a large population of university students.

MATERIALS AND METHODS

The current study was performed in the framework of the Mental and Physical Health Assessment of University Student (MEPHASOUS) project. Overall, 67,011 university students with complete information were included in the statistical analysis. To assess dairy consumption, a self-administered dietary habits questionnaire was employed. Blood pressure was measured using a standard protocol. The systolic/diastolic blood pressure of ≥140/90 mmHg was considered hypertension.

RESULTS

Hypertension was prevalent among 6.9% of students. A significant inverse association was found between dairy consumption and the odds of hypertension; such that after taking potential confounders into account, individuals in the highest levels of dairy consumption had 85% lower odds for having hypertension compared with those in the lowest levels (odds ratio (OR): 0.15, 95% confidence interval (CI): 0.13-0.18). Such an inverse association was also seen among males (OR: 0.14, 95% CI: 0.11-0.18) and females (OR: 0.16, 95% CI: 0.12-0.21), normal-weight students (OR: 0.15, 95% CI: 0.12-0.18) and those with overweight or obesity (OR: 0.15, 95% CI: 0.11-0.21), and individuals with (OR: 0.13, 95% CI: 0.11-0.16) and without (OR: 0.24, 95% CI: 0.17-0.35) family history of hypertension.

CONCLUSION

Our results support the previous findings on the inverse association between dairy consumption and hypertension among university students.

Association of vitamin D, retinol and zinc deficiencies with stunting in toddlers: findings from a national study in Iran

OBJECTIVE

The objective of this study was to investigate the association of serum levels of 25(OH)D₃ (vitamin D), retinol (vitamin A) and zinc with stunting in a large sample of Iranian toddlers.

STUDY DESIGN

This was a cross-sectional study.

METHODS

A total of 4261 children, aged 10-36 months, who had Iranian birth certificates were included in the present study. Weight and height were measured by experienced professionals in accordance with standard protocols. Stunting was defined as a height-for-age z-score of <-1 standard deviation (SD) based on the World Health Organization (WHO) criteria (the WHO Child Growth Standards median). Serum levels of 25(OH)D₃, retinol and zinc were examined based on standard methods.

RESULTS

The mean age of the study participants was 19.2 ± 8.4 months. A significant inverse association was found between serum retinol concentrations and the odds of stunting such that after controlling for potential confounders, toddlers in the highest quartile of serum retinol levels had 29% lower odds of stunting than those in the lowest quartile (odds ratio [OR]: 0.71, 95% confidence interval [CI]: 0.53-0.97). Furthermore, a significant inverse association was found between serum levels of retinol and stunting in girls (OR: 0.57, 95% CI: 0.34-0.94), urban toddlers (OR: 0.66, 95% CI: 0.44-0.99) and those who did not use nutritional supplements (OR: 0.70, 95% CI: 0.52-0.95). Although serum 25(OH)D₃ levels were not significantly associated with stunting in the overall study population, we found a positive association among toddlers who used nutritional supplements. No significant association was found between serum levels of zinc and stunting.

CONCLUSION

We found a significant inverse association between serum levels of retinol and stunting in toddlers aged 10-36 months.

The optimal vitamin D cut-off value associated with hyperglycemia in an Iranian population

Background

Vitamin D deficiency may accelerate the risk of type 2 diabetes mellitus. The association of vitamin D with hyperglycemia may be influenced by lifestyle.

Objective

To evaluate the relationship between vitamin D status and hyperglycemia among the workers' population.

Methods

This was a medical records review of 7054 Iranian factory workers participating in an annual health check-up for employees. Of those, potential participants were included in this analysis if data for serum 25-hydroxyvitamin D [25(OH) D] levels were also available.

Results

Data of 429 male participants were used for this analysis. Of those, 61.07% had serum 25(OH)D concentrations lower than the sufficient level [≥20 ng/ml]. Hyperglycemic participants had significantly lower 25(OH)D than those with normal fasting blood glucose (FBG). Regression analyses highlighted serum 25(OH)D as a significant determinant of hyperglycemia [OR: 0.943(0.901, 988); p = 0.01]. The association between 25(OH)D and FBG remained significant after adjustment for potential confounders (p = 0.008). Using the ROC analysis, the serum 25(OH)D value of 14.7 ng/ml was the optimal cut-off point to predict hyperglycemia in this population (sensitivity: 63.6%, specificity: 62.3%, p = 0.01).

Conclusion

Our results revealed a considerable proportion of participants with serum 25(OH)D below the optimal level as well as a significant inverse association between vitamin D status and hyperglycemia among the factory workers. These findings highlight the importance of including the evaluation of vitamin D status as a part of annual health examinations for employees, and may help health policy- makers prevent or delay type 2 diabetes mellitus among the workers' population.

The deficiency and the supplementation of vitamin D and liver: Lessons of chronic fructose-rich diet in mice

The fructose added to soft drinks and processed food, as well as frequent detection of vitamin D deficiency in the body, are two insults increasingly considered to cause lesions in target organs. We studied the liver after a chronic high-fructose diet deficient and supplemented with vitamin D. Sixty C57BL/6 mature male mice were allocated into six groups (n = 10) for ten weeks: control (C), control deficient in vitamin D (CDD), control supplemented with vitamin D (CDS), fructose (F), fructose deficient in vitamin D (FDD), and fructose supplemented with vitamin D (FDS). The gene expressions of vitamin D receptor and CYP27B1 and 25 hydroxyvitamin D plasma level ensured that the diets caused vitamin D deficiency or supplementation. Body mass did not change, but blood pressure (BP) increased in CDD, F, and FDD, whereas BP was controlled in FDS. Insulinemia, insulin tolerance and resistance were seen in both vitamin D deficiency and fructose groups but improved with vitamin D supplementation. The steatosis and fibrosis were observed in the CDD, F and FDD groups. Also, F and FDD showed activation of stellate cells (HSC). Lipogenesis and inflammation gene expressions were enhanced in the CDD, F and FDD groups, but diminished with vitamin D supplementation. In conclusion, we demonstrated the adverse effects of vitamin D deficiency on metabolism, liver steatosis and, combined with fructose intake, liver interstitial fibrosis with hepatic stellate cell activation, and alteration of the lipogenesis, beta-oxidation, and liver inflammation. All these data improved when vitamin D was supplemented in the animals.

The relationship between hypertriglyceridemic-waist phenotype and vitamin D status in type 2 diabetes

Background: The aim of the study was to explore the relationship between hypertriglyceridemic-waist (HTW) phenotype and vitamin D status in type 2 diabetes. Methods: A cross-sectional study was conducted in subjects with type 2 diabetes. This study enrolled 338 type 2 diabetic (190 males and 148 females). The HTW phenotype was defined as serum triglyceride concentrations ≥1.7 mmol/L and waist circumference ≥90 cm (male) and 85 cm (female). Multiple logistic regression models were used for modeling relationships between HTW phenotype and vitamin D status. Results: The prevalence of HTW phenotype was 36.4%. The prevalence of HTW phenotype was 10.5%, 27.2%, and 41.6% in type 2 diabetes with vitamin D sufficiency, vitamin D insufficiency, and vitamin D deficiency, respectively. In multiple logistic regression analysis, subjects with vitamin D deficiency were more likely to have HTW phenotype (OR=6.222, 95%CI: 1.307-29.620, P=0.022) compared with subjects with vitamin D sufficiency. Conclusions: There was a significant correlation between HTW phenotype and vitamin D status in type 2 diabetes.