Prevalence and Trends of Vitamin D Deficiency among Iranian Adults: A Longitudinal Study from 2001-2013.

Vitamin D deficiency/insufficiency is currently considered to be a re-emerging public health problem globally. This study was designed to determine the prevalence of vitamin D deficiency and insufficiency and to investigate its trend from 2001 to 2013 in a longitudinal study of Iranian adults. This study was part of a population-based, longitudinal ongoing study of Iranian healthy adults aged 35 y and older at baseline. Serum vitamin D level was assessed in a sub-sample of 370 subjects, who were apparently healthy at the time of recruitment in 2001 and were free from MetS, in three phases (2001, 2007 and 2013) during the 12-y study period. Adjusted prevalence and trend of vitamin D deficiency were calculated. Mean serum vitamin D levels increased over the time of the study (52.12, 54.27 and 62.28 nmol/L, respectively) and the prevalence of vitamin D deficiency decreased (30.5, 27.0 and 24.4, respectively). However, the prevalence of vitamin D insufficiency did not change over this time period. The risk of vitamin D deficiency decreased significantly in 2007 [OR: 0.73 (95% CI: 0.53, 0.99)] and 2013 [OR: 0.50 (95% CI: 0.36, 0.70)] compared to the baseline. The present study demonstrated some improvement in serum vitamin D levels, while the prevalence of vitamin D inadequacy was still high. Considering the possible health consequences of vitamin D deficiency, there is an urgent need for developing population-wide strategies, such as supplementation and fortification, to prevent or control vitamin D deficiency.

Secular Trend of Metabolic Syndrome and Its Components in a Cohort of Iranian Adults from 2001 to 2013.

BACKGROUND: Metabolic syndrome (MetS) and its components increase the risk of developing cardiovascular diseases, type 2 diabetes, and all-cause mortality. Reports on the trends of MetS and its components in longitudinal studies are scarce, especially in low- and middle-income countries. This study was designed to investigate the prevalence and trends of MetS and its components in a cohort of Iranian adults from 2001 to 2013. METHODS: Participants were followed up for 12 years in a longitudinal population-based study of 6500 adults aged 35 years and older in 2001. Participants were randomly selected from three provinces in central Iran. Sociodemographic characteristics, anthropometry, blood pressure, and various biochemical indices were collected in 2001, 2007, and 2013. Secular trend and age-adjusted trend of MetS and its components were calculated from 2001 to 2013. RESULTS: The standardized prevalence of MetS, hypertension, low high-density lipoprotein cholesterol (HDL-C), abdominal obesity, and diabetes/impaired glucose tolerance (IGT) increased over the 12 years (6.9%, 5.5%, 12.0%, 2.3%, and 18.7%, respectively), while the prevalence of hypertriglyceridemia decreased by 15.5% during this period. The prevalence of MetS, low HDL-C, and abdominal obesity were higher in females than males in all three phases. Moreover, the increases in the prevalence of these metabolic abnormalities were higher in the rural population than in the urban population. CONCLUSIONS: The present study underscored the increasing trends in MetS and most of its risk factors, thus, to prevent an increase in the cardiovascular risk factors, there is a need to improve lifestyle by education, screening, and treatment of abnormalities.

Magnesium status and the metabolic syndrome: A systematic review and meta-analysis.

OBJECTIVES: To systematically review the published evidence regarding the association between Mg intake and serum concentrations with MetS and, if possible, to summarize the results using a meta-analysis. METHODS: PubMed, ISI Web of Science, Scopus, and Google Scholar were searched to identify related articles. Fully adjusted odds ratios (ORs) of MetS in participants with the highest intake of Mg compared with those who had the least consumption, and the mean difference in serum Mg levels between patients with MetS and their controls were extracted for the meta-analysis. RESULTS: In total, 9 articles with 31 876 participants were included in the meta-analysis regarding the association between dietary Mg intake and MetS, and 8 studies that assessed the mean level of serum Mg in 3487 individuals with and without MetS were eligible. Our analysis found that higher consumption of Mg is associated with lower risk of MetS (OR = 0.73; 95% confidence interval: 0.62, 0.86; P < 0.001); we also could find a significant but heterogeneous association between serum Mg and MetS (mean difference: -0.19; 95% confidence interval: -0.36, 0.03; P = 0.023). CONCLUSIONS: The present systematic review and meta-analysis found an inverse association between Mg intake and MetS. However, the inverse association for serum Mg levels was highly heterogeneous and sensitive. The link between Mg status and MetS should be confirmed by prospective cohort studies controlling the association for other nutrients related to MetS risk.

Does the impact of metabolic syndrome on cardiovascular events vary by using different definitions?

BACKGROUND: Metabolic Syndrome (MetS) is a complex disorder which increases the risk of chronic diseases, including cardiovascular diseases and diabetes mellitus. As a result of modern lifestyles, the prevalence of MetS has been rising globally. This study aims to investigate whether overall prevalence of MetS varies when using different definitions of MetS and to identify the best and most predictive definition of the MetS for cardiovascular disease (CVD) events over 10 years in a cohort of an Iranian population. METHOD: Adults aged ≥ 35 years from urban and rural regions in central Iran were selected at baseline and followed up for more than 10 years. Data on socio-demographic characteristics, anthropometry, blood pressure and smoking status were collected at baseline. In addition, various biochemical indices were assessed. MetS was defined based on five available definitions, and cardiovascular events during 10 years follow up were confirmed by an expert group. The hazard ratios were calculated by the Cox proportional hazards model. RESULTS: The highest prevalence of MetS was observed by using AHA-NHBI definition (36.9%), followed by JIS definition (31.2%). On the other hand, EGIR (8.8%) provided the lowest prevalence. The risk of developing CVD, irrespective of definitions, was approximately two fold higher in the presence of MetS. After controlling for possible confounders, AHA-NHBI definition was found to be the best predictor of CVD. CONCLUSION: This study demonstrated a great variability in the prevalence of MetS among Iranian adults when using different definitions of MetS. CVD risk was significantly higher in MetS participants, as well as in participants with any risk factors of MetS; however, the AHA-NHBI definition was found to be the best predictor of CVD. Thus protective measures, including lifestyle modifications, plus control of individual risk factors is necessary to prevent cardiovascular events.