Vitamin D status, hypertension and body mass index in an urban black community in Mangaung, South Africa

Geographic variations and potential macro-environmental exposure of hypertension: from the China hypertension survey

OBJECTIVES

The study aimed to investigate the spatial variation of hypertension (HTN) and the associations between the risk of HTN and altitude, longitude, latitude in Chinese population.

METHODS

The newest China Hypertension Survey (CHS) study, which used a nationally representative sample, was conducted between 2012 and 2015. A total of 451 755 participants aged at least 18 years from 262 county-level regions in 31 provinces were analyzed to explore the geographical variations of HTN prevalence at county-level. A total of 444 375 participants were included in two-level logistic regression model to examine the association between HTN risk and exposure to altitude, longitude, and latitude after adjusting for potential confounding variables at individual level.

RESULTS

The findings of spatial analysis indicated that there were remarkably high and low HTN prevalence zones. High HTN prevalence zones extended from parts of the southeast to northern China and the northeast. The risk of HTN increased with increasing longitude, with adjusted odds ratios (aORs, 95% confidence interval [CI]) of 2.08 (1.04--4.18), 2.21 (1.15--4.22), 2.54 (1.31--4.93), 2.59 (1.32--5.08), and 2.81 (1.12--7.08) for longitudes of 90-100°E, 100-110°E, 110-120°E, 120-130°E, and at least 130°E, respectively, with a significant dose--response relationship that HTN risks increase as longitude rises from 90°E to ≥130°E(Ptrend <0.001), compared with the longitude group of less than 80°E, consistent with the conclusion that geographical variations of high HTN prevalence zones by spatial analysis.

CONCLUSION

The findings of remarkably high HTN prevalence zones modified previous understandings about the regional difference of HTN distribution, and provide an important basis for future efforts to prevent and control HTN in different regions of China.

Meta-Analysis of the Association Between the rs228570 Vitamin D Receptor Gene Polymorphism and Arterial Hypertension Risk

The association between FokI polymorphism in the vitamin D receptor (VDR) gene and susceptibility to arterial hypertension (HT) is controversial. Thus, we evaluated the relation between FokI and HT according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using MEDLINE® (Medical Literature Analysis and Retrieval System Online)/PubMed, Scopus, and Cochrane Library CENTRAL databases. Data from case-control studies, including the number of participants, age, 25-hydroxyvitamin D concentrations, systolic and diastolic blood pressure values, FokI allele, and genotype frequency were extracted by 2 independent authors and OR was calculated with the 95% CI to assess the strength of the association between the FokI variant and odds of HT. In general and subgroup analyses, we used allelic (f compared with F), common (ff compared with FF + Ff), risk (ff + Ff compared with FF), and additive (ff compared with FF) models. Six case-control studies including 3140 cases and 3882 controls were reviewed in the meta-analysis. Global assessment revealed a correlation between FokI and reduced odds of HT in the additive/homozygote model (ff compared with FF; OR: 0.65; 95% CI: 0.45-0.94) and common/recessive model (ff compared with FF + Ff; OR: 0.75; 95% CI: 0.57-0.99). In Asian subjects, there was a significant reduction in the odds of HT in additive (ff compared with FF; OR: 0.84; 95% CI: 0.73-0.98) and risk models (ff + Ff compared with FF; OR: 0.87, 95% CI: 0.78-0.97), in particular, for Indians (South). In Africans, the statistically significant association occurred in the additive and common models. Allele f in the FokI polymorphism of the VDR gene was associated with reduced odds of HT in the general population based on the risk model. Thus, nutritional genomics can help understand the influence of nutrition on metabolic homeostasis pathways and the clinical consequences of hypertension. This study shows the need for healthy, anti-inflammatory, and antioxidant compounds to prevent or treat chronic complications.

Association of Vitamin D Status with Body Mass Index in Adolescents in Ukraine

Background and aims: Vitamin D status in many health managements have been researched extensively, but its dependence with obesity still remains controversial. This article is devoted to examination of blood cholecalciferol levels in Ukrainian population with establishment the association of cholecalciferol levels and body mass index (BMI). Materials and methods: For this observed investigation, data were collected during the summer 2017, over a period of one week from three township areas in Carpathian region, Ukraine from 304 adults aged 19-78 years. Measured variables contained 25(OH)D level, weight and weight applied to check BMI degree. The average level of vitamin D among adolescents presented 23.1 ± 8.2 ng/ml. Female gender was associated with lower vitamin D concentrations (22.9 ± 9.3 ng/ml vs. 26.2 ± 8.5 ng/ml for men). Among the participants, 74.4% had a BMNI of 25 kg/m2 and over, and in 27.3% of them the number was 30 kg/m2 and over. Results: Violation of vitamin D status was detected in 90.5% persons. 1.8% people had been identified as severe 25(OH)D deficiency. Measurement of cholecalciferol demonstrated meaningful connection between its level and BMI only in persons with BMI 25-29.9 kg/m2. Average vitamin D concentrations in persons with BMI over30 kg/m2 did not vary to a significant range from data in persons with normal body weight. Conclusions: Vitamin D status among the adolescents in Ukraine is far from optimum. Our results confirm reliable association between cholecalciferol level and BMI in persons with overweight. Interchange between conservation of vitamin D and BMI needs additional surveys.

CRP Genotypes Predict Increased Risk to Co-Present with Low Vitamin D and Elevated CRP in a Group of Healthy Black South African Women

Low 25-hydroxyvitamin D (25(OH)D) and elevated C-reactive protein (CRP) concentrations are independently associated with adverse health outcomes, including cardiovascular disease (CVD). Although an inverse association between these factors has been described, the underlying mechanisms remain unknown. We postulate that environment-gene interactions, through which 25(OH)D interacts with single nucleotide polymorphisms (SNPs) within the CRP gene, modulate CRP; that certain CRP genotypes predispose individuals to a co-phenotype of low 25(OH)D and elevated CRP concentrations; and that this co-phenotype is associated with higher CVD risk. Twelve CRP SNPs were genotyped, and both 25(OH)D and CRP were quantified, in 505 black South African women. Alarmingly, 66% and 60% of the women presented with deficient/insufficient 25(OH)D and elevated CRP concentrations, respectively. CRP concentrations were higher in individuals with lower 25(OH)D concentrations. However, no 25(OH)D-CRP genotype interactions were evident. Several genotypes were associated with an altered risk of presenting with the co-phenotype, indicating a genetic predisposition. Women presenting with this co-phenotype had higher blood pressure and increased anthropometric measures, which may predispose them to develop CVD. We recommend increasing vitamin D fortification and supplementation efforts to reduce inflammation among black women with vitamin D deficiency, thereby possibly curbing diseases contingent on the co-phenotype described here.