Vitamin D Level Of People Over 30 Years Old And Vitamin D Nutritional Status Of People With Different Genetic Charateristics In Shunde Area

Objective1.To understand the serum vitamin D（VD）nutritional status of people over 30 years old in Shunde,Guangdong province,and to guide the population to take reasonable and effective intervention measures to prevent or treat serum vitamin D deficiency or vitamin D deficiency related diseases.2.To explore the serum vitamin D nutritional status of different genotypes of genetic variants in DHCR7,CYP2R1 and GC genes,and to indentify high-risk genetic characteristics population,and to provide reference for the application of genetic variation to individualized prevention and treatment of vitamin D deficiency or vitamin D deficiency related diseases in the future.MethodsFrom March to April 2018,a cross-sectional study was conducted based on Shunde hospital of Southern Medical University for epidemiological survey of residents in 22 communities or administrative villages in Shunde area.A face-to-face interview was used to collect characteristics,such as gender,age,and exercise status of the subjects,the height and weight information of subjects were collected by physical examination,and a total of2,000 subjects were collected.The genes（DHCR7,CYP2R1 and GC）related to vitamin D levels were screened out by literature,and genetic variants with statistical associations in regions of exons,3’UTR,5’UTR were screened out combining with bioinformatics tools,such as GWAS Catalog database,ensemble database,TaqMan PCR technology was applied to genotyping.And enzyme-linked immunosorbent assay（ELIAS）method was used to measure serum vitamin D levels.The t-test,analysis of variance andχ² test were used to compare the differences of serum vitamin D nutritional status among different characteristic populations and different genotype carriers.Simple unweighted genetic risk score（GRS）was applied to evaluate the accumulation effect of risk genotypes,and generalized linear regression model was evaluate the relationship of serum vitamin D levels in different GRS carriers.The prevalence ratio（PR）estimated by the log-binomial model was used to assess the effects of vitamin D deficiency in different genetic characteristics carriers and in different GRS carriers.Results1.The average serum vitamin D level of subjects over 30 years old was（49.60±12.09）nmol/L in Shunde area,and the vitamin D deficiency rate,insufficiency rate and sufficiency rate were 56.25%,40.25%and 3.50%,respectively.2.There were statistical differences in genders,ages,education levels and occupational groups（P<0.05）.The average serum vitamin D level of males and females were（52.48±13.23）nmol/L and（46.03±11.98）nmol/L,respectively,t=11.37,P<0.001.The vitamin D deficiency rate of females（67.77%）was higher than that of males（46.10%）,χ2=100.29,P<0.001.The average serum vitamin D level of subjects over 50 years old was higher than that of subjects under 50 years old（F=22.76,P<0.001）,and the vitamin D deficiency rate was lower than that of people aged 50 and lower（χ2=60.43,P<0.001）,among which the lowest average serum vitamin D level in 30³9years old was（47.08±12.13）nmol/L,and the highest vitamin D deficiency rate was 64.64%.The average serum vitamin D level of primary school and lower（52.09±13.87 nmol/L）was higher than that of junior college and above（46.39±11.18 nmol/L）,F=18.65,P<0.001,and the vitamin D deficiency wate was the lowest among those in primary school and lower,which was 50.00%（χ2=52.40,P<0.001）.The average vitamin D level of workers who working in the agriculture,forestry,fishery,animal husbandry and water conservancy was the highest among all occupational groups（55.60±15.45 nmol/L）,and the vitamin D deficiency rate was the lowest（37.50%）,while the professional technicians had the lowest average serum vitamin D level（45.24±11.30nmol/L）,and the vitamin D deficiency rate was the highest（72.05%）,P<0.001.3.There were statistically significant differences about the average level of serum vitamin D and the vitamin D deficiency rate in different genotype carriers of GC rs4588 and CYP2R1 rs12794714（P<0.05）.The average serum vitamin D level of rs4588 GG,GT and TT genotypes carriers were（50.87±13.76）nmol/L,（48.20±11.86）nmol/L,and（44.86±11.79）nmol/L,respectively,and the vitamin D deficiency rate were 51.80%,60.48%and69.34%,respectively.The average serum vitamin D level of rs12794714 GG,AG and AA genotypes carriers were（52.25±14.11）nmol/L,（49.11±12.30）nmol/L,and（44.59±11.38）nmol/L,respectively,and the vitamin D deficiency rate were 46.49%,57.19%and 74.14%,respectively.The results of univariate and multivariate log-binominal analysis showed that the risk of vitamin D deficiency in rs4588 GT and TT genotype carriers was 1.14 times(95%CI=1.05¹.22,P_FDR=3.135×10^-3)and 1.31 times(95%CI=1.16¹.39,P_FDR=7.853×10^-7)higher than that of GG genotype carriers after adjustment for gender,age,and other factors and false discovery rate（FDR）correction,besides,the risk of vitamin D deficiency was increased in the dominant,recessive and additive models(PR>1.00,P_FDR<0.05).The risk of vitamin D deficiency rate in rs12794714 AG and AA genotypes carriers were 1.19 times(95%CI=1.18¹.38,P_FDR=3.137×10^-3)and 1.50 times(95%CI=1.48¹.51,P_FDR=1.308×10^-10)higher than that of GG genotypes(PR>1.00,P_FDR<0.05).The results of other genetic variants were found in the text.4.Generalized linear regression analysis showed that after adjustment gender,age and other factors,the average serum vitamin D level of GRS≥4（GRS=4,5,6,7,8,9,10¹2）were 5.31 nmol/L,5.28 nmol/L,6.38 nmol/L,7.54 nmol/L,8.39 nmol/L,10.63 nmol/L and 14.39 nmol/L lower than that of GRS in 0²,respectively（P<0.05）.The average serum vitamin D levels of carriers of GRS in 0³,4⁶,7⁹ and 10¹2 were（53.86±14.66）nmol/L,（50.24±13.10）nmol/L,（47.98±12.25）nmol/L,and（41.64±10.18）nmol/L,respectively,and the vitamin D deficiency rate were 40.30%,54.92%,60.03%and 80.28%,respectively.Took the low-risk group（GRS in 0³ scores）as a reference,after adjustment gender,age and other factors,it was found that the risks of vitamin D deficiency in risk-genotype carriers of 4⁶,7⁹,and 10¹2were 1.35 times（95%CI=1.14¹.62,P=0.015）,1.50 times(95%CI=1.28¹.78,P=6.929×10^-4)and 1.74 times(95%CI=1.45¹.88,P=2.039×10^-5),respectively.Conclusions1.There is a common phenomenon of serum vitamin D deficiency in people over 30 years old in Shunde,Guangdong provience.2.Women,young age,high education level,professional technical/social production services/manufacturing personnel and obese people have lower serum vitamin D levels.3.There are differences in serum vitamin D nutritional status among different genotype carriers of GC rs4588 and CYP2R1 rs12794714.In addition,carriers of rs4588 GT and TT,and rs12794714 AG and AA genotype may be high-risk groups of low serum vitamin D level or vitamin D deficiency in Shunde area.4.Multiple genetic variants have cumulative effect.The greater the cumulative effect,the lower serum vitamin D level,the higher the vitamin D deficiency rate,and the higher risk of vitamin D deficiency.