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Objectives Vitamin D deficiency was associated with obesity. However, the causal relationship remains controversial. We hypothesized that there would be family-based associations in both vitamin D deficient families and obese families for the SNPs associated with vitamin D deficiency, if vitamin D deficiency was a causal factor of obesity. We aimed to investigate the family-based association of SNPs in CYP27B1 with both vitamin D deficiency and obesity. Methods Four hundred and nineteen pedigrees containing 1505 rural individuals aged from 18 to 79 years in Henan Province of China were included in this study. Family-based associations of rs10877012 and rs4646536 in CYP27B1 with vitamin D deficiency and obesity were investigated. Serum 25(OH)D3 concentration Results It was shown that vitamin D deficiency was a risk factor of obesity (adjusted OR: 1.332, 95% CI: 1.042-1.703, P = 0.022). Furthermore, there were family-based associations for allele T of rs10877012 and allele T of rs4646536 in both vitamin D deficient families and obese families (P < 0.05). Both rs10877012 and rs4646536 were associated with serum 25(OH)D3 levels between siblings (P < 0.05), but not BMI (P > 0.05). In addition, there is linkage disequilibrium between rs10877012 and rs4646536 (D' = 1.0, r.sup.2 = 0.992). Conclusion Vitamin D deficiency may be a causal factor of obesity. Maintaining sufficient vitamin D is beneficial to obesity prevention. Vitamin D deficiency was associated with obesity. But their causal relationship is still controversial. CYP27B1 plays a direct role in circulating the concentration of 25(OH)D, which can be used to investigate causal relationships. In this study, allele T of rs10877012 and allele T of rs4646536 in CYP27B1 were family-based linked with both vitamin D deficiency and obesity. In addition, both rs10877012 and rs4646536 were associated with serum 25(OH)D.sub.3 levels between siblings but not BMI. Therefore, vitamin D deficiency may be a causal factor of obesity. Maintaining sufficient vitamin D is beneficial to obesity prevention., Author(s): Songcheng Yu [sup.1], Yinhua Feng [sup.1], Chenling Qu [sup.2], Wenqian Huo [sup.1], Zhenxing Mao [sup.1], Chongjian Wang [sup.1], Wenjie Li [sup.1], Xing Li [sup.1] Author Affiliations: (1) College of [...]

Objective: Despite studies on offspring obesity and delayed parenthood, little attention has been paid to the central obesity of offspring. The purpose of this study was to test the hypothesis that maternal age at childbirth (MAC) was associated with central obesity in offspring among the adult population, and fasting insulin may play a role in this association as a mediating factor. Methods: A total of 423 adults (mean age 37.9 years, 37.1% female) were included. Information about maternal variables and other confounders was collected by face‐to‐face interview. Waist circumference and insulin were determined through physical measurements and biochemical examinations. Logistic regression model and restricted cubic spline model were used to analyze the relationship between MAC and central obesity of offspring. The mediating effect of fasting insulin levels on association between MAC and offspring waist circumference was also analyzed. Results: There was a nonlinear relationship between MAC and central obesity in offspring. Compared with subjects with MAC 27–32 years, those with MAC 21–26 years (OR = 1.814, 95% CI: 1.129–2.915) and MAC ≥33 years (OR = 3.337, 95% CI: 1.638–6.798) had higher odds to develop central obesity. Offspring fasting insulin was also higher in MAC 21–26 years and MAC ≥33 years compared with those with MAC 27–32 years. Taking the group MAC 27–32 years as reference, the mediating effect of fasting insulin levels on the waist circumference was 20.6% and 12.4% for MAC 21–26 years and ≥ 33 years, respectively. Conclusion: MAC 27–32 years has the lowest odds of central obesity in offspring. Fasting insulin levels may have a partial mediating effect on the association between MAC and central obesity. [ABSTRACT FROM AUTHOR]

Background: Physical activity and vitamin D receptor (VDR) have been associated with type 2 diabetes mellitus (T2DM). However, the associations of VDR methylation with T2DM and physical activity remained unknown. We aimed to investigate whether VDR methylation was a link between physical activity and T2DM. Methods: A 1:1 matching case‐control study was designed based on the Henan Rural Cohort Study, including 272 pairs of T2DM patients and nonpatients. Physical activity level was assessed using the International Physical Activity Questionnaire. The high‐resolution melt method was applied to determine the methylation level of the promoter region of VDR. The association between physical activity and T2DM was analyzed with a conditional logistic regression model. The effect modification of VDR methylation levels on the association between physical activity and T2DM was conducted. A multivariate correlation analysis model was applied to investigate correlations of VDR methylation with insulin sensitivity. Results: Physical activity level was associated with T2DM risk (crude model: odds ratio [OR] 0.611; 95% CI, 0.416‐0.897; adjusted model: OR 0.619; 95% CI, 0.418‐0.917). In effect modification analysis, the effects of physical activity on T2DM were stronger for low VDR methylation levels than for high (P =.025). Moreover, VDR methylation levels were associated with insulin (r = −0.089, P =.039) as well as homeostatic model assessment of insulin resistance (r = −0.098, P =.022). Conclusions: The methylation status of the VDR promoter is associated with the secretion and sensitivity of insulin. VDR methylation attenuates the association between physical activity and T2DM, indicating that proactively physical activity may reduce the risk of T2DM, especially in people with low VDR methylation level. [ABSTRACT FROM AUTHOR]

This work aimed to develop an ultrasensitive and specific immunosorbent assay for simultaneous detection of double DNA methylation marks. Being considered the most important indicators in disease diagnosis, clinical treatment, and prognosis, 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) were chosen as the proof-of-concept targets. The described strategy consisted of Phos-tag Biotin anchoring at streptavidin-magnetic nanoparticles, specific immune recognition of anti-5mC antibody and anti-5hmC antibody and labeling of Barcode-antibody, signal amplification of immune PCR and digital PCR machine. Under optimal conditions, the digital immuno-PCR assay showed a board dynamic range from 2.7 × 10−13 mol/L to 2.7 × 10−9 mol/L and the detection limits were 61.7 fmol/L for 5mC, and of 0.111 pmol/L for 5hmC. A 16-fold and 186-fold improvement of LOD were obtained by the proposed approach for 5mC and 5hmC detection compared with real-time immune PCR. The approach also showed ideal specificity, repeatability and stability. The recovery test demonstrated that the digital immuno-PCR assay is a promising platform for the simultaneous determination of the two DNA methylation marks in human serum sample. In this work, a simple and sensitive digital immune PCR assay was developed for simultaneous determination of 5-methylcytosine and 5-hydroxymethylcytosine in human serum. This simultaneous detection method can effectively save serum sample and improve efficiency. [Display omitted] • Simultaneous detection of 5mC and 5hmC were of great importance for physiological and pathological study. • We successfully developed a novel digital immuno-PCR assay for simultaneous detection of 5mC and 5hmC in human serum. • The LOD of digital immuno-PCR signal readout for 5mC was 6.17 × 10−14 mol/L (61.7 fmol/L) and for 5hmC was 1.11 × 10−13 mol/L (0.111 pmol/L). [ABSTRACT FROM AUTHOR]

Objective: The prevalence of type 2 diabetes mellitus (T2DM) varies greatly in different regions and populations. This study aims to assess the heritability and environmental risk factors of T2DM among rural Chinese adults. Methods: Thousand five hundred thirty three participants from 499 extended families, which included 24 nuclear families, were recruited in the family-based study to assess the heritable risk of T2DM. Heritability of T2DM was estimated by the Falconer method. Using conditional logistic regression model, couple case-control study involving 127 couples were applied to assess the environmental risk factors of T2DM. Results: Compared with the Henan Rural Cohort, T2DM was significantly clustered in the nuclear families (OR: 8.389, 95% CI: 5.537-12.711, P < 0.001) and heritability was 0.74. No association between the heredity of T2DM and sex was observed between the extended families and the Henan Rural Cohort. Besides, results from the couple case-control study showed that physical activity (OR: 0.482, 95% CI: 0.261-0.893, P = 0.020) and fat intake (OR: 3.036, 95% CI: 1.070-8.610, P = 0.037) was associated with T2DM, and the proportion of offspring engaged in medium and high physical activity was higher than that of mothers in mother-offspring pairs. Conclusion: People with a family history of T2DM may have a higher risk of developing T2DM, however, there was no difference in genetic risk between males and females. Adherence to active physical activity and low fat intake can reduce the risk of T2DM., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Feng, Li, Mao, Huo, Hou, Wang, Li and Yu.)