Background DNA methylation is associated with cancer, metabolic, neurological, and autoimmune disorders. Hypomethylation of aryl hydrocarbon receptor repressor (AHRR) especially at cg05575921 is associated with smoking and lung cancer. Studies on the association between AHRR methylation at cg05575921 and sources of polycyclic aromatic hydrocarbon (PAH) other than smoking are limited. The aim of our study was to assess the pattern of blood DNA methylation at cg05575921 in non-smoking Taiwanese adults living in areas with different PM 2.5 levels. Methods Data on blood DNA methylation, smoking, and residence were retrieved from the Taiwan Biobank dataset (2008–2015). Current and former smokers, as well as individuals with incomplete information were excluded from the current study. The final analysis included 708 participants (279 men and 429 women) aged 30–70 years. PM 2.5 levels have been shown to increase as one moves from the northern through central towards southern Taiwan. Based on this trend, the study areas were categorized into northern, north-central, central, and southern regions. Results Living in PM 2.5 areas was associated with lower methylation levels: compared with the northern area (reference area), living in north-central, central, and southern areas was associated with lower methylation levels at cg05575921. However, only methylation levels in those living in central and southern areas were significant ( β = − 0.01003, P = 0.009 and β = − 0.01480, P < 0.001, respectively. Even though methylation levels in those living in the north-central area were not statistically significant, the test for linear trend was significant ( P < 0.001). When PM 2.5 was included in the regression model, a unit increase in PM 2.5 was associated with 0.00115 ( P < 0.001) lower cg05575921 methylation levels. Conclusion Living in PM 2.5 areas was inversely associated with blood AHRR methylation levels at cg05575921. The methylation levels were lowest in participants residing in southern followed by central and north-central areas. Moreover, when PM 2.5 was included in the regression model, it was inversely associated with methylation levels at cg05575921. Blood methylation at cg05575921 (AHRR) in non-smokers might indicate different exposures to PM 2.5 and lung cancer which is a PM 2.5 -related disease. Electronic supplementary material The online version of this article (10.1186/s13148-019-0662-9) contains supplementary material, which is available to authorized users.

Elevated levels of high-density lipoprotein cholesterol (HDL-C) have been associated with a decreased risk of coronary heart disease (CHD). An active lifestyle is necessary in order to improve lipid HDL-C, including (but not limited to) physical exercise. Research on the association between badminton, an intermittent exercise, and HDL-C is limited. We investigated the impact of aerobic exercise and badminton on HDL-C levels in Taiwanese adults. The sociodemographic data of 7797 participants comprising 3559 men and 4238 women aged between 30 to 70 years were retrieved from the Taiwan Biobank. The participants were grouped into three exercise categories—no exercise, aerobic exercise, and badminton exercise. The HDL-C levels were compared using an analysis of variance (ANOVA). The multivariate linear regression models were used to determine the associations between HDL and exercise. Comparing the other two groups to the no-exercise group, the individuals who were engaged in aerobic and badminton exercise were significantly associated with a higher HDL-C (β =1.3154; p <0.0001 and β = 6.5954; p = 0.0027, respectively). Aerobic exercise and badminton were also associated with higher HDL-C levels among carriers of the lipoprotein lipase (LPL) rs328 genotypes. Aerobic exercise and regular badminton were associated with higher levels of HDL-C, with the badminton group being more significant.

BackgroundBoth SOX2 promoter methylation and air pollution have been associated with lung cancer risk. However, little has been done to assess SOX2 promoter methylation in individuals living in air pollution areas. The aim of this study was to investigate SOX2 promoter methylation in non-smoking Taiwanese adults living in areas with different levels of air pollution especially particulate matter with diameter < 2.5 μm (PM2.5).MethodsA total of 1142 individuals aged 30–70 years were recruited. Data on SOX2 methylation, residence, age, and exposure to second-hand smoke (SHS) among others were extracted from the Taiwan Biobank dataset (2008–2015). After excluding former and current smokers, alongside those with incomplete information, a total of 461 non-smokers comprising 176 men and 285 women were included in the study. Participants’ residences were grouped under northern and central/southern areas because air pollution (PM2.5) is lower in northern compared to central and southern areas.ResultsThe methylation levels in men (0.16310 ± 0.01230) and women (0.15740 ± 0.01240) were significantly different (P < .0001). In both sexes, the SOX2 promoter region was shown to be significantly hypermethylated in central and southern areas compared with the northern areas. The regression coefficient (β) was 0.00331 (P = 0.0257) in men and 0.00514 (P < .0001) in women.ConclusionSOX2 was significantly hypermethylated in both men and women residing in central and southern areas. The consistency in the results for both sexes shows that SOX2 promoter methylation could serve as a potential biomarker for industrial air pollution exposure. Moreover, it might reflect predisposition to cancer. Hence, healthy non-smokers at precancerous stages who have not been clinically diagnosed could be identified.Electronic supplementary materialThe online version of this article (10.1186/s13148-019-0647-8) contains supplementary material, which is available to authorized users.

Increased levels of high-density lipoprotein cholesterol (HDL-C) can improve endothelial function. This may help reduce cardiovascular risks and mortality. Evidence has been provided on the association between cardiometabolic traits, such as HDL-C and exercise modalities. However, there is the absence of studies investigating this association in Taiwan. We assessed the relationship between exercise type and HDL-C among Taiwanese adults. Data were collected from Taiwan Biobank (TWB), a national biomedical research database that contains the genetic information of ethnic Taiwanese residents gathered from 2008 to 2016. We enrolled 24,856 participants aged 30 to 70 years who completed a questionnaire about their recent health behaviors including smoking, drinking, and exercise. Regular exercise was categorized as non-aerobic exercise (separated as weight training, ball game, and mixed exercise) and strict aerobic exercise. Linear regression models were used to assess the effects of exercise in a questionnaire-based manner. After multivariate adjustments, HDL-C was positively associated with aerobic (β = 1.33748, p < 0.0001) and non-aerobic (β = 2.56210; p < 0.0001) exercise. Positive associations were also found for resistance training (β = 4.01828, p = 0.0020), ballgame (β = 2.43815, p = 0.0001), and mixed exercise (β = 2.47021, p < 0.0001). This study demonstrated that both aerobic and non-aerobic exercise have positive effects on HDL-C among Taiwanese adults. Among the non-aerobic exercise groups, resistance training had the greatest effect.

CDKAL1 rs10946398 is a type 2 diabetes (T2D)-associated variant. It is a new body mass index (BMI)-associated variant in Asian populations. We investigated the association between rs10946398 and T2D among 9908 participants aged 30–70 years based on BMI: normal weight; 18.5 ≤ BMI < 24 kg/m2, overweight; 24 ≤ BMI < 27 kg/m2, and obesity; BMI ≥27 kg/m2. The CC genotype conferred a higher risk of T2D than the CA genotype. The odds ratios (ORs) were 1.83; 95% confidence interval (CI) 1.49–2.26 and 1.20; 95% CI 1.02–1.40, respectively. The C allele was the significant risk allele compared with A allele (OR = 1.32; 95% CI 1.19–1.47). For normal, overweight and obese participants with CC genotype, the ORs were respectively 1.69; 95% CI 1.02–2.81, 2.34; 95% CI 1.50–3.66, and 1.58; 95% CI 1.02–2.45 among men and 1.22; 95% CI 0.67–2.22, 2.42; 95% CI 1.30–4.52, and 2.3; 95% CI 1.19–4.50 among women. The C allele ORs were higher in obese and overweight women. In conclusion, the rs10946398 CC/CA genotypes, as well as the C allele increased the risk of T2D. The ORs were higher in women who were overweight and obese than in those with normal weight. Nonetheless, significant results were prominent only among those with CC genotype and C allele.

Low high-density lipoprotein cholesterol (HDL-C) is a major risk factor for cardiovascular diseases (CVDs), the leading cause of global mortality. We aimed to determine the effect of coffee drinking and sex and their interaction, as well as rs1800588 and rs1800775 polymorphisms on HDL-C levels in Taiwanese adults. Data of 4262 men and 4813 women, aged 30–70 years, were retrieved from Taiwan Biobank. The interaction between sex and coffee drinking on HDL-C was significant (p = 0.0452). Coffee consumption was significantly associated with higher HDL-C levels in only women (β = 0.81679; p = 0.0246). However, rs1800588 and rs1800775 variants were significantly associated with HDL-C in both sexes. In women, β-values were 0.99080; p = 0.0059 and 3.16277; p < 0.0001 for rs1800588 CT and TT genotypes, respectively and −1.80954; p < 0.0001 and −2.81512; p < 0.0001 for rs1800775 AC and CC genotypes, respectively. In men, β-values were 1.32430; p < 0.0001 and 3.24976; p < 0.0001 for rs1800775 CT and TT genotypes, respectively and −1.96232; p < 0.0001 and −2.71536, p < 0.0001 for the AC and CC genotypes, respectively. In conclusion, coffee drinking was significantly associated with higher high-density lipoprotein (HDL) levels in women but not men after adjusting for confounders including rs1800588 (LIPC) and rs1800775 (CETP) variants.

Changes in concentrations of high-density lipoprotein cholesterol (HDL-C) are modified by several factors. We examined the relationship between aerobic exercise and HDL-C among different categories of body mass index (BMI) and waist-hip ratio (WHR) and the impact of rs1800588 variant in the hepatic lipase (LIPC) gene. We analyzed data from 6184 men and 8353 women aged 30–70 years. Participants were grouped into two WHR categories: Normal (0 < WHR < 0.9 for men and 0 < WHR < 0.8 for women) and abnormal (WHR ≥ 0.9 for men and WHR ≥ 0.8 for women). The BMI categories were: Underweight (BMI < 18.5 kg/m2), normal weight (18.5 ≤ BMI < 24 kg/m2), overweight (24 ≤ BMI < 27 kg/m2), and obese (BMI ≥ 27 kg/m2). Multivariate linear regression models were used to investigate associations between HDL-C and exercise. Aerobic exercise was significantly associated with higher HDL-C (β = 1.18325; p < 0.0001) when compared with no exercise. HDL-C was significantly lower in persons with abnormal compared to those with normal WHR (β = −3.06689; p < 0.0001). Compared with normal weight, overweight and obese categories were associated with lower HDL-C, with β values of −4.31095 and −6.44230, respectively (p < 0.0001). Unlike rs1800588 CT and TT genotypes, associations between aerobic exercise and HDL were not significant among CC carriers no matter their BMI or WHR.

Elevated levels of high-density lipoprotein cholesterol (HDL-C) have been associated with a decreased risk of coronary heart disease (CHD). An active lifestyle is necessary to improve HDL-C, including (but not limited to) physical exercise. Research on the association between badminton, an intermittent exercise, and HDL-C is limited. We investigated the impact of aerobic exercise and badminton on HDL-C levels in Taiwanese adults. The sociodemographic data of 7543 participants, comprising 3472 men and 4071 women aged between 30 and 70 years, were retrieved from the Taiwan Biobank. The participants were grouped into three exercise categories—no exercise, aerobic exercise, and badminton exercise. The HDL-C levels were compared using an analysis of variance (ANOVA). Multivariate linear regression models were used to determine the associations between HDL and exercise. Comparing the other two groups to the no-exercise group, the individuals who were engaged in aerobic and badminton exercise were significantly associated with higher HDL-C levels (β = 1.4077; p < 0.0001 and β = 5.6052; p = 0.0079, respectively). Aerobic exercise and badminton were also associated with higher HDL-C levels among carriers of the lipoprotein lipase (LPL) rs328 genotypes. Aerobic exercise and regular badminton were associated with higher levels of HDL-C, with the badminton group being more significant.