Sex-specific relationship between visceral fat index and dyslipidemia in Chinese rural adults: The Henan Rural Cohort Study

Relationships of Fat Mass Index and Fat-Free Mass Index with Low-Density Lipoprotein Cholesterol Levels in the Tohoku Medical Megabank Community-Based Cohort Study

AIMS

Although fat mass (FM) and fat-free mass (FFM) have an impact on lipid metabolism, the relationship between different body composition phenotypes and lipid profiles is still unclear. By dividing the FM and FFM by the square of the height, respectively, the fat mass index (FMI) and fat-free mass index (FFMI) can be used to determine the variations in body composition. This study aimed to investigate the relationship of combined FMI and FFMI with low-density lipoprotein cholesterol (LDL-C) levels.

METHODS

This cross-sectional study comprised 5,116 men and 13,630 women without cardiovascular disease and without treatment for hypertension, and diabetes. Following sex-specific quartile classification, FMI and FFMI were combined into 16 groups. Elevated LDL-C levels were defined as LDL-C ≥ 140 mg/dL and/or dyslipidemia treatment. Multivariable logistic regression models were used to examine the relationships between combined FMI and FFMI and elevated LDL-C levels.

RESULTS

Overall, elevated LDL-C levels were found in 1,538 (30.1%) men and 5,434 (39.9%) women. In all FFMI subgroups, a higher FMI was associated with elevated LDL-C levels. Conversely, FFMI was inversely associated with elevated LDL-C levels in most FMI subgroups. Furthermore, the groups with the highest FMI and lowest FFMI had higher odds ratios for elevated LDL-C levels than those with the lowest FMI and highest FFMI.

CONCLUSIONS

Regardless of FFMI, FMI was positively associated with elevated LDL-C levels. Conversely, in the majority of FMI subgroups, FFMI was inversely associated with elevated LDL-C levels.

Investigation on the association between serum lipid levels and periodontitis: a bidirectional Mendelian randomization analysis

OBJECTIVE

Several research has considered the potential correlation between periodontitis and serum lipids. However, serum lipid profiles correlation with periodontitis remains largely unknown. The investigation objective was to examine periodontitis correlation with serum lipid levels using a bidirectional Mendelian randomization (MR) analysis.

METHODS

The study employed a bidirectional MR analysis with two samples, utilizing a freely accessible genome-wide association study (GWAS). Furthermore, the primary analysis employed the inverse variance weighted (IVW) method. To determine whether the lipid profiles were associated with periodontitis, a variety of sensitivity analyses (including MR-Egger regression, MR-PRESSO, and weighted median), as well as multivariable MR, were employed.

RESULTS

MR analysis performed by IVW did not reveal any relationship between periodontitis and low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), or total cholesterol (TC). It was also found that LDL, HDL, TG, and TC were not associated to periodontitis. Furthermore, the MR estimations exhibited consistency with other MR sensitivity and multivariate MR (MVMR) analyses. These results show that the correlation between serum lipid levels and periodontitis could not be established.

CONCLUSION

The finding indicates a negligible link between periodontitis and serum lipid levels were identified, despite previous observational studies reporting a link between periodontitis and serum lipid levels.

Associations of spicy food flavour and intake frequency with blood lipid levels and risk of abnormal serum lipid levels in Chinese rural population: a cross-sectional study

OBJECTIVE

The purpose of the current study was to investigate associations between spicy food intake and serum lipids levels in Chinese rural population.

DESIGN

Information on spicy food flavour and intake frequency was obtained using a two-item questionnaire survey. Dietary data were collected using a validated thirteen-item FFQ. Fasting blood samples were collected and measured for total cholesterol (TC), TAG, HDL-cholesterol and LDL-cholesterol. Multivariate linear and logistic regression models were employed to examine the relationship between spicy food and serum lipids levels according to the spicy food flavour and intake frequency, respectively.

SETTING

A cross-sectional study in Henan Province.

PARTICIPANTS

38 238 participants aged 18-79 years old.

RESULTS

Spicy flavour and intake frequency were consistently associated with decreased TC and non-HDL-cholesterol levels but mildly associated with elevated TAG levels. Each level increment in spicy flavour was inversely associated with high TC (OR: 0·91; 95 % CI 0·88, 0·93) and high non-HDL-cholesterol (OR: 0·88; 95 % CI 0·85, 0·91) but positively associated with high TAG (OR: 1·04; 95 % CI 1·01, 1·07). Similarly, 1-d increment in spicy food intake frequency was also inversely associated with high TC (OR: 0·92; 95 % CI 0·91, 0·94) and high non-HDL-cholesterol (OR: 0·91; 95 % CI 0·89, 0·93) but positively associated with high TAG (OR: 1·04; 95 % CI 1·02, 1·06).

CONCLUSIONS

Spicy food intake was mildly associated with increased risk of abnormal TAG level, significantly associated with decreased risk of abnormal TC and non-HDL levels. Spicy food intake may be contribute to the management of lipid levels.

Relations of Lifestyle Behavior Clusters to Dyslipidemia in China: A Compositional Data Analysis

Dyslipidemia is associated with lifestyle behaviors, while several lifestyle behaviors exist collectively among some populaitons. This study aims to identify lifestyle behavior clusters and their relations to dyslipidemia. This cross-sectional study was conducted in Wuhai City, China. Cluster analysis combined with compositional data analysis was conducted, with 24-h time-use on daily activities and dietary patterns as input variables. Multiple logistic regression was conducted to compare dyslipidemia among clusters. A total of 4306 participants were included. A higher prevalence of newly diagnosed dyslipidemia was found among participants in cluster 1 (long sedentary behavior (SB) and the shortest sleep, high-salt and oil diet) /cluster 5 (the longest SB and short sleep), relative to the other clusters in both age groups (<50 years and ≥50 years). In conclusion, unhealthy lifestyle behaviors may exist together among some of the population, suggesting that these people are potential subjects of health education and behavior interventions. Future research should be conducted to investigate the relative significance of specific lifestyle behaviors in relation to dyslipidemia.

Night sleep duration and sleep initiation time with hypertension in Chinese rural population: the Henan Rural Cohort

BACKGROUND

The study was conducted to evaluate the independent dose-response of the night sleep duration and sleep initiation time on hypertension, and to explore their combined effect with hypertension.

METHODS

Participants from the Henan Rural Cohort were enrolled in this study. Information on sleep was collected using the Pittsburgh Sleep Quality Index. Hypertension was defined as systolic blood pressure/diastolic blood pressure ≥140/90 mmHg or self-reported hypertension and current use of anti-hypertensive medicines. Logistic regression and restricted cubic spline were conducted to evaluate the association of night sleep duration and sleep initiation time with hypertension.

RESULTS

Of the 37 317 included participants, 12 333 suffered from hypertension. 14 474 (38.79%) were men and 22 843 (61.21%) were women, the mean age were 57.18 ± 12.10 and 55.24 ± 11.98 in men and women. Compared to reference (7-h), fully adjusted odd ratios (ORs) and 95% confidence interval (CI) of hypertension were 0.91 (0.66-1.25) in <5 h group and 1.74 (1.41-2.16) in ≥10 h among men, respectively. Fully adjusted ORs (95% CIs) for hypertension compared with reference (21:00-22:00) were 1.05 (95% CI 0.78-1.41) in the <20:00 group, 1.52 (1.25-1.85) in ≥24:00 in men. The combined effect of sleep duration and sleep initiation time on hypertension were statistically significant in the category of (≥8 h)/night and ≥24:00 (OR 1.87, 95% CI 1.07-3.25) compared to reference in fully adjusted model among men.

CONCLUSIONS

Long night sleep duration and late sleep initiation time were associated with the higher odds of hypertension, and the sleep duration and sleep initiation time might cumulatively increase the prevalence of hypertension in men.

CLINICAL TRIAL REGISTRATION

The Henan Rural Cohort Study has been registered at the Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). http://www.chictr.org.cn/showproj.aspx? proj=11375.

Long-term changes in body composition and their relationships with cardiometabolic risk factors: A population-based cohort study

The aim of the present study was to classify the latent body fat trajectories of Chinese adults and their relationships with cardiometabolic risk factors. Data were obtained from the China Health Nutrition Survey for 3,013 participants, who underwent six follow-up visits between 1993 and 2009. Skinfold thickness and other anthropometric indicators were used to estimate body composition. The latent growth model was used to create fat mass to fat-free mass ratio (F2FFMR) trajectory groups. Blood pressure, fasting plasma glucose, total cholesterol, triglycerides, and high- and low-density lipoprotein-cholesterol were measured in venous blood after an overnight fast. Logistic regression was used to explore the relationships of F2FFMR trajectory with cardiometabolic risk factors. In men, four types of F2FFMR trajectory were identified. After adjustment for behavioral and lifestyle factors, age, and weight status, and compared with the Low stability group, the High stability group showed a significant association with diabetes. In women, three types of F2FFMR trajectory were identified. Compared to the Low stability group, the High stability group showed significant associations with diabetes and hypertension after adjustment for the same covariates as in men. Thus, in this long-term study we have identified three F2FFMR trajectory groups in women and four in men. In both sexes, the highly stable F2FFMR is associated with the highest risk of developing diabetes, independent of age and body mass. In addition, in women, it is associated with the highest risk of hypertension, independent of age and body mass.

Age at menopause, body mass index, and risk of type 2 diabetes mellitus in postmenopausal Chinese women: The Henan Rural Cohort study

BACKGROUND AND AIM

The present study was conducted to explore the stratified and joint effects of age at menopause and body mass index (BMI) with the risk of type 2 diabetes mellitus (T2DM) in Chinese rural adults.

METHODS AND RESULTS

A total of 15,406 postmenopausal Chinese women were included in this study. Multivariable logistic regression analysis was used to quantify the stratified and joint effects of age at menopause and BMI on T2DM. Overall, the mean age at menopause and BMI was 48.8 ± 4.7 years and 25.1 ± 3.6 kg/m², respectively. In general, data suggest that: 1) women with BMI ≥ 24 had a higher risk of T2DM, irrespective of age at menopause; 2) in women with BMI < 24, later menopause had a higher risk of T2DM (OR, 1.52; 95% CI, 1.16-2.01); 3) the risk of T2DM was higher only in patients with early or normal age at menopause and BMI ≥ 24, with 0R (95% CI) of (1.58, 1.28-1.94) and (1.48, 1.31-1.67), respectively.

CONCLUSION

Our findings suggest that: 1) women with BMI ≥ 24 had a higher risk of T2DM, irrespective of age at menopause; 2) in women with BMI < 24, a higher risk of T2DM was found only in those with later menopause; 3) women with later menopause had a higher risk of T2DM, irrespective of BMI; 4) in patients with early or normal age at menopause, a higher risk of T2DM was found only in patients with BMI ≥ 24.

THE CHINESE CLINICAL TRIAL REGISTRATION

ChiCTR-OOC-1500669(URL:http://www.chictr.org.cn/showproj.aspx?proj=11375).

Is long-term PM1 exposure associated with blood lipids and dyslipidemias in a Chinese rural population?

BACKGROUND

Air pollution has been shown to be associated with blood lipid levels. However, studies on long-term ambient particulate matter with aerodynamic diameter ≤1 μm (PM₁) exposure in high-exposure areas are still limited. This study aimed to explore the associations among long-term PM₁ exposure, blood lipids and dyslipidemias.

METHODS

Baseline data of The Henan Rural Cohort study was used in present study, including a total of 39,259 participants aged from 18 to 79 years. Daily levels of PM₁ were estimated by a spatiotemporal model using ground-level measurements of PM₁, satellite remote sensing data and other predictors, according to participants' home addresses. Individual exposure to PM₁ was the 3-year average before baseline investigation. Linear regression and logistic regression models were applied to examine the associations among PM₁, blood lipids ((total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C)), and prevalence of dyslipidemias.

RESULTS

The 3-year concentration of PM₁ was 55.7 ± 2.1 μg/m³. Each 1 μg/m³ increment of PM₁ was associated with an increase of 0.21% (95% confidence interval (CI): 0.11%-0.31%) in TC and 0.75% (95% CI: 0.61%-0.90%) in LDL-C, while decrease of 2.68% (95% CI: 2.43%-2.93%) in TG and 0.47% (95% CI: 0.35%-0.59%) in HDL-C. Each 1 μg/m³ increase in PM₁ was associated with 6% (95% CI: 4%-8%), 3% (95% CI: 2%-5%) and 5% (95% CI: 3%-7%) higher risks of hypercholesterolemia, hyperbetalipoproteinemia and hypoalphalipoproteinemia. Sex, age and BMI statistically modified the associations between PM₁ with blood lipid levels and dyslipidemias.

CONCLUSIONS

Higher PM₁ exposure was associated with adverse changes of blood lipid levels and dyslipidemias. Males, older and overweight participants were susceptive to the adverse effects of PM₁.

Association between long-term exposure to ambient air pollution and obesity in a Chinese rural population: The Henan Rural Cohort Study

Association between long-term exposure to ambient air pollution and obesity remains inconclusive, and the evidence from rural areas was limited. Thus, this study aimed to assess the association between ambient air pollution and obesity based on different anthropometric indices in Chinese rural adults, and further to compare the effect sizes of different air pollution types. A total of 38,824 participants (aged 18-79 years) were recruited from the Henan Rural Cohort Study. Logistic and multivariable linear regression model were used to examine the association between ambient air pollution exposure (including particulate matter with aerodynamic diameters ≤ 1.0 μm (PM₁), ≤2.5 μm (PM_2.5), and ≤10 μm (PM₁₀), and nitrogen dioxide (NO₂)) and obesity as well as obese anthropometric indices (including body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), body fat percentage (BFP), and visceral fat index (VFI)). The potential effect modifications were also examined. Positive associations were found between long-term exposure to PM₁, PM_2.5, PM₁₀ and NO₂ and obesity regardless of how obesity was defined (false discovery rate (FDR) < 0.05). Moreover, BMI, WC, WHR, WHtR, BFP, and VFI displayed increased trends with PM₁, PM_2.5, PM₁₀ and NO₂ concentrations increasing (all FDR<0.05). PM₁₀ had the largest effects on obesity among the four types of air pollution. The elderly, women, individuals with low level of education and income, and those who had high fat diet were more vulnerable to the adverse effects of air pollution. In addition, the results of the sensitivity analysis showed that those associations between ambient air pollution and obesity remained robust. These findings suggest that long-term exposure to ambient air pollutant (particularly PM₁₀) may be positively associated with obesity in Chinese rural adults, especially among the elderly, women, individuals with low education and income, as well as unhealthy lifestyles.

Associations of SRD5A1 gene variants and testosterone with dysglycemia: Henan Rural Cohort study

BACKGROUND AND AIM

Multiple studies support a complex relationship between testosterone and type 2 diabetes mellitus (T2DM) and the transformation of testosterone is affected by several reductases. Thus, we aimed to explore the associations of steroid-5α-reductase type 1 (SRD5A1) gene polymorphism with impaired fasting glucose (IFG) and T2DM and the interactive effects of testosterone and genotypes on glycometabolism.

METHODS AND RESULTS

A case-control study including 2365 participants was performed. Genomic DNA was extracted from the whole blood and genotyped for the SRD5A1 single nucleotide polymorphisms (SNP) rs1691053. Multivariable logistic regression and linear regression were performed to estimate the associations of SRD5A1 rs1691053 alleles and genotypes with glycometabolism. Generalized linear models were used to investigate the modulatory effects of serum testosterone on glycometabolism indexes in males. After multivariable adjustment, the odds ratio (OR) of homozygous CC genotypes in male carriers was 2.62 (95%CI: 1.11-6.18) for IFG. Furthermore, significant associations of SRD5A1 rs1691053 polymorphisms with adverse indices of glycometabolism were observed in males. Interestingly, the opposite associations in females were observed. The interactive associations of SNP and testosterone were found and mutations were more likely to lead unfavorable metabolic phenotypes.

CONCLUSION

These results showed that SRD5A1 rs1691053 gene polymorphism was independently associated with glycometabolism. The interaction between a genetic polymorphism from SRD5A1 and testosterone involved glycometabolism was identified in males. Although this preliminary data should be replicated with other rigorous researches, it highlighted the importance of the SNP-testosterone interaction over the present of glycometabolism.

Visceral fat index: a novel predictor for coronary collateral circulation

Objective This study was designed to investigate the role of visceral adiposity along with other clinical parameters in predicting poor coronary collateral circulation (CCC) among patients with severe obstructive coronary artery disease (CAD). Subjects and methods A total of 135 patients with severe obstructive CAD and good (n = 70) or poor (n = 65) CCC were included. Data on angiographically detected CCC, the quality criteria for CCC (Rentrop scores) and visceral fat index (VFI) obtained via bioelectrical impedance were compared between good and poor CCC groups. Independent predictors of poor CCC, the correlation between VFI and Rentrop score and the role of VFI in the identification of CCC were analyzed. Results A significant negative correlation was noted between VFI and Rentrop scores (r = -0.668, < 0.001). The presence of hypertension (OR 4.244, 95% CI 1.184 to 15.211, p = 0.026) and higher VFI (OR 1.955, 95% CI 1.342 to 2.848, p < 0.001) were shown to be independent predictors of an increased risk for poor CCC. ROC analysis revealed a VFI > 9 (AUC [area under the curve] (95% CI): 0.898 (0.834-0.943), p < 0.0001) to be a potential predictor of poor CCC with a sensitivity of 95.38% and specificity of 85.71%. Conclusion In conclusion, our findings revealed comorbid hypertension and higher VFI to significantly predict the risk of poor CCC in patients with severe obstructive CAD.

Effect of the Age at Menarche and Menopause Status Interaction on Type 2 Diabetes: The Henan Rural Cohort Study

PURPOSE

The aims of this study were to evaluate the effect of age at menarche (AM) on type 2 diabetes mellitus (T2DM) and to assess whether the fasting plasma glucose (FPG) and homeostasis model assessment (HOMA) index responses to AM and menopause status interact in Chinese rural adults.

METHODS

A cross-sectional, population-based study including 23 138 participants was performed. Logistic regression and multivariable linear regression were performed to investigate the relationship between AM and glucose status. Generalized linear model was used to calculate the interaction term of AM and menopause status on FPG and the HOMA index. Interaction plot was used to interpret the significant interaction effect.

RESULTS

Women in the later menarche age group (≥18 years) had a 17.7% lower risk of T2DM (95% confidence interval [CI]: 0.712-0.951, P = .008), after adjusting for multiple variables. Further adjustment for body mass index (BMI) completely attenuated this association (odds ratio = 0.884, 95% CI: 0.764-1.024, P = .099). A significant interaction effect of AM and menopause status on T2DM (P = .004) was observed. The adverse effects of menopausal status on FPG and HOMA-2 of insulin resistance decreased with increasing menarche age, and the age ranges were limited to <18 and 9 to 19 years, respectively.

CONCLUSIONS

Later menarche was associated with a lower risk of T2DM, and the association appears to be mediated by BMI. More importantly, the adverse effect of menopause status on T2DM was decreased along with increasing menarche age.

Associations between long-term exposure to air pollution and blood pressure and effect modifications by behavioral factors

BACKGROUND

Studies on the hypertensive effect of long-term air pollution exposure were inconclusive and showed scarce evidence from rural areas in developing countries. In this context, we examined the associations of air pollution exposure with hypertension and blood pressure, and their effect modifiers in rural Chinese adults.

METHODS

We studied 39,259 participants from a cohort established in five rural regions of central China. Individual exposures to PM2.5 and PM10 (particulate matter with an aerodynamic diameter less than or equal to 2.5 μm and 10 μm) and nitrogen dioxide (NO2) was evaluated using satellite-based spatiotemporal models. Mixed-effect regression models were applied to examine the associations of long-term exposure to air pollution with hypertension and four blood pressure component measurements, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP). Several potential effect modifiers related to demographic and behavioral factors were also examined.

RESULTS

The results showed that for each 1 μg/m3 increase in PM2.5, PM10 and NO2, the adjusted odds ratio of hypertension was 1.029 (95%CI: 1.001,1.057), 1.015 (95%CI: 1.001, 1.029) and 1.069 (95%CI: 1.038, 1.100), respectively. These three air pollutants were also associated with increased SBP (except for PM10), DBP and MAP. The hypertensive effects of air pollution were more pronounced among males, smokers, drinkers, individuals with a high-fat diet, and those with high-level physical activity.

CONCLUSION

Long-term exposure to PM2.5, PM10 and NO2 was associated with increased blood pressure and hypertension in rural Chinese adults, and the associations were modified by several behavioral factors.

Long-term effects of ambient air pollutants to blood lipids and dyslipidemias in a Chinese rural population

Both air pollution and dyslipidemias contributed to large number of deaths and disability-adjusted life lost years. Long-term air pollution exposure was related to changed blood lipids and risk of dyslipidemias. This study was designed to evaluate relationships between air pollutants, blood lipids and prevalence of dyslipidemias in a Chinese rural population exposed to high-level air pollution based on baseline data of The Henan Rural Cohort study. An amount of 39,057 participants from rural areas in China were included. The 3-year average exposure of air pollutants (PM_2.5, PM₁₀, NO₂) was estimated by a spatiotemporal model. Logistic and linear regression models were employed to explore relationships between air pollutants, blood lipids (TC, TG, HDL-C and LDL-C) and prevalence of dyslipidemias. The three-year concentration of PM_2.5, PM₁₀ and NO₂ was 72.8 ± 2.3 μg/m³, 131.5 ± 5.7 μg/m³and 39.1 ± 3.1 μg/m³, respectively. Overall, increased air pollution exposure was related to increased TC and LDL-C, while decreased TG and HDL-C. Each 1-μg/m³ increment of PM_2.5 was related to 0.10% (0.07%-0.19%) increase in TC, 0.63% (0.50%-0.77%) increase in LDL-C, 2.93% (2.70%-3.16%) decrease in TG, 0.49% (0.38%-0.60%) decrease in HDL-C; and 5.7% (95%CI: 3.7%-7.6%), 4.0% (95%CI: 2.1%-6.0%) and 3.8% (95%CI: 2.5%-5.1%) increase in odds for hypercholesterolemia, hyperbetalipoproteinemia and hypoalphalipoproteinemia, respectively. Stronger associations were found in male and older participants. Findings suggest that air pollutants were associated with changed blood lipid levels and higher risk of dyslipidemias among rural population. Male and elder people should pay more attention to personal safety protection.

Epidemiology and prevalence of hyperuricemia among men and women in Chinese rural population: The Henan Rural Cohort Study

Objective: The aim of this study was to explore the latest prevalence of hyperuricemia and influencing factors in Chinese rural population.Methods: A survey was conducted from July 2015 to September 2017. A total of 38,855 (15,371 men and 23,484 women) subjects were recruited from the Henan Rural Cohort Study. Hyperuricemia was defined as a serum urate level of >7.0 mg/dL for men and >6.0 mg/dL for women. A meta-analysis of 19 studies that focused on hyperuricemia prevalence was performed to validate the result of the cross-sectional survey.Results: The crude and age-standardized prevalence of hyperuricemia was 10.24% and 12.60%, respectively. The prevalence of hyperuricemia decreased in men with increasing age, but the opposite trend was observed in women. The results of meta-analysis demonstrated that hyperuricemia prevalence in Chinese rural areas was 11.7%, consistent with the result of current survey. Multivariate logistic regression revealed that overweight or obesity, hypercholesterolemia, hypertriglyceridemia, hypoalphalipoproteinemia and high serum creatinine level could increase the risk of hyperuricemia, while high physical activity and fasting plasma glucose were associated with a lower risk of hyperuricemia in all participants.Conclusion: The latest prevalence of hyperuricemia is high in rural China and is associated with multiple factors, indicating that prevention and control strategies for hyperuricemia are needed urgently.

Associations of long-term exposure to ambient PM1 with hypertension and blood pressure in rural Chinese population: The Henan rural cohort study

BACKGROUND

The epidemiological evidence on relationships between long-term exposure to particulate matter and hypertension and blood pressure has been inconclusive. Limited evidence was available for particulate matter with an aerodynamic diameter ≤ 1 μm (PM1) in rural areas of developing countries.

OBJECTIVE

This study aimed to investigate the associations between long-term exposure to PM1 and hypertension and blood pressure among rural Chinese population.

METHODS

This study included 39,259 participants who had completed the baseline survey from Henan Rural Cohort. Participants' exposure to PM1 was assessed by a satellite-based spatiotemporal model. The binary logistic regression model was used to examine the association between long-term PM1 exposure and hypertension, and multivariable linear regression model was used to investigate the associations between long-term PM1 exposure and systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP). Moreover, we examined potential effect modifications by demographic, lifestyle and diet factors.

RESULTS

The mean concentration of PM1 for all participants during the 3-year before baseline survey was 59.98 μg/m3. Each 1 μg/m3 increase in PM1 concentration was significantly associated with an increase of 4.3% [Odds ratio(OR) = 1.043, 95% confidence interval(CI): 1.033, 1.053] in odds for hypertension, an increase of 0.401 mm Hg (95% CI, 0.335, 0.467), 0.328 mm Hg (95% CI, 0.288, 0.369), 0.353 mm Hg (95% CI, 0.307, 0.399) and 0.073 mm Hg (95% CI, 0.030, 0.116) in SBP, DBP, MAP and PP, respectively. Further stratified analyses showed that the effect of PM1 on hypertension and blood pressure could be modified by sex, lifestyle and diet.

CONCLUSIONS

This study suggests that long-term exposure to ambient PM1 increases the risk of hypertension and is associated with elevations in blood pressure in rural Chinese adults, especially in male and those with unhealthy habits.

Association of serum testosterone with different classes of glucose metabolism and the mediation effect of obesity: The Henan Rural Cohort Study

AIMS

We aimed to investigate the association of serum testosterone with impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM) and calculate the proportion explained by obesity status on the relationship.

MATERIALS AND METHODS

A case-control study including 2775 participants was performed. Serum testosterone was quantified by liquid chromatography-tandem mass spectrometry. Conditional logistic regression and multivariable linear regression were performed to estimate the relationships between testosterone and different glucose status. Waist circumference (WC) was used as a mediator to estimate the mediation effect.

RESULTS

After adjusting for multiple variables, serum testosterone levels were negatively associated with T2DM in males (per 1 unit natural log-transformed, odd ratio (OR) = 0.73, 95% confidence interval (CI): 0.56, 0.96; Tertile 3 vs Tertile 1, OR = 0.46, 95% CI:0.29, 0.72) while were positively in females (per 1 unit natural log-transformed, OR = 1.56, 95% CI:1.32, 1.84; Tertile 3 vs Tertile 1, OR = 3.55, 95% CI: 2.22, 5.66). In males, a higher testosterone tended to be associated with a lower fasting plasma glucose level and a weaker HOMA2-IR but a stronger HOMA2-β. Opposite findings were observed in females. Furthermore, WC played a full and partial mediating role in the relationship between testosterone and IFG and T2DM both in males and females.

CONCLUSION

Serum testosterone levels had opposite effects on IFG and T2DM in males and females. With higher serum testosterone levels, the dysglycemia progression was decreased among males while increased among females. In addition, WC played a full and partial mediating role in the relationship between testosterone and IFG and T2DM.