Associations between Serum Betaine, Methyl-Metabolizing Genetic Polymorphisms and Risk of Incident Type 2 Diabetes: A Prospective Cohort Study in Community-Dwelling Chinese Adults

Previous studies have explored associations between betaine and diabetes, but few have considered the effects of genes on them. We aimed to examine associations between serum betaine, methyl-metabolizing genetic polymorphisms and the risk of type 2 diabetes in Chinese adults. This prospective study comprised 1565 subjects aged 40–75 without type 2 diabetes at baseline. Serum betaine was measured by high-performance liquid chromatography tandem mass spectrometry. Genotyping of methyl-metabolizing genes was detected by Illumina ASA-750K arrays. Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During a median of 8.9 years of follow-up, 213 participants developed type 2 diabetes. Compared with participants in the lowest quartile of serum betaine, those in the highest quartile had lower risk of type 2 diabetes, adjusted HRs (95%CIs) was 0.46 (0.31, 0.69). For methylenetetrahydrofolate reductase (MTHFR) G1793A (rs2274976) and MTHFR A1298C (rs1801131), participants carrying 1793GA + AA and 1298AC + CC had lower risk of type 2 diabetes. Interactions of serum betaine and genotype of MTHFR G1793A and MTHFR A1298C could be found influencing type 2 diabetes risk. Our findings indicate that higher serum betaine, mutations of MTHFR G1793A and A1298C, as well as the joint effects of them, are associated with lower risk of type 2 diabetes.

Nutrition Literacy Measurement Tool With Multiple Features for Chinese Adults

Background: Nutrition literacy is an emerging term which is increasingly used in policy and research. Progression is limited by the lack of an accepted method to measure nutrition literacy in Chinese adult, even research in this area is growing. Objective: The objective of this study is to develop a valid instrument to assess nutrition literacy in Chinese adults. Methods: The process involved 2 steps: constructed nutrition literacy conceptual framework, and developed potential items of scale based on literature review; and conducted 2 rounds of Delphi consultation to select items of the preliminary questionnaire. Results: In Delphi survey, the content validity index for each domain, level, and dimension of nutrition literacy was 1.0, coefficient of variation was less than 0.10, and Kendall’s coefficient of concordance was greater than 0.83. All of the 2 domains, 3 levels, and 6 dimensions initially formulated by our research team were reserved in the conceptual framework of nutrition literacy. Furthermore, a 43-item nutrition literacy measurement scale was established. Each item kept in the final scale reaches a high degree of concentration and a high degree of coordination, with the mean of importance ranging from 4.38 to 5.00. Conclusions: A nutrition literacy measurement scale with multiple features was established for Chinese adults, providing an operationalized tool to assess comprehensively nutrition literacy for research and practice in the field of nutrition, diet, and health.

Association between Milk Intake and All-Cause Mortality among Chinese Adults: A Prospective Study

Background: Little is known about the effect of milk intake on all-cause mortality among Chinese adults. The present study aimed to explore the association between milk intake and all-cause mortality in the Chinese population. Methods: Data from 1997 to 2015 of the China Health and Nutrition Survey (CHNS) were used. A total of 14,738 participants enrolled in the study. Dietary data were obtained by three day 24-h dietary recall. All-cause mortality was assessed according to information reported. The association between milk intake and all-cause mortality were explored using Cox regression and further stratified with different levels of dietary diversity score (DDS) and energy intake. Results: 11,975 (81.25%) did not consume milk, 1341 (9.10%) and 1422 (9.65%) consumed 0.1–2 portions/week and >2 portions/week, respectively. Milk consumption of 0.1–2 portions/week was related to the decreased all-cause mortality (HR: 0.59, 95% CI: 0.41–0.85). In stratified analysis, consuming 0.1–2 portions/week was associated with decreased all-cause mortality among people with high DDS and energy intake. Conclusions: Milk intake is low among Chinese adults. Consuming 0.1–2 portions of milk/week might be associated with the reduced risk of death among Chinese adults by advocating health education. Further research is required to investigate the relationships between specific dairy products and cause-specific mortality.

Contact Heat Evoked Potentials in China: Normal Values and Reproducibility

Background: Contact heat evoked potentials (CHEPs) is used to diagnose small fiber neuropathy (SFN). We established the normal values of CHEPs parameters in Chinese adults, optimized the test technique, and determined its reproducibility.Methods: We recruited 151 healthy adults (80 men; mean age, 37 ± 14 years). CHEPs was performed on the right forearm to determine the optimal number of stimuli, and then conducted at different sites to establish normal values, determine the effects of demographic characteristics and baseline temperature, and assess the short- (30 min) and long-term (1 year) reproducibility. N2 latency/height varied with age and sex, while P2 latency/height and N2–P2 amplitude varied with age. The optimal number of stimuli was three.Results: N2 latency/height (t = 5.45, P < 0.001) and P2 latency/height (χ2 = −4.06, P < 0.001) decreased and N2–P2 amplitude (t = −5.01, P < 0.001) and visual analog scale score (χ2 = −5.84, P < 0.001) increased with increased baseline temperature (35 vs. 32°C). CHEPs parameters did not differ with time (baseline vs. 30 min vs. 1 year).Conclusion: We established normal CHEPs values in Chinese adults. We found that CHEPs parameters changed with baseline temperature and that the short- and long-term test reproducibility were satisfactory.

Serum Uric Acid Might Be Positively Associated With Hypertension in Chinese Adults: An Analysis of the China Health and Nutrition Survey

Background: Previous studies have clarified the relationship between serum uric acid (SUA) and hypertension; most of previous studies suggest that elevated uric acid levels are associated with an increased risk of hypertension, while in China, there are relatively few studies to explore above association. The objective of this longitudinal study is to investigate the correlation of SUA and hypertension in Chinese adults with a nationwide large-scale sample.Methods: Data from the China Health and Nutrition Survey 2009, 2011, and 2016 were used; a total of 8,469 participants (3,973 men and 4,496 women) were involved. This study was conducted separately by gender. Clinical characteristics of the participants among different uric acid groups are compared. The binary logistic regression analysis was conducted to examine the association between SUA and hypertension. Restricted cubic spline analysis with three knots of the SUA concentration were used to characterize the dose-response relationship. Additionally, we compared the incidence of hypertension in the different baseline uric acid groups during follow-up in 2011 and 2015.Results: After the covariates were fully adjusted, we found that elevated uric acid levels were correlated with increased risk of hypertension in both males (p < 0.01) and females (p < 0.01). With 2-year or 6-year of follow-up, we found participants with higher baseline uric acid levels had a higher incidence of hypertension (p < 0.01). In stratified analysis by obesity, above relationship remained significant in nonobesity population (males: p < 0.05, females: p < 0.01) and became nonsignificant in obesity people. In stratified analysis by age, above positively correlation remained significant in middle-aged men (p < 0.05) and elderly women (p < 0.01). Restricted cubic spline revealed the dose-response relationship between SUA and hypertension; we also found that above relationship was much stronger in females.Conclusion: This study suggests that elevated SUA levels might be positively associated with an increased risk of hypertension in general Chinese adults.

Speech Perception in Noise Is Associated With Different Cognitive Abilities in Chinese-Speaking Older Adults With and Without Hearing Aids

Chinese-speaking older adults usually do not perceive a hearing problem until audiometric thresholds exceed 45 dB HL, and the audiometric thresholds of the average hearing-aid (HA) user often exceed 60 dB HL. The purpose of this study was to examine the relationships between cognitive and hearing functions (measured as audiometric or speech reception thresholds) in older Chinese adults with HAs and with untreated hearing loss (HL). Participants were 49 Chinese older adults who used HAs and had moderate to severe HL (HA group), and 46 older Chinese who had mild to moderately severe HL but did not use HAs (untreated; or UT group). Multiple linear regression analysis was employed to evaluate how well age, education level, audiometric thresholds, and speech perception in noise were related to performance on general cognitive function, working memory, executive function, attention, and verbal learning tests. Results showed that speech perception in noise alone accounted for 13–25% of the variance in general cognitive function, working memory, and executive function in the UT group, and 9–21% of the variance in general cognitive function and verbal learning in the HA group (i.e., medium effect sizes). Audiometric thresholds did not explain any proportion of the variance in cognitive functioning in the HA or UT group. Thus, speech perception in noise accounts for more variance in cognitive performance than audiometric thresholds, and is significantly associated with different cognitive functions in older Chinese adults with HAs and with untreated HL.

Association Between Basal Metabolic Rate and All-Cause Mortality in a Prospective Cohort of Southern Chinese Adults

Objective: The aim of this study was to assess the relationship between basal metabolic rate (BMR) and all-cause mortality in southern Chinese adults.Methods: We prospectively examined the relationship between BMR and all-cause mortality in 12,608 Southern Chinese adults with age ≥ 35 years who participated in the National Key R&D Program from 2013–2014 to 2019–2020. Cox proportional hazard models were used to examine the association between BMR and all-cause mortality.Results: A total of 809 deaths (including 478 men and 331 women) occurred during a median follow-up period of 5.60 years. All-cause mortality was higher in elderly individuals than in non-elderly individuals (11.48 vs. 2.04%, P < 0.001) and was higher in male subjects than in female subjects (9.84 vs. 4.56%, P < 0.001). There was a significantly inverse relationship between BMR levels and all-cause mortality in elderly male individuals (adjusted-HR per SD increase: 0.80, 95% CI: 0.70–0.91, P < 0.001). Compared with BMR levels ≤ 1,115 kJ/day, there was lower all-cause mortality in third and highest BMR quartiles in the elderly male subjects (adjusted-HR: 0.71, 95% CI: 0.53–0.95, P = 0.022; adjusted-HR: 0.60, 95% CI: 0.43–0.84, P = 0.003, respectively).Conclusion: An elevated BMR was independently inversely associated with all-cause mortality in elderly male subjects in a southern Chinese population.