Folic Acid Is Related to Muscle Strength and Vitamin A Is Related to Health-Related Quality of Life: Results of the Korea National Health and Nutrition Examination Survey (KNHANES VII 2016-2018)

Cross-Sectional Associations between Clinical Biochemistry and Nutritional Biomarkers and Sarcopenic Indices of Skeletal Muscle in the Baltimore Longitudinal Study of Aging

BACKGROUND

Investigating relationships between nutritional and clinical biochemistry biomarkers and skeletal muscle mass, strength and function (sarcopenic indices) may 1) highlight micronutrients of interest for potential preventive or treatment strategies for sarcopenia, or 2) highlight biomarkers that may be useful for identifying individuals at risk of sarcopenia.

OBJECTIVES

Investigate associations between nutritional biomarkers (vitamin D, vitamin B12, folate, magnesium, potassium, calcium, and iron), clinical biomarkers (hemoglobin, ferritin, albumin, creatinine, and hemoglobin A1c: HbA1c), and sarcopenic indices (appendicular lean mass: ALM); height-adjusted ALM: ALMht; fat-free mass as a percentage of total body weight; extended short physical performance battery score: extSPPB; height-adjusted hand grip strength: HGSht; height-adjusted knee extension concentric strength, and; height-adjusted knee extension isometric strength) in males and females.

METHODS

Using multivariable linear regression analysis, we investigated cross-sectional associations between biomarkers and sarcopenic indices in data collected from 1761 participants (age 22-103 y) from the Baltimore Longitudinal Study of Aging.

RESULTS

Hemoglobin was positively associated with ALM (β = 0.20, P = 0.021), HGSht (β = 0.25, P = 0.001), and extSPPB (β = 0.13, P = 0.024) in males, and with extSPPB in females (β = 0.15, P = 0.019). In males, serum iron was positively associated with ALMht (β = 0.0021, P = 0.038) and extSPPB (β = 0.0043, P = 0.045). In females, ferritin was positively associated with knee-extension strength measurements. Serum creatinine was positively associated with lean mass measures in males and females and with muscle strength and function measures in males with normal renal function (estimated glomerular filtration rate ≥60 mL/min/1.73 m2). In males, high HbA1c was associated with lower ALMht (β = -0.21, P = 0.023), extSPPB (β = -0.40, P = 0.027), and HGSht (β = -0.56, P = 0.031). In males and females, magnesium was positively associated with extSPPB, and potassium was positively associated with measures of knee-extension strength.

CONCLUSIONS

The associations found between measures of iron status and creatinine and sarcopenic indices, in males in particular, indicate potential importance for muscle health. Future longitudinal and intervention studies are warranted to confirm these findings.

Association between dietary folate and hyperuricemia based on inflammation and cardiovascular disease status

BACKGROUND AND AIMS

The impact of dietary folate intake on serum uric acid is not yet conclusive. This study aims to investigate the association between dietary folate intake and the risk of hyperuricemia according to inflammatory status and comorbidities in Korean adults.

METHODS AND RESULTS

The cross-sectional analysis was conducted on 14,445 subjects aged ≥19 years enrolled in the Korea National Health and Nutrition Examination Survey (KNHNES) from 2016 to 2021. Dietary folate intake was assessed using the 24-h recall method. Dietary folate consumption was positively associated with the intake of beans, vegetables, and fruits, and negatively associated with cereals and meat intake. After adjusting for potential confounders, increased folate intake was found to be associated with a decreased risk of hyperuricemia (odds ratio for the highest tertile compared to the lowest tertile = 0.71 (95 % CI: 0.62-0.82)). The protective effect of folate intake against hyperuricemia was higher in individuals with normal inflammatory status compared to those with low-grade inflammation. Furthermore, the protective effect was greater in individuals without hypertension, dyslipidemia, and cardiovascular disease compared to those with these conditions.

CONCLUSION

These results suggest that dietary intake may help mitigate hyperuricemia, and individuals with inflammatory condition or cardiovascular diseases may require higher intake levels to achieve similar protective effects compared to healthy individuals.

The unique presentation of the relationship between red blood cell folate and appendicular skeletal muscle mass: a cross-sectional study

The overconsumption of folic acid has been associated with deleterious health effects; however, the extant body of research on this matter remains controversial. The principal objective of our investigation was to scrutinize the correlation between red blood cell (RBC) folate levels and appendicular skeletal muscle mass (ASM) among adult individuals. A total of 4117 adults aged over 20 years were included. The weighted prevalence of low muscle mass status (LMMS) was 14.50%. The correlation between RBC folate and ASM showed an inverted U-shaped curve. When the RBC folate concentration is below 500 nmol/L, ASM increases with increasing RBC folate concentration. However, when the RBC folate level exceeds 500 nmol/L, ASM decreases with increased RBC folate level. After correcting multiple confounding factors, a positive correlation was found between RBC folate and LMMS (p < 0.001). Compared with the RBC folate first quartile, the multivariable-adjusted ORs and 95% CIs of the second quartile, third quartile, and highest quartile were 1.08(0.81-1.44), 1.06(0.79-1.43), and 1.96(1.47-2.61), respectively. Our research suggested that excessive levels of RBC folate may be associated with an increased risk of LMMS in adults. Thus, being more cautious when considering folic acid supplementation is recommended.

Higher dietary methyl donor micronutrient consumption is associated with higher muscle strength in adults: a cross-sectional study

Methyl donor micronutrients might affect muscle strength via DNA methylation. We aimed to evaluate the combined relationship of dietary methyl donor micronutrients containing betaine, choline, methionine, vitamin B12, vitamin B6 and folate on muscle strength. This cross-sectional study was conducted on 267 subjects including 113 men and 154 women. Dietary intake of micronutrients was assessed utilising a validated 168-item semi-quantitative FFQ, and methyl donor micronutrient score (MDMS) was calculated. The muscle strength of the participants was measured using a digital handgrip dynamometer. The association was determined using linear regression analysis. The mean age of participants was 36·8 ± 13·2 years. After taking into account potential confounding variables, there was no significant association between dietary methyl donor micronutrient score (MDMS) and the mean left-hand muscle strength (β: 0·07, se: 0·05, P = 0·07); however, the changes were significant in the mean right-hand muscle strength (β: 0·09, se: 0·04, P = 0·03). There was also a significant positive relationship between mean muscle strength and methyl donors' intake after fully adjusting for potential confounders (β: 0·08, se: 0·04, P = 0·04). In conclusion, our findings revealed that higher dietary methyl donor micronutrient consumption is associated with enhanced muscle strength. As a result, advice on a higher intake of methyl donor-rich foods including grains, nuts, dairy products and seafood might be recommended by dietitians as a general guideline to adhere to. Additional prospective studies are needed to confirm the findings.

Association between composite dietary antioxidant index and handgrip strength in American adults: Data from National Health and Nutrition Examination Survey (NHANES, 2011-2014)

Background

The Composite Dietary Antioxidant Index (CDAI), a composite score of multiple dietary antioxidants (including vitamin A, C, and E, selenium, zinc, and carotenoids), represents an individual's comprehensive dietary antioxidant intake profile. CDAI was developed based on its combined effect on pro-inflammatory markers Tumor Necrosis Factor-α (TNF-α) and anti-inflammatory effects of Interleukin-1β (IL-1β), which are associated with many health outcomes, including depression, all-cause mortality, colorectal cancer, etc. Handgrip strength is used as a simple measure of muscle strength, not only is it highly correlated with overall muscle strength, but also serves as a diagnostic tool for many adverse health outcomes, including sarcopenia and frailty syndromes.

Purpose

The association between CDAI and Handgrip strength (HGS) is currently unclear. This study investigated the association between CDAI (including its components) and HGS in 6,019 American adults.

Method

The research data were selected from the 2011-2014 National Health and Nutrition Survey (NHANES), and a total of 6,019 American adults were screened and included. A weighted generalized linear regression model was used to evaluate CDAI (including its components) and HGS.

Results

(1) CDAI was significantly positively correlated with HGS (β = 0.009, 0.005∼0.013, P < 0.001), and the trend test showed that compared with the lowest quartile of CDAI, the highest quartile of CDAI was positively correlated with HGS (β = 0.084, 0.042∼0.126, P = 0.002) and significant in trend test (P for trend < 0.0100). Gender subgroup analysis showed that male CDAI was significantly positively correlated with HGS (β = 0.015, 0.007∼0.023, P = 0.002), and the trend test showed that compared with the lowest quartile of CDAI, the highest quartile of CDAI was positively correlated with HGS (β = 0.131, 0.049∼0.213, P = 0.006) and the trend test was significant (P for trend < 0.0100). There was no correlation between female CDAI and HGS, and the trend test was not statistically significant (P > 0.05). (2) The intake of dietary vitamin E, Zinc and Selenium showed a significant positive correlation with HGS (β = 0.004, 0.002∼0.007, P = 0.006; β = 0.007, 0.004∼0.009, P < 0.001; β = 0.001, 0.001∼0.001, P < 0.001), vitamin A, vitamin C and carotenoid were significantly associated with HGS in the Crude Model, but this significant association disappeared in the complete model with the increase of control variables. Gender subgroup analysis showed that in model 3, male dietary intake levels of vitamin E, Zinc, and Selenium were significantly positively correlated with HGS (β = 0.005, 0.002∼0.009, P = 0.011; β = 0.007, 0.004∼0.011, P = 0.001; β = 0.001, 0.001∼0.001, P = 0.004), the rest of the indicators had no significant correlation with HGS. Among the female subjects, dietary zinc intake was significantly positively correlated with HGS (β = 0.005, 0.001∼0.008, P = 0.008), and there was no significant correlation between other indicators and HGS (P > 0.05).

Conclusion

There was an association between the CDAI and HGS, but there was a gender difference, and there was an association between the CDAI and HGS in male, but the association was not significant in female. Intake of the dietary antioxidants vitamin E, selenium, and zinc was associated with HGS in male, but only zinc was associated with HGS among dietary antioxidants in female.