Plasma methylmalonic acid predicts risk of acute myocardial infarction and mortality in patients with coronary heart disease: A prospective 2-cohort study

Mitochondrial Metabolite Methylmalonic Acid, Subclinical Myocardial Injury, and its Incremental Predictive Value for Cardiovascular Mortality Risk

BACKGROUND AND AIMS

Methylmalonic acid (MMA) is involved in myocardial mitochondrial damage and energy metabolism disorders. We sought to investigate the association of MMA with subclinical myocardial injury and its incremental value in predicting cardiovascular mortality risk based on conventional risk factors and cardiac biomarkers.

METHODS

This study included 11,373 participants aged ≥18 years without prevalent cardiovascular disease (CVD). The cross-sectional associations of MMA with subclinical elevation of cardiac biomarkers (high-sensitivity cardiac troponin [hs-cTn] and N-terminal pro-B-type natriuretic peptide [NT-proBNP]), and their prospective associations with long-term mortality, were assessed. The predictive performance for 10-year cardiovascular mortality was estimated.

RESULTS

The association between MMA and elevated cardiac biomarkers was significant with a dose-response pattern. Compared with participants in the lowest quartile of MMA, the multivariable-adjusted rate ratios (95% CIs) in the highest quartile for elevated hs-cTnT and NT-proBNP were 2.35 (1.64-3.37) and 1.35 (1.12-1.62), respectively (each p trend <0.001). Strikingly, the cardiovascular mortality risk associated with elevated hs-cTnT or NT-proBNP was at least two-fold higher in adults with elevated MMA levels than in those with lower MMA levels. The adjusted hazard ratios (95% CIs) of elevated hs-cTnT for cardiovascular mortality were 1.58 (1.00-2.50) among individuals with MMA ≤125 nmol/L and 2.45 (1.94-3.11) among participants with MMA >125 nmol/L.

CONCLUSION

MMA accumulation is independently associated with subclinical myocardial injury before cardiovascular events occur. These findings support the additional value of mitochondria-related indicators to guide cardiac biomarker-based screening of populations at high risk for cardiovascular events.

Hypertension may lead to cognitive dysfunction in older adults via methylmalonic acid: evidence from NHANES 2011-2014 population

BACKGROUND

An enriched understanding is necessary concerning the association between hypertension and cognitive impairment in older adults, particularly regarding the potential underlying mechanisms at a biological level. This study aimed to explore the mediating role of methylmalonic acid (MMA) in the hypertension-cognition link in the older population.

METHODS

A total of 2762 adults (age > = 60 years) from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 participated. Cognitive function was assessed using a combination of the Animal Fluency Test (AFT), the Digit Symbol Substitution Test (DSST), and the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Learning Test. Self-reported hypertension diagnosis, antihypertensive medications use, and blood pressure examinations were used to identify hypertension. Serum MMA (sMMA) levels were collected. Weighted multiple linear regressions and mediation analysis were applied. A subgroup analysis by sex and age was performed.

RESULTS

After adjusting for potential confounding factors, we observed a significant mediating effect of the sMMA level in the hypertension-cognition link, accounting for 11.14% (95% CI 4.09%-14.00%, p < 0.001) of the relationship in older adults. The proportion mediated by the sMMA level in the relationship between hypertension and cognitive function was higher in males (15.23%, 95%CI 1.32%-27.00%, p < 0.001) than in females (6.61%, 95%CI 2.12%-10.00%, p < 0.001). This mediating effect of sMMA was observed only in individuals aged 68 years and older (11.31%, 95%CI 3.80%-16.00%, p < 0.001), with no significant mediation detected in those younger than 68 years.

CONCLUSION

Hypertension may lead to cognitive dysfunction in older adults through MMA. Apart from its role as a biomarker reflecting vitamin B12, MMA may act as an independent neurotoxin capable of inducing brain injury and cognitive impairment. Addressing MMA accumulation, such as through Vitamin B12 supplementation, may have a potential to mitigate hypertension-induced cognitive decline in older adults. Special attention could be paid to hypertensive males with an advanced age (> = 68) to address MMA-related cognitive decline.

Association between oxidative balance score and cardiovascular diseases: mediating analysis of methylmalonic acid based on the NHANES database

Aim

To explore the association between oxidative balance score (OBS) and cardiovascular diseases (CVD) in patients with hypertension, and further clarify the mediating role of methylmalonic acid (MMA) in the relationship between OBS and CVD risk.

Methods

We included 4,137 participants with hypertension from the 2011-2014 National Health and Nutrition Examination Survey cohort. The study endpoint was the incidence of CVD in patients with hypertension. OBS was calculated based on 16 dietary and 4 lifestyle components. Weighted multivariable logistic regression models were adopted to assess the associations between OBS and CVD risk, OBS and MMA levels, and MMA levels and CVD risk. Odds ratios (OR) and 95% confidence interval (CI) were estimated. We used distribution-of-product method to test for mediation effect, with a presence of mediation indicated by 95% CI that does not include 0 for the distribution-of-product method and 95% CI that does not include 1 for the indirect effect.

Results

Totally 812 developed CVD. In weighted multivariable logistic regression models, lower OBS category (OBS < 15.72) was associated with increased odds of CVD (OR = 1.53, 95%CI: 1.17-2.01) and MMA levels (OR = 1.32, 95%CI: 1.06-1.65), respectively, compared with higher OBS category as reference. A positive relationship between higher MMA levels (≥154.90 nmol/L) and CVD risk was observed (OR = 1.34, 95%CI: 1.07-1.68). Importantly, according to the distribution-of-product test, a potential mediating effect of MMA on the relationship between OBS and CVD was found (OR = 1.08, 95%CI: 1.01-1.19), with a 95% CI for distribution-of-product of 0.08 (95% CI: 0.01-0.17). The mediated proportion was 17.8%. Subgroup analysis revealed a mediating effect of MMA in individuals with dyslipidemia, with a mediated proportion of 14.9%.

Conclusion

MMA plays a critical mediating role in the pathway between OBS and CVD risk.

The independent and joint associations of vitamin B12 and methylmalonic acid on the risk of mortality in individuals with metabolic dysfunction-associated steatotic liver disease

PURPOSE

To investigate the independent and joint associations of vitamin B12 and methylmalonic acid (MMA) with all-cause, cardiovascular disease (CVD), and cancer mortality in patients with metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

We included 6797 individuals with MASLD from the U.S. National Health and Nutrition Examination Survey. Serum MMA was measured using gas/liquid chromatography-mass spectrometry. Serum vitamin B12 was measured using commercial kits. The separate and joint associations of dietary intake and serum vitamin B12 (cutoff: 400 pg/mL) and MMA (cutoff: 250 nmol/L) levels with mortality were assessed by Cox proportional hazards regression.

RESULTS

During a median follow-up of 9.3 years, 1604 deaths were documented, including 438 from CVD and 365 from cancer. In MASLD patients, dietary intake and serum vitamin B12 did not associate with mortality, while MMA was associated with a 1.35-fold increased risk of all-cause mortality (P-trend < 0.001). The adjusted hazard ratios for the joint association of vitamin B12 and MMA with all-cause and CVD mortality were 1 in the B12lowMMAlow group (reference), 1.02 (0.87-1.20) and 1.15 (0.90-1.47) in the B12highMMAlow group, 1.55 (1.29-1.86) and 1.84 (1.28-2.65) in the B12lowMMAhigh group, and 1.82 (1.49-2.21) and 2.28 (1.40-3.71) in the B12highMMAhigh group, respectively. The joint association was modified by serum folate (P-interaction = 0.001).

CONCLUSIONS

In MASLD patients, MMA rather than dietary and serum vitamin B12 was positively associated with all-cause mortality. The joint effect of high levels of MMA and vitamin B12 showed the strongest associations with all-cause and CVD mortality, with a significant interaction with serum folate.

Association between dietary macronutrient composition and plasma one-carbon metabolites and B-vitamin cofactors in patients with stable angina pectoris

Elevated plasma concentrations of several one-carbon metabolites are associated with increased CVD risk. Both diet-induced regulation and dietary content of one-carbon metabolites can influence circulating concentrations of these markers. We cross-sectionally analysed 1928 patients with suspected stable angina pectoris (geometric mean age 61), representing elevated CVD risk, to assess associations between dietary macronutrient composition (FFQ) and plasma one-carbon metabolites and related B-vitamin status markers (GC-MS/MS, LC-MS/MS or microbiological assay). Diet-metabolite associations were modelled on the continuous scale, adjusted for age, sex, BMI, smoking, alcohol and total energy intake. Average (geometric mean (95 % prediction interval)) intake was forty-nine (38, 63) energy percent (E%) from carbohydrate, thirty-one (22, 45) E% from fat and seventeen (12, 22) E% from protein. The strongest associations were seen for higher protein intake, i.e. with higher plasma pyridoxal 5'-phosphate (PLP) (% change (95 % CI) 3·1 (2·1, 4·1)), cobalamin (2·9 (2·1, 3·7)), riboflavin (2·4 (1·1, 3·7)) and folate (2·1 (1·2, 3·1)) and lower total homocysteine (tHcy) (-1·4 (-1·9, -0·9)) and methylmalonic acid (MMA) (-1·4 (-2·0, -0·8)). Substitution analyses replacing MUFA or PUFA with SFA demonstrated higher plasma concentrations of riboflavin (5·0 (0·9, 9·3) and 3·3 (1·1, 5·6)), tHcy (2·3 (0·7, 3·8) and 1·3 (0·5, 2·2)) and MMA (2·0 (0·2, 3·9) and 1·7 (0·7, 2·7)) and lower PLP (-2·5 (-5·3, 0·3) and -2·7 (-4·2, -1·2)). In conclusion, a higher protein intake and replacing saturated with MUFA and PUFA were associated with a more favourable metabolic phenotype regarding metabolites associated with CVD risk.

Methylmalonic acid in aging and disease

Metabolic byproducts have conventionally been disregarded as waste products without functions. In this opinion article, we bring to light the multifaceted role of methylmalonic acid (MMA), a byproduct of the propionate metabolism pathway mostly commonly known as a clinical biomarker of vitamin B12 deficiency. MMA is normally present at low levels in the body, but increased levels can come from different sources, such as vitamin B12 deficiency, genetic mutations in enzymes related to the propionate pathway, the gut microbiota, and aggressive cancers. Here, we describe the diverse metabolic and signaling functions of MMA and discuss the consequences of increased MMA levels, such as during the aging process, for several age-related human pathologies.

Methylmalonic acid, vitamin B12, and mortality risk in patients with preexisting coronary heart disease: a prospective cohort study

BACKGROUND

The inconsistent relationship between Vitamin B12 (B12), methylmalonic acid (MMA, marker of B12 deficiency) and mortality was poorly understood, especially in patients with coronary heart disease (CHD). This study aims to investigate the association of serum MMA, and B12-related biomarkers (serum level, dietary intake, supplement use, and sensibility to B12) with all-cause and cardiovascular mortality in adults with CHD.

METHODS

The data of this study were from a subcohort within the US National Health and Nutrition Examination Survey (NHANES). We included adults with preexisting CHD with serum MMA and B12, and dietary B12 intake measurements at recruitment. All participants were followed up until 31 December 2019. Weighted Cox proportional hazard regression was used to estimate hazard ratios (HR) and 95% CI of mortality risk.

RESULTS

Overall, 1755 individuals (weighted mean [SE] age, 65.2 [0.5] years; 1047 men [weighted 58.5%]) with CHD were included, with geometric mean levels of serum MMA 182.4 nmol/L, serum B12 494.5 pg/ml, and dietary B12 intake 4.42 mg/day, and percentage of B12 supplements use 39.1%. During a median follow-up of 7.92 years, 980 patients died. Serum B12 concentration, dietary B12 intake and supplements use were not significantly associated with mortality risk (each p ≥ 0.388). In contrast, individuals in the top tertile of MMA had multivariable-adjusted HRs (95% CIs) of 1.70 (1.31-2.20) for all-cause mortality, and 2.00 (1.39-2.89) for cardiovascular mortality (both p trend < 0.001) compared to those in the bottom tertile of MMA. MMA-related mortality risk was particularly higher among participants with sufficient serum B12 (p < 0.001). CHD patients with increased levels of both MMA and B12 had a doubled mortality risk compared to those with lower MMA and B12 (p < 0.001).

CONCLUSION

MMA accumulation but not serum or dietary vitamin B12 was associated with increased cardiovascular mortality risk among patients with CHD. This paradox may be related to decreased response to vitamin B12.

Association of Serum Vitamin B12 and Circulating Methylmalonic Acid Levels with All-Cause and Cardiovascular Disease Mortality among Individuals with Chronic Kidney Disease

(1) Background: it is unclear whether serum vitamin B₁₂ and circulating methylmalonic acid (MMA) are related with a poor prognosis among individuals with chronic kidney disease (CKD); (2) Methods: this prospective cohort study included 2589 individuals with CKD who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004, and from 2011 to 2014, respectively. Hazard ratios (HRs) and 95% Cis for the associations of MMA and vitamin B₁₂ levels with the risk of all-cause and cardiovascular disease (CVD) mortality were calculated using multivariable Cox proportional hazards regression models. Restricted cubic spline analyses were used to examine the non-linear association of MMA levels with all-cause and CVD mortality. (3) Results: among the 2589 participants, we identified 1192 all-cause deaths and 446 CVD deaths, respectively, with a median follow-up of 7.7 years. Compared with participants with MMA < 123 nmol/L, those with MMA ≥ 240 nmol/L had an increased all-cause and CVD mortality in the multivariable-adjusted model [HR (95% CI), 2.01 (1.54-2.62) and 1.76 (1.18-2.63), respectively]; (4) Conclusions: higher circulating MMA levels were found to be strongly associated with an elevated all-cause and CVD mortality among individuals with CKD, while serum vitamin B₁₂ levels were not associated.

Sexual dimorphism in mitochondrial dysfunction and diabetes mellitus: evidence from a population-based cohort study

BACKGROUND

Pathophysiological mechanisms underlying sex-based differences in diabetes remain poorly understood. Mitochondrial metabolite methylmalonic acid (MMA) accumulation reflects mitochondrial dysfunction which is involved in sex-specific pathophysiological responses biologically. We aimed to investigate the sex-specific associations between mortality risk and MMA in adults with the presence or absence of type 2 diabetes.

METHODS

This cohort study included 24,164 adults (12,123 females and 12,041 males) from the NHANES study during 1999-2014. Both sexes were separately categorized as those with no diabetes, prediabetes, undiagnosed diabetes, and diagnosed diabetes. Circulating MMA level was measured at baseline by mass-spectrometric detection. Mortality status was ascertained from baseline until December 31, 2015.

RESULTS

During a median follow-up of 11.1 years, 3375 deaths were documented. Males had a particularly higher mortality than females in adults with diagnosed diabetes compared to differences in those with no diabetes, prediabetes and undiagnosed diabetes (sex differences in mortality rate per 1000 person-years across diabetic status: 0.62, 1.44, 5.78, and 9.77, p < 0.001). Notably, the sex-specific difference in associations between MMA and mortality was significant only in adults with diagnosed diabetes (p for interaction = 0.028), not in adults with no diabetes and prediabetes. Adjusted HRs (95%CIs) per doubling of MMA for all-cause mortality were 1.19 (1.04-1.37) in females with diagnosed diabetes versus 1.58 (1.36-1.86) in male counterparts. In addition, MMA levels had an insignificant or weak correlation with sex hormone profiles at baseline, regardless of diabetes status and sex.

CONCLUSIONS

Sex difference in mortality risk was especially significant in diagnosed type 2 diabetes. Increasing equivalent exposure to mitochondrial metabolite MMA was associated with a greater excess risk of future mortality in males with diabetes than in females.

Role of Vitamins in Cardiovascular Health: Know Your Facts - Part 1

Cardiovascular (CV) disease (CVD) is a major cause of morbidity and mortality world-wide, thus it is important to adopt preventive interventions. Observational data demonstrating CV benefits of vitamin supplements, advanced by self-proclaimed experts have resulted in ~50% of Americans reporting the use of multivitamins for health promotion; this practice has led to a multi-billion-dollar business of the multivitamin-industry. However, the data on the extensive use of multivitamins show no consistent benefit for CVD prevention or all-cause mortality, while the use of certain vitamins might prove harmful. Thus, the focus of this two-part review is on the attributes or concerns about specific vitamins on CVD. In Part 1, the CV effects of specific vitamins are discussed, indicating the need for further supportive evidence of potential benefits. Vitamin A preserves CV homeostasis as it participates in many biologic functions, including atherosclerosis. However, supplementation could potentially be harmful. Betacarotene, a pro-vitamin A, conveys pro-oxidant actions that may mitigate any other benefits. Folic acid alone and certain B-vitamins (e.g., B1/B2/B6/B12) may reduce CVD, heart failure, and/or stroke, while niacin might increase mortality. Vitamin C has antioxidant and cardioprotective effects. Vitamin D may confer CV protection, but all the data are not in agreement. Combined vitamin E and C have antiatherogenic effects but clinical evidence is inconsistent. Vitamin K seems neutral. Thus, there are individual vitamin actions with favorable CV impact (certain B-vitamins and vitamins C and D), but other vitamins (β-carotene, niacin) may potentially have deleterious effects, which also holds true for high doses of fat-soluble vitamins (A/D/E/K).