Vitamin B-6 May Affect Risk of Heart Disease

HEALTH NEWS

Low levels of vitamin B-6 may increase the risk of inflammation and metabolic conditions—and subsequently, cardiovascular disease risk—according to a new study.

A cross-sectional study with 1,205 people found that higher levels of pyridoxal-5’-phosphate (PLP), the active form of vitamin B-6, were linked to lower levels of C-reactive protein (CRP), a marker of inflammation, as well as lower levels of 8-hydroxy-2’-deoxyguanosine (8-OHdG), a marker for oxidative stress, both of which are related to heart disease risk.

CRP is produced in the liver and is a known indicator of inflammation. Increased levels of CRP are a good predictor for the onset of both type 2 diabetes and cardiovascular disease.

Researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University reported their findings in the American Journal of Clinical Nutrition.

"Our data suggest that vitamin B-6 may influence cardiovascular disease risk through mechanisms other than [reduction of the amino acid] homocysteine and support the notion that nutritional status may influence the health disparities present in this population," wrote the researchers, led by Jian Shen.

Shen and co-workers measured levels of PLP, CRP and 8-OHdG in 1,205 Puerto Rican adults aged between 45 and 75 living in Massachusetts.

Results showed a strong dose-dependent relationship between PLP levels and CRP levels, with the highest PLP levels associated with CRP levels almost 50% lower than low PLP levels.

Furthermore, the highest average levels of PLP were associated with 8-OHdG concentrations of 108 nanograms per milligram, compared to 124 ng/mg for low PLP levels. The associations were observed even after the researchers took into account homocysteine levels.

Source: American Journal of Clinical Nutrition 91(2):337-342, 2010

Inflammatory Markers Predict Congestive Heart Failure

HEALTH NEWS

Inflammatory markers are independent predictors of congestive heart failure (CHF) and likely reflect the link between obesity and CHF, a new study suggests.(1) In a new analysis of the Multi-Ethnic Study of Atherosclerosis (MESA), researchers led by Dr Hossein Bahrami (Johns Hopkins, Baltimore, MD) report that serum interleukin-6 (IL-6), C-reactive protein (CRP), and albuminuria all predicted the development of CHF over four years, independent of obesity or other established risk factors.

"Our results suggest that inflammation might be involved, directly or as a marker of other underlying conditions, (emphasis added) in the pathologic pathways that link obesity to left ventricular [LV] dysfunction and ultimately CHF," Bahrami et al write.

The study appears in the May 6, 2008 issue of the Journal of the American College of Cardiology.

Authors of the study calculated the hazard ratios (HRs) linking baseline metabolic syndrome, inflammatory markers, insulin resistance, and albuminuria with incidence CHF in the MESA population, after taking into account standard risk factors, interim myocardial infarction (MI), and left ventricular structure and function. MESA enrolled 6814 participants from multiple ethnic backgrounds; median follow-up for the current analysis was four years.

Baharmi and colleagues report that 79 patients developed CHF during follow-up: while obesity was significantly associated with subsequent CHF, the association lost statistical significance after inflammatory markers were included in the model. Obese patients, however were found to have much higher levels of interleukin 6, CRP, and fibrinogen.

According to Baharmi, the findings suggest a mechanistic link between obesity, inflammation, and CHF.

"The implication may be that greater control of obesity may reduce the risk of heart failure and down the road, maybe targeting inflammatory markers may reduce the risk of heart failure related to obesity."

Inflammation may also help explain the link between the metabolic syndrome and CHF risk: inflammation is a known characteristic of the metabolic syndrome, and metabolic syndrome is associated with a higher risk of developing CHF, the authors note.

Reference 

1. Bahrami H, Bluemke DA, Kronmal R, et al. Novel metabolic risk factors for incident heart failure and their relationship with obesity. The Multi-Ethnic Study of Atherosclerosis Study. J Am Coll Cardiol. 2008;51:1775-1783.