Serum sialic acid, a reputed cardiovascular risk factor, is related to serum leptin concentrations in Fijians

Dietary selenium intake is negatively associated with serum sialic acid and metabolic syndrome features in healthy young adults

Low-grade and chronic inflammation related to excessive body weight can increase the risk for type 2 diabetes and cardiovascular disease, whereas the intake of antioxidant nutrients appears to produce anti-inflammatory effects. The purpose of this observational study was to assess the potential relationships between serum SA levels, metabolic syndrome features, and dietary selenium intake to test the hypothesis that this antioxidant micronutrient may also have anti-inflammatory properties in healthy young adults. Forty-three healthy participants with a mean age of 18.0 +/- 0.93 years and a mean body mass index of 22.2 +/- 2.7 kg/m(2) were enrolled. Anthropometric, body composition, and blood pressure determinations were measured as well as serum lipid profile, glucose, insulin, and SA concentrations. Nutritional intake was estimated by a computerized, validated semiquantitative food frequency questionnaire. The findings included a positive correlation between SA and triacylglycerol levels (r = 0.317, P = .038) and a trend to significance with the homeostatic model assessment of insulin resistance index (r = 0.297, P = .053). Moreover, subjects with higher dietary selenium intake showed statistically lower SA levels compared with subjects with lower dietary selenium intake (1.8 +/- 0.4 vs 2.1 +/- 0.4 mmol/L, P = .037), while dietary selenium negatively correlated with SA (r = -0.331, P = .030) and triacylglycerol levels (r = -0.312, P = .041). It can be concluded that a relationship of SA, an inflammatory marker, with metabolic syndrome features such as lipid profile impairment and insulin resistance has been envisaged. In addition, we report (apparently for the first time) a negative association between SA and selenium intake, a recognized antioxidant trace element, in healthy young subjects, reinforcing the view of selenium as a potential anti-inflammatory nutrient.

Serum sialic acid, hs-CRP and oxidative stress parameters in obese children

BACKGROUND

Obesity is a common health problem that is rapidly increasing among children. Obesity is accompanied by a high incidence of atherosclerosis, arterial hypertension and type 2 diabetes mellitus. We tested the hypothesis that the risk for atherosclerosis may be increased in obese children and measured some risk factors for atherosclerosis.

PATIENTS AND METHODS

We determined sialic acid levels and investigated correlations with malondialdehyde (MDA), susceptibility to oxidation, total thiol concentrations, glucose and lipid profile in 39 obese (BMI 26.6 +/- 3.9) and 33 sex- and age-matched healthy children (BMI 15.9 +/- 1.7).

RESULTS

MDA concentrations, susceptibility to oxidation and hs-CRP were significantly higher in obese children than controls. Sialic acid and total thiol concentrations were higher in controls but this did not reach statistical significance. Total cholesterol, LDL-cholesterol and glucose concentrations were significantly higher in the obese group and there was a positive correlation between BMI and MDA, susceptibility to oxidation, hs-CRP and glucose concentrations, and a negative correlation between BMI and HDL-cholesterol. Although sialic acid levels were not different between the groups, they showed a correlation with hs-CRP.

CONCLUSIONS

A higher risk was found in obese children in relation to oxidative stress parameters, hs-CRP and lipid profile, and this risk showed a positive correlation with BMI. These results are important because children will encounter this increased risk for a longer time than adults, and taking care of obesity in childhood is especially important.

Percentage of body fat and plasma glucose predict plasma sialic acid concentration in type 2 diabetes mellitus

Circulating sialic acid is an independent risk factor for cardiovascular disease and is higher in people with type 2 diabetes mellitus. Sialic acid is associated with body mass index, but it is uncertain whether body fat contributes to the higher levels of sialic acid in type 2 diabetes mellitus. Therefore, we have investigated whether the higher levels of sialic acid observed in type 2 diabetes mellitus persist when controlling for fatness. Fasting plasma samples were collected from 24 individuals with type 2 diabetes mellitus and 24 controls. Percentage of body fat was measured by bioelectrical impedance. Plasma sialic acid was quantified by an enzymatic method. Plasma sialic acid was higher in the group with type 2 diabetes mellitus than controls (602 +/- 14 vs 545 +/- 14 mg/L, P = .007). Percentage of body fat was associated with plasma sialic acid concentration in both the control group (r = 0.481, P = .020) and the group with type 2 diabetes mellitus (r = 0.527, P = .007). Fasting glucose was also associated with plasma sialic acid in the group with type 2 diabetes mellitus (r = 0.700, P < .001). Adjustment for percentage of body fat accounted for the higher levels of sialic acid in type 2 diabetes mellitus. Using linear regression, 54.3% of the variation of plasma sialic acid was explained by percentage of body fat and glucose concentrations in the whole group. Seventy-four percent of sialic acid variation was explained by the same model in type 2 diabetes mellitus. In conclusion, this is the first study to show that percentage of body fat predicts plasma sialic acid concentration and contributes toward higher levels of sialic acid in type 2 diabetes mellitus.

Sialic acid: a novel marker of cardiovascular disease?

The global burden posed by cardiovascular disease (CVD), due to a rising incidence of known risk factors, underlines an urgent need to identify other potential risk factors. Sialic acid (SA), an abundant terminal monosaccharide of glycoconjugates, is a possible risk factor for CVD. Although large-scale epidemiological surveys have shown that serum total sialic acid (TSA) is positively associated with mortality from coronary artery disease (CAD) and stroke, studies investigating the correlation between serum TSA and the severity of atherosclerosis are conflicting. Clinical and epidemiological studies indicate that serum TSA is a marker of a sustained inflammatory response in CVD, rather than causal in nature. Data also indicates ethnic variation in baseline TSA. This article reviews current methods for determining serum TSA and evidence supporting serum TSA as a risk factor for CVD. Potential mechanisms for this role are examined. The use of serum TSA as a marker of atherosclerotic disease is evaluated.