Biomarkers Of Nutritional Status Research Articles

Serum Albumin as Predictor of Nutritional Status in Patients with ESRD

Serum albumin is a widely used biomarker of nutritional status in patients with CKD; however, its usefulness is debated. This study investigated serum albumin and its correlation with several markers of nutritional status in incident and prevalent dialysis patients. In a cross sectional study, serum albumin (bromocresol purple), and other biochemical (serum creatinine), clinical (subjective global assessment [SGA]), anthropometric (handgrip strength, skinfold thicknesses), and densitometric (dual energy x-ray absorptiometry) markers of nutritional status were assessed in 458 incident (61% male; mean age 54 +/- 13 years; GFR, 6.6 +/-2.3 ml/min per 1.73 m(2); recruited 1994–2010) and 383 prevalent (56% male; mean age 62 +/- 14 years; recruited 1989–2004) dialysis patients. In incident patients: serum albumin was correlated with sex (beta = -0.13; P = 0.02), diabetes mellitus (beta = -0.18; P = 0.004), and urinary albumin excretion (beta = -0.42; P = 0.001) but less so with poor nutritional status (SGA score >1; beta = -0.19; P = 0.001). In prevalent patients, serum albumin was correlated with age (beta = -0.14; P = 0.05), high-sensitivity C-reactive protein (beta = -0.34; P = 0.001), diabetes mellitus (beta = -0.11; P = 0.04), and SGA score >1 (beta = -0.14; P = 0.003). In predicting nutritional status assessed by SGA and other markers, adding serum albumin to models that included age, sex, diabetes, and cardiovascular disease did not significantly increase explanatory power. In incident and prevalent dialysis patients,serum albumin correlates poorly with several markers of nutritional status. Thus, its value as a reliable marker of nutritional status in patients with ESRD is limited. In addition, the following inconsistencies between the main text and Tables 1 and 3 are also corrected as follows. (1) In Table 1, the GFR initially written as 6 +/- 3 ml/min per 1.73(2) should be corrected to 6.6 +/- 2.3 ml/min per 1.73(2). (2) On line 11 of page 1448, under the Clinical Correlates of Serum Albumin Concentration section describing the multiple regression models (Table 3), the P value was initially written as“serum albumin was associated with age (beta = -0.14; P = 0.05).” The P value should be corrected to have the same value as that given in Table 3 (beta = -0.14; P = 0.005. [corrected].

Biochemical markers of nutritional status and childhood malaria severity in Cameroon

To investigate the part played by undernutrition in malaria severity, some biomarkers of nutritional status were assessed in children with severe malarial anaemia (MA) and cerebral malaria (CM) in comparison with healthy children or those with uncomplicated malaria. Undernutrition was assessed using the weight-for-age Z score (WAZ). Retinol was determined by HPLC; lipid profile, Ca, Mg and albumin were determined by spectrophotometry. Severe and moderate undernutritions were more prevalent in children with MA and those with the combined symptoms of CM and MA, but not in those with CM alone. Some perturbations were noticed in the lipid profile, but most of the values remained within the normal ranges. The risk of vitamin A deficiency, as assessed by plasma retinol concentration, was noteworthy in children with severe malaria: 0.48 × 10(-6) and 0.50 × 10(-6) mol/l, respectively, in children with MA and CM (reference value: >0.7 × 10(-6) mol/l). A significant difference was obtained for retinol values after an ANOVA of all the groups (P = 0.0029), with the value in the MA group being significantly low than that in the control group (P < 0.05); likewise, a significant difference was obtained after comparison of all the groups for Mg and albumin (P = 0.0064 and 0.0082, respectively). Despite their low number (n 6), fatal cases of CM had a normal mean WAZ on admission, but low values of retinol, albumin and HDL:LDL ratio. Despite these associations, undernutrition itself did not appear to be a primary factor associated with fatal outcome.

Adjusting Serum Biomarker of Vitamin D Status for Within‐person Variation

Adjusting for within‐person variability (Sw2) is an important strategy in estimating prevalence for nutritional biomarkers. Using replicate biomarker data from the NHANES III (NH3) we computed the Sw2 for serum 25‐hydroxyvitamin D (25OHD) &amp; serum total cholesterol (TC) for the DRI age &amp; sex groups. Overall the ratio of within to between‐person ( Sb2) variation for 25OHD was about 0.2, a low value, while that for TC was very similar, i.e. ≈ 0.25. Age‐Sex specific Sw2 estimates for those biomarkers were then applied to the corresponding groups to adjust NH3 &amp; NHANES 2001–2006 (NH01‐06) data for ages 12 +y. Adjusting for Sw2 had an impact on the estimates of the % below cut‐points for 25(OH)D but not for TC. For 25(OH)D the % &lt; 27.5 nmol/L before &amp; after adjustment in NH3 &amp; NH01‐06 were &lt;4% to 1% &amp; about 7% to &lt;4%, respectively. The decrease in % &lt; than selected cut‐points after adjustment for Sw2 diminished steadily with increasing level of 25(OH)D so that approximately no difference was found for the % &lt; 50 nmol/L &amp; the % &lt; 75nmol/L increased after adjustment. The results indicate that regardless of the size of the Sw2, it is important to assess its impact on prevalence estimates in biomarkers of nutritional status.

The Use of Prealbumin Concentration as a Biomarker of Nutritional Status in Treated Phenylketonuric Patients

Background/Aims: The neurological sequelae resulting from untreated phenylketonuria are diminished by the success of early introduced and continued dietary treatment. Nowadays, nutritional status is gaining importance in the follow-up of these patients. The aim of this work was to study the relevance of prealbumin concentration as biomarker of protein nutritional status of phenylketonuric patients. Methods: We collected data from 69 phenylketonuric patients on food intake, blood prealbumin and blood phenylalanine concentrations. Protein insufficiency was defined as prealbumin z-scores below the 5th percentile of reference population. Additionally, we considered a prealbumin concentration of 20 mg/dl as a threshold level. Results: Nine patients (13%) showed signs of protein insufficiency. When the threshold of 20 mg/dl for prealbumin was used, we found 38 patients (55%) with low prealbumin concentrations. Conclusion: A significant group presented signs of protein insufficiency either using prealbumin z-scores or prealbumin concentration threshold, especially in milder forms of the disease. The results of this seem to confirm the already described threshold level for prealbumin concentration, suggesting that its measurement may be important for nutritional status evaluation, preventing protein insufficiency in milder forms of phenylketonuria.

Probiotics and Natural Defense Function of the Host

The natural defense systems of animals, including humans, have been developed to maintain the hosts' health by fighting exogenous microbes. Immune systems, which have functions to recognize and keep out exogenous organisms, play a central role in the host defense systems. Intestinal microflora, mainly composed of commensal bacteria, also provide defense functions called colonization resistance to keep out exogenous bacteria. We have been investigating probiotic strains Lactobacillus johnsonii Lal (NCC533) and Bifidobacterium animalis subspp. lactis Bb-12 to elucidate the efficacy of these probiotic strains in strengthening the natural defense system of the host and their potential for risk reduction of infections as an end point benefit. Feeding trials using fermented milk with L. johnsonii Lal (LC1®) showed that intestinal microflora were improved and blood phagocytic activity, a biomarker for natural immunity, increased in healthy adults. In a feeding trial of LC1 in the elderly, we found that the frequency of infection was reduced by administration of the probiotics. In the LCl-fed elderly, blood phagocytic activity increased, and serum TNF-α, an inflammation biomarker, was lowered. Serum albumin, a biomarker for nutritional status, also increased in the LCl-fed elderly, suggesting that probiotic feeding may contribute to regulation of infection through immune system modulation, activation of immunity and suppression of inflammation, and nutritional status improvement. The Lal strain was shown to stimulate the parasympathetic nerve system in vivo, implying that anabolic action might contribute to nutritional status improvement. An anti-inflammatory effect of the Lal strain was also observed in the animal studies using colitis, Helicobacter pylori-infection, and atopic dermatitis models, and a human study in pollen allergy patients. Feeding of the Bb-12 strain in weaning children improved intestinal microflora and increased intestinal IgA production. Probiotics such as L. johnsonii Lal and Bifidobacterium Bb-12 could play a significant role in improving the QOL of human beings through strengthening the natural defense systems of the host. In this paper, we review and discuss our recent work with references to other research.

Nutritional assessment of independent‐living older adults in central North Carolina

Older adults have increased risk for nutrition deficiencies. Nutritional inadequacy in older adults is associated with increased rates of depression. Assessments of dietary intake, depressive state, and biomarkers of nutritional status were conducted among independent-living older adults in central North Carolina (NC). A convenience sample of older adults provided blood samples and were interviewed for health status (N = 85; age = 74 ± 6.9; 21% male; 79% female; 29% African American (AA); 71% Caucasian (C)). A self-conducted food frequency questionnaire was used to evaluate dietary intake. Depression was determined using the Geriatric Depression Scale (19% depressed). Depressive state was significant by race (p =.05; AA > C). Blood samples were analyzed and categorized for optimal levels of total cholesterol (<200 mg/dL), triglycerides (<150 mg/dL), HDL (> 40 mg/dL), and LDL (<100 mg/dL). Overall, 78% met recommendations for triglycerides and 93% for HDL. Significant differences were found by gender for both total cholesterol and LDL (p =.05; males > females). Nearly 60% met recommendations for percent of total kcal from total fat (20–35%) and saturated fat (<10%). All subjects met minimum guidelines for blood vitamin B12 and folate levels. These findings suggest low rates of depression, but overall adequacy in selected indicators of nutritional status of independent-living older adults in central NC. Supported in part by NC Agriculture Research Services.

Influence of Nutritional Recovery on the Leptin Axis in Severely Malnourished Children

Leptin might be more important as a starvation hormone than as a satiety signal. The role of the soluble leptin receptor (sOB-R) and its regulation in children with protein energy malnutrition (PEM) is poorly understood. We elucidated the effect of intensive nutritional support on the leptin axis in 26 severely malnourished toddlers who received infant milk-based formula for 2 wk via continuous enteral tube feeding followed by 2 wk ad libitum feeding. Serum levels of leptin, sOB-R, IGF-I, and IGF-binding protein-3 as well as anthropometric measurements were determined at the beginning of the study and at 2-wk intervals. The control group consisted of 13 well-nourished children. The following were changes in the PEM toddlers after the nutritional support. Leptin increased significantly (P < 0.001), reaching 166% of levels observed in control group. sOB-R decreased significantly (P < 0.001), and a 142-fold molar excess of sOB-R over leptin was found. There were significant correlations between leptin and IGF-I after 2 wk and IGF-binding protein-3 during the whole study. sOB-R was not correlated with any anthropometric data, whereas IGF-I was a predictor of sOB-R variance in the PEM toddlers (19.9%, P = 0.022). It can be concluded that sOB-R has a modulatory effect on leptin in PEM children during nutritional recovery and participates in their adaptive survival mechanisms. Leptin and the molar excess of sOB-R over leptin are better biomarkers of nutritional status than IGF-I in PEM children during nutritional recovery.

Micronutrients in childhood and the influence of subclinical inflammation

In the present paper biomarkers of micronutrient status in childhood and some of the factors influencing them, mainly dietary intake, requirements and inflammation will be examined. On a body-weight basis the micronutrient requirements of children are mostly higher than those of an adult, but most biomarkers of status are not age-related. A major factor that is often overlooked in assessing status is the influence of subclinical inflammation on micronutrient biomarkers. In younger children particularly the immune system is still developing and there is a higher frequency of sickness than in adults. The inflammatory response rapidly influences the concentration in the blood of several important micronutrients such as vitamin A, Fe and Zn, even in the first 24 h, whereas dietary deficiencies can be envisaged as having a more gradual effect on biomarkers of nutritional status. The rapid response to infection may be for protective reasons, i.e. conservation of reserves, or by placing demands on those reserves to mount an effective immune response. However, because there is a high prevalence of disease in many developing countries, an apparently-healthy child may well be at the incubation stage or convalescing when blood is taken for nutritional assessment and the concentration of certain micronutrient biomarkers will not give a true indication of status. Most biomarkers influenced by inflammation are known, but often they are used because they are convenient or cheap and the influence of subclinical inflammation is either ignored or overlooked. The objective of the present paper is to discuss: (1) some of the important micronutrient deficiencies in childhood influenced by inflammation; (2) ways of correcting the interference from inflammation.

Transthyretin, a Biomarker for Nutritional Status and Ovarian Cancer

Transthyretin, a Biomarker for Nutritional Status and Ovarian Cancer

Glutathione Peroxidase, Selenoprotein P and Selenium in Serum of Elderly Subjects in Relation to Other Biomarkers of Nutritional Status and Food Intake

The relation of the intake of selenium and different food groups to serum levels of selenium, glutathione peroxidase and selenoprotein P, and urinary selenium was studied in 50- to 69-year-old subjects (101 men, 105 women). Blood was sampled six times during the course of 1 year, and during the same time the subjects performed six 3-day weighed dietary records. The concentration of glutathione peroxidase in serum was higher among men (4.3 (0.74) mg/L) (mean (SD)) than among women (4.0 (0.76) mg/L, P < 0.03), whereas men had lower serum selenium (1.10 (0.17) μmol/L) vs. 1.17 (0.19) μmol/L, P < 0.01). The intake of selenium among men was calculated to be 36 (18–54) μg/day and among women 29 (13–48) μg/day (geometric means (90% central range)), but there was no significant gender difference when the selenium intake was corrected for energy intake. No difference between men and women was observed for serum selenoprotein P (1.47 (0.25) a.u. versus 1.47 (0.24) a.u. (mean(SD)) or urinary selenium excretion (0.31 (0.09) μmol/d vs. 0.27 (0.08) μmol/d). Serum selenium was significantly associated with selenoprotein P in both sexes but with glutathione peroxidase only in men. Serum selenium had a marked association with urinary selenium excretion. Selenium intake was significantly associated with serum selenium in men, and with selenoprotein P and urinary selenium in women. Among 11 major food groups, the intakes of fish and milk products were significantly associated with biomarkers of selenium status among women. Calculation of the association between biomarkers of selenium status and variables on intake and serum content of nutrients using multiple regression analysis resulted in most cases in low explanatory power. The variables most consistently related to more than one variable of selenium status were serum levels of retinol, α-tocopherol and eicosapentaenoic acid, and intake of protein. The study shows that individual biomarkers of selenium status are associated differently to variables on dietary intake and nutritional status.