Leptin a new biological marker for evaluating malnutrition in elderly patients

BACKGROUND: There is no single universally accepted biochemical marker of nutritional status in the elderly. Many markers are affected by non-nutritional factors. OBJECTIVE: The purpose of this study was to determine the biological parameters best related to anthropometric markers of malnutrition in an elderly polypathological population, and determine cutoff values for these potential parameters to diagnose malnutrition. DESIGN: This prospective study enrolled 116 elderly hospitalized patients and 76 elderly outpatients. Nutritional status (albumin, transthyretin, body mass index (BMI), skinfold thickness) and biological parameters (leptin, insulin-like growth factor-1 (IGF-1), IGF binding protein-1 (IGFBP-1), IGFBP-3, C-reactive protein (CRP), orosomucoid) were assessed. We defined malnutrition according to the lowest quartile of BMI and skinfold thickness measured in a large healthy elderly French sample population. RESULTS: In this sample of elderly patients (age: 85+/-7 years old), leptin concentration was the only biological parameter significantly related to nutrition status. Independent correlations were found between leptin concentration and BMI, skinfold thickness and sex. The relationship between nutritional status and leptin concentration is significantly different in each sex: the more the patients are undernourished, the lower the leptin concentration in both sexes. The optimal leptin cutoff value for the diagnosis of malnutrition in this population was 4 microg/l in men (sensitivity 0.89, specificity 0.82) and 6.48 microg/l in women (sensitivity 0.90, specificity 0.83). CONCLUSION: Leptin concentration is highly correlated with anthropometric data whereas albumin or transthyretin are known to be also influenced by morbidity and inflammatory conditions. Serum leptin concentration could be used for nutritional assessment in elderly patients with acute diseases.     

子宫内膜异位症患者外周血清细胞因子标志物的筛选研究

目的:探讨血清细胞因子作为诊断子宫内膜异位症标志物的可能性。方法:随机选择行腹腔镜手术患者125例,按病理学分为EMS组62例和对照组(非EMS)63例,后者为盆腔无病理改变的不孕患者,术前抽取外周静脉血,采用Bio-Plex悬浮蛋白芯片系统检测血清细胞因子浓度。结果:两组中IL-6、MCP-1、INF-γ血清浓度差异有统计学意义(P<0.01),而IL-8、VEGF、TNF-α血清浓度差异无统计学意义(P>0.05),IL-2、IL-10和IL-15血清浓度在两组中的值均低于检测下限;除了IL-8和INF-α血清浓度Ⅲ和Ⅳ期比Ⅰ和Ⅱ期稍高,其余细胞因子血清浓度均系Ⅲ和Ⅳ期比Ⅰ和Ⅱ期较低,但是两者差异均无统计学意义;所有血清细胞因子在不同月经周期的浓度差异均无统计学意义;多变量回归分析血清细胞因子中,在取界值2.1 pg/ml时,单项IL-6检测EMS的能力最强(P<0.05),IL-6的ROC曲线面积为73.21%,IL-6、MCP-1、INF-γ三者联合检测EMS的ROC曲线面积为73.55%,但两者的检测能力差别无统计学意义(P<0.01)。结论:EMS患者血清IL-6、MCP-1、INF-γ浓度较对照组高,血清IL-6浓度在2.1 pg/ml时具有良好的敏感度和特异度,可作为一种检测EMS患者的简便而重要的辅助诊断手段。     

Alcoholism and associated malnutrition in the elderly.

Although most free-living people over age 55 yr use alcohol occasionally, both the fraction of people drinking and the magnitude of individual alcohol consumption decrease with every decade of age. Overall, approximately 5% of drinkers over age 55 yr use alcohol at excessive levels, i.e., sufficient to interfere with health or social functioning. As age increases, the fraction of drinkers with alcohol-caused central nervous system disease and cirrhosis increases, indicating increased sensitivity to alcohol injury. Beyond age 70 yr, new-onset alcoholism is more common than long-standing alcoholism. Malnutrition in the elderly alcoholic person is rare; it usually is caused by multiple factors, including alcohol displacing nutrient-rich diet factors, disease, limited availability of food, or altered metabolism increasing nutrient requirement. The recognition of alcohol and malnutrition problems in the elderly is more difficult than in younger people.     

Warning signals for malnutrition in the elderly

Aging and disability are often assumed to coexist in Western society. Nevertheless, most elderly people live in noninstitutional settings. Monitoring and improving the nutritional integrity of the elderly could play a part in helping them remain healthy and independent. A community-based approach to the prevention of malnutrition in elderly people has been developed. This approach teaches warning signals for malnutrition to care providers who are in contact with elderly men and women. Care providers learn to recognize a group of circumstances (warning signals) that could have a negative impact on an elderly person's nutritional status. Examples of risk factors are given, and the interplay between risk factors and warning signals is discussed as well as their combined application. Practical steps for simple intervention are suggested. The dietitian is the nutrition educator and coordinator of this service.     

Low serum leptin serves as a biomarker of malnutrition in elderly patients

Anthropometric and classical biologic markers of malnutrition, such as serum albumin, are limited because they are influenced by nonnutritional factors. We propose that a biologic parameter that both predicts nutritional status and is unaffected by nonnutritional factors would facilitate the diagnosis of malnutrition in the elderly. This cross-sectional study included 179 randomized elderly patients. Nutritional status was assessed by the Mini-Nutritional Assessment (MNA) instrument; other end points included anthropometric measures and biologic parameters. Subjects were divided into 3 groups based on MNA-defined nutritional status, and end point means were compared using 2-way analyses of variance adjusted by sex. Correlations between the most accurate biologic marker in predicting malnutrition and other biologic and clinical variables were assessed using Pearson correlation test. Multiple linear regressions were then performed to relate the best biomarker of malnutrition to specific parameters. Finally, leptin levels that predict malnutrition were determined using receiver operating characteristic curve cutoff values. The well-nourished group had significantly higher leptin (P = .001), weight, body mass index, mid-arm circumference, and calf circumference (all, P < .001) compared with the malnourished group and the at risk of malnutrition group. Serum leptin was the optimal biomarker of MNA-defined malnutrition and had significant positive correlations with weight (P = .003) and with all anthropometric values (all P < .001), but no significant correlation with C-reactive protein. Sex, weight, and triglyceride were the best predictors of serum leptin (all P < .001). The optimal cutoff value of serum leptin to detect malnutrition was 4.3 ng/mL in men and 25.7 ng/mL in women. Serum leptin may be a good predictor of nutritional status in elderly patients.     

Relationship between malnutrition and falls in the elderly.

Due to the multifactorial nature of falls in the elderly population, it is difficult to determine causal relationships for risk factors for falls. In some cases, other risk factors may play a role. For example, the association between poor nutrition status and falls has not been studied extensively. The association of commonly demonstrated nutritional deficiencies in the elderly with factors such as balance, gait, and mobility may lead to new insights into causes of falls in the elderly not previously established. In this article, we review how malnutrition can be a risk factor for falls, how falls can induce malnutrition, and the possible relationship between mobility and nutrition in the elderly.     

Serum levels of phytoestrogens as biomarkers of intake in Mexican women

Abstract

Phytoestrogens have generated interest in human health in view of their potential effect to reduce the risk of developing chronic diseases. Serum levels of phytoestrogens have been proposed as an alternative to measure the exposure of phytoestrogens. We evaluated the use of serum as a biomarker of phytoestrogen’s intake in healthy women. Phytoestrogens in serum (luteolin, kaempferol, equol, biochanin A, formononetin, quercetin, naringenin, coumestrol, secoisolariciresinol, genistein, matairesinol, enterolactone, enterodiol, daidzein, glycitein and resveratrol) were analyzed by HPLC-ESI-MS. Subjects were asked to recall all foods and beverages consumed the previous 24 h. Association of dietary intake and serum concentrations was performed by Spearman correlation. Correlations were found for naringenin (r?=?0.47, p?<?0.001), luteolin (r?=?0.4 p?<?0.001), genistein (r?=?0.32, p?<?0.01) enterolactone (r?=?0.35, p?=?0.0553), coumestrol (r?=?0.26, p?=?0.0835) and resveratrol (r?=?0.29, p?=?0.0517). Serum levels as biomarkers of intake along with a 24-h recall would be useful in order to investigate the relationship between phytoestrogens and health.     

Unmetabolized VOCs in urine as biomarkers of low level exposure in indoor environments

This study aimed to test the possible use of unmetabolized volatile organic compounds (VOCs) in urine as biomarkers of low-level indoor environmental exposure. Twenty-four subjects in 13 dwellings in a prefecture of Japan participated in this study. Air samples of the breathing zone were collected in the living room and bedroom, along with spot urine samples (before bedtime and first morning voids). Toluene, ethylbenzene, xylene isomers, styrene and p-dichlorobenzene in the air and urine samples were measured by gas chromatography/mass spectrometry. For the 21 subjects without solvent exposure at work, there were significant correlations between the time-weighted average air concentrations in the bedroom and morning urinary concentrations for toluene, o-xylene, total xylene and p-dichlorobenzene (correlation coefficients of 0.54, 0.61, 0.56 and 0.84, respectively). Multiple linear regression analysis showed only air VOCs in the bedroom influenced the morning urinary VOC concentrations. We concluded that unmetabolized VOCs in the urine can provide a reliable biological indicator for air VOC exposures in non-occupational environments.     

Gases and organic solvents in urine as biomarkers of occupational exposure: a review

A brief review of urine analysis in studies of occupational exposure to volatile organic compounds and gases is provided. Analysis of exhaled breath for volatile compounds does not have a long history in occupational medicine. A number of studies has been undertaken since the 1980s, and the methods are well enough accepted to be put forward as biological equivalents of threshold limit values (TLVs) for some volatile organic compounds (VOCs) such as acetone; methanol; methyl ethyl ketone (MEK); methyl isobutyl ketone (MIBK); tetrahydrofurane; dichloromethane. In the last 20 years many scientific articles have shown that the urinary concentrations of unchanged solvents are correlated with environmental exposure and could be used for biological monitoring. The use of urine analysis of unchanged solvents in occupational applications is not yet widespread. Nonetheless, in the short time since its application, a number of important discoveries has been made, and the future appears bright for this branch of analysis. In this paper, the basic concepts and methodology of urine analysis are briefly presented with a critical revision of the literature on this matter. The excretion mechanisms of organic solvents in urine are discussed, with regard to biological variability, and the future directions of research are described.     

Malabsorption may contribute to malnutrition in the elderly

Malnutrition, either actually malnourished or at risk, is present in 80% of the elderly population presenting to hospital for admission. Although many factors contribute to this situation, one yet to be explored is malabsorption. We therefore aimed to assess nutritional status as well as the prevalence of altered mucosal permeability and celiac disease among a group of elderly patients presenting for rehabilitation. Forty-eight subjects were recruited (16 females) with a mean age of 83.7 (SD 6.1), body mass index 21.8 kg/m² (SD 3.9), mini-nutritional assessment (MNA) 19.5 (SD 3.4). They had no current gastrointestinal symptoms and undertook an assessment of mucosal permeability using the dual sugar absorption test of lactulose (7.5 g) and rhamnose (1 g). Ten of the 48 subjects had increased mucosal permeability with an L:R ration ranging from 0.0860 to 7.706 (N 0.01–0.08). These subjects were all at risk or malnourished according to the MNA score and they had a significantly lower mean MNA score of 17.2 (SD 3.5) compared to normal absorbers with a mean of 19.5 (SD 3.4). Two of the subjects had positive tissue trans-glutaminase antibodies. The higher risk of potential malabsorption in this elderly population has significant implications both for nutritional supplementation and for drug absorption as well as being a possible major contributor to malnutrition.     

Energy balance and malnutrition in institutionalized elderly people

Screening tools and more extensive assessment methods have signaled that malnutrition is common in institutionalized elderly. There are multiple factors - physiologic and non-physiologic - which hereby increase the risk of negative energy balance leading to weight loss and subsequent undesirable outcomes. Addressing this problem a number of controlled intervention studies have shown positive effects of 'simple' nutrition interventions in institutionalized older persons.     

Role of visceral proteins in detecting malnutrition in the elderly

OBJECTIVE: In the clinical practice, visceral proteins are used as indirect markers of protein energy malnutrition (PEM), but their reliability could be reduced with advancing age. The aim of this work is to investigate the reliability of albumin, prealbumin, retinol-binding protein (RBP) and transferrin in evaluating nutritional status in old patients and their relationship with fat-free mass (FFM). DESIGN: Cross-sectional study. SETTING: Padua, Italy. SUBJECTS: In 44 underweight (body mass index < 20 kg/m(2)) (66-97 years) and 69 normal weight or overweight elderly subjects (62-98 years), albumin, prealbumin, transferrin and RBP were determined in the plasma. Body composition and particularly FFM was obtained by dual X-ray absorptiometry. FFM was also expressed as FFM index (FFMI) calculated as FFM divided by height squared. Subjects affected by acute illnesses and inflammatory states were excluded. RESULTS: Albumin, prealbumin and RBP mean values were significantly lower in underweight subjects. No differences between two groups were found for transferrin. Albumin prealbumin and RBP resulted under the normal range in 55, 25 and 54% of underweight subjects, respectively. Transferrin's values were low in about 40% of underweight and normal weight subjects, respectively. In all subjects, FFMI shows a significant correlation with albumin (r: 0.52), prealbumin (r: 0.64) and RBP (r: 0.57). No correlation between FFMI and transferrin was found. CONCLUSIONS: Visceral proteins, except for transferrin, seem to be useful indexes in detecting malnutrition in the elderly; low values still in the normal range should also be carefully evaluated because they could suggest a poor nutritional status.     

Dietary intervention induces flow of changes within biomarkers of lipids, inflammation, liver enzymes, and glycemic control

ObjectiveTo determine how changes in lipids, liver enzymes, and inflammatory and glycemia markers intercorrelate during prolonged dietary intervention in obese participants with or without type 2 diabetes (T2D).MethodsWe examined the dynamics and intercorrelations among changes in biomarkers during the 2-y Dietary Intervention Randomized Controlled Trial (DIRECT) in 322 participants (including 46 with T2D; 52 y of age, body mass index 31 kg/m²) throughout rapid weight loss (0–6 mo) and weight-maintenance/regain (7–24 mo) phases.ResultsThe 2-y increase of high-density lipoprotein cholesterol was greater in participants with T2D (+9.41 versus+6.57 mg/dL, P < 0.05), although they tended to have smaller waist circumferences (?2.1 versus ?4.0 cm, P = 0.08). In models adjusted for age, sex, and weight loss, the 2-year decrease of triacylglycerols was associated with increases of low-density and high-density lipoprotein cholesterol. An increase of apolipoprotein A1 was associated with a decrease in high-sensitive C-reactive protein (P < 0.05 for all comparisons). Exclusively in participants with T2D, the 2-year decrease in triacylglycerols was further correlated with decreases in apolipoprotein B100 and liver enzymes, and a decrease in fasting glucose correlated with decreases in low-density lipoprotein cholesterol, apolipoprotein B100, and alanine aminotransferase (P < 0.05 for all comparisons). In the entire group, multivariate models adjusted for age, sex, intervention group, and 6-mo weight loss identified decreased high-sensitive C-reactive protein at 6 mo as an exclusive predictor of a greater decrease in triacylglycerols (β = 0.154, P = 0.008) and a greater increase in high-density lipoprotein cholesterol (β = ?0.452, P = 0.005) during the subsequent 18 mo.ConclusionsLong-term dietary intervention induces a flow of changes within biomarkers and the cross-talk is likely to be stronger in T2D. A decrease in systemic inflammation during the weight-loss phase may predict greater long-term improvement in lipids (www.ClinicalTrials.gov, identifier NCT00160108).