A systematic review of the determinants of seafood consumption.

Although seafood is considered to be an important part of a balanced diet, many national food consumption surveys suggest that seafood is not consumed in sufficient amounts. As consumers are moving to diversify their diet from animal-based protein, it is important to understand the factors influencing consumption of marine foods. This review aims to assess the characteristics of seafood consumers as well as the influences on seafood consumption in Europe, USA, Canada, Australia and New Zealand. Systematic search strategies were used to identify relevant journal articles from three electronic databases (PubMed, Web of Science and Embase). Three searches were carried out and identified 4405 unique publications from which 121 met the criteria for the review process. The reviewed studies revealed that seafood consumers were more likely to be older, more affluent and more physically active and were less likely to smoke compared with non-seafood consumers. Sex and BMI did not appear to have a directional association with seafood consumption. The most commonly reported barriers to seafood consumption were cost, followed by sensory or physical barriers, health and nutritional beliefs, habits, availability and cooking skills. The most commonly reported influences were beliefs about the contribution of seafood to health, environmental influences and personal preferences. Based on the findings of this review, future intervention strategies to increase seafood consumption may need to consider affordability and education in terms of health, nutrition and cooking skills. More research is needed to explore the effectiveness of specific interventions at increasing the consumption of seafood.

Folic acid levels in some food staples in Ireland are on the decline: implications for passive folic acid intakes?

BACKGROUND: Neural tube defects are largely preventable by the maternal periconceptual consumption of folic acid. The aim of this study was to examine the levels of synthetic folic acid in foods and the range of food stuffs with added folic acid available to consumers in Ireland at the current time. METHODS: Three audits of fortified foods available in supermarkets in the Republic of Ireland were conducted. Researchers visited supermarkets and obtained folic acid levels from nutrition labels in 2004, 2008 and 2013/4. Levels were compared using MS Excel. RESULTS: The profile of foods fortified with folic acid in 2013/4 has changed since 2004. The percentage of foods fortified with folic acid has decreased as has the level of added folic acid in some food staples, such as fat/dairy spreads. CONCLUSION: Bread, milk and spreads no longer contain as much folic acid as previously (2004 and 2008). This may contribute to a decrease in folate intake and therefore may contribute to an increase in NTD rates. Research on current blood concentrations of folate status markers is now warranted.

Quantifying consumer portion control practices. A cross-sectional study.

The use of portion control practices has rarely been quantified. The present study aimed to: (1) explore which portion control practices are actually used by the general population and their association with cognitive restraint, demographic background and general health interest (GHI), and (2) examine how the usage of portion control practices predicts the estimated consumption of an energy dense food (i.e. pizza). Twenty-two portion control practices were rated in terms of their frequency of use from 'never' to 'very often' by a representative sample of 1012 consumers from the island of Ireland. Three factors were extracted and named: measurement-strategy scale, eating-strategy scale, and purchasing-strategy scale. The eating-strategy scale score was the highest, while the measurement-strategy scale carried the lowest frequency score. For each strategy scale score, the strongest predictor was GHI, followed by gender. Having higher GHI and being female were independently associated with more frequent portion control. Both the eating-strategy scale score and the purchasing-strategy scale score were negatively associated with pizza portion size consumption estimates. In conclusion, while this study demonstrates that the reported use of portion control practices is low, the findings provide preliminary evidence for their validity. Further studies are needed to explore how portion control practices are used in different kinds of portion size decisions and what their contribution is to the intake of food over an extended period of time.

Dietary isoflavone intake is associated with evoked responses to inflammatory cardiometabolic stimuli and improved glucose homeostasis in healthy volunteers.

BACKGROUND AND AIMS: Consumption of foods that modulate inflammatory stress in genetically-prone individuals may influence development of cardiometabolic diseases. Isoflavones in soy-derived foods function as phytoestrogens, have antioxidant and anti-inflammatory activity, inhibit protein-tyrosine kinase activity, and may be atheroprotective. We examined the relationship between soy food consumption and inflammatory responses to endotoxemia, postprandial responses to oral lipid tolerance test (OLTT), and insulin sensitivity from frequently sampled intravenous tolerance tests (FSIGTT). METHODS AND RESULTS: We administered low-dose endotoxin (LPS 1 ng/kg) to induce transient endotoxemia in young, healthy volunteers (N = 215) of African (AA), and European (EA) ancestry as part of the GENE Study. We further supported these findings in two independent samples: the MECHE Study and NHANES. Soy food consumption was a significant predictor of peak cytokine response following LPS. Individuals with moderate-high (>1.48 mg/day, N = 65) vs. low-no (<1.48 mg/day, N = 150) isoflavone consumption had significantly higher tumor necrosis factor alpha (TNFα) post-LPS (AUC, P = 0.009). Further, high-isoflavone consumers were protected against inflammation-induced decline in insulin sensitivity (SI) in GENE. We observed significant differences by soy consumption in the interferon gamma (IFNγ) response to OLTT, and the insulin response to OGTT in MECHE, as well as significantly lower fasting insulin, and 2-hour glucose post-OGTT in EA NHANES subjects. CONCLUSION: We demonstrate that soy consumption may influence inflammatory and metabolic responses. In research of nutritional exposures, measuring evoked phenotypes may be more informative than describing resting characteristics. The GENE Study was registered under NCT00953667 and the MECHE Study under NCT01172951, both at clinicaltrials.gov.

Pregnant immigrant Nigerian women: an exploration of dietary intakes.

OBJECTIVE: The aim of the study is to explore the dietary intakes of a prominent ethnic minority group of women from Sub-Saharan Africa during pregnancy, in order to identify nutritional issues of concern which may impact on pregnancy outcomes and whether different food based dietary guidelines may be required to meet their needs. STUDY DESIGN: This is an observational study with quantitative assessment of nutrient intakes and an exploration of meal composition and food choices. METHODS: Fifty-two Nigerian pregnant women in their second or third trimester of pregnancy were recruited from antenatal clinics in the National Maternity Hospital, Dublin, Ireland. Early pregnancy weight was measured and body mass index recorded. A 24 h dietary recall was used to assess food and nutrient intakes. RESULTS: Eighty-nine per cent of the study population were classified as overweight or obese. These women appear to be maintaining traditional African dietary habits and have a healthy macronutrient composition in the diet. The intake of key pregnancy micronutrients such as calcium, vitamin D and folate may be insufficient from diet alone to meet requirements and supplements may be inadequately utilized in a timely manner. CONCLUSIONS: These women represent a vulnerable obstetric group that may be at risk of adverse pregnancy outcomes due to high obesity rates and inadequate micronutrient status in early pregnancy. Provision of dietary advice should be tailored to suit their cultural dietary practices and food preferences. Pre-conception counselling on healthy lifestyle and appropriate supplement usage may be beneficial, although larger studies are required to assess the need for specific nutrition policy recommendations.

Comparison of Meal Patterns Across Common Racial Groups in the UK and the USA, Examining Associations with Weight Status and Diet Quality: a Secondary Analysis of NDNS and NHANES Datasets.

OBJECTIVE: Understanding diets of population subgroups is essential for monitoring health of diversifying populations, but currently, meal patterns of many population subgroups are not widely known. This paper aimed to identify meal patterns of racial groups in the UK and USA, considering if racial groups exhibit similar patterns of intake irrespective of location and relationships between meal patterns and health parameters. DESIGN: Data were extracted from the UK (National Diet and Nutrition Survey) and the USA (National Health and Nutrition Examination Survey) national dietary surveys. Temporal and content meal patterns among racial groups in the UK and USA (White, Black, Asian and Other, n = 1780 and n = 4339, respectively) were examined. Kruskal-Wallis tests were applied to understand differences across groups. Logistic regression models identified associations between meal patterns and body mass index and diet quality. RESULTS: Black groups consumed fewer eating occasions than White and Other groups in both countries, while UK racial groups consumed significantly more snacks than USA groups. Food group contribution to eating occasion consumption was similar across countries where Asian groups in the USA and UK had the lowest meat intake at lunch and dinner. Meal frequency was positively associated with diet quality. CONCLUSIONS: Overall, meal patterns differ across racial groups within a single country, and some differences were observed within groups of the same race across countries. Learnings from this research highlight the differences in consumption patterns across racial groups and the importance of considering a meal-based approach to dietary guidelines by racial group.

Maternal nutrition among women from Sub-Saharan Africa, with a focus on Nigeria, and potential implications for pregnancy outcomes among immigrant populations in developed countries.

Pregnant women in countries of Sub-Saharan Africa (SSA) are at risk of poor nutritional status and adverse outcomes as a result of poverty, food insecurity, sub-optimal healthcare facilities, frequent infections and frequent pregnancies. Studies from Nigeria, for example, have revealed a high prevalence of both under- and over-nutrition, as well as nutrient deficiencies, including iron, folate, vitamin D and vitamin A. Subsequently, obstetric complications, including hypertension, anaemia, neural tube defects, night-blindness, low birth weight and maternal and perinatal mortality, are common. Migration patterns from SSA to the Western world are on the rise in recent years, with Nigerians now representing the most prevalent immigrant African population in many developed countries. However, the effect of immigration, if any, on the nutritional status and pregnancy outcomes of these women in their host countries has not yet been studied. Consequently, it is unknown to what extent the nutritional deficiencies and pregnancy complications occurring in Nigeria, and other countries of SSA, present in these women post-emigration. This may result in missed opportunities for appropriate antenatal care of a potential high-risk group in pregnancy. The present review discusses the literature regarding nutrition in pregnancy among SSA women, using Nigeria as an example, the common nutrition-related complications that arise and the subsequent obstetric outcomes. The concept of dietary acculturation among immigrant groups is also discussed and deficiencies in the literature regarding studies on the diets of pregnant immigrant women are highlighted.

Genetic and environmental influences on serum oxylipins, endocannabinoids, bile acids and steroids.

Lipid bioactivity is a result of direct action and the action of lipid mediators including oxylipins, endocannabinoids, bile acids and steroids. Understanding the factors contributing to biological variation in lipid mediators may inform future approaches to understand and treat complex metabolic diseases. This research aims to determine the contribution of genetic and environmental influences on lipid mediators involved in the regulation of inflammation and energy metabolism. This study recruited 138 monozygotic (MZ) and dizygotic (DZ) twins aged 18-65 years and measured serum oxylipins, endocannabinoids, bile acids and steroids using liquid chromatography mass-spectrometry (LC-MS). In this classic twin design, the similarities and differences between MZ and DZ twins are modelled to estimate the contribution of genetic and environmental influences to variation in lipid mediators. Heritable lipid mediators included the 12-lipoxygenase products 12-hydroxyeicosatetraenoic acid [0.70 (95% CI: 0.12,0.82)], 12-hydroxyeicosatetraenoic acid [0.73 (95% CI: 0.30,0.83)] and 14­hydroxy-docosahexaenoic acid [0.51 (95% CI: 0.07,0.71)], along with the endocannabinoid docosahexaenoy-lethanolamide [0.52 (95% CI: 0.15,0.72)]. For others such as 13-hydroxyoctadecatrienoic acid and lithocholic acid the contribution of environment to variation was stronger. With increased understanding of lipid mediator functions in health, it is important to understand the factors contributing to their variance. This study provides a comprehensive analysis of lipid mediators and extends pre-existing knowledge of the genetic and environmental influences on the human lipidome.

Use of the cellular model of body composition to describe changes in body water compartments after total fasting, very low calorie diet and low calorie diet in obese men.

INTRODUCTION: The cellular model of body composition divides the body in body cell mass (BCM), extracellular solids and extracellular fluids. This model has been infrequently applied for the evaluation of weight loss (WL) programmes. OBJECTIVES: (1) To assess changes in body compartments in obese men undergoing fasting, very low calorie diet (VLCD) and low calorie diet (LCD); (2) to evaluate two cellular models for the determination of changes in BCM, fat mass (FM) and body fluids. MATERIALS AND METHODS: Three groups of six, obese men participated in a total fast (F) for 6 days, a VLCD (2.5 MJ per day) for 3 weeks or an LCD (5.2 MJ per day) for 6 weeks. Body composition was measured at baseline and after small ( approximately 5%) and moderate ( approximately 10%) WL. FM was measured using a four-compartment model. Total body water (TBW) and extracellular water (ECW) were, respectively, measured by deuterium and sodium bromide dilution and intracellular water (ICW) calculated by difference. Two cellular models were used to measure BCM, FM and body fluids distribution. RESULTS: After about 5%WL changes in TBW were F=-3.2+/-1.2 kg (P<0.01), VLCD=-1.2+/-0.6 kg (P<0.01), LCD=-0.3+/-0.9 kg(n.s.). The contribution of TBW to total body mass loss was indirectly associated with FM loss. ECW increased during fasting (+1.5+/-3.1 kg, n.s.), decreased during the VLCD (-2.0+/-1.5 kg, P<0.05) and remained unchanged at the end of the LCD (-0.3+/-1.6 kg, n.s.). ICW significantly decreased during fasting (-4.7+/-3.9 kg, P<0.05) but did not change in the LCD and VLCD groups. The loss of BCM was more significant in the fasting group and it was directly associated with changes in ICW. CONCLUSIONS: After a 6-day period of fasting we observed more ICW losses and less fat mobilization compared with VLCD and LCD. The cellular model of body composition is suitable for the characterization of changes in body fluids distribution during WL.

Epigenetics and gene expression.

Transcription, translation and subsequent protein modification represent the transfer of genetic information from the archival copy of DNA to the short-lived messenger RNA, usually with subsequent production of protein. Although all cells in an organism contain essentially the same DNA, cell types and functions differ because of qualitative and quantitative differences in their gene expression. Thus, control of gene expression is at the heart of differentiation and development. Epigenetic processes, including DNA methylation, histone modification and various RNA-mediated processes, are thought to influence gene expression chiefly at the level of transcription; however, other steps in the process (for example, translation) may also be regulated epigenetically. The following paper will outline the role epigenetics is believed to have in influencing gene expression.

Embryonic avian cornea contains layers of collagen with greater than average stability.

A unique morphological feature of the embryonic avian cornea is the uniformity of its complement of striated collagen fibrils, each of which has a diameter of 25 nm. We have asked whether this apparent morphological uniformity also reflects an inherent uniformity of the structural and physical properties of these fibrils. For this we have examined the in situ thermal stability of the type I collagen within these fibrils. Corneal tissue sections were reacted at progressively higher temperatures with conformation-dependent monoclonal antibodies directed against the triple-helical domain of the type I collagen molecule. These studies show that the cornea contains layers of collagen fibrils with greater than average stability. The two most prominent of these extend uninterrupted across the entire width of the cornea, and then appear to insert into thick bundles of scleral collagen, which in turn appear to insert into the scleral ossicles, a ring of bony plates which circumscribe the sclera of the avian eye. Once formed, the bands may act to stabilize the shape of the cornea or, conversely, to alter it during accommodation.

Thermal stability of the helical structure of type IV collagen within basement membranes in situ: determination with a conformation-dependent monoclonal antibody.

To examine the thermal stability of the helical structure of type IV collagen within basement membranes in situ, we have employed indirect immunofluorescence histochemistry performed at progressively higher temperatures using a conformation-dependent antibody, IV-IA8. We previously observed by competition enzyme-linked immunosorbent assay that, in neutral solution, the helical epitope to which this antibody binds undergoes thermal denaturation over the range of 37-40 degrees C. In the present study, we have reacted unfixed cryostat tissue sections with this antibody at successively higher temperatures. We have operationally defined denaturation as the point at which type IV-specific fluorescence is no longer detectable. Under these conditions, the in situ denaturation temperature of this epitope in most basement membranes is 50-55 degrees C. In capillaries and some other small blood vessels the fluorescent signal is still clearly detectable at 60 degrees C, the highest temperature at which we can confidently use this technique. We conclude that the stability of the helical structure of type IV collagen within a basement membrane is considerably greater than it is in solution, and that conformation-dependent monoclonal antibodies can be useful probes for investigations of molecular structure in situ.

Domain and basement membrane specificity of a monoclonal antibody against chicken type IV collagen.

A monoclonal antibody, IV-IA8, generated against chicken type IV collagen has been characterized and shown to bind specifically to a conformational-dependent site within a major, triple helical domain of the type IV molecule. Immunohistochemical localization of the antigenic determinant with IV-IA8 revealed that the basement membranes of a variety of chick tissues were stained but that the basement membrane of the corneal epithelium showed little, if any, staining. Thus, basement membranes may differ in their content of type IV collagen, or in the way in which it is assembled. The specificity of the antibody was determined by inhibition ELISA using purified collagen types I-V and three purified molecular domains of chick type IV collagen ([F1]2F2, F3, and 7S) as inhibitors. Only unfractionated type IV collagen and the (F1)2F2 domain bound the antibody. Antibody binding was destroyed by thermal denaturation of the collagen, the loss occurring at a temperature similar to that at which previous optical rotatory dispersion studies had shown melting of the triple helical structure of (F1)2F2. Such domain-specific monoclonal antibodies should prove to be useful probes in studies involving immunological dissection of the type IV collagen molecule, its assembly within basement membranes, and changes in its distribution during normal development and in disease.

Type V collagen: molecular structure and fibrillar organization of the chicken alpha 1(V) NH2-terminal domain, a putative regulator of corneal fibrillogenesis.

Previous work from our laboratories has demonstrated that: (a) the striated collagen fibrils of the corneal stroma are heterotypic structures composed of type V collagen molecules coassembled along with those of type I collagen, (b) the high content of type V collagen within the corneal collagen fibrils is one factor responsible for the small, uniform fibrillar diameter (25 nm) characteristic of this tissue, (c) the completely processed form of type V collagen found within tissues retains a large noncollagenous region, termed the NH2-terminal domain, at the amino end of its alpha 1 chain, and (d) the NH2-terminal domain may contain at least some of the information for the observed regulation of fibril diameters. In the present investigation we have employed polyclonal antibodies against the retained NH2-terminal domain of the alpha 1(V) chain for immunohistochemical studies of embryonic avian corneas and for immunoscreening a chicken cDNA library. When combined with cDNA sequencing and molecular rotary shadowing, these approaches provide information on the molecular structure of the retained NH2-terminal domain as well as how this domain might function in the regulation of fibrillar structure. In immunofluorescence and immunoelectron microscopy analyses, the antibodies against the NH2-terminal domain react with type V molecules present within mature heterotypic fibrils of the corneal stroma. Thus, epitopes within at least a portion of this domain are exposed on the fibril surface. This is in marked contrast to mAbs which we have previously characterized as being directed against epitopes located in the major triple helical domain of the type V molecule. The helical epitopes recognized by these antibodies are antigenically masked on type V molecules that have been assembled into fibrils. Sequencing of the isolated cDNA clones has provided the conceptual amino acid sequence of the entire amino end of the alpha 1(V) procollagen chain. The sequence shows the location of what appear to be potential propeptidase cleavage sites. One of these, if preferentially used during processing of the type V procollagen molecule, can provide an explanation for the retention of the NH2-terminal domain in the completely processed molecule. The sequencing data also suggest that the NH2-terminal domain consists of several regions, providing a structure which fits well with that of the completely processed type V molecule as visualized by rotary shadowing.

Monoclonal antibodies against chicken type V collagen: production, specificity, and use for immunocytochemical localization in embryonic cornea and other organs.

Two monoclonal antibodies have been produced against chick type V collagen and shown to be highly specific for separate, conformational dependent determinants within this molecule. When used for immunocytochemical tissue localization, these antibodies show that a major site for the in situ deposition of type V is within the extracellular matrices of many dense connective tissues. In these, however, it is largely in a form unavailable to the antibodies, thus requiring a specific "unmasking" treatment to obtain successful immunocytochemical staining. The specificity of these two IgG antibodies was determined by inhibition ELISA, in which only type V and no other known collagen shows inhibition. In ELISA, mixtures of the two antibodies give an additive binding reaction to the collagen, suggesting that each is against a different antigenic determinant. That both antigenic determinants are conformational dependent, being either in, or closely associated with, the collagen helix is demonstrated by the loss of antibody binding to molecules that have been thermally denatured. The temperature at which this occurs, as assayed by inhibition ELISA, is very similar to that at which the collagen helix melts, as determined by optical rotation. This gives strong additional evidence that the antibodies are directed against the collagen. The antibodies were used for indirect immunofluorescence analyses of cryostat sections of corneas and other organs from 17 to 18-day-old chick embryos. Of all tissues examined only Bowman's membrane gave a strong staining reaction with cryostat sections of unfixed material. Staining in other areas of the cornea and in other tissues was very light or nonexistent. When, however, sections were pretreated with pepsin dissolved in dilute HAc or, surprisingly, with the dilute HAc itself dramatic new staining by the antibodies was observed in most tissues examined. The staining, which was specific for the anti-type V collagen antibodies, was largely confined to extracellular matrices of dense connective tissues. Experiments using protease inhibitors suggested that the "unmasking" did not involve proteolysis. We do not yet know the mechanism of this unmasking; however, one possibility is that the dilute acid causes swelling or conformational changes in a type-V collagen-containing supramolecular structure. Further studies should allow us to determine whether this is the case.

Upregulation of cytokines is detected in the placentas of cattle infected with Neospora caninum and is more marked early in gestation when fetal death is observed.

The protozoan parasite Neospora caninum causes fetal death after experimental infection of pregnant cattle in early gestation, but the fetus survives a similar infection in late gestation. An increase in Th1-type cytokines in the placenta in response to the presence of the parasite has been implicated as a contributory factor to fetal death due to immune-mediated pathological alterations. We measured, using real-time reverse transcription-PCR and enzyme-linked immunosorbent assay, the levels of cytokines in the placentas of cattle experimentally infected with N. caninum in early and late gestation. After infection in early gestation, fetal death occurred, and the levels of mRNA of both Th1 and Th2 cytokines, including interleukin-2 (IL-2), gamma interferon (IFN-gamma), IL-12p40, tumor necrosis factor alpha (TNF-alpha), IL-18, IL-10, and IL-4, were significantly (P < 0.01) increased by up to 1,000-fold. There was extensive placental necrosis and a corresponding infiltration of CD4(+) T cells and macrophages. IFN-gamma protein expression was also highly increased, and a modest increase in transforming growth factor beta was detected. A much smaller increase in the same cytokines and IFN-gamma protein expression, with minimal placental necrosis and inflammatory infiltration, occurred after N. caninum infection in late gestation when the fetuses survived. Comparison of cytokine mRNA levels in separated maternal and fetal placental tissue that showed maternal tissue was the major source of all cytokine mRNA except for IL-10 and TNF-alpha, which were similar in both maternal and fetal tissues. These results suggest that the magnitude of the cytokine response correlates with but is not necessarily the cause of fetal death and demonstrate that a polarized Th1 response was not evident in the placentas of N. caninum-infected cattle.

The extent of parasite-associated necrosis in the placenta and foetal tissues of cattle following Neospora caninum infection in early and late gestation correlates with foetal death.

The protozoan parasite Neospora caninum is the most frequently diagnosed abortifacient in the UK and a leading cause of abortion worldwide but the mechanisms leading to abortion are not fully understood. The distribution of parasites and the histopathological changes in the placenta and foetus were compared in 12 cows following experimental infection of cattle with N. caninum in early (n=6) and late (n=6) gestation, by PCR, immunohistology, light microscopy and transmission electron microscopy. Twelve uninfected pregnant cattle were used as controls. Infection in early gestation led to foetal death. In the placentae of cattle immediately following foetal death, N. caninum DNA was detected and there was evidence of widespread parasite dissemination. This was associated with extensive focal epithelial necrosis, serum leakage and moderate maternal interstitial mononuclear cell infiltration. In the foetuses, parasites were evident in all tissues examined and were associated with necrosis. In the placenta of cattle infected in late gestation, N. caninum DNA was detected sporadically but parasites were not evident immunohistologically. Small foci of necrosis were seen associated with mild interstitial mononuclear cell infiltration. Detection of N. caninum DNA in the foetuses was sporadic and parasites were demonstrated immunohistologically in brain and spinal cord only, with an associated mononuclear cell infiltration. This data is consistent with uncontrolled parasite spread in an immunologically immature foetus and could, via multiparenchymal necrosis of foetal tissues or the widespread necrosis and inflammation observed in the placenta, be the cause of Neospora-associated abortions.

Age, gender, race, and associations with kidney failure following living kidney donation.

INTRODUCTION: Our previous reports suggested that African Americans (AA) are more likely to develop end-stage renal disease (ESRD) following kidney donation when compared with white counterparts. We sought information on age, gender, and race of kidney donors to determine which groups were over-represented on the kidney transplant waiting list. METHODS: We queried the United Network for Organ Sharing United Network for Organ Sharing (UNOS) Organ Procurement Transplantation Network (OPTN) database for former donors who were subsequently placed on the kidney transplant waiting list. Information was retrieved on race, gender, age at donation, years between donation and listing, and diagnosis leading to ESRD. Comparisons were made to all kidney donors between 1988 and 2006 using chi-square testing. RESULTS: In this study, 126 individual kidney donors entered the kidney transplant waiting list. Fifty of the 126 (40%) were AA (P < .0001 compared with all donors, 13% AA). For both AA and whites, male donors and those who donated before age 35 made up a larger proportion of donors on the waiting list than would be expected by their proportion of overall donors. CONCLUSION: AA, males, and young donors may be at higher risk for kidney failure in the years following kidney donation. Mechanisms of increased risk are unclear but deserve further scrutiny. Our data are limited by the small number of patients developing kidney failure, the lack of complete follow-up on all living kidney donors, and the possibility that older donors with kidney failure were not listed because of death or other medical conditions. We believe that discussion of long-term risks may be different for various subgroups, especially for young AA kidney donors.