Children and overweight people are important patient subgroups that are often under-represented in clinical literature. In a recent survey, readers of Nature Clinical Practice Nephrology requested more-frequent publication of articles discussing management issues specific to these subgroups. In this month's issue, several papers address this need.

A dearth of reliable data makes selecting the optimum point for transplantation in the course of a child's end-stage renal disease (ESRD) more of an art than a science. If the availability of donor organs were to be miraculously enhanced, would transplant physicians know how best to take advantage of the opportunity? Which clinical variables predict the temporal 'tipping point' between optimum outcome and graft failure? On page 312, Bradley Warady, from Children's Mercy Hospital in Kansas City, addresses these questions by commenting on a recent analysis of an antipodean database. Recipients aged 13 years at the time of transplantation were most likely to lose their graft in comparison with other children. Poor adherence to immunosuppressive regimens probably underlies this finding. For adolescents, in whom this behavioral quirk is unlikely to be overcome, optimum outcomes are achieved via pre-emptive transplantation with a kidney from a living donor.

Age at transplantation also has a marked impact on the growth of children with ESRD. In the early days of renal grafting, it was assumed that receipt of a functional organ would go some way to kickstarting growth, which is retarded during ESRD. Unfortunately, this promise has not been realized. In his Review on page 318, Richard Fine from Stony Brook University Medical Center discusses the factors that underlie post-transplantation growth retardation, and the steps that can be taken to overcome it.

IgA nephropathy often presents in childhood or late adolescence. The under-recognized familial forms of this disease are the subject of a Review by Ali Gharavi and colleagues on page 325. The authors discuss the progress that has been made towards identifying causative genetic factors, and outline the clinical patterns of hereditary IgA nephropathy.

Three articles in the journal this month focus on overweight patients. A Research Highlight on page 301 summarizes a recent report of the heightened risk of renal damage secondary to nephrolithiasis associated with bariatric surgery. Despite being safer than jejunoileal bypass procedures (which have been banned in the US), physicians should be aware that surgical interventions for weight loss in morbidly obese individuals, such as gastric banding and resection, increase the risk of stone formation in patients prone to this problem.

... there is no basis for indiscriminately encouraging obese patients waitlisted for kidney transplantation to dramatically reduce their body mass

In another Research Highlight, authors have waded through conflicting data on the benefits of reducing the BMI of obese candidates before kidney transplantation. There is evidence to indicate that weight loss increases the likelihood of death for patients on dialysis, so is the practice of recommending BMI reduction to overweight people on the transplant waiting list valid? In the study outlined on page 300, complex patterns of risk and benefit emerged when patients were stratified according to BMI, leading the analysts to conclude that there is no basis for indiscriminately encouraging obese patients waitlisted for kidney transplantation to dramatically reduce their body mass.

In a Practice Point on page 308, Arif Asif looks into why the prevalence of arteriovenous fistulas seems to be lower in obese maintenance hemodialysis patients than in their nonobese counterparts. In the paper on which he comments, the authors found no difference in rates of fistula creation between the two cohorts; however, obese patients had a markedly higher rate of secondary fistula failure. Dr Asif recommends that vascular mapping, fistula transposition and early postoperative evaluation, followed by timely salvage of dysfunctional fistulas, should be aggressively pursued in obese patients.