[Falls and renal function: a dangerous association].
Falls are an important health problem and the risk of falling increases with age. The costs due to falls are related to the progressive decline of patients' clinical conditions, with functional inability inducing increasing social costs, morbidity and mortality. Renal dysfunction is mostly present in elderly people who often have several comorbidities. Risk factors for falls have been classified as intrinsic and extrinsic, and renal dysfunction is included among the former. Chronic kidney disease per se is an important risk factor for falls, and the risk correlates negatively with creatinine clearance. Vitamin D deficiency, dysfunction of muscles and bones, nerve degeneration, cognitive decline, electrolyte imbalance, anemia, and metabolic acidosis have been reported to be associated with falls. Falls seem to be very frequent in dialysis patients: 44% of subjects on hemodialysis fall at least once a year with a 1-year mortality due to fractures of 64%. Male sex, comorbidities, predialysis hypotension, and a history of previous falls are the main risk factors, together with events directly related to renal replacement therapy such as biocompatibility of the dialysis membrane, arrhythmias, fluid overload and length of dialysis treatment. Peripheral nerve degeneration and demyelination as well as altered nerve conduction resulting in muscular weakness and loss of peripheral sensitivity are frequent when the glomerular filtration rate is less than 12 mL/min. Moreover, depression and sleep disorders can also increase the risk of falls. Kidney function is an important parameter to consider when evaluating the risk of falls in the elderly, and the development of specific guidelines for preventing falls in the uremic population should be considered.