Clinical and psychological correlates of somatic symptoms in patients on dialysis.

Somatic symptoms are common in patients on dialysis. Their causes are largely unknown and their therapy is unsatisfactory. To examine the relationship of psychological and clinical factors to these symptoms, 191 interviews were done in patients on hemo- and peritoneal dialysis. The severity of 8 somatic symptoms (tiredness, sleep disturbance, cramps, pruritus, headache, nausea, dyspnea, joint pain) of importance in dialysis patients was measured using previously validated scales. Indices of affect and quality of life were obtained, as was demographic, clinical and laboratory information. The severity of each symptom was significantly related to the indices of affect and quality of life. Using multiple logistic regression, poor affect score was the strongest correlate of each of the following somatic symptoms, tiredness, pruritus, sleep disturbance and cramps. It was ahead of any clinical or demographic variable and was also significantly correlated with the severity of the other symptoms. Indices of hyperparathyroidism were significantly associated with headache, joint pain, dyspnea and nausea. We conclude that the strongest correlate of common somatic symptoms in dialysis patients is affect disturbance, and that therapy aimed at improving the affect may improve the symptoms.