Biopsychosocial correlates of persistent somatic symptoms in patients with chronic kidney disease – results of the Hamburg City Health Study (HCHS)

Abstract

Persistent somatic symptoms (PSS) in patients with chronic kidney disease (CKD) are present in all stages and influence the patients' quality of life, morbidity and mortality. Aim of this study was to unravel interactions between biopsychosocial factors and symptom burden in patients with CKD. This cross-sectional study analysed individuals with impaired renal function (GFR <60 mL/min/1,73 m2) out of the first cohort (10,000 individuals) of the epidemiological Hamburg City Health Study (HCHS). As primary outcome somatic symptom burden (PHQ-15) was analysed. As potential correlates, biological (e.g., renal function, comorbidities), psychological (e.g., depression, anxiety, quality of life), and sociodemographic factors were analysed in a multivariate prediction model. Of the cohort, 588 participants (5,9%) had a reduced GFR. Of these, only 159 (27%) were aware of their renal dysfunction. Individuals with reduced GFR reported higher symptom burden compared to healthy controls (mean PHQ-15 (SD): 4,8 (3,9) vs. 5,4 (4,0), p = 0,002, Cohen's d = 0.15). In individuals with reduced kidney function higher symptom burden correlated with reduced GFR ( r = −0.17, p < 0.001). In the multivariate prediction model, GFR was not correlated with symptom burden, which was predicted by depressive symptoms, self-reported coronary heart disease and quality of life. This shows that symptom burden is only marginally related to renal function, while other biopsychosocial factors might play a more important role. Therefore, it is important to take a biopsychosocial perspective on PSS in CKD.