Sleep and activity in chronic kidney disease: a longitudinal study

Abstract

Background and objectives: Commonly sleep is disrupted and physical activity is restricted among patients with CKD and those on long-term dialysis. However, few studies have assessed patients longitudinally.

Design, setting, participants, & measurements: We compared the prevalence of sleep disturbances measured both subjectively using a questionnaire and objectively using actimetry among patients with CKD (n = 145), those on hemodialysis (n = 116), and people without kidney disease (n = 19). Activity level during the day was measured using actimetry, and patients were then followed for up to 2 years.

Results: Compared with people without kidney disease, patients with CKD not on dialysis had disruption of sleep that was independent of several risk factors. However, disrupted sleep was correlated with neither estimated GFR in cross-sectional nor longitudinal assessment. Those on hemodialysis had sleep disruption that was of much greater severity than that found among those with CKD not on dialysis. Furthermore, missing or shortening the prescribed duration of dialysis was associated with greater severity of sleep disturbance in cross-sectional but not in longitudinal assessment. Day-time activity declined both in duration and intensity from controls to CKD to hemodialysis.

Conclusions: The loss of kidney function is related to both reduced duration and intensity of day time physical activity. Although patients with CKD have disrupted sleep, this is independent of estimated GFR. However, compared with those with CKD, dialysis patients have more severely disrupted sleep; this is related to missing dialysis. Thus, shortening patients' dialysis may reduce their sleep.

Figure 1.

The figure shows the levels of day-time activity by patient group. The raw minutes spent in each activity are shown on the left, and percentages are shown on the right. These values are adjusted for age, sex, race, body mass index, diabetes, and cardiovascular disease. The solid line represents the activity level of zero or rest; the dotted lines show increasing levels of activity. For both graphs (waking minutes and percentages of waking minutes), there was a significant group × activity level interaction (P < 0.0001). In other words, patients with CKD tended to rest more and were less physically active compared with controls. Patients on hemodialysis were the least physically active.