Is nutritional status associated with self-reported sleep quality in the HEMO study cohort?

OBJECTIVES

To explore the relationship between sleep quality and common measures of nutritional status in the Hemodialysis (HEMO) Study cohort. To investigate sleep quality scores based on longitudinal changes in measures of nutritional status, adjusting for case mix, lifestyle, and comorbidity factors.

DESIGN

Secondary analysis of the HEMO Study data.

SETTING

A 7-year, prospective, multicenter, randomized clinical trial in maintenance hemodialysis patients.

PATIENTS

Eighteen hundred forty-six patients aged between 18 and 80 years were randomized; 1,803 (97.7%) completed the Kidney Disease Quality of Life Long Form (KDQOL-LF) at baseline. Mean age was 58 years, 44% were male, 64% were Black, 37% had diabetes, and 32% had hypertension; mean duration of dialysis was 3.8 years.

MAIN OUTCOME MEASURES

The univariate and multivariate relationships of measures of nutritional status (i.e., serum albumin, serum creatinine, postdialysis weight, body mass index, dietary protein and energy intake, and assessment of appetite) and sleep quality assessed using the sleep subscale from the KDQOL-LF.

RESULTS

In univariate analysis, sleep quality score decreased significantly in a linear fashion as appetite rating decreased from very good to very poor on both dialysis days (63.6 ± 21.8 to 43.6 ± 22.9, P < .0001) and nondialysis days (63.2 ± 21.6 to 40.7 ± 25.7, P < .0001), with higher scores reflecting better sleep quality. In multivariable analysis, serum creatinine was the only laboratory variable that was significantly associated with sleep quality score (β = 0.49, P = .0004). Poorer appetite on both dialysis days (β = -1.5, P < .0001) and nondialysis days (β = -1.7, P < .0001) was associated with poor sleep quality.

CONCLUSIONS

Self-reported sleep quality was associated with appetite and serum creatinine. A simple questionnaire to assess sleep disorders in dialysis patients should be administered routinely to detect those patients at risk of sleep complaints. However, further studies are needed to determine whether improving sleep quality, directly or indirectly, would improve morbidity and mortality.