1. Prevalence of over- and under nutrition among Danish dialysis patients and historical
comparison with data form 1988
Abstract
Background: Protein-energy wasting (PEW) is a syndrome, defined by the International Society of
Renal Nutrition and Metabolism (ISRNM), describing the negative changes in body composition related
both to insufficient nutrient intake and general catabolism mediated by the systemic inflammation and
acidosis. PEW is strongly correlated with increased mortality risk and is highly prevalent among
patients in regular dialysis therapy. The prevalence however has not been investigated in Denmark since
1988 and it has been unclear whether nutritional status has improved over the last three decades.
Following the general population, there has been an increased prevalence of obesity among dialysis
patients. However, obesity does not excludes PEW as the inflammatory stress metabolic response still
contributes to wasting of endogenous proteins; a phenomenon labeled sarcopen obesity. Patients in
dialysis therapy are at high risk of poor nutritional status, often regardless of high total body mass.
Objectives: Primary it is sought to uncover the prevalence of over- and under nutrition as defined by
ISRNM and WHO, based on anthropometry and relevant biomarkers. When compared with prevalence
data from 1988 it is sought to shine light on whether there has been an improvement in nutritional
status. The prevalence of patients suffering from sarcopen obesity is investigated. Secondary it is
investigated whether there is sufficient correlation between fat mass measured with bioelectric
impedance analysis (BIA) and 4-site skin fold thickness (SFT), to see if they can be used independently
to assess body composition in clinical practice.
Methods: An observational descriptive cross-sectional study of the prevalence of PEW based on s-
albumin, BMI, mid-upper arm muscle area (cMAMA) and normalized protein catabolic rate (nPCR)
was carried out. Direct historical comparison with results from 1988 using a former diagnostic system
was performed. Based on total body fat, waist circumference and BMI/fat mass combination, the
prevalence of obesity was investigated and with PEW diagnosis. BIA and skin fold as an expression of
body fat percentage (BFP) was examined for covariance.
Results: 90 % of the population included agreed to participate per protocol (n = 79), for whom only
PEW, but not obesity, could be diagnosed. Of these, 30% were diagnosed with PEW, with no variation
between haemodialysis and peritoneal dialysis. 68 took part per protocol (PP), where both PEW and was
possible to diagnose. Of these, 21-72% were obese to varying degrees, depending on the criterion used,
with the greatest prevalence seen for BFP alone and for the combination of BFP and BMI. 20 % of the
obese segment, independent of the criterion used, also had PEW. By directly comparing results by
formerly used diagnostic criteria the nutritional status has significantly approved since 1988. There was
a significant difference in BFP measured by BIA and SFT. Statistically there was a degree of correlation
between the methods.
Conclusion: Based on consensus criteria defined by ISRNM, 30% suffered from PEW. Diagnostic
criteria taken into consideration, a high risk of a significant amount of false negatives is assumed,
hereby underestimating true prevalence. The uncertainties that lies with comparing recent results
directly with those of 1988, points towards inconclusive results for the historical comparison to tell
whether or not nutritional status has improved. Since dialysis patients are now older, it may be assumed
that age-related sarcopenia and other age-related conditions contribute to unfavorable conditions for
optimal nutritional status. Obesity is common among the patient group, but does not rule out PEW.