Low muscle mass, malnutrition, sarcopenia, and associations with survival in adults with cancer in the UK Biobank cohort

Abstract

Background: Low muscle mass (MM) is a common component of cancer-related malnutrition and sarcopenia, conditions that are all independently associated with an increased risk of mortality. This study aimed to (1) compare the prevalence of low MM, malnutrition, and sarcopenia and their association with survival in adults with cancer from the UK Biobank and (2) explore the influence of different allometric scaling (height [m² ] or body mass index [BMI]) on low MM estimates.

Methods: Participants in the UK Biobank with a cancer diagnosis within 2 years of the baseline assessment were identified. Low MM was estimated by appendicular lean soft tissue (ALST) from bioelectrical impedance analysis derived fat-free mass. Malnutrition was determined using the Global Leadership in Malnutrition criteria. Sarcopenia was defined using the European Working Group on Sarcopenia in Older People criteria (version 2). All-cause mortality was determined from linked national mortality records. Cox-proportional hazards models were fitted to estimate the effect of low MM, malnutrition, and sarcopenia on all-cause mortality.

Results: In total, 4122 adults with cancer (59.8 ± 7.1 years; 49.2% male) were included. Prevalence of low MM (8.0% vs. 1.7%), malnutrition (11.2% vs. 6.2%), and sarcopenia (1.4% vs. 0.2%) was higher when MM was adjusted using ALST/BMI compared with ALST/height² , respectively. Low MM using ALST/BMI identified more cases in participants with obesity (low MM 56.3% vs. 0%; malnutrition 50% vs. 18.5%; sarcopenia 50% vs. 0%). During a median 11.2 (interquartile range: 10.2, 12.0) years of follow up, 901 (21.7%) of the 4122 participants died, and of these, 744 (82.6%) deaths were cancer-specific All conditions were associated with a higher hazard of mortality using either method of MM adjustment: low MM (ALST/height² : HR 1.9 [95% CI 1.3, 2.8], P = 0.001; ALST/BMI: HR 1.3 [95% CI 1.1, 1.7], P = 0.005; malnutrition (ALST/height² : HR 2.5 [95% CI 1.1, 1.7], P = 0.005; ALST/BMI: HR 1.3 [95% CI 1.1, 1.7], P = 0.005; sarcopenia (ALST/height² : HR 2.9 [95% CI 1.3, 6.5], P = 0.013; ALST/BMI: HR 1.6 [95% CI 1.0, 2.4], P = 0.037).

Conclusions: In adults with cancer, malnutrition was more common than low MM or sarcopenia, although all conditions were associated with a higher mortality risk, regardless of the method of adjusting for MM. In contrast, adjustment of low MM for BMI identified more cases of low MM, malnutrition, and sarcopenia overall and in participants with obesity compared with height adjustment, suggesting it is the preferred adjustment.

Keywords: Cancer; Low muscle mass; Malnutrition; Mortality; Sarcopenia; UK Biobank.

Figure 1

Study flow chart. ^aExcludes participants' who have requested their data are removed from the UK Biobank. ^bExcludes non‐melanoma skin cancer and benign tumours.

Figure 2

Venn diagrams demonstrating proportion of participants with (A) obesity and low ALST adjusted for height and BMI; (B) obesity and malnutrition when low ALST is adjusted for height and BMI; (C) obesity and sarcopenia when low ALST is adjusted for height and BMI; (D) obesity and sarcopenia/probable sarcopenia when low ALST is adjusted for height and BMI (N = 4122). Ht, height; BMI, body mass index; ALST, appendicular lean soft tissue.

Figure 3

Estimated prevalence of malnutrition by cancer type when (A) muscle mass is adjusted for body mass index and (B) when muscle mass is adjusted for height squared. BST, bone and soft tissue; CPN, central and peripheral nervous system.

Figure 4

Covariate‐adjusted Kaplan–Meier overall survival curves for (A) ALST adjusted for height, (B) malnutrition using ALST adjusted for height, (C) sarcopenia using ALST adjusted for height (unadjusted for coavriates), d) ALST adjusted for BMI, (E) malnutrition using ALST adjusted for BMI, and (F) sarcopenia using ALST adjusted for BMI (N = 4122). ALST, appendicular lean soft tissue; BMI, body mass index. The curves were estimated based on the mean level of the covariates.