BackgroundHeart failure (HF) and malnutrition exhibit overlapping risk factors, characterized by increased levels of natriuretic peptides and an inflammatory profile. The aim of this study was to compare the differences in plasma brain natriuretic peptide (BNP), N‐terminal‐pro B‐type natriuretic peptide (NT‐proBNP), and C‐reactive protein (CRP) in patients with HF and malnutrition versus normal nutrition.MethodsFrom inception until July 2023, the databases, PubMed, Scopus, Web of Science, and Cochrane Library were searched. To examine the association among malnutrition [controlling nutritional status (CONUT) score ≥2; Geriatric Nutritional Risk Index (GNRI) score <92] with BNP, NT‐proBNP and CRP in patients with HF, a meta‐analysis using a random‐effects model was conducted (CRD42023445076).ResultsA significant association of GNRI with increased levels of BNP were demonstrated [mean difference (MD): 204.99, 95% confidence interval (CI) (101.02, 308.96, I2 = 88%, P < 0.01)], albeit no statistically significant findings were shown using CONUT [MD: 158.51, 95% CI (−1.78 to 318.79, I2 = 92%, P = 0.05)]. GNRI [MD: 1885.14, 95% CI (1428.76–2341.52, I2 = 0%, P < 0.01)] and CONUT [MD: 1160.05, 95% CI (701.04–1619.07, I2 = 0%, P < 0.01)] were associated with significantly higher levels of NT‐proBNP. Patients with normal GNRI scores had significantly lower levels of CRP [MD: 0.50, 95% CI (0.12–0.88, I2 = 87%, P = 0.01)] whereas significantly higher levels of CRP were observed in those with higher CONUT [MD: 0.40, 95% CI (0.08–0.72, I2 = 88%, P = 0.01)]. Employing meta‐regression, age was deemed a potential moderator between CRP and GNRI.ConclusionsNormal nutrition scores in patients with HF are linked to lower BNP, NT‐proBNP, and CRP levels compared with malnourished counterparts. Despite the significant link between CRP and malnutrition, their relationship may be influenced in older groups considering the sensitivity of GNRI due to ageing factors.