Renal and Functional Vulnerability in Hansen Disease: A Framework for Chronic Infectious Disability in Endemic Settings

OBJECTIVES: Hansen disease is a neglected infectious disease associated with reactional inflammation, neuropathy and long-term disability. Renal involvement and sarcopenia have been described separately, but their clinical coexistence has received limited attention. This review examines evidence for a hypothesised renal-functional vulnerability interface and proposes a pragmatic monitoring framework for endemic settings. METHODS: We conducted a critical narrative review using structured, targeted searches of PubMed/MEDLINE, Embase, Scopus and Web of Science from database inception to 1 June 2026, supplemented by manual reference screening. Eligible sources addressed Hansen disease, renal involvement, urinary abnormalities, sarcopenia, body composition, muscle strength, disability, neuropathy, reactional states, nutrition and treatment exposure. No formal risk-of-bias tool was applied; greater interpretive weight was given to primary clinical data, systematic reviews, consensus statements and guidelines. RESULTS: Evidence indicates heterogeneous renal manifestations in Hansen disease, including proteinuria, haematuria, albuminuria, urinary biomarker abnormalities, glomerulonephritis, tubulointerstitial disease and amyloidosis. Separately, older survivor cohorts show increased adiposity, reduced appendicular skeletal muscle mass and higher sarcopenia prevalence. Sarcopenia should be interpreted primarily through neuropathy, pain, deformity, ulcers, immobility, ageing, corticosteroid exposure and social or nutritional vulnerability; renal involvement is, at most, a plausible cofactor. Low muscle mass may also lead to under-recognition of renal impairment when creatinine-based eGFR is used. CONCLUSIONS: Current evidence does not prove a causal renal-muscle relationship, but supports a hypothesised renal-functional vulnerability interface. Integrated renal and functional assessment may help identify high-risk patients and guide prospective cohorts.