Low cholesterol levels are associated with a high mortality risk in older adults without statins therapy: An externally validated cohort study

Abstract

BackgroundThe relationship of total cholesterol (TC) levels with mortality among older adults without statin therapy has not been fully studied. AimsTo examine the relationship between TC and all-cause mortality in adults aged 65 years and older in Russia without statin therapy. MethodsThis was a population-based prospective cohort study of community-dwelling people aged 65 years and older in Russia. Data from 379 individuals on cardiovascular risk factors; comorbidities; cognitive, physical and autonomous function; lipid panel; B-type natriuretic peptide; C-reactive protein; and others were collected through interviews, clinical examinations, and laboratory tests. The total follow-up time was 3 years. Cox proportional hazards models for all-cause mortality, C-statistics, internal validation and external validation using the Belgian population from the BELFRAIL study were performed. ResultsA U-shaped association between the TC level and all-cause mortality was identified. Older adults without statin therapy and with low/high TC levels were at higher risk for mortality even after adjustment for covariates, with a hazard ratio (HR) of 5.78 (1.96–17.03) for TC < 5.4 mmol/L and an HR of 6.24 (1.69–22.94) for TC levels > 7.2 mmol/L. The association between low TC and all-cause mortality was confirmed in an external population of adults 80 years and older. ConclusionThe TC level range associated with the lowest mortality was 5.4–7.2 mmol/L, irrespective of concomitant diseases or health status. The association between low TC levels and a high risk of all-cause mortality was confirmed in a Belgian cohort of adults 80 years and older.