Imputation of untreated LDL-C in treated subjects with homozygous familial hypercholesterolaemiaMancini, John (Avtor) Ryomoto, Arnold (Avtor) Ruel, Isabelle (Avtor) Iatan, Iulia (Avtor) Raal, Frederick J. (Avtor) Santos, Raul D. (Avtor) Grošelj, Urh (Sodelavec pri raziskavi) homozygous familial hypercholesterolaemialow density lipoprotein-cholesterolimputationLDL-receptorlipid lowering therapyestimated untreated low-density lipoproteincholesterolBackground and aims: Diagnosis of Homozygous Familial Hypercholesterolaemia (HoFH) relies on untreated low-density lipoprotein-cholesterol (LDL-C) which is often unknown. We determine whether untreated LDL-C can be imputed from treated LDL-C in HoFH. Methods: Two groups with HoFH were identified: Group 1 (n = 193) from Canada, Brazil and South Africa; Group 2 (n = 206) from the HoFH International Clinical Collaboration. Pre- and post-treatment LDL-C and lipid lowering therapy (LLT) intensity from Group 1 were used to develop a regression model and applied to treated LDL-C in Group 2 to impute pre-treatment LDL-C. The same process was performed in reverse. A final imputation model was created from combining both groups. Results: There was a curvilinear relationship between the expected and observed % lowering of LDL-C on LLT (r = 0.3923, p < 0.0001, Standard Error [SE] = 23 %). Using this relationship, LDL-C was imputed from treated values and showed significant correlation with pre-treatment LDL-C (r = 0.71, p < 0.001; mean values 13.4 ± 4.7 [Standard Deviation] and 13.6 ± 7.3 mmol/L, respectively, ns). Concordance between actual and imputed values ≥ 10 or <10 mmol/L was 80 %. Whereas 36 % of patients had treated LDL-C ≥ 10 mmol/L, 64 % had treated or imputed pre-treatment LDL-C ≥ 10 mmol/L. Conclusions: In HoFH, the response to LLT can be quantified and used to impute untreated LDL-C from treated LDL-C. Imputation may augment awareness of possible HoFH in treated subjects lacking records of untreated LDL-C.20262026-06-02 14:01:14Neznano29662UDK: 616.1ISSN pri članku: 1879-1484DOI: 10.1016/j.atherosclerosis.2025.120590COBISS_ID: 280043011sl