Table 2.

Difference in LDL-cholesterol-change according to use of AIT in a nationwide cohort of postmenopausal women with early breast cancer, January 2009 to December 2020, Denmark

	Women	Pre-breast cancer LDL-cholesterola	Post-breast cancer LDL-cholesterol		LDL-cholesterol-change	Difference in LDL-cholesterol-change
	n	Mean (mmol/L)	n	Mean (mmol/L)	Mean (mmol/L)	Crude (mmol/L)	Adjustedb (mmol/L)
No use of AIT	2542	2.97	10,210	2.82	− 0.15c	0 ref	0 ref
Use of AIT	7919	2.94	32,540	2.78	− 0.16c	− 0.02(− 0.05,0.01)	− 0.03(− 0.07,0.003)

AIT, aromatase inhibitor treatment; LDL, low density lipoprotein.

‘Use of AIT’ is defined as allocated and dispensed treatment with AIT, and ‘No use of AIT’ is defined as no allocated and no dispensed treatment with AIT; both as recorded in the clinical database of the Danish Breast Cancer Group (see Table S3 for further definitions).

^aThe pre-breast cancer LDL-cholesterol level is predicted using a linear effects model for all women with at least one LDL-cholesterol-measurement prior to breast cancer diagnosis (see Supplementary Methods for further details); the difference between the mean of the observed LDL-cholesterol-levels prior to breast cancer diagnosis and the predicted one was < 0.02 mmol/L.

^bThe model included, as fixed effects, use of AIT, demographic characteristics (age [2-year intervals], calendar period [1-year intervals], education, region of residence, disposable household income, and cohabitory status), tumor characteristics (laterality, size, histology and malignancy grade, lymph node involvement, human epidermal growth factor receptor 2-status), other anti-cancer treatments (type of surgery, chemotherapy, and radiotherapy), the interaction between laterality and radiotherapy, and the time of lipid-measurement; and a random intercept, to account for the inter-individual variability.

^cThe absolute change in pre- vs. post-breast cancer LDL-cholesterol is explained by age- and period-differences in LDL-cholesterol levels.