Abstract
Background Cardiovascular risk factors accelerate around the final menstrual period (FMP), yet clinicians lack an operational way to separate expected reproductive-ageing physiology from risk-relevant lipid divergence, and age-weighted calculators may under-recognise midlife women. We aimed to define, benchmark and stratify menopausal lipid remodelling against incident major adverse cardiovascular events (MACE). Methods We analysed 273,036 UK Biobank women (63,939 premenopausal; 165,276 postmenopausal; 43,821 uncertain, excluded from the primary contrast). Linked analyses used NMR metabolomics (n=222,487), cardiac MRI (n=42,033), oestradiol (n=57,999), an age-matched male reference cohort (n=228,900), serial Lp(a) (n=6,104 paired), and a Welsh FSH-confirmatory cohort (n=330). Incident-event analyses used a base cohort of 224,256 women (16,961 MACE) and an age-as-timescale Cox lipid cohort of 151,812 women (11,237 events). We integrated FMP-anchored trajectories, male-matched signal classification, treatment-adjusted change, counterfactual oestradiol mediation, one-sample Mendelian randomisation (MR) with LDLR ClinVar stratification, event-type dissociation, marker-added discrimination, guideline cutpoint calibration, and an internal sex-specific calibration stress test. Results Postmenopausal women had higher LDL-C (3.23 to 3.72 mmol/L; +15.3%), ApoB (+13.5%), non-HDL-C (+16.8%) and triglycerides (+29.9%); treatment adjustment raised the LDL-C and ApoB estimates to +19.8% and +17.5%. Male-matched analysis classified ApoB, LDL-C, non-HDL-C and remnant cholesterol as menopause-linked and TC:HDL and TG:HDL as age-driven. LDL-C and ApoB accelerated around the FMP (breakpoints 4.32 and 4.48 years). Oestradiol mediated 61.5% of the LDL-C difference. MR supported LDL-C causality (causal HR 1.196 [1.018-1.374]) with a null menopause interaction (P=0.826); LDLR carriers started higher but did not rise faster (Δ +11.5% vs +15.3%). ApoB tracked IHD (HR 1.125 [1.104-1.146]) but not higher HF risk (HR 0.916 [0.889-0.943]). In postmenopausal women, TC:HDL and TG:HDL, not ApoB, added short-term discrimination. At age 58, ApoB ≥1.2 g/L corresponded to 10.88% 10-year MACE risk in men versus 4.34% in postmenopausal women; a sex-neutral internal model over-predicted women (observed/expected 0.65-0.78) and under-predicted men (1.19). Ten-year MACE risk ranged from 1.09% (premenopausal, ApoB <1.2) to 5.89% (postmenopausal, ApoB ≥1.2). Conclusions Menopausal lipid remodelling comprises an expected physiological envelope and a risk-relevant, ApoB-rich, remnant-enriched divergence that predicts IHD. Because static sex-neutral cutpoints mis-estimate female risk and LDLR carriage is additive rather than synergistic, transition-era prevention needs sex-specific absolute-risk interpretation and treatment-aware relative-change monitoring. The proposed bands extend SWAN and align with ESC/EAS 2025 and AHA/ACC 2026 but are hypothesis-generating and require prospective validation.</p>