---
type: source
title: "RGA GLP-1 Study: Anti-Obesity Medications Could Reduce US Mortality by 3.5% by 2045"
author: "RGA (Reinsurance Group of America)"
url: https://www.rgare.com/knowledge-center/article/rga-glp-1-study--weighing-the-evidence
date: 2025-06-01
domain: health
secondary_domains: []
format: industry-research
status: unprocessed
priority: high
tags: [GLP-1, semaglutide, obesity, population-mortality, timeline, cardiovascular, belief-1, structural-change, 2045-projection]
---

## Content

RGA (Reinsurance Group of America) actuarial analysis of the population-level mortality impact of anti-obesity medications (AOMs), primarily GLP-1 receptor agonists. Approximate publication date mid-2025.

**Core finding:**
Anti-obesity medications (semaglutide, tirzepatide) could reduce US mortality by **3.5% by 2045** under central (base case) assumptions. Greater reductions possible under optimistic adoption scenarios.

**What this implies:**
- The 3.5% mortality reduction is projected to become visible at the **population level by 2045** — approximately 20 years from current date (2026)
- Population-level cardiovascular mortality reductions from GLP-1 adoption are NOT expected to appear in aggregate mortality statistics for current data periods (2024-2026)
- The central assumption implies broad but not universal access and adherence rates consistent with observed real-world patterns (30-50% discontinuation at 1 year)

**Individual-level evidence (established separately):**
The SELECT trial demonstrated 20% reduction in MACE and 19% improvement in all-cause mortality in high-risk obese patients without diabetes. Meta-analysis of 13 CVOT trials (83,258 patients) confirmed significant MACE reductions. Real-world studies (STEER: 10,625 patients) showed 57% greater MACE reduction with semaglutide vs comparator in obese patients with established CVD. This individual-level evidence is robust.

**The gap:**
The gap between robust individual-level evidence (SELECT, STEER) and projected population-level impact (RGA 2045) reflects:
1. Access barriers: only 19% of large employers cover GLP-1s for weight loss (2025 data); California Medi-Cal ended weight-loss GLP-1 coverage January 1, 2026
2. Adherence: 30-50% discontinuation at 1 year — population effect requires sustained treatment
3. Lag time: CVD mortality effects require 5-10+ years of follow-up to manifest at population scale
4. Absolute coverage gap: approximately 48 million Americans want GLP-1 access; current coverage severely constrained

**Key caveats per RGA:**
Uncertainty around: GLP-1 discontinuation rates, maintenance dosing requirements, long-term safety profile beyond 5 years, health equity implications (access concentrated in wealthy/insured populations).

## Agent Notes
**Why this matters:** This is the critical link in the GLP-1 → CVD mortality chain. Individual RCT evidence is compelling (SELECT, STEER). But the population-level binding constraint question depends on the aggregate effect, not the individual effect. RGA's actuarial 2045 timeline resolves the question directly: GLP-1s are NOT a near-term structural change to population health — they are a long-horizon intervention, if access and adherence problems are solved.
**What surprised me:** The 20-year timeline is longer than I expected given the clinical trial evidence strength. The SELECT trial showed 20% MACE reduction. But actuarial modeling incorporates real-world adherence, access constraints, and the lag structure of CVD mortality — which stretches the timeline significantly. This means the 2024 life expectancy record CANNOT be attributed to GLP-1 effects.
**What I expected but didn't find:** Evidence that GLP-1 population impact is already visible in 2023-2024 mortality data. It is not, and the RGA modeling suggests it won't be for approximately 20 more years under central assumptions.
**KB connections:** Direct relevance to Sessions 1-2 GLP-1 adherence thread (adherence paradox); ICER access gap paper (access barrier constraint); SELECT trial evidence (individual level); Belief 1 (binding constraint timeline).
**Extraction hints:**
- "GLP-1 receptor agonists show robust individual-level cardiovascular mortality reduction (SELECT trial: 20% MACE reduction) but are projected to reduce US population mortality by only 3.5% by 2045 under central assumptions — the access and adherence barriers constrain population-level impact to a 20-year horizon"
- "The gap between GLP-1 individual-level efficacy (SELECT RCT) and population-level impact (RGA 2045 projection) reflects access barriers (19% employer coverage for weight loss), adherence constraints (30-50% discontinuation at 1 year), and the long lag structure of cardiovascular mortality — GLP-1s are a structural intervention on a long timeline, not a near-term fix"
**Context:** RGA is a major reinsurance company with actuarial modeling capacity. Their mortality projections are informed by industry risk models, not just clinical trial extrapolation. The 3.5% figure is a central estimate with wide confidence intervals.

## Curator Notes
PRIMARY CONNECTION: GLP-1 adherence thread (Sessions 1-2); ICER access gap; AHA 2026 stats (no GLP-1 signal in 2023 data)
WHY ARCHIVED: Resolves the key question of whether GLP-1 effects are already visible in population data — they are not, and projected timeline is 2045. Critical for Belief 1 assessment: binding constraint is not loosening on a near-term horizon despite compelling individual-level evidence.
EXTRACTION HINT: The individual-population gap claim is the extractable insight. Not "GLP-1s work" (established) but "GLP-1 individual efficacy does not translate to population-level detectability for ~20 years under current access constraints." This is a genuinely novel structural claim.