rs2918418 — NR3C1

The Third NR3C1 Longevity Variant — Completing the Glucocorticoid Receptor Picture

The glucocorticoid receptor gene NR3C1 encodes the primary cellular transducer of cortisol signaling — a protein that, when activated, reshapes gene expression programs governing inflammation, metabolism, immune function, and the molecular hallmarks of cellular aging. This intronic variant (rs2918418) is the third of three NR3C1 variants identified in the same Polish centenarian study, alongside rs2963154¹¹ rs2963154 and rs10515522²² rs10515522, both of which showed related but stronger longevity associations.

The finding for rs2918418 inverts the allele-frequency pattern seen in its sister variants: here it is the rare CC genotype (approximately 2% of Europeans) that is enriched among those who reached ages 95–106, while the common GG genotype carries the cholesterol-elevation signal. This means that in most people the common genotype — not the rare one — marks the metabolic disadvantage, offering an interpretive window into how this locus may contribute to population-level aging trajectories.

The Mechanism

rs2918418 sits at chromosome 5, position 143,343,808 (GRCh38), within an intron of NR3C1. The NR3C1 gene is transcribed from the minus strand; the plus-strand alleles are G (reference, major, ~85%) and C (alternate, minor, ~15%). This is a simple C/G SNP at an intron position with no protein-coding consequence. The mechanism, as with rs2963154 and rs10515522, is most likely regulatory: altered NR3C1 transcription rate, splicing efficiency, or the relative production of the major GRα versus glucocorticoid-resistant GRβ isoforms.

The cholesterol-elevation signal for the GG genotype fits within an established mechanistic framework. A 2025 study in the Journal of Clinical Investigation³³ A 2025 study in the Journal of Clinical Investigation
Durumutla et al. The human glucocorticoid receptor variant rs6190 increases blood cholesterol and promotes atherosclerosis. J Clin Invest. 2025 demonstrated that altered GR transactivation in liver cells directly upregulates PCSK9 and BHLHE40 — negative regulators of LDL and HDL receptor expression respectively — resulting in elevated circulating LDL and total cholesterol. NR3C1 intronic variants that alter GR expression level or isoform ratio in hepatocytes would access this same pathway. The GG genotype's association with both elevated total cholesterol (p = 0.03) and LDL cholesterol (p = 0.03) is particularly notable because LDL elevation is a direct cardiovascular risk factor, not merely an incidental metabolic marker.

The rare CC genotype's enrichment in centenarians suggests it may confer a hepatic glucocorticoid signaling environment less prone to GR-driven LDL elevation — potentially a more favorable metabolic set point maintained across decades. This remains speculative given the intronic location and absence of direct functional characterization.

The Evidence

All three rs2918418 findings emerge from a single cohort study. Olczak et al. (2019)⁴⁴ Olczak et al. (2019)
Glucocorticoid receptor (NR3C1) gene polymorphisms are associated with age and blood parameters in Polish Caucasian nonagenarians and centenarians. Exp Gerontol. 2019;116:20-24 genotyped three NR3C1 intronic variants in 552 long-lived subjects (ages 95–106) and 284 cord blood controls of Polish Caucasian ancestry.

For rs2918418, two statistically significant associations were reported: the CC genotype was more frequent in the long-lived cohort (p = 0.028), and the GG genotype was specifically associated with elevated total cholesterol (p = 0.03) and LDL cholesterol (p = 0.03) within the centenarian population. The longevity association (p = 0.028) is the weakest of the three NR3C1 variants studied — rs2963154 showed p = 0.002 for TT enrichment and rs10515522 showed p = 0.016 for TT enrichment. Importantly, rs2918418 is the only one of the three variants where the rare homozygote, rather than the common genotype, shows the longevity enrichment.

The LDL finding is particularly actionable: unlike HDL, which has complex and context-dependent cardiovascular consequences at elevated levels, elevated LDL is a well-established independent cardiovascular risk factor. The GG genotype's association with both elevated total cholesterol and LDL in an elderly cohort who have survived to extreme age suggests this genotype imposes a lipid-metabolism burden that persists even in robust long-term survivors.

No independent replication of this specific variant's longevity or cholesterol associations has been published. The variant does not appear in GWAS catalog hits for lipid traits or longevity phenotypes in larger European cohorts, consistent with a modest or population-specific effect. The evidence level is emerging.

Practical Implications

For the majority of people carrying the GG genotype, the association with elevated LDL and total cholesterol in the oldest-old argues for proactive lipid monitoring — not as a response to current disease, but as a mechanism to detect GR-driven hepatic cholesterol dysregulation before it accumulates cardiovascular risk over decades. The GR-to-PCSK9 pathway is pharmacologically relevant: if LDL elevation is detected and partially driven by altered NR3C1 hepatic signaling, PCSK9 inhibitors (evolocumab, alirocumab) target the mechanism more precisely than dietary LDL reduction alone.

For the rare CC carriers, no longevity intervention is warranted — the CC enrichment in centenarians reflects a favorable metabolic background, not a pharmacological target. The practical value is contextual: CC status provides reassurance that this particular NR3C1 locus is not contributing to GR-driven LDL elevation.

Interactions

rs2918418 operates in the same gene as three other NR3C1 variants in the GeneOps database: rs6198 (9β)⁵⁵ rs6198 (9β), which favors the glucocorticoid-resistant GRβ isoform and blunts cortisol response; rs41423247 (BclI)⁶⁶ rs41423247 (BclI), which increases GR sensitivity to glucocorticoids; and rs2963154⁷⁷ rs2963154, whose TT genotype is the strongest longevity signal in the same cohort.

The three longevity variants (rs2918418, rs2963154, rs10515522) were studied together in the same population and may partially tag overlapping regulatory haplotypes within the NR3C1 intron. A person carrying GG at rs2918418, CC at rs2963154 (elevated cholesterol + depleted from centenarians), and TT at rs10515522 (no survival benefit) would accumulate a full unfavorable NR3C1 longevity profile — a combination that warrants cholesterol surveillance regardless of which individual variant drives the effect.