A 2010 meta-analysis of up to 122,744 people without diabetes found 16 loci shaping fasting glucose as a continuous measurement — related to, but distinct from, the diagnosis of type 2 diabetes.
What this condition connects to
Prevalence
Not applicable in the usual sense — fasting blood glucose is a continuously measured trait, not a condition. The study behind this page examined up to 122,744 people combined across discovery and follow-up (Dupuis et al. 2010, PMID:20081858), all specifically without diabetes at the time of measurement.
Inheritance
Polygenic: 16 loci were found for fasting glucose and beta-cell function in this study, with no single variant — including TCF7L2, the field's most consistently replicated diabetes-related gene — coming close to determining an individual's fasting glucose level on its own.
Fasting blood glucose is the blood sugar level measured after a period without eating, one of the standard tests used to screen for and monitor diabetes. Like most physiological measurements, it varies continuously across the population — most people are not diabetic, but everyone has some fasting glucose level, and genetics shapes part of that variation even among people who will never develop diabetes. This page is about that continuous measurement specifically, distinct from this site's separate Type 2 Diabetes page, which covers disease-risk variants in people who do and don't develop the condition.
A large meta-analysis, specifically in people without diabetes
Dupuis et al. 2010, the MAGIC consortium, meta-analysed 21 genome-wide association studies covering up to 46,186 nondiabetic participants, with follow-up in up to 76,558 more, to study fasting glucose, fasting insulin, and two related indices of how well the body handles glucose (beta-cell function and insulin resistance). The study found 16 loci for fasting glucose and beta-cell function, 9 of them newly identified at the time — including rs11920090 in SLC2A2, rs7944584 in MADD, and rs11605924 in CRY2, all named directly in the paper — plus 2 more loci for fasting insulin and insulin resistance.
The study went further than just cataloguing loci for the continuous measurement: it separately tested whether the same variants were also associated with type 2 diabetes itself, and confirmed several were (including PROX1 and GCKR) — while explicitly noting that some loci raise fasting glucose modestly without being associated with overt diabetes. That distinction is exactly why this page exists separately from the diabetes page: a variant that nudges a measurement is not the same claim as a variant that raises disease risk, even when the same gene sometimes does both.
Two more of this page's variants are worth naming directly: rs12243326, in TCF7L2 — the single most consistently replicated type 2 diabetes gene in human genetics, though this specific variant is tagged here for its effect on the continuous glucose measurement rather than disease odds — and rs34177044 and rs2232326, both in G6PC2, a gene that directly controls how much glucose the liver releases into the blood.
Clinical detail
What this page does and does not measure
Fasting glucose is measured directly with a blood test, not estimated from genotype, and this page's variants are not used by any guideline to diagnose diabetes or prediabetes. The variants here describe why fasting glucose varies among people who do not have diabetes — not who will go on to develop it.
Diabetes and prediabetes are diagnosed using standard fasting glucose, oral glucose tolerance, or HbA1c thresholds set by clinical guidelines — not genotype. Nothing on this page changes how those tests are interpreted or how diabetes risk is clinically assessed; for disease-specific genetics, see this site's Type 2 Diabetes page.
Related variants MyGeneLog™ checks for
What a 23andMe/AncestryDNA export or raw VCF can and can't tell you about Fasting Blood Glucose comes down to these specific, well-studied positions — not a diagnosis.
Nature genetics · 2010 · PMID 20081858 · open access
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Questions about Fasting Blood Glucose
What is fasting blood glucose, and how is it different from type 2 diabetes?
Fasting blood glucose is blood sugar measured after a period without eating — a continuous measurement everyone has, whether or not they have diabetes. This page covers genetic variants affecting that measurement specifically, distinct from this site's separate page on type 2 diabetes, the diagnosed disease.
What did the 2010 study find?
Studying up to 122,744 people without diabetes combined across discovery and follow-up, it found 16 loci associated with fasting glucose and beta-cell function, 9 of them newly identified, including SLC2A2, MADD, and CRY2.
Do these variants mean someone will develop diabetes?
Not on their own. The study specifically found that some loci raise fasting glucose modestly without being associated with overt diabetes — a nudge to a measurement, not a diagnosis.
Does a variant on this page predict my fasting glucose?
No individual variant does. These are population-level statistical associations from a study of people without diabetes, and fasting glucose is measured directly with a blood test, not estimated from genotype.
Free to reuse. This page's text is original writing from freely-available research, licensed CC BY 4.0 — reuse it, including commercially, with attribution to MyGeneLog™. It's general research-derived information, not medical advice or a diagnosis — see Terms of Use.